Merge branch 'dev.ssa' into mergebranch
Merge dev.ssa branch back into master.
Change-Id: Ie6fac3f8d355ab164f934415fe4fc7fcb8c3db16
diff --git a/src/cmd/compile/internal/gc/ssa.go b/src/cmd/compile/internal/gc/ssa.go
new file mode 100644
index 0000000..6bf0861
--- /dev/null
+++ b/src/cmd/compile/internal/gc/ssa.go
@@ -0,0 +1,5235 @@
+// Copyright 2015 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package gc
+
+import (
+ "bytes"
+ "fmt"
+ "html"
+ "math"
+ "os"
+ "strings"
+
+ "cmd/compile/internal/ssa"
+ "cmd/internal/obj"
+ "cmd/internal/obj/x86"
+)
+
+// Smallest possible faulting page at address zero.
+const minZeroPage = 4096
+
+var ssaConfig *ssa.Config
+var ssaExp ssaExport
+
+func initssa() *ssa.Config {
+ ssaExp.unimplemented = false
+ ssaExp.mustImplement = true
+ if ssaConfig == nil {
+ ssaConfig = ssa.NewConfig(Thearch.Thestring, &ssaExp, Ctxt, Debug['N'] == 0)
+ }
+ return ssaConfig
+}
+
+func shouldssa(fn *Node) bool {
+ if Thearch.Thestring != "amd64" {
+ return false
+ }
+
+ // Environment variable control of SSA CG
+ // 1. IF GOSSAFUNC == current function name THEN
+ // compile this function with SSA and log output to ssa.html
+
+ // 2. IF GOSSAHASH == "" THEN
+ // compile this function (and everything else) with SSA
+
+ // 3. IF GOSSAHASH == "n" or "N"
+ // IF GOSSAPKG == current package name THEN
+ // compile this function (and everything in this package) with SSA
+ // ELSE
+ // use the old back end for this function.
+ // This is for compatibility with existing test harness and should go away.
+
+ // 4. IF GOSSAHASH is a suffix of the binary-rendered SHA1 hash of the function name THEN
+ // compile this function with SSA
+ // ELSE
+ // compile this function with the old back end.
+
+ // Plan is for 3 to be removed when the tests are revised.
+ // SSA is now default, and is disabled by setting
+ // GOSSAHASH to n or N, or selectively with strings of
+ // 0 and 1.
+
+ name := fn.Func.Nname.Sym.Name
+
+ funcname := os.Getenv("GOSSAFUNC")
+ if funcname != "" {
+ // If GOSSAFUNC is set, compile only that function.
+ return name == funcname
+ }
+
+ pkg := os.Getenv("GOSSAPKG")
+ if pkg != "" {
+ // If GOSSAPKG is set, compile only that package.
+ return localpkg.Name == pkg
+ }
+
+ return initssa().DebugHashMatch("GOSSAHASH", name)
+}
+
+// buildssa builds an SSA function.
+func buildssa(fn *Node) *ssa.Func {
+ name := fn.Func.Nname.Sym.Name
+ printssa := strings.HasSuffix(name, "_ssa") || strings.Contains(name, "_ssa.") || name == os.Getenv("GOSSAFUNC")
+ if printssa {
+ fmt.Println("generating SSA for", name)
+ dumpslice("buildssa-enter", fn.Func.Enter.Slice())
+ dumpslice("buildssa-body", fn.Nbody.Slice())
+ dumpslice("buildssa-exit", fn.Func.Exit.Slice())
+ }
+
+ var s state
+ s.pushLine(fn.Lineno)
+ defer s.popLine()
+
+ if fn.Func.Pragma&CgoUnsafeArgs != 0 {
+ s.cgoUnsafeArgs = true
+ }
+ // TODO(khr): build config just once at the start of the compiler binary
+
+ ssaExp.log = printssa
+
+ s.config = initssa()
+ s.f = s.config.NewFunc()
+ s.f.Name = name
+ s.exitCode = fn.Func.Exit
+ s.panics = map[funcLine]*ssa.Block{}
+
+ if name == os.Getenv("GOSSAFUNC") {
+ // TODO: tempfile? it is handy to have the location
+ // of this file be stable, so you can just reload in the browser.
+ s.config.HTML = ssa.NewHTMLWriter("ssa.html", s.config, name)
+ // TODO: generate and print a mapping from nodes to values and blocks
+ }
+ defer func() {
+ if !printssa {
+ s.config.HTML.Close()
+ }
+ }()
+
+ // Allocate starting block
+ s.f.Entry = s.f.NewBlock(ssa.BlockPlain)
+
+ // Allocate starting values
+ s.labels = map[string]*ssaLabel{}
+ s.labeledNodes = map[*Node]*ssaLabel{}
+ s.startmem = s.entryNewValue0(ssa.OpInitMem, ssa.TypeMem)
+ s.sp = s.entryNewValue0(ssa.OpSP, Types[TUINTPTR]) // TODO: use generic pointer type (unsafe.Pointer?) instead
+ s.sb = s.entryNewValue0(ssa.OpSB, Types[TUINTPTR])
+
+ s.startBlock(s.f.Entry)
+ s.vars[&memVar] = s.startmem
+
+ s.varsyms = map[*Node]interface{}{}
+
+ // Generate addresses of local declarations
+ s.decladdrs = map[*Node]*ssa.Value{}
+ for _, n := range fn.Func.Dcl {
+ switch n.Class {
+ case PPARAM, PPARAMOUT:
+ aux := s.lookupSymbol(n, &ssa.ArgSymbol{Typ: n.Type, Node: n})
+ s.decladdrs[n] = s.entryNewValue1A(ssa.OpAddr, Ptrto(n.Type), aux, s.sp)
+ if n.Class == PPARAMOUT && s.canSSA(n) {
+ // Save ssa-able PPARAMOUT variables so we can
+ // store them back to the stack at the end of
+ // the function.
+ s.returns = append(s.returns, n)
+ }
+ case PAUTO | PHEAP:
+ // TODO this looks wrong for PAUTO|PHEAP, no vardef, but also no definition
+ aux := s.lookupSymbol(n, &ssa.AutoSymbol{Typ: n.Type, Node: n})
+ s.decladdrs[n] = s.entryNewValue1A(ssa.OpAddr, Ptrto(n.Type), aux, s.sp)
+ case PPARAM | PHEAP, PPARAMOUT | PHEAP:
+ // This ends up wrong, have to do it at the PARAM node instead.
+ case PAUTO:
+ // processed at each use, to prevent Addr coming
+ // before the decl.
+ case PFUNC:
+ // local function - already handled by frontend
+ default:
+ str := ""
+ if n.Class&PHEAP != 0 {
+ str = ",heap"
+ }
+ s.Unimplementedf("local variable with class %s%s unimplemented", classnames[n.Class&^PHEAP], str)
+ }
+ }
+
+ // Convert the AST-based IR to the SSA-based IR
+ s.stmts(fn.Func.Enter)
+ s.stmts(fn.Nbody)
+
+ // fallthrough to exit
+ if s.curBlock != nil {
+ s.stmts(s.exitCode)
+ m := s.mem()
+ b := s.endBlock()
+ b.Kind = ssa.BlockRet
+ b.Control = m
+ }
+
+ // Check that we used all labels
+ for name, lab := range s.labels {
+ if !lab.used() && !lab.reported {
+ yyerrorl(int(lab.defNode.Lineno), "label %v defined and not used", name)
+ lab.reported = true
+ }
+ if lab.used() && !lab.defined() && !lab.reported {
+ yyerrorl(int(lab.useNode.Lineno), "label %v not defined", name)
+ lab.reported = true
+ }
+ }
+
+ // Check any forward gotos. Non-forward gotos have already been checked.
+ for _, n := range s.fwdGotos {
+ lab := s.labels[n.Left.Sym.Name]
+ // If the label is undefined, we have already have printed an error.
+ if lab.defined() {
+ s.checkgoto(n, lab.defNode)
+ }
+ }
+
+ if nerrors > 0 {
+ s.f.Free()
+ return nil
+ }
+
+ // Link up variable uses to variable definitions
+ s.linkForwardReferences()
+
+ // Don't carry reference this around longer than necessary
+ s.exitCode = Nodes{}
+
+ // Main call to ssa package to compile function
+ ssa.Compile(s.f)
+
+ return s.f
+}
+
+type state struct {
+ // configuration (arch) information
+ config *ssa.Config
+
+ // function we're building
+ f *ssa.Func
+
+ // labels and labeled control flow nodes (OFOR, OSWITCH, OSELECT) in f
+ labels map[string]*ssaLabel
+ labeledNodes map[*Node]*ssaLabel
+
+ // gotos that jump forward; required for deferred checkgoto calls
+ fwdGotos []*Node
+ // Code that must precede any return
+ // (e.g., copying value of heap-escaped paramout back to true paramout)
+ exitCode Nodes
+
+ // unlabeled break and continue statement tracking
+ breakTo *ssa.Block // current target for plain break statement
+ continueTo *ssa.Block // current target for plain continue statement
+
+ // current location where we're interpreting the AST
+ curBlock *ssa.Block
+
+ // variable assignments in the current block (map from variable symbol to ssa value)
+ // *Node is the unique identifier (an ONAME Node) for the variable.
+ vars map[*Node]*ssa.Value
+
+ // all defined variables at the end of each block. Indexed by block ID.
+ defvars []map[*Node]*ssa.Value
+
+ // addresses of PPARAM and PPARAMOUT variables.
+ decladdrs map[*Node]*ssa.Value
+
+ // symbols for PEXTERN, PAUTO and PPARAMOUT variables so they can be reused.
+ varsyms map[*Node]interface{}
+
+ // starting values. Memory, stack pointer, and globals pointer
+ startmem *ssa.Value
+ sp *ssa.Value
+ sb *ssa.Value
+
+ // line number stack. The current line number is top of stack
+ line []int32
+
+ // list of panic calls by function name and line number.
+ // Used to deduplicate panic calls.
+ panics map[funcLine]*ssa.Block
+
+ // list of FwdRef values.
+ fwdRefs []*ssa.Value
+
+ // list of PPARAMOUT (return) variables. Does not include PPARAM|PHEAP vars.
+ returns []*Node
+
+ cgoUnsafeArgs bool
+}
+
+type funcLine struct {
+ f *Node
+ line int32
+}
+
+type ssaLabel struct {
+ target *ssa.Block // block identified by this label
+ breakTarget *ssa.Block // block to break to in control flow node identified by this label
+ continueTarget *ssa.Block // block to continue to in control flow node identified by this label
+ defNode *Node // label definition Node (OLABEL)
+ // Label use Node (OGOTO, OBREAK, OCONTINUE).
+ // Used only for error detection and reporting.
+ // There might be multiple uses, but we only need to track one.
+ useNode *Node
+ reported bool // reported indicates whether an error has already been reported for this label
+}
+
+// defined reports whether the label has a definition (OLABEL node).
+func (l *ssaLabel) defined() bool { return l.defNode != nil }
+
+// used reports whether the label has a use (OGOTO, OBREAK, or OCONTINUE node).
+func (l *ssaLabel) used() bool { return l.useNode != nil }
+
+// label returns the label associated with sym, creating it if necessary.
+func (s *state) label(sym *Sym) *ssaLabel {
+ lab := s.labels[sym.Name]
+ if lab == nil {
+ lab = new(ssaLabel)
+ s.labels[sym.Name] = lab
+ }
+ return lab
+}
+
+func (s *state) Logf(msg string, args ...interface{}) { s.config.Logf(msg, args...) }
+func (s *state) Log() bool { return s.config.Log() }
+func (s *state) Fatalf(msg string, args ...interface{}) { s.config.Fatalf(s.peekLine(), msg, args...) }
+func (s *state) Unimplementedf(msg string, args ...interface{}) {
+ s.config.Unimplementedf(s.peekLine(), msg, args...)
+}
+func (s *state) Warnl(line int, msg string, args ...interface{}) { s.config.Warnl(line, msg, args...) }
+func (s *state) Debug_checknil() bool { return s.config.Debug_checknil() }
+
+var (
+ // dummy node for the memory variable
+ memVar = Node{Op: ONAME, Class: Pxxx, Sym: &Sym{Name: "mem"}}
+
+ // dummy nodes for temporary variables
+ ptrVar = Node{Op: ONAME, Class: Pxxx, Sym: &Sym{Name: "ptr"}}
+ capVar = Node{Op: ONAME, Class: Pxxx, Sym: &Sym{Name: "cap"}}
+ typVar = Node{Op: ONAME, Class: Pxxx, Sym: &Sym{Name: "typ"}}
+ idataVar = Node{Op: ONAME, Class: Pxxx, Sym: &Sym{Name: "idata"}}
+ okVar = Node{Op: ONAME, Class: Pxxx, Sym: &Sym{Name: "ok"}}
+)
+
+// startBlock sets the current block we're generating code in to b.
+func (s *state) startBlock(b *ssa.Block) {
+ if s.curBlock != nil {
+ s.Fatalf("starting block %v when block %v has not ended", b, s.curBlock)
+ }
+ s.curBlock = b
+ s.vars = map[*Node]*ssa.Value{}
+}
+
+// endBlock marks the end of generating code for the current block.
+// Returns the (former) current block. Returns nil if there is no current
+// block, i.e. if no code flows to the current execution point.
+func (s *state) endBlock() *ssa.Block {
+ b := s.curBlock
+ if b == nil {
+ return nil
+ }
+ for len(s.defvars) <= int(b.ID) {
+ s.defvars = append(s.defvars, nil)
+ }
+ s.defvars[b.ID] = s.vars
+ s.curBlock = nil
+ s.vars = nil
+ b.Line = s.peekLine()
+ return b
+}
+
+// pushLine pushes a line number on the line number stack.
+func (s *state) pushLine(line int32) {
+ s.line = append(s.line, line)
+}
+
+// popLine pops the top of the line number stack.
+func (s *state) popLine() {
+ s.line = s.line[:len(s.line)-1]
+}
+
+// peekLine peek the top of the line number stack.
+func (s *state) peekLine() int32 {
+ return s.line[len(s.line)-1]
+}
+
+func (s *state) Error(msg string, args ...interface{}) {
+ yyerrorl(int(s.peekLine()), msg, args...)
+}
+
+// newValue0 adds a new value with no arguments to the current block.
+func (s *state) newValue0(op ssa.Op, t ssa.Type) *ssa.Value {
+ return s.curBlock.NewValue0(s.peekLine(), op, t)
+}
+
+// newValue0A adds a new value with no arguments and an aux value to the current block.
+func (s *state) newValue0A(op ssa.Op, t ssa.Type, aux interface{}) *ssa.Value {
+ return s.curBlock.NewValue0A(s.peekLine(), op, t, aux)
+}
+
+// newValue0I adds a new value with no arguments and an auxint value to the current block.
+func (s *state) newValue0I(op ssa.Op, t ssa.Type, auxint int64) *ssa.Value {
+ return s.curBlock.NewValue0I(s.peekLine(), op, t, auxint)
+}
+
+// newValue1 adds a new value with one argument to the current block.
+func (s *state) newValue1(op ssa.Op, t ssa.Type, arg *ssa.Value) *ssa.Value {
+ return s.curBlock.NewValue1(s.peekLine(), op, t, arg)
+}
+
+// newValue1A adds a new value with one argument and an aux value to the current block.
+func (s *state) newValue1A(op ssa.Op, t ssa.Type, aux interface{}, arg *ssa.Value) *ssa.Value {
+ return s.curBlock.NewValue1A(s.peekLine(), op, t, aux, arg)
+}
+
+// newValue1I adds a new value with one argument and an auxint value to the current block.
+func (s *state) newValue1I(op ssa.Op, t ssa.Type, aux int64, arg *ssa.Value) *ssa.Value {
+ return s.curBlock.NewValue1I(s.peekLine(), op, t, aux, arg)
+}
+
+// newValue2 adds a new value with two arguments to the current block.
+func (s *state) newValue2(op ssa.Op, t ssa.Type, arg0, arg1 *ssa.Value) *ssa.Value {
+ return s.curBlock.NewValue2(s.peekLine(), op, t, arg0, arg1)
+}
+
+// newValue2I adds a new value with two arguments and an auxint value to the current block.
+func (s *state) newValue2I(op ssa.Op, t ssa.Type, aux int64, arg0, arg1 *ssa.Value) *ssa.Value {
+ return s.curBlock.NewValue2I(s.peekLine(), op, t, aux, arg0, arg1)
+}
+
+// newValue3 adds a new value with three arguments to the current block.
+func (s *state) newValue3(op ssa.Op, t ssa.Type, arg0, arg1, arg2 *ssa.Value) *ssa.Value {
+ return s.curBlock.NewValue3(s.peekLine(), op, t, arg0, arg1, arg2)
+}
+
+// newValue3I adds a new value with three arguments and an auxint value to the current block.
+func (s *state) newValue3I(op ssa.Op, t ssa.Type, aux int64, arg0, arg1, arg2 *ssa.Value) *ssa.Value {
+ return s.curBlock.NewValue3I(s.peekLine(), op, t, aux, arg0, arg1, arg2)
+}
+
+// entryNewValue0 adds a new value with no arguments to the entry block.
+func (s *state) entryNewValue0(op ssa.Op, t ssa.Type) *ssa.Value {
+ return s.f.Entry.NewValue0(s.peekLine(), op, t)
+}
+
+// entryNewValue0A adds a new value with no arguments and an aux value to the entry block.
+func (s *state) entryNewValue0A(op ssa.Op, t ssa.Type, aux interface{}) *ssa.Value {
+ return s.f.Entry.NewValue0A(s.peekLine(), op, t, aux)
+}
+
+// entryNewValue0I adds a new value with no arguments and an auxint value to the entry block.
+func (s *state) entryNewValue0I(op ssa.Op, t ssa.Type, auxint int64) *ssa.Value {
+ return s.f.Entry.NewValue0I(s.peekLine(), op, t, auxint)
+}
+
+// entryNewValue1 adds a new value with one argument to the entry block.
+func (s *state) entryNewValue1(op ssa.Op, t ssa.Type, arg *ssa.Value) *ssa.Value {
+ return s.f.Entry.NewValue1(s.peekLine(), op, t, arg)
+}
+
+// entryNewValue1 adds a new value with one argument and an auxint value to the entry block.
+func (s *state) entryNewValue1I(op ssa.Op, t ssa.Type, auxint int64, arg *ssa.Value) *ssa.Value {
+ return s.f.Entry.NewValue1I(s.peekLine(), op, t, auxint, arg)
+}
+
+// entryNewValue1A adds a new value with one argument and an aux value to the entry block.
+func (s *state) entryNewValue1A(op ssa.Op, t ssa.Type, aux interface{}, arg *ssa.Value) *ssa.Value {
+ return s.f.Entry.NewValue1A(s.peekLine(), op, t, aux, arg)
+}
+
+// entryNewValue2 adds a new value with two arguments to the entry block.
+func (s *state) entryNewValue2(op ssa.Op, t ssa.Type, arg0, arg1 *ssa.Value) *ssa.Value {
+ return s.f.Entry.NewValue2(s.peekLine(), op, t, arg0, arg1)
+}
+
+// const* routines add a new const value to the entry block.
+func (s *state) constBool(c bool) *ssa.Value {
+ return s.f.ConstBool(s.peekLine(), Types[TBOOL], c)
+}
+func (s *state) constInt8(t ssa.Type, c int8) *ssa.Value {
+ return s.f.ConstInt8(s.peekLine(), t, c)
+}
+func (s *state) constInt16(t ssa.Type, c int16) *ssa.Value {
+ return s.f.ConstInt16(s.peekLine(), t, c)
+}
+func (s *state) constInt32(t ssa.Type, c int32) *ssa.Value {
+ return s.f.ConstInt32(s.peekLine(), t, c)
+}
+func (s *state) constInt64(t ssa.Type, c int64) *ssa.Value {
+ return s.f.ConstInt64(s.peekLine(), t, c)
+}
+func (s *state) constFloat32(t ssa.Type, c float64) *ssa.Value {
+ return s.f.ConstFloat32(s.peekLine(), t, c)
+}
+func (s *state) constFloat64(t ssa.Type, c float64) *ssa.Value {
+ return s.f.ConstFloat64(s.peekLine(), t, c)
+}
+func (s *state) constInt(t ssa.Type, c int64) *ssa.Value {
+ if s.config.IntSize == 8 {
+ return s.constInt64(t, c)
+ }
+ if int64(int32(c)) != c {
+ s.Fatalf("integer constant too big %d", c)
+ }
+ return s.constInt32(t, int32(c))
+}
+
+func (s *state) stmts(a Nodes) {
+ for _, x := range a.Slice() {
+ s.stmt(x)
+ }
+}
+
+// ssaStmtList converts the statement n to SSA and adds it to s.
+func (s *state) stmtList(l *NodeList) {
+ for ; l != nil; l = l.Next {
+ s.stmt(l.N)
+ }
+}
+
+// ssaStmt converts the statement n to SSA and adds it to s.
+func (s *state) stmt(n *Node) {
+ s.pushLine(n.Lineno)
+ defer s.popLine()
+
+ // If s.curBlock is nil, then we're about to generate dead code.
+ // We can't just short-circuit here, though,
+ // because we check labels and gotos as part of SSA generation.
+ // Provide a block for the dead code so that we don't have
+ // to add special cases everywhere else.
+ if s.curBlock == nil {
+ dead := s.f.NewBlock(ssa.BlockPlain)
+ s.startBlock(dead)
+ }
+
+ s.stmtList(n.Ninit)
+ switch n.Op {
+
+ case OBLOCK:
+ s.stmtList(n.List)
+
+ // No-ops
+ case OEMPTY, ODCLCONST, ODCLTYPE, OFALL:
+
+ // Expression statements
+ case OCALLFUNC, OCALLMETH, OCALLINTER:
+ s.call(n, callNormal)
+ if n.Op == OCALLFUNC && n.Left.Op == ONAME && n.Left.Class == PFUNC &&
+ (compiling_runtime != 0 && n.Left.Sym.Name == "throw" ||
+ n.Left.Sym.Pkg == Runtimepkg && (n.Left.Sym.Name == "gopanic" || n.Left.Sym.Name == "selectgo" || n.Left.Sym.Name == "block")) {
+ m := s.mem()
+ b := s.endBlock()
+ b.Kind = ssa.BlockExit
+ b.Control = m
+ // TODO: never rewrite OPANIC to OCALLFUNC in the
+ // first place. Need to wait until all backends
+ // go through SSA.
+ }
+ case ODEFER:
+ s.call(n.Left, callDefer)
+ case OPROC:
+ s.call(n.Left, callGo)
+
+ case OAS2DOTTYPE:
+ res, resok := s.dottype(n.Rlist.N, true)
+ s.assign(n.List.N, res, needwritebarrier(n.List.N, n.Rlist.N), false, n.Lineno)
+ s.assign(n.List.Next.N, resok, false, false, n.Lineno)
+ return
+
+ case ODCL:
+ if n.Left.Class&PHEAP == 0 {
+ return
+ }
+ if compiling_runtime != 0 {
+ Fatalf("%v escapes to heap, not allowed in runtime.", n)
+ }
+
+ // TODO: the old pass hides the details of PHEAP
+ // variables behind ONAME nodes. Figure out if it's better
+ // to rewrite the tree and make the heapaddr construct explicit
+ // or to keep this detail hidden behind the scenes.
+ palloc := prealloc[n.Left]
+ if palloc == nil {
+ palloc = callnew(n.Left.Type)
+ prealloc[n.Left] = palloc
+ }
+ r := s.expr(palloc)
+ s.assign(n.Left.Name.Heapaddr, r, false, false, n.Lineno)
+
+ case OLABEL:
+ sym := n.Left.Sym
+
+ if isblanksym(sym) {
+ // Empty identifier is valid but useless.
+ // See issues 11589, 11593.
+ return
+ }
+
+ lab := s.label(sym)
+
+ // Associate label with its control flow node, if any
+ if ctl := n.Name.Defn; ctl != nil {
+ switch ctl.Op {
+ case OFOR, OSWITCH, OSELECT:
+ s.labeledNodes[ctl] = lab
+ }
+ }
+
+ if !lab.defined() {
+ lab.defNode = n
+ } else {
+ s.Error("label %v already defined at %v", sym, Ctxt.Line(int(lab.defNode.Lineno)))
+ lab.reported = true
+ }
+ // The label might already have a target block via a goto.
+ if lab.target == nil {
+ lab.target = s.f.NewBlock(ssa.BlockPlain)
+ }
+
+ // go to that label (we pretend "label:" is preceded by "goto label")
+ b := s.endBlock()
+ b.AddEdgeTo(lab.target)
+ s.startBlock(lab.target)
+
+ case OGOTO:
+ sym := n.Left.Sym
+
+ lab := s.label(sym)
+ if lab.target == nil {
+ lab.target = s.f.NewBlock(ssa.BlockPlain)
+ }
+ if !lab.used() {
+ lab.useNode = n
+ }
+
+ if lab.defined() {
+ s.checkgoto(n, lab.defNode)
+ } else {
+ s.fwdGotos = append(s.fwdGotos, n)
+ }
+
+ b := s.endBlock()
+ b.AddEdgeTo(lab.target)
+
+ case OAS, OASWB:
+ // Check whether we can generate static data rather than code.
+ // If so, ignore n and defer data generation until codegen.
+ // Failure to do this causes writes to readonly symbols.
+ if gen_as_init(n, true) {
+ var data []*Node
+ if s.f.StaticData != nil {
+ data = s.f.StaticData.([]*Node)
+ }
+ s.f.StaticData = append(data, n)
+ return
+ }
+
+ var t *Type
+ if n.Right != nil {
+ t = n.Right.Type
+ } else {
+ t = n.Left.Type
+ }
+
+ // Evaluate RHS.
+ rhs := n.Right
+ if rhs != nil && (rhs.Op == OSTRUCTLIT || rhs.Op == OARRAYLIT) {
+ // All literals with nonzero fields have already been
+ // rewritten during walk. Any that remain are just T{}
+ // or equivalents. Use the zero value.
+ if !iszero(rhs) {
+ Fatalf("literal with nonzero value in SSA: %v", rhs)
+ }
+ rhs = nil
+ }
+ var r *ssa.Value
+ needwb := n.Op == OASWB && rhs != nil
+ deref := !canSSAType(t)
+ if deref {
+ if rhs == nil {
+ r = nil // Signal assign to use OpZero.
+ } else {
+ r = s.addr(rhs, false)
+ }
+ } else {
+ if rhs == nil {
+ r = s.zeroVal(t)
+ } else {
+ r = s.expr(rhs)
+ }
+ }
+ if rhs != nil && rhs.Op == OAPPEND {
+ // Yuck! The frontend gets rid of the write barrier, but we need it!
+ // At least, we need it in the case where growslice is called.
+ // TODO: Do the write barrier on just the growslice branch.
+ // TODO: just add a ptr graying to the end of growslice?
+ // TODO: check whether we need to do this for ODOTTYPE and ORECV also.
+ // They get similar wb-removal treatment in walk.go:OAS.
+ needwb = true
+ }
+
+ s.assign(n.Left, r, needwb, deref, n.Lineno)
+
+ case OIF:
+ bThen := s.f.NewBlock(ssa.BlockPlain)
+ bEnd := s.f.NewBlock(ssa.BlockPlain)
+ var bElse *ssa.Block
+ if n.Rlist != nil {
+ bElse = s.f.NewBlock(ssa.BlockPlain)
+ s.condBranch(n.Left, bThen, bElse, n.Likely)
+ } else {
+ s.condBranch(n.Left, bThen, bEnd, n.Likely)
+ }
+
+ s.startBlock(bThen)
+ s.stmts(n.Nbody)
+ if b := s.endBlock(); b != nil {
+ b.AddEdgeTo(bEnd)
+ }
+
+ if n.Rlist != nil {
+ s.startBlock(bElse)
+ s.stmtList(n.Rlist)
+ if b := s.endBlock(); b != nil {
+ b.AddEdgeTo(bEnd)
+ }
+ }
+ s.startBlock(bEnd)
+
+ case ORETURN:
+ s.stmtList(n.List)
+ s.exit()
+ case ORETJMP:
+ s.stmtList(n.List)
+ b := s.exit()
+ b.Kind = ssa.BlockRetJmp // override BlockRet
+ b.Aux = n.Left.Sym
+
+ case OCONTINUE, OBREAK:
+ var op string
+ var to *ssa.Block
+ switch n.Op {
+ case OCONTINUE:
+ op = "continue"
+ to = s.continueTo
+ case OBREAK:
+ op = "break"
+ to = s.breakTo
+ }
+ if n.Left == nil {
+ // plain break/continue
+ if to == nil {
+ s.Error("%s is not in a loop", op)
+ return
+ }
+ // nothing to do; "to" is already the correct target
+ } else {
+ // labeled break/continue; look up the target
+ sym := n.Left.Sym
+ lab := s.label(sym)
+ if !lab.used() {
+ lab.useNode = n.Left
+ }
+ if !lab.defined() {
+ s.Error("%s label not defined: %v", op, sym)
+ lab.reported = true
+ return
+ }
+ switch n.Op {
+ case OCONTINUE:
+ to = lab.continueTarget
+ case OBREAK:
+ to = lab.breakTarget
+ }
+ if to == nil {
+ // Valid label but not usable with a break/continue here, e.g.:
+ // for {
+ // continue abc
+ // }
+ // abc:
+ // for {}
+ s.Error("invalid %s label %v", op, sym)
+ lab.reported = true
+ return
+ }
+ }
+
+ b := s.endBlock()
+ b.AddEdgeTo(to)
+
+ case OFOR:
+ // OFOR: for Ninit; Left; Right { Nbody }
+ bCond := s.f.NewBlock(ssa.BlockPlain)
+ bBody := s.f.NewBlock(ssa.BlockPlain)
+ bIncr := s.f.NewBlock(ssa.BlockPlain)
+ bEnd := s.f.NewBlock(ssa.BlockPlain)
+
+ // first, jump to condition test
+ b := s.endBlock()
+ b.AddEdgeTo(bCond)
+
+ // generate code to test condition
+ s.startBlock(bCond)
+ if n.Left != nil {
+ s.condBranch(n.Left, bBody, bEnd, 1)
+ } else {
+ b := s.endBlock()
+ b.Kind = ssa.BlockPlain
+ b.AddEdgeTo(bBody)
+ }
+
+ // set up for continue/break in body
+ prevContinue := s.continueTo
+ prevBreak := s.breakTo
+ s.continueTo = bIncr
+ s.breakTo = bEnd
+ lab := s.labeledNodes[n]
+ if lab != nil {
+ // labeled for loop
+ lab.continueTarget = bIncr
+ lab.breakTarget = bEnd
+ }
+
+ // generate body
+ s.startBlock(bBody)
+ s.stmts(n.Nbody)
+
+ // tear down continue/break
+ s.continueTo = prevContinue
+ s.breakTo = prevBreak
+ if lab != nil {
+ lab.continueTarget = nil
+ lab.breakTarget = nil
+ }
+
+ // done with body, goto incr
+ if b := s.endBlock(); b != nil {
+ b.AddEdgeTo(bIncr)
+ }
+
+ // generate incr
+ s.startBlock(bIncr)
+ if n.Right != nil {
+ s.stmt(n.Right)
+ }
+ if b := s.endBlock(); b != nil {
+ b.AddEdgeTo(bCond)
+ }
+ s.startBlock(bEnd)
+
+ case OSWITCH, OSELECT:
+ // These have been mostly rewritten by the front end into their Nbody fields.
+ // Our main task is to correctly hook up any break statements.
+ bEnd := s.f.NewBlock(ssa.BlockPlain)
+
+ prevBreak := s.breakTo
+ s.breakTo = bEnd
+ lab := s.labeledNodes[n]
+ if lab != nil {
+ // labeled
+ lab.breakTarget = bEnd
+ }
+
+ // generate body code
+ s.stmts(n.Nbody)
+
+ s.breakTo = prevBreak
+ if lab != nil {
+ lab.breakTarget = nil
+ }
+
+ // OSWITCH never falls through (s.curBlock == nil here).
+ // OSELECT does not fall through if we're calling selectgo.
+ // OSELECT does fall through if we're calling selectnb{send,recv}[2].
+ // In those latter cases, go to the code after the select.
+ if b := s.endBlock(); b != nil {
+ b.AddEdgeTo(bEnd)
+ }
+ s.startBlock(bEnd)
+
+ case OVARKILL:
+ // Insert a varkill op to record that a variable is no longer live.
+ // We only care about liveness info at call sites, so putting the
+ // varkill in the store chain is enough to keep it correctly ordered
+ // with respect to call ops.
+ if !s.canSSA(n.Left) {
+ s.vars[&memVar] = s.newValue1A(ssa.OpVarKill, ssa.TypeMem, n.Left, s.mem())
+ }
+
+ case OVARLIVE:
+ // Insert a varlive op to record that a variable is still live.
+ if !n.Left.Addrtaken {
+ s.Fatalf("VARLIVE variable %s must have Addrtaken set", n.Left)
+ }
+ s.vars[&memVar] = s.newValue1A(ssa.OpVarLive, ssa.TypeMem, n.Left, s.mem())
+
+ case OCHECKNIL:
+ p := s.expr(n.Left)
+ s.nilCheck(p)
+
+ default:
+ s.Unimplementedf("unhandled stmt %s", opnames[n.Op])
+ }
+}
+
+// exit processes any code that needs to be generated just before returning.
+// It returns a BlockRet block that ends the control flow. Its control value
+// will be set to the final memory state.
+func (s *state) exit() *ssa.Block {
+ // Run exit code. Typically, this code copies heap-allocated PPARAMOUT
+ // variables back to the stack.
+ s.stmts(s.exitCode)
+
+ // Store SSAable PPARAMOUT variables back to stack locations.
+ for _, n := range s.returns {
+ aux := &ssa.ArgSymbol{Typ: n.Type, Node: n}
+ addr := s.newValue1A(ssa.OpAddr, Ptrto(n.Type), aux, s.sp)
+ val := s.variable(n, n.Type)
+ s.vars[&memVar] = s.newValue1A(ssa.OpVarDef, ssa.TypeMem, n, s.mem())
+ s.vars[&memVar] = s.newValue3I(ssa.OpStore, ssa.TypeMem, n.Type.Size(), addr, val, s.mem())
+ // TODO: if val is ever spilled, we'd like to use the
+ // PPARAMOUT slot for spilling it. That won't happen
+ // currently.
+ }
+
+ // Do actual return.
+ m := s.mem()
+ b := s.endBlock()
+ b.Kind = ssa.BlockRet
+ b.Control = m
+ return b
+}
+
+type opAndType struct {
+ op Op
+ etype EType
+}
+
+var opToSSA = map[opAndType]ssa.Op{
+ opAndType{OADD, TINT8}: ssa.OpAdd8,
+ opAndType{OADD, TUINT8}: ssa.OpAdd8,
+ opAndType{OADD, TINT16}: ssa.OpAdd16,
+ opAndType{OADD, TUINT16}: ssa.OpAdd16,
+ opAndType{OADD, TINT32}: ssa.OpAdd32,
+ opAndType{OADD, TUINT32}: ssa.OpAdd32,
+ opAndType{OADD, TPTR32}: ssa.OpAdd32,
+ opAndType{OADD, TINT64}: ssa.OpAdd64,
+ opAndType{OADD, TUINT64}: ssa.OpAdd64,
+ opAndType{OADD, TPTR64}: ssa.OpAdd64,
+ opAndType{OADD, TFLOAT32}: ssa.OpAdd32F,
+ opAndType{OADD, TFLOAT64}: ssa.OpAdd64F,
+
+ opAndType{OSUB, TINT8}: ssa.OpSub8,
+ opAndType{OSUB, TUINT8}: ssa.OpSub8,
+ opAndType{OSUB, TINT16}: ssa.OpSub16,
+ opAndType{OSUB, TUINT16}: ssa.OpSub16,
+ opAndType{OSUB, TINT32}: ssa.OpSub32,
+ opAndType{OSUB, TUINT32}: ssa.OpSub32,
+ opAndType{OSUB, TINT64}: ssa.OpSub64,
+ opAndType{OSUB, TUINT64}: ssa.OpSub64,
+ opAndType{OSUB, TFLOAT32}: ssa.OpSub32F,
+ opAndType{OSUB, TFLOAT64}: ssa.OpSub64F,
+
+ opAndType{ONOT, TBOOL}: ssa.OpNot,
+
+ opAndType{OMINUS, TINT8}: ssa.OpNeg8,
+ opAndType{OMINUS, TUINT8}: ssa.OpNeg8,
+ opAndType{OMINUS, TINT16}: ssa.OpNeg16,
+ opAndType{OMINUS, TUINT16}: ssa.OpNeg16,
+ opAndType{OMINUS, TINT32}: ssa.OpNeg32,
+ opAndType{OMINUS, TUINT32}: ssa.OpNeg32,
+ opAndType{OMINUS, TINT64}: ssa.OpNeg64,
+ opAndType{OMINUS, TUINT64}: ssa.OpNeg64,
+ opAndType{OMINUS, TFLOAT32}: ssa.OpNeg32F,
+ opAndType{OMINUS, TFLOAT64}: ssa.OpNeg64F,
+
+ opAndType{OCOM, TINT8}: ssa.OpCom8,
+ opAndType{OCOM, TUINT8}: ssa.OpCom8,
+ opAndType{OCOM, TINT16}: ssa.OpCom16,
+ opAndType{OCOM, TUINT16}: ssa.OpCom16,
+ opAndType{OCOM, TINT32}: ssa.OpCom32,
+ opAndType{OCOM, TUINT32}: ssa.OpCom32,
+ opAndType{OCOM, TINT64}: ssa.OpCom64,
+ opAndType{OCOM, TUINT64}: ssa.OpCom64,
+
+ opAndType{OIMAG, TCOMPLEX64}: ssa.OpComplexImag,
+ opAndType{OIMAG, TCOMPLEX128}: ssa.OpComplexImag,
+ opAndType{OREAL, TCOMPLEX64}: ssa.OpComplexReal,
+ opAndType{OREAL, TCOMPLEX128}: ssa.OpComplexReal,
+
+ opAndType{OMUL, TINT8}: ssa.OpMul8,
+ opAndType{OMUL, TUINT8}: ssa.OpMul8,
+ opAndType{OMUL, TINT16}: ssa.OpMul16,
+ opAndType{OMUL, TUINT16}: ssa.OpMul16,
+ opAndType{OMUL, TINT32}: ssa.OpMul32,
+ opAndType{OMUL, TUINT32}: ssa.OpMul32,
+ opAndType{OMUL, TINT64}: ssa.OpMul64,
+ opAndType{OMUL, TUINT64}: ssa.OpMul64,
+ opAndType{OMUL, TFLOAT32}: ssa.OpMul32F,
+ opAndType{OMUL, TFLOAT64}: ssa.OpMul64F,
+
+ opAndType{ODIV, TFLOAT32}: ssa.OpDiv32F,
+ opAndType{ODIV, TFLOAT64}: ssa.OpDiv64F,
+
+ opAndType{OHMUL, TINT8}: ssa.OpHmul8,
+ opAndType{OHMUL, TUINT8}: ssa.OpHmul8u,
+ opAndType{OHMUL, TINT16}: ssa.OpHmul16,
+ opAndType{OHMUL, TUINT16}: ssa.OpHmul16u,
+ opAndType{OHMUL, TINT32}: ssa.OpHmul32,
+ opAndType{OHMUL, TUINT32}: ssa.OpHmul32u,
+
+ opAndType{ODIV, TINT8}: ssa.OpDiv8,
+ opAndType{ODIV, TUINT8}: ssa.OpDiv8u,
+ opAndType{ODIV, TINT16}: ssa.OpDiv16,
+ opAndType{ODIV, TUINT16}: ssa.OpDiv16u,
+ opAndType{ODIV, TINT32}: ssa.OpDiv32,
+ opAndType{ODIV, TUINT32}: ssa.OpDiv32u,
+ opAndType{ODIV, TINT64}: ssa.OpDiv64,
+ opAndType{ODIV, TUINT64}: ssa.OpDiv64u,
+
+ opAndType{OMOD, TINT8}: ssa.OpMod8,
+ opAndType{OMOD, TUINT8}: ssa.OpMod8u,
+ opAndType{OMOD, TINT16}: ssa.OpMod16,
+ opAndType{OMOD, TUINT16}: ssa.OpMod16u,
+ opAndType{OMOD, TINT32}: ssa.OpMod32,
+ opAndType{OMOD, TUINT32}: ssa.OpMod32u,
+ opAndType{OMOD, TINT64}: ssa.OpMod64,
+ opAndType{OMOD, TUINT64}: ssa.OpMod64u,
+
+ opAndType{OAND, TINT8}: ssa.OpAnd8,
+ opAndType{OAND, TUINT8}: ssa.OpAnd8,
+ opAndType{OAND, TINT16}: ssa.OpAnd16,
+ opAndType{OAND, TUINT16}: ssa.OpAnd16,
+ opAndType{OAND, TINT32}: ssa.OpAnd32,
+ opAndType{OAND, TUINT32}: ssa.OpAnd32,
+ opAndType{OAND, TINT64}: ssa.OpAnd64,
+ opAndType{OAND, TUINT64}: ssa.OpAnd64,
+
+ opAndType{OOR, TINT8}: ssa.OpOr8,
+ opAndType{OOR, TUINT8}: ssa.OpOr8,
+ opAndType{OOR, TINT16}: ssa.OpOr16,
+ opAndType{OOR, TUINT16}: ssa.OpOr16,
+ opAndType{OOR, TINT32}: ssa.OpOr32,
+ opAndType{OOR, TUINT32}: ssa.OpOr32,
+ opAndType{OOR, TINT64}: ssa.OpOr64,
+ opAndType{OOR, TUINT64}: ssa.OpOr64,
+
+ opAndType{OXOR, TINT8}: ssa.OpXor8,
+ opAndType{OXOR, TUINT8}: ssa.OpXor8,
+ opAndType{OXOR, TINT16}: ssa.OpXor16,
+ opAndType{OXOR, TUINT16}: ssa.OpXor16,
+ opAndType{OXOR, TINT32}: ssa.OpXor32,
+ opAndType{OXOR, TUINT32}: ssa.OpXor32,
+ opAndType{OXOR, TINT64}: ssa.OpXor64,
+ opAndType{OXOR, TUINT64}: ssa.OpXor64,
+
+ opAndType{OEQ, TBOOL}: ssa.OpEq8,
+ opAndType{OEQ, TINT8}: ssa.OpEq8,
+ opAndType{OEQ, TUINT8}: ssa.OpEq8,
+ opAndType{OEQ, TINT16}: ssa.OpEq16,
+ opAndType{OEQ, TUINT16}: ssa.OpEq16,
+ opAndType{OEQ, TINT32}: ssa.OpEq32,
+ opAndType{OEQ, TUINT32}: ssa.OpEq32,
+ opAndType{OEQ, TINT64}: ssa.OpEq64,
+ opAndType{OEQ, TUINT64}: ssa.OpEq64,
+ opAndType{OEQ, TINTER}: ssa.OpEqInter,
+ opAndType{OEQ, TARRAY}: ssa.OpEqSlice,
+ opAndType{OEQ, TFUNC}: ssa.OpEqPtr,
+ opAndType{OEQ, TMAP}: ssa.OpEqPtr,
+ opAndType{OEQ, TCHAN}: ssa.OpEqPtr,
+ opAndType{OEQ, TPTR64}: ssa.OpEqPtr,
+ opAndType{OEQ, TUINTPTR}: ssa.OpEqPtr,
+ opAndType{OEQ, TUNSAFEPTR}: ssa.OpEqPtr,
+ opAndType{OEQ, TFLOAT64}: ssa.OpEq64F,
+ opAndType{OEQ, TFLOAT32}: ssa.OpEq32F,
+
+ opAndType{ONE, TBOOL}: ssa.OpNeq8,
+ opAndType{ONE, TINT8}: ssa.OpNeq8,
+ opAndType{ONE, TUINT8}: ssa.OpNeq8,
+ opAndType{ONE, TINT16}: ssa.OpNeq16,
+ opAndType{ONE, TUINT16}: ssa.OpNeq16,
+ opAndType{ONE, TINT32}: ssa.OpNeq32,
+ opAndType{ONE, TUINT32}: ssa.OpNeq32,
+ opAndType{ONE, TINT64}: ssa.OpNeq64,
+ opAndType{ONE, TUINT64}: ssa.OpNeq64,
+ opAndType{ONE, TINTER}: ssa.OpNeqInter,
+ opAndType{ONE, TARRAY}: ssa.OpNeqSlice,
+ opAndType{ONE, TFUNC}: ssa.OpNeqPtr,
+ opAndType{ONE, TMAP}: ssa.OpNeqPtr,
+ opAndType{ONE, TCHAN}: ssa.OpNeqPtr,
+ opAndType{ONE, TPTR64}: ssa.OpNeqPtr,
+ opAndType{ONE, TUINTPTR}: ssa.OpNeqPtr,
+ opAndType{ONE, TUNSAFEPTR}: ssa.OpNeqPtr,
+ opAndType{ONE, TFLOAT64}: ssa.OpNeq64F,
+ opAndType{ONE, TFLOAT32}: ssa.OpNeq32F,
+
+ opAndType{OLT, TINT8}: ssa.OpLess8,
+ opAndType{OLT, TUINT8}: ssa.OpLess8U,
+ opAndType{OLT, TINT16}: ssa.OpLess16,
+ opAndType{OLT, TUINT16}: ssa.OpLess16U,
+ opAndType{OLT, TINT32}: ssa.OpLess32,
+ opAndType{OLT, TUINT32}: ssa.OpLess32U,
+ opAndType{OLT, TINT64}: ssa.OpLess64,
+ opAndType{OLT, TUINT64}: ssa.OpLess64U,
+ opAndType{OLT, TFLOAT64}: ssa.OpLess64F,
+ opAndType{OLT, TFLOAT32}: ssa.OpLess32F,
+
+ opAndType{OGT, TINT8}: ssa.OpGreater8,
+ opAndType{OGT, TUINT8}: ssa.OpGreater8U,
+ opAndType{OGT, TINT16}: ssa.OpGreater16,
+ opAndType{OGT, TUINT16}: ssa.OpGreater16U,
+ opAndType{OGT, TINT32}: ssa.OpGreater32,
+ opAndType{OGT, TUINT32}: ssa.OpGreater32U,
+ opAndType{OGT, TINT64}: ssa.OpGreater64,
+ opAndType{OGT, TUINT64}: ssa.OpGreater64U,
+ opAndType{OGT, TFLOAT64}: ssa.OpGreater64F,
+ opAndType{OGT, TFLOAT32}: ssa.OpGreater32F,
+
+ opAndType{OLE, TINT8}: ssa.OpLeq8,
+ opAndType{OLE, TUINT8}: ssa.OpLeq8U,
+ opAndType{OLE, TINT16}: ssa.OpLeq16,
+ opAndType{OLE, TUINT16}: ssa.OpLeq16U,
+ opAndType{OLE, TINT32}: ssa.OpLeq32,
+ opAndType{OLE, TUINT32}: ssa.OpLeq32U,
+ opAndType{OLE, TINT64}: ssa.OpLeq64,
+ opAndType{OLE, TUINT64}: ssa.OpLeq64U,
+ opAndType{OLE, TFLOAT64}: ssa.OpLeq64F,
+ opAndType{OLE, TFLOAT32}: ssa.OpLeq32F,
+
+ opAndType{OGE, TINT8}: ssa.OpGeq8,
+ opAndType{OGE, TUINT8}: ssa.OpGeq8U,
+ opAndType{OGE, TINT16}: ssa.OpGeq16,
+ opAndType{OGE, TUINT16}: ssa.OpGeq16U,
+ opAndType{OGE, TINT32}: ssa.OpGeq32,
+ opAndType{OGE, TUINT32}: ssa.OpGeq32U,
+ opAndType{OGE, TINT64}: ssa.OpGeq64,
+ opAndType{OGE, TUINT64}: ssa.OpGeq64U,
+ opAndType{OGE, TFLOAT64}: ssa.OpGeq64F,
+ opAndType{OGE, TFLOAT32}: ssa.OpGeq32F,
+
+ opAndType{OLROT, TUINT8}: ssa.OpLrot8,
+ opAndType{OLROT, TUINT16}: ssa.OpLrot16,
+ opAndType{OLROT, TUINT32}: ssa.OpLrot32,
+ opAndType{OLROT, TUINT64}: ssa.OpLrot64,
+
+ opAndType{OSQRT, TFLOAT64}: ssa.OpSqrt,
+}
+
+func (s *state) concreteEtype(t *Type) EType {
+ e := t.Etype
+ switch e {
+ default:
+ return e
+ case TINT:
+ if s.config.IntSize == 8 {
+ return TINT64
+ }
+ return TINT32
+ case TUINT:
+ if s.config.IntSize == 8 {
+ return TUINT64
+ }
+ return TUINT32
+ case TUINTPTR:
+ if s.config.PtrSize == 8 {
+ return TUINT64
+ }
+ return TUINT32
+ }
+}
+
+func (s *state) ssaOp(op Op, t *Type) ssa.Op {
+ etype := s.concreteEtype(t)
+ x, ok := opToSSA[opAndType{op, etype}]
+ if !ok {
+ s.Unimplementedf("unhandled binary op %s %s", opnames[op], Econv(etype))
+ }
+ return x
+}
+
+func floatForComplex(t *Type) *Type {
+ if t.Size() == 8 {
+ return Types[TFLOAT32]
+ } else {
+ return Types[TFLOAT64]
+ }
+}
+
+type opAndTwoTypes struct {
+ op Op
+ etype1 EType
+ etype2 EType
+}
+
+type twoTypes struct {
+ etype1 EType
+ etype2 EType
+}
+
+type twoOpsAndType struct {
+ op1 ssa.Op
+ op2 ssa.Op
+ intermediateType EType
+}
+
+var fpConvOpToSSA = map[twoTypes]twoOpsAndType{
+
+ twoTypes{TINT8, TFLOAT32}: twoOpsAndType{ssa.OpSignExt8to32, ssa.OpCvt32to32F, TINT32},
+ twoTypes{TINT16, TFLOAT32}: twoOpsAndType{ssa.OpSignExt16to32, ssa.OpCvt32to32F, TINT32},
+ twoTypes{TINT32, TFLOAT32}: twoOpsAndType{ssa.OpCopy, ssa.OpCvt32to32F, TINT32},
+ twoTypes{TINT64, TFLOAT32}: twoOpsAndType{ssa.OpCopy, ssa.OpCvt64to32F, TINT64},
+
+ twoTypes{TINT8, TFLOAT64}: twoOpsAndType{ssa.OpSignExt8to32, ssa.OpCvt32to64F, TINT32},
+ twoTypes{TINT16, TFLOAT64}: twoOpsAndType{ssa.OpSignExt16to32, ssa.OpCvt32to64F, TINT32},
+ twoTypes{TINT32, TFLOAT64}: twoOpsAndType{ssa.OpCopy, ssa.OpCvt32to64F, TINT32},
+ twoTypes{TINT64, TFLOAT64}: twoOpsAndType{ssa.OpCopy, ssa.OpCvt64to64F, TINT64},
+
+ twoTypes{TFLOAT32, TINT8}: twoOpsAndType{ssa.OpCvt32Fto32, ssa.OpTrunc32to8, TINT32},
+ twoTypes{TFLOAT32, TINT16}: twoOpsAndType{ssa.OpCvt32Fto32, ssa.OpTrunc32to16, TINT32},
+ twoTypes{TFLOAT32, TINT32}: twoOpsAndType{ssa.OpCvt32Fto32, ssa.OpCopy, TINT32},
+ twoTypes{TFLOAT32, TINT64}: twoOpsAndType{ssa.OpCvt32Fto64, ssa.OpCopy, TINT64},
+
+ twoTypes{TFLOAT64, TINT8}: twoOpsAndType{ssa.OpCvt64Fto32, ssa.OpTrunc32to8, TINT32},
+ twoTypes{TFLOAT64, TINT16}: twoOpsAndType{ssa.OpCvt64Fto32, ssa.OpTrunc32to16, TINT32},
+ twoTypes{TFLOAT64, TINT32}: twoOpsAndType{ssa.OpCvt64Fto32, ssa.OpCopy, TINT32},
+ twoTypes{TFLOAT64, TINT64}: twoOpsAndType{ssa.OpCvt64Fto64, ssa.OpCopy, TINT64},
+ // unsigned
+ twoTypes{TUINT8, TFLOAT32}: twoOpsAndType{ssa.OpZeroExt8to32, ssa.OpCvt32to32F, TINT32},
+ twoTypes{TUINT16, TFLOAT32}: twoOpsAndType{ssa.OpZeroExt16to32, ssa.OpCvt32to32F, TINT32},
+ twoTypes{TUINT32, TFLOAT32}: twoOpsAndType{ssa.OpZeroExt32to64, ssa.OpCvt64to32F, TINT64}, // go wide to dodge unsigned
+ twoTypes{TUINT64, TFLOAT32}: twoOpsAndType{ssa.OpCopy, ssa.OpInvalid, TUINT64}, // Cvt64Uto32F, branchy code expansion instead
+
+ twoTypes{TUINT8, TFLOAT64}: twoOpsAndType{ssa.OpZeroExt8to32, ssa.OpCvt32to64F, TINT32},
+ twoTypes{TUINT16, TFLOAT64}: twoOpsAndType{ssa.OpZeroExt16to32, ssa.OpCvt32to64F, TINT32},
+ twoTypes{TUINT32, TFLOAT64}: twoOpsAndType{ssa.OpZeroExt32to64, ssa.OpCvt64to64F, TINT64}, // go wide to dodge unsigned
+ twoTypes{TUINT64, TFLOAT64}: twoOpsAndType{ssa.OpCopy, ssa.OpInvalid, TUINT64}, // Cvt64Uto64F, branchy code expansion instead
+
+ twoTypes{TFLOAT32, TUINT8}: twoOpsAndType{ssa.OpCvt32Fto32, ssa.OpTrunc32to8, TINT32},
+ twoTypes{TFLOAT32, TUINT16}: twoOpsAndType{ssa.OpCvt32Fto32, ssa.OpTrunc32to16, TINT32},
+ twoTypes{TFLOAT32, TUINT32}: twoOpsAndType{ssa.OpCvt32Fto64, ssa.OpTrunc64to32, TINT64}, // go wide to dodge unsigned
+ twoTypes{TFLOAT32, TUINT64}: twoOpsAndType{ssa.OpInvalid, ssa.OpCopy, TUINT64}, // Cvt32Fto64U, branchy code expansion instead
+
+ twoTypes{TFLOAT64, TUINT8}: twoOpsAndType{ssa.OpCvt64Fto32, ssa.OpTrunc32to8, TINT32},
+ twoTypes{TFLOAT64, TUINT16}: twoOpsAndType{ssa.OpCvt64Fto32, ssa.OpTrunc32to16, TINT32},
+ twoTypes{TFLOAT64, TUINT32}: twoOpsAndType{ssa.OpCvt64Fto64, ssa.OpTrunc64to32, TINT64}, // go wide to dodge unsigned
+ twoTypes{TFLOAT64, TUINT64}: twoOpsAndType{ssa.OpInvalid, ssa.OpCopy, TUINT64}, // Cvt64Fto64U, branchy code expansion instead
+
+ // float
+ twoTypes{TFLOAT64, TFLOAT32}: twoOpsAndType{ssa.OpCvt64Fto32F, ssa.OpCopy, TFLOAT32},
+ twoTypes{TFLOAT64, TFLOAT64}: twoOpsAndType{ssa.OpCopy, ssa.OpCopy, TFLOAT64},
+ twoTypes{TFLOAT32, TFLOAT32}: twoOpsAndType{ssa.OpCopy, ssa.OpCopy, TFLOAT32},
+ twoTypes{TFLOAT32, TFLOAT64}: twoOpsAndType{ssa.OpCvt32Fto64F, ssa.OpCopy, TFLOAT64},
+}
+
+var shiftOpToSSA = map[opAndTwoTypes]ssa.Op{
+ opAndTwoTypes{OLSH, TINT8, TUINT8}: ssa.OpLsh8x8,
+ opAndTwoTypes{OLSH, TUINT8, TUINT8}: ssa.OpLsh8x8,
+ opAndTwoTypes{OLSH, TINT8, TUINT16}: ssa.OpLsh8x16,
+ opAndTwoTypes{OLSH, TUINT8, TUINT16}: ssa.OpLsh8x16,
+ opAndTwoTypes{OLSH, TINT8, TUINT32}: ssa.OpLsh8x32,
+ opAndTwoTypes{OLSH, TUINT8, TUINT32}: ssa.OpLsh8x32,
+ opAndTwoTypes{OLSH, TINT8, TUINT64}: ssa.OpLsh8x64,
+ opAndTwoTypes{OLSH, TUINT8, TUINT64}: ssa.OpLsh8x64,
+
+ opAndTwoTypes{OLSH, TINT16, TUINT8}: ssa.OpLsh16x8,
+ opAndTwoTypes{OLSH, TUINT16, TUINT8}: ssa.OpLsh16x8,
+ opAndTwoTypes{OLSH, TINT16, TUINT16}: ssa.OpLsh16x16,
+ opAndTwoTypes{OLSH, TUINT16, TUINT16}: ssa.OpLsh16x16,
+ opAndTwoTypes{OLSH, TINT16, TUINT32}: ssa.OpLsh16x32,
+ opAndTwoTypes{OLSH, TUINT16, TUINT32}: ssa.OpLsh16x32,
+ opAndTwoTypes{OLSH, TINT16, TUINT64}: ssa.OpLsh16x64,
+ opAndTwoTypes{OLSH, TUINT16, TUINT64}: ssa.OpLsh16x64,
+
+ opAndTwoTypes{OLSH, TINT32, TUINT8}: ssa.OpLsh32x8,
+ opAndTwoTypes{OLSH, TUINT32, TUINT8}: ssa.OpLsh32x8,
+ opAndTwoTypes{OLSH, TINT32, TUINT16}: ssa.OpLsh32x16,
+ opAndTwoTypes{OLSH, TUINT32, TUINT16}: ssa.OpLsh32x16,
+ opAndTwoTypes{OLSH, TINT32, TUINT32}: ssa.OpLsh32x32,
+ opAndTwoTypes{OLSH, TUINT32, TUINT32}: ssa.OpLsh32x32,
+ opAndTwoTypes{OLSH, TINT32, TUINT64}: ssa.OpLsh32x64,
+ opAndTwoTypes{OLSH, TUINT32, TUINT64}: ssa.OpLsh32x64,
+
+ opAndTwoTypes{OLSH, TINT64, TUINT8}: ssa.OpLsh64x8,
+ opAndTwoTypes{OLSH, TUINT64, TUINT8}: ssa.OpLsh64x8,
+ opAndTwoTypes{OLSH, TINT64, TUINT16}: ssa.OpLsh64x16,
+ opAndTwoTypes{OLSH, TUINT64, TUINT16}: ssa.OpLsh64x16,
+ opAndTwoTypes{OLSH, TINT64, TUINT32}: ssa.OpLsh64x32,
+ opAndTwoTypes{OLSH, TUINT64, TUINT32}: ssa.OpLsh64x32,
+ opAndTwoTypes{OLSH, TINT64, TUINT64}: ssa.OpLsh64x64,
+ opAndTwoTypes{OLSH, TUINT64, TUINT64}: ssa.OpLsh64x64,
+
+ opAndTwoTypes{ORSH, TINT8, TUINT8}: ssa.OpRsh8x8,
+ opAndTwoTypes{ORSH, TUINT8, TUINT8}: ssa.OpRsh8Ux8,
+ opAndTwoTypes{ORSH, TINT8, TUINT16}: ssa.OpRsh8x16,
+ opAndTwoTypes{ORSH, TUINT8, TUINT16}: ssa.OpRsh8Ux16,
+ opAndTwoTypes{ORSH, TINT8, TUINT32}: ssa.OpRsh8x32,
+ opAndTwoTypes{ORSH, TUINT8, TUINT32}: ssa.OpRsh8Ux32,
+ opAndTwoTypes{ORSH, TINT8, TUINT64}: ssa.OpRsh8x64,
+ opAndTwoTypes{ORSH, TUINT8, TUINT64}: ssa.OpRsh8Ux64,
+
+ opAndTwoTypes{ORSH, TINT16, TUINT8}: ssa.OpRsh16x8,
+ opAndTwoTypes{ORSH, TUINT16, TUINT8}: ssa.OpRsh16Ux8,
+ opAndTwoTypes{ORSH, TINT16, TUINT16}: ssa.OpRsh16x16,
+ opAndTwoTypes{ORSH, TUINT16, TUINT16}: ssa.OpRsh16Ux16,
+ opAndTwoTypes{ORSH, TINT16, TUINT32}: ssa.OpRsh16x32,
+ opAndTwoTypes{ORSH, TUINT16, TUINT32}: ssa.OpRsh16Ux32,
+ opAndTwoTypes{ORSH, TINT16, TUINT64}: ssa.OpRsh16x64,
+ opAndTwoTypes{ORSH, TUINT16, TUINT64}: ssa.OpRsh16Ux64,
+
+ opAndTwoTypes{ORSH, TINT32, TUINT8}: ssa.OpRsh32x8,
+ opAndTwoTypes{ORSH, TUINT32, TUINT8}: ssa.OpRsh32Ux8,
+ opAndTwoTypes{ORSH, TINT32, TUINT16}: ssa.OpRsh32x16,
+ opAndTwoTypes{ORSH, TUINT32, TUINT16}: ssa.OpRsh32Ux16,
+ opAndTwoTypes{ORSH, TINT32, TUINT32}: ssa.OpRsh32x32,
+ opAndTwoTypes{ORSH, TUINT32, TUINT32}: ssa.OpRsh32Ux32,
+ opAndTwoTypes{ORSH, TINT32, TUINT64}: ssa.OpRsh32x64,
+ opAndTwoTypes{ORSH, TUINT32, TUINT64}: ssa.OpRsh32Ux64,
+
+ opAndTwoTypes{ORSH, TINT64, TUINT8}: ssa.OpRsh64x8,
+ opAndTwoTypes{ORSH, TUINT64, TUINT8}: ssa.OpRsh64Ux8,
+ opAndTwoTypes{ORSH, TINT64, TUINT16}: ssa.OpRsh64x16,
+ opAndTwoTypes{ORSH, TUINT64, TUINT16}: ssa.OpRsh64Ux16,
+ opAndTwoTypes{ORSH, TINT64, TUINT32}: ssa.OpRsh64x32,
+ opAndTwoTypes{ORSH, TUINT64, TUINT32}: ssa.OpRsh64Ux32,
+ opAndTwoTypes{ORSH, TINT64, TUINT64}: ssa.OpRsh64x64,
+ opAndTwoTypes{ORSH, TUINT64, TUINT64}: ssa.OpRsh64Ux64,
+}
+
+func (s *state) ssaShiftOp(op Op, t *Type, u *Type) ssa.Op {
+ etype1 := s.concreteEtype(t)
+ etype2 := s.concreteEtype(u)
+ x, ok := shiftOpToSSA[opAndTwoTypes{op, etype1, etype2}]
+ if !ok {
+ s.Unimplementedf("unhandled shift op %s etype=%s/%s", opnames[op], Econv(etype1), Econv(etype2))
+ }
+ return x
+}
+
+func (s *state) ssaRotateOp(op Op, t *Type) ssa.Op {
+ etype1 := s.concreteEtype(t)
+ x, ok := opToSSA[opAndType{op, etype1}]
+ if !ok {
+ s.Unimplementedf("unhandled rotate op %s etype=%s", opnames[op], Econv(etype1))
+ }
+ return x
+}
+
+// expr converts the expression n to ssa, adds it to s and returns the ssa result.
+func (s *state) expr(n *Node) *ssa.Value {
+ s.pushLine(n.Lineno)
+ defer s.popLine()
+
+ s.stmtList(n.Ninit)
+ switch n.Op {
+ case OCFUNC:
+ aux := s.lookupSymbol(n, &ssa.ExternSymbol{n.Type, n.Left.Sym})
+ return s.entryNewValue1A(ssa.OpAddr, n.Type, aux, s.sb)
+ case OPARAM:
+ addr := s.addr(n, false)
+ return s.newValue2(ssa.OpLoad, n.Left.Type, addr, s.mem())
+ case ONAME:
+ if n.Class == PFUNC {
+ // "value" of a function is the address of the function's closure
+ sym := funcsym(n.Sym)
+ aux := &ssa.ExternSymbol{n.Type, sym}
+ return s.entryNewValue1A(ssa.OpAddr, Ptrto(n.Type), aux, s.sb)
+ }
+ if s.canSSA(n) {
+ return s.variable(n, n.Type)
+ }
+ addr := s.addr(n, false)
+ return s.newValue2(ssa.OpLoad, n.Type, addr, s.mem())
+ case OCLOSUREVAR:
+ addr := s.addr(n, false)
+ return s.newValue2(ssa.OpLoad, n.Type, addr, s.mem())
+ case OLITERAL:
+ switch n.Val().Ctype() {
+ case CTINT:
+ i := Mpgetfix(n.Val().U.(*Mpint))
+ switch n.Type.Size() {
+ case 1:
+ return s.constInt8(n.Type, int8(i))
+ case 2:
+ return s.constInt16(n.Type, int16(i))
+ case 4:
+ return s.constInt32(n.Type, int32(i))
+ case 8:
+ return s.constInt64(n.Type, i)
+ default:
+ s.Fatalf("bad integer size %d", n.Type.Size())
+ return nil
+ }
+ case CTSTR:
+ return s.entryNewValue0A(ssa.OpConstString, n.Type, n.Val().U)
+ case CTBOOL:
+ v := s.constBool(n.Val().U.(bool))
+ // For some reason the frontend gets the line numbers of
+ // CTBOOL literals totally wrong. Fix it here by grabbing
+ // the line number of the enclosing AST node.
+ if len(s.line) >= 2 {
+ v.Line = s.line[len(s.line)-2]
+ }
+ return v
+ case CTNIL:
+ t := n.Type
+ switch {
+ case t.IsSlice():
+ return s.entryNewValue0(ssa.OpConstSlice, t)
+ case t.IsInterface():
+ return s.entryNewValue0(ssa.OpConstInterface, t)
+ default:
+ return s.entryNewValue0(ssa.OpConstNil, t)
+ }
+ case CTFLT:
+ f := n.Val().U.(*Mpflt)
+ switch n.Type.Size() {
+ case 4:
+ return s.constFloat32(n.Type, mpgetflt32(f))
+ case 8:
+ return s.constFloat64(n.Type, mpgetflt(f))
+ default:
+ s.Fatalf("bad float size %d", n.Type.Size())
+ return nil
+ }
+ case CTCPLX:
+ c := n.Val().U.(*Mpcplx)
+ r := &c.Real
+ i := &c.Imag
+ switch n.Type.Size() {
+ case 8:
+ {
+ pt := Types[TFLOAT32]
+ return s.newValue2(ssa.OpComplexMake, n.Type,
+ s.constFloat32(pt, mpgetflt32(r)),
+ s.constFloat32(pt, mpgetflt32(i)))
+ }
+ case 16:
+ {
+ pt := Types[TFLOAT64]
+ return s.newValue2(ssa.OpComplexMake, n.Type,
+ s.constFloat64(pt, mpgetflt(r)),
+ s.constFloat64(pt, mpgetflt(i)))
+ }
+ default:
+ s.Fatalf("bad float size %d", n.Type.Size())
+ return nil
+ }
+
+ default:
+ s.Unimplementedf("unhandled OLITERAL %v", n.Val().Ctype())
+ return nil
+ }
+ case OCONVNOP:
+ to := n.Type
+ from := n.Left.Type
+
+ // Assume everything will work out, so set up our return value.
+ // Anything interesting that happens from here is a fatal.
+ x := s.expr(n.Left)
+
+ // Special case for not confusing GC and liveness.
+ // We don't want pointers accidentally classified
+ // as not-pointers or vice-versa because of copy
+ // elision.
+ if to.IsPtr() != from.IsPtr() {
+ return s.newValue2(ssa.OpConvert, to, x, s.mem())
+ }
+
+ v := s.newValue1(ssa.OpCopy, to, x) // ensure that v has the right type
+
+ // CONVNOP closure
+ if to.Etype == TFUNC && from.IsPtr() {
+ return v
+ }
+
+ // named <--> unnamed type or typed <--> untyped const
+ if from.Etype == to.Etype {
+ return v
+ }
+
+ // unsafe.Pointer <--> *T
+ if to.Etype == TUNSAFEPTR && from.IsPtr() || from.Etype == TUNSAFEPTR && to.IsPtr() {
+ return v
+ }
+
+ dowidth(from)
+ dowidth(to)
+ if from.Width != to.Width {
+ s.Fatalf("CONVNOP width mismatch %v (%d) -> %v (%d)\n", from, from.Width, to, to.Width)
+ return nil
+ }
+ if etypesign(from.Etype) != etypesign(to.Etype) {
+ s.Fatalf("CONVNOP sign mismatch %v (%s) -> %v (%s)\n", from, Econv(from.Etype), to, Econv(to.Etype))
+ return nil
+ }
+
+ if flag_race != 0 {
+ // These appear to be fine, but they fail the
+ // integer constraint below, so okay them here.
+ // Sample non-integer conversion: map[string]string -> *uint8
+ return v
+ }
+
+ if etypesign(from.Etype) == 0 {
+ s.Fatalf("CONVNOP unrecognized non-integer %v -> %v\n", from, to)
+ return nil
+ }
+
+ // integer, same width, same sign
+ return v
+
+ case OCONV:
+ x := s.expr(n.Left)
+ ft := n.Left.Type // from type
+ tt := n.Type // to type
+ if ft.IsInteger() && tt.IsInteger() {
+ var op ssa.Op
+ if tt.Size() == ft.Size() {
+ op = ssa.OpCopy
+ } else if tt.Size() < ft.Size() {
+ // truncation
+ switch 10*ft.Size() + tt.Size() {
+ case 21:
+ op = ssa.OpTrunc16to8
+ case 41:
+ op = ssa.OpTrunc32to8
+ case 42:
+ op = ssa.OpTrunc32to16
+ case 81:
+ op = ssa.OpTrunc64to8
+ case 82:
+ op = ssa.OpTrunc64to16
+ case 84:
+ op = ssa.OpTrunc64to32
+ default:
+ s.Fatalf("weird integer truncation %s -> %s", ft, tt)
+ }
+ } else if ft.IsSigned() {
+ // sign extension
+ switch 10*ft.Size() + tt.Size() {
+ case 12:
+ op = ssa.OpSignExt8to16
+ case 14:
+ op = ssa.OpSignExt8to32
+ case 18:
+ op = ssa.OpSignExt8to64
+ case 24:
+ op = ssa.OpSignExt16to32
+ case 28:
+ op = ssa.OpSignExt16to64
+ case 48:
+ op = ssa.OpSignExt32to64
+ default:
+ s.Fatalf("bad integer sign extension %s -> %s", ft, tt)
+ }
+ } else {
+ // zero extension
+ switch 10*ft.Size() + tt.Size() {
+ case 12:
+ op = ssa.OpZeroExt8to16
+ case 14:
+ op = ssa.OpZeroExt8to32
+ case 18:
+ op = ssa.OpZeroExt8to64
+ case 24:
+ op = ssa.OpZeroExt16to32
+ case 28:
+ op = ssa.OpZeroExt16to64
+ case 48:
+ op = ssa.OpZeroExt32to64
+ default:
+ s.Fatalf("weird integer sign extension %s -> %s", ft, tt)
+ }
+ }
+ return s.newValue1(op, n.Type, x)
+ }
+
+ if ft.IsFloat() || tt.IsFloat() {
+ conv, ok := fpConvOpToSSA[twoTypes{s.concreteEtype(ft), s.concreteEtype(tt)}]
+ if !ok {
+ s.Fatalf("weird float conversion %s -> %s", ft, tt)
+ }
+ op1, op2, it := conv.op1, conv.op2, conv.intermediateType
+
+ if op1 != ssa.OpInvalid && op2 != ssa.OpInvalid {
+ // normal case, not tripping over unsigned 64
+ if op1 == ssa.OpCopy {
+ if op2 == ssa.OpCopy {
+ return x
+ }
+ return s.newValue1(op2, n.Type, x)
+ }
+ if op2 == ssa.OpCopy {
+ return s.newValue1(op1, n.Type, x)
+ }
+ return s.newValue1(op2, n.Type, s.newValue1(op1, Types[it], x))
+ }
+ // Tricky 64-bit unsigned cases.
+ if ft.IsInteger() {
+ // therefore tt is float32 or float64, and ft is also unsigned
+ if tt.Size() == 4 {
+ return s.uint64Tofloat32(n, x, ft, tt)
+ }
+ if tt.Size() == 8 {
+ return s.uint64Tofloat64(n, x, ft, tt)
+ }
+ s.Fatalf("weird unsigned integer to float conversion %s -> %s", ft, tt)
+ }
+ // therefore ft is float32 or float64, and tt is unsigned integer
+ if ft.Size() == 4 {
+ return s.float32ToUint64(n, x, ft, tt)
+ }
+ if ft.Size() == 8 {
+ return s.float64ToUint64(n, x, ft, tt)
+ }
+ s.Fatalf("weird float to unsigned integer conversion %s -> %s", ft, tt)
+ return nil
+ }
+
+ if ft.IsComplex() && tt.IsComplex() {
+ var op ssa.Op
+ if ft.Size() == tt.Size() {
+ op = ssa.OpCopy
+ } else if ft.Size() == 8 && tt.Size() == 16 {
+ op = ssa.OpCvt32Fto64F
+ } else if ft.Size() == 16 && tt.Size() == 8 {
+ op = ssa.OpCvt64Fto32F
+ } else {
+ s.Fatalf("weird complex conversion %s -> %s", ft, tt)
+ }
+ ftp := floatForComplex(ft)
+ ttp := floatForComplex(tt)
+ return s.newValue2(ssa.OpComplexMake, tt,
+ s.newValue1(op, ttp, s.newValue1(ssa.OpComplexReal, ftp, x)),
+ s.newValue1(op, ttp, s.newValue1(ssa.OpComplexImag, ftp, x)))
+ }
+
+ s.Unimplementedf("unhandled OCONV %s -> %s", Econv(n.Left.Type.Etype), Econv(n.Type.Etype))
+ return nil
+
+ case ODOTTYPE:
+ res, _ := s.dottype(n, false)
+ return res
+
+ // binary ops
+ case OLT, OEQ, ONE, OLE, OGE, OGT:
+ a := s.expr(n.Left)
+ b := s.expr(n.Right)
+ if n.Left.Type.IsComplex() {
+ pt := floatForComplex(n.Left.Type)
+ op := s.ssaOp(OEQ, pt)
+ r := s.newValue2(op, Types[TBOOL], s.newValue1(ssa.OpComplexReal, pt, a), s.newValue1(ssa.OpComplexReal, pt, b))
+ i := s.newValue2(op, Types[TBOOL], s.newValue1(ssa.OpComplexImag, pt, a), s.newValue1(ssa.OpComplexImag, pt, b))
+ c := s.newValue2(ssa.OpAnd8, Types[TBOOL], r, i)
+ switch n.Op {
+ case OEQ:
+ return c
+ case ONE:
+ return s.newValue1(ssa.OpNot, Types[TBOOL], c)
+ default:
+ s.Fatalf("ordered complex compare %s", opnames[n.Op])
+ }
+ }
+ return s.newValue2(s.ssaOp(n.Op, n.Left.Type), Types[TBOOL], a, b)
+ case OMUL:
+ a := s.expr(n.Left)
+ b := s.expr(n.Right)
+ if n.Type.IsComplex() {
+ mulop := ssa.OpMul64F
+ addop := ssa.OpAdd64F
+ subop := ssa.OpSub64F
+ pt := floatForComplex(n.Type) // Could be Float32 or Float64
+ wt := Types[TFLOAT64] // Compute in Float64 to minimize cancellation error
+
+ areal := s.newValue1(ssa.OpComplexReal, pt, a)
+ breal := s.newValue1(ssa.OpComplexReal, pt, b)
+ aimag := s.newValue1(ssa.OpComplexImag, pt, a)
+ bimag := s.newValue1(ssa.OpComplexImag, pt, b)
+
+ if pt != wt { // Widen for calculation
+ areal = s.newValue1(ssa.OpCvt32Fto64F, wt, areal)
+ breal = s.newValue1(ssa.OpCvt32Fto64F, wt, breal)
+ aimag = s.newValue1(ssa.OpCvt32Fto64F, wt, aimag)
+ bimag = s.newValue1(ssa.OpCvt32Fto64F, wt, bimag)
+ }
+
+ xreal := s.newValue2(subop, wt, s.newValue2(mulop, wt, areal, breal), s.newValue2(mulop, wt, aimag, bimag))
+ ximag := s.newValue2(addop, wt, s.newValue2(mulop, wt, areal, bimag), s.newValue2(mulop, wt, aimag, breal))
+
+ if pt != wt { // Narrow to store back
+ xreal = s.newValue1(ssa.OpCvt64Fto32F, pt, xreal)
+ ximag = s.newValue1(ssa.OpCvt64Fto32F, pt, ximag)
+ }
+
+ return s.newValue2(ssa.OpComplexMake, n.Type, xreal, ximag)
+ }
+ return s.newValue2(s.ssaOp(n.Op, n.Type), a.Type, a, b)
+
+ case ODIV:
+ a := s.expr(n.Left)
+ b := s.expr(n.Right)
+ if n.Type.IsComplex() {
+ // TODO this is not executed because the front-end substitutes a runtime call.
+ // That probably ought to change; with modest optimization the widen/narrow
+ // conversions could all be elided in larger expression trees.
+ mulop := ssa.OpMul64F
+ addop := ssa.OpAdd64F
+ subop := ssa.OpSub64F
+ divop := ssa.OpDiv64F
+ pt := floatForComplex(n.Type) // Could be Float32 or Float64
+ wt := Types[TFLOAT64] // Compute in Float64 to minimize cancellation error
+
+ areal := s.newValue1(ssa.OpComplexReal, pt, a)
+ breal := s.newValue1(ssa.OpComplexReal, pt, b)
+ aimag := s.newValue1(ssa.OpComplexImag, pt, a)
+ bimag := s.newValue1(ssa.OpComplexImag, pt, b)
+
+ if pt != wt { // Widen for calculation
+ areal = s.newValue1(ssa.OpCvt32Fto64F, wt, areal)
+ breal = s.newValue1(ssa.OpCvt32Fto64F, wt, breal)
+ aimag = s.newValue1(ssa.OpCvt32Fto64F, wt, aimag)
+ bimag = s.newValue1(ssa.OpCvt32Fto64F, wt, bimag)
+ }
+
+ denom := s.newValue2(addop, wt, s.newValue2(mulop, wt, breal, breal), s.newValue2(mulop, wt, bimag, bimag))
+ xreal := s.newValue2(addop, wt, s.newValue2(mulop, wt, areal, breal), s.newValue2(mulop, wt, aimag, bimag))
+ ximag := s.newValue2(subop, wt, s.newValue2(mulop, wt, aimag, breal), s.newValue2(mulop, wt, areal, bimag))
+
+ // TODO not sure if this is best done in wide precision or narrow
+ // Double-rounding might be an issue.
+ // Note that the pre-SSA implementation does the entire calculation
+ // in wide format, so wide is compatible.
+ xreal = s.newValue2(divop, wt, xreal, denom)
+ ximag = s.newValue2(divop, wt, ximag, denom)
+
+ if pt != wt { // Narrow to store back
+ xreal = s.newValue1(ssa.OpCvt64Fto32F, pt, xreal)
+ ximag = s.newValue1(ssa.OpCvt64Fto32F, pt, ximag)
+ }
+ return s.newValue2(ssa.OpComplexMake, n.Type, xreal, ximag)
+ }
+ if n.Type.IsFloat() {
+ return s.newValue2(s.ssaOp(n.Op, n.Type), a.Type, a, b)
+ } else {
+ // do a size-appropriate check for zero
+ cmp := s.newValue2(s.ssaOp(ONE, n.Type), Types[TBOOL], b, s.zeroVal(n.Type))
+ s.check(cmp, panicdivide)
+ return s.newValue2(s.ssaOp(n.Op, n.Type), a.Type, a, b)
+ }
+ case OMOD:
+ a := s.expr(n.Left)
+ b := s.expr(n.Right)
+ // do a size-appropriate check for zero
+ cmp := s.newValue2(s.ssaOp(ONE, n.Type), Types[TBOOL], b, s.zeroVal(n.Type))
+ s.check(cmp, panicdivide)
+ return s.newValue2(s.ssaOp(n.Op, n.Type), a.Type, a, b)
+ case OADD, OSUB:
+ a := s.expr(n.Left)
+ b := s.expr(n.Right)
+ if n.Type.IsComplex() {
+ pt := floatForComplex(n.Type)
+ op := s.ssaOp(n.Op, pt)
+ return s.newValue2(ssa.OpComplexMake, n.Type,
+ s.newValue2(op, pt, s.newValue1(ssa.OpComplexReal, pt, a), s.newValue1(ssa.OpComplexReal, pt, b)),
+ s.newValue2(op, pt, s.newValue1(ssa.OpComplexImag, pt, a), s.newValue1(ssa.OpComplexImag, pt, b)))
+ }
+ return s.newValue2(s.ssaOp(n.Op, n.Type), a.Type, a, b)
+ case OAND, OOR, OHMUL, OXOR:
+ a := s.expr(n.Left)
+ b := s.expr(n.Right)
+ return s.newValue2(s.ssaOp(n.Op, n.Type), a.Type, a, b)
+ case OLSH, ORSH:
+ a := s.expr(n.Left)
+ b := s.expr(n.Right)
+ return s.newValue2(s.ssaShiftOp(n.Op, n.Type, n.Right.Type), a.Type, a, b)
+ case OLROT:
+ a := s.expr(n.Left)
+ i := n.Right.Int()
+ if i <= 0 || i >= n.Type.Size()*8 {
+ s.Fatalf("Wrong rotate distance for LROT, expected 1 through %d, saw %d", n.Type.Size()*8-1, i)
+ }
+ return s.newValue1I(s.ssaRotateOp(n.Op, n.Type), a.Type, i, a)
+ case OANDAND, OOROR:
+ // To implement OANDAND (and OOROR), we introduce a
+ // new temporary variable to hold the result. The
+ // variable is associated with the OANDAND node in the
+ // s.vars table (normally variables are only
+ // associated with ONAME nodes). We convert
+ // A && B
+ // to
+ // var = A
+ // if var {
+ // var = B
+ // }
+ // Using var in the subsequent block introduces the
+ // necessary phi variable.
+ el := s.expr(n.Left)
+ s.vars[n] = el
+
+ b := s.endBlock()
+ b.Kind = ssa.BlockIf
+ b.Control = el
+ // In theory, we should set b.Likely here based on context.
+ // However, gc only gives us likeliness hints
+ // in a single place, for plain OIF statements,
+ // and passing around context is finnicky, so don't bother for now.
+
+ bRight := s.f.NewBlock(ssa.BlockPlain)
+ bResult := s.f.NewBlock(ssa.BlockPlain)
+ if n.Op == OANDAND {
+ b.AddEdgeTo(bRight)
+ b.AddEdgeTo(bResult)
+ } else if n.Op == OOROR {
+ b.AddEdgeTo(bResult)
+ b.AddEdgeTo(bRight)
+ }
+
+ s.startBlock(bRight)
+ er := s.expr(n.Right)
+ s.vars[n] = er
+
+ b = s.endBlock()
+ b.AddEdgeTo(bResult)
+
+ s.startBlock(bResult)
+ return s.variable(n, Types[TBOOL])
+ case OCOMPLEX:
+ r := s.expr(n.Left)
+ i := s.expr(n.Right)
+ return s.newValue2(ssa.OpComplexMake, n.Type, r, i)
+
+ // unary ops
+ case OMINUS:
+ a := s.expr(n.Left)
+ if n.Type.IsComplex() {
+ tp := floatForComplex(n.Type)
+ negop := s.ssaOp(n.Op, tp)
+ return s.newValue2(ssa.OpComplexMake, n.Type,
+ s.newValue1(negop, tp, s.newValue1(ssa.OpComplexReal, tp, a)),
+ s.newValue1(negop, tp, s.newValue1(ssa.OpComplexImag, tp, a)))
+ }
+ return s.newValue1(s.ssaOp(n.Op, n.Type), a.Type, a)
+ case ONOT, OCOM, OSQRT:
+ a := s.expr(n.Left)
+ return s.newValue1(s.ssaOp(n.Op, n.Type), a.Type, a)
+ case OIMAG, OREAL:
+ a := s.expr(n.Left)
+ return s.newValue1(s.ssaOp(n.Op, n.Left.Type), n.Type, a)
+ case OPLUS:
+ return s.expr(n.Left)
+
+ case OADDR:
+ return s.addr(n.Left, n.Bounded)
+
+ case OINDREG:
+ if int(n.Reg) != Thearch.REGSP {
+ s.Unimplementedf("OINDREG of non-SP register %s in expr: %v", obj.Rconv(int(n.Reg)), n)
+ return nil
+ }
+ addr := s.entryNewValue1I(ssa.OpOffPtr, Ptrto(n.Type), n.Xoffset, s.sp)
+ return s.newValue2(ssa.OpLoad, n.Type, addr, s.mem())
+
+ case OIND:
+ p := s.expr(n.Left)
+ s.nilCheck(p)
+ return s.newValue2(ssa.OpLoad, n.Type, p, s.mem())
+
+ case ODOT:
+ t := n.Left.Type
+ if canSSAType(t) {
+ v := s.expr(n.Left)
+ return s.newValue1I(ssa.OpStructSelect, n.Type, fieldIdx(n), v)
+ }
+ p := s.addr(n, false)
+ return s.newValue2(ssa.OpLoad, n.Type, p, s.mem())
+
+ case ODOTPTR:
+ p := s.expr(n.Left)
+ s.nilCheck(p)
+ p = s.newValue2(ssa.OpAddPtr, p.Type, p, s.constInt(Types[TINT], n.Xoffset))
+ return s.newValue2(ssa.OpLoad, n.Type, p, s.mem())
+
+ case OINDEX:
+ switch {
+ case n.Left.Type.IsString():
+ a := s.expr(n.Left)
+ i := s.expr(n.Right)
+ i = s.extendIndex(i)
+ if !n.Bounded {
+ len := s.newValue1(ssa.OpStringLen, Types[TINT], a)
+ s.boundsCheck(i, len)
+ }
+ ptrtyp := Ptrto(Types[TUINT8])
+ ptr := s.newValue1(ssa.OpStringPtr, ptrtyp, a)
+ ptr = s.newValue2(ssa.OpAddPtr, ptrtyp, ptr, i)
+ return s.newValue2(ssa.OpLoad, Types[TUINT8], ptr, s.mem())
+ case n.Left.Type.IsSlice():
+ p := s.addr(n, false)
+ return s.newValue2(ssa.OpLoad, n.Left.Type.Type, p, s.mem())
+ case n.Left.Type.IsArray():
+ // TODO: fix when we can SSA arrays of length 1.
+ p := s.addr(n, false)
+ return s.newValue2(ssa.OpLoad, n.Left.Type.Type, p, s.mem())
+ default:
+ s.Fatalf("bad type for index %v", n.Left.Type)
+ return nil
+ }
+
+ case OLEN, OCAP:
+ switch {
+ case n.Left.Type.IsSlice():
+ op := ssa.OpSliceLen
+ if n.Op == OCAP {
+ op = ssa.OpSliceCap
+ }
+ return s.newValue1(op, Types[TINT], s.expr(n.Left))
+ case n.Left.Type.IsString(): // string; not reachable for OCAP
+ return s.newValue1(ssa.OpStringLen, Types[TINT], s.expr(n.Left))
+ case n.Left.Type.IsMap(), n.Left.Type.IsChan():
+ return s.referenceTypeBuiltin(n, s.expr(n.Left))
+ default: // array
+ return s.constInt(Types[TINT], n.Left.Type.Bound)
+ }
+
+ case OSPTR:
+ a := s.expr(n.Left)
+ if n.Left.Type.IsSlice() {
+ return s.newValue1(ssa.OpSlicePtr, n.Type, a)
+ } else {
+ return s.newValue1(ssa.OpStringPtr, n.Type, a)
+ }
+
+ case OITAB:
+ a := s.expr(n.Left)
+ return s.newValue1(ssa.OpITab, n.Type, a)
+
+ case OEFACE:
+ tab := s.expr(n.Left)
+ data := s.expr(n.Right)
+ // The frontend allows putting things like struct{*byte} in
+ // the data portion of an eface. But we don't want struct{*byte}
+ // as a register type because (among other reasons) the liveness
+ // analysis is confused by the "fat" variables that result from
+ // such types being spilled.
+ // So here we ensure that we are selecting the underlying pointer
+ // when we build an eface.
+ // TODO: get rid of this now that structs can be SSA'd?
+ for !data.Type.IsPtr() {
+ switch {
+ case data.Type.IsArray():
+ data = s.newValue2(ssa.OpArrayIndex, data.Type.Elem(), data, s.constInt(Types[TINT], 0))
+ case data.Type.IsStruct():
+ for i := data.Type.NumFields() - 1; i >= 0; i-- {
+ f := data.Type.FieldType(i)
+ if f.Size() == 0 {
+ // eface type could also be struct{p *byte; q [0]int}
+ continue
+ }
+ data = s.newValue1I(ssa.OpStructSelect, f, i, data)
+ break
+ }
+ default:
+ s.Fatalf("type being put into an eface isn't a pointer")
+ }
+ }
+ return s.newValue2(ssa.OpIMake, n.Type, tab, data)
+
+ case OSLICE, OSLICEARR:
+ v := s.expr(n.Left)
+ var i, j *ssa.Value
+ if n.Right.Left != nil {
+ i = s.extendIndex(s.expr(n.Right.Left))
+ }
+ if n.Right.Right != nil {
+ j = s.extendIndex(s.expr(n.Right.Right))
+ }
+ p, l, c := s.slice(n.Left.Type, v, i, j, nil)
+ return s.newValue3(ssa.OpSliceMake, n.Type, p, l, c)
+ case OSLICESTR:
+ v := s.expr(n.Left)
+ var i, j *ssa.Value
+ if n.Right.Left != nil {
+ i = s.extendIndex(s.expr(n.Right.Left))
+ }
+ if n.Right.Right != nil {
+ j = s.extendIndex(s.expr(n.Right.Right))
+ }
+ p, l, _ := s.slice(n.Left.Type, v, i, j, nil)
+ return s.newValue2(ssa.OpStringMake, n.Type, p, l)
+ case OSLICE3, OSLICE3ARR:
+ v := s.expr(n.Left)
+ var i *ssa.Value
+ if n.Right.Left != nil {
+ i = s.extendIndex(s.expr(n.Right.Left))
+ }
+ j := s.extendIndex(s.expr(n.Right.Right.Left))
+ k := s.extendIndex(s.expr(n.Right.Right.Right))
+ p, l, c := s.slice(n.Left.Type, v, i, j, k)
+ return s.newValue3(ssa.OpSliceMake, n.Type, p, l, c)
+
+ case OCALLFUNC, OCALLINTER, OCALLMETH:
+ a := s.call(n, callNormal)
+ return s.newValue2(ssa.OpLoad, n.Type, a, s.mem())
+
+ case OGETG:
+ return s.newValue1(ssa.OpGetG, n.Type, s.mem())
+
+ case OAPPEND:
+ // append(s, e1, e2, e3). Compile like:
+ // ptr,len,cap := s
+ // newlen := len + 3
+ // if newlen > s.cap {
+ // ptr,_,cap = growslice(s, newlen)
+ // }
+ // *(ptr+len) = e1
+ // *(ptr+len+1) = e2
+ // *(ptr+len+2) = e3
+ // makeslice(ptr,newlen,cap)
+
+ et := n.Type.Type
+ pt := Ptrto(et)
+
+ // Evaluate slice
+ slice := s.expr(n.List.N)
+
+ // Allocate new blocks
+ grow := s.f.NewBlock(ssa.BlockPlain)
+ assign := s.f.NewBlock(ssa.BlockPlain)
+
+ // Decide if we need to grow
+ nargs := int64(count(n.List) - 1)
+ p := s.newValue1(ssa.OpSlicePtr, pt, slice)
+ l := s.newValue1(ssa.OpSliceLen, Types[TINT], slice)
+ c := s.newValue1(ssa.OpSliceCap, Types[TINT], slice)
+ nl := s.newValue2(s.ssaOp(OADD, Types[TINT]), Types[TINT], l, s.constInt(Types[TINT], nargs))
+ cmp := s.newValue2(s.ssaOp(OGT, Types[TINT]), Types[TBOOL], nl, c)
+ s.vars[&ptrVar] = p
+ s.vars[&capVar] = c
+ b := s.endBlock()
+ b.Kind = ssa.BlockIf
+ b.Likely = ssa.BranchUnlikely
+ b.Control = cmp
+ b.AddEdgeTo(grow)
+ b.AddEdgeTo(assign)
+
+ // Call growslice
+ s.startBlock(grow)
+ taddr := s.newValue1A(ssa.OpAddr, Types[TUINTPTR], &ssa.ExternSymbol{Types[TUINTPTR], typenamesym(n.Type)}, s.sb)
+
+ r := s.rtcall(growslice, true, []*Type{pt, Types[TINT], Types[TINT]}, taddr, p, l, c, nl)
+
+ s.vars[&ptrVar] = r[0]
+ // Note: we don't need to read r[1], the result's length. It will be nl.
+ // (or maybe we should, we just have to spill/restore nl otherwise?)
+ s.vars[&capVar] = r[2]
+ b = s.endBlock()
+ b.AddEdgeTo(assign)
+
+ // assign new elements to slots
+ s.startBlock(assign)
+
+ // Evaluate args
+ args := make([]*ssa.Value, 0, nargs)
+ store := make([]bool, 0, nargs)
+ for l := n.List.Next; l != nil; l = l.Next {
+ if canSSAType(l.N.Type) {
+ args = append(args, s.expr(l.N))
+ store = append(store, true)
+ } else {
+ args = append(args, s.addr(l.N, false))
+ store = append(store, false)
+ }
+ }
+
+ p = s.variable(&ptrVar, pt) // generates phi for ptr
+ c = s.variable(&capVar, Types[TINT]) // generates phi for cap
+ p2 := s.newValue2(ssa.OpPtrIndex, pt, p, l)
+ // TODO: just one write barrier call for all of these writes?
+ // TODO: maybe just one writeBarrier.enabled check?
+ for i, arg := range args {
+ addr := s.newValue2(ssa.OpPtrIndex, pt, p2, s.constInt(Types[TINT], int64(i)))
+ if store[i] {
+ if haspointers(et) {
+ s.insertWBstore(et, addr, arg, n.Lineno)
+ } else {
+ s.vars[&memVar] = s.newValue3I(ssa.OpStore, ssa.TypeMem, et.Size(), addr, arg, s.mem())
+ }
+ } else {
+ if haspointers(et) {
+ s.insertWBmove(et, addr, arg, n.Lineno)
+ } else {
+ s.vars[&memVar] = s.newValue3I(ssa.OpMove, ssa.TypeMem, et.Size(), addr, arg, s.mem())
+ }
+ }
+ }
+
+ // make result
+ delete(s.vars, &ptrVar)
+ delete(s.vars, &capVar)
+ return s.newValue3(ssa.OpSliceMake, n.Type, p, nl, c)
+
+ default:
+ s.Unimplementedf("unhandled expr %s", opnames[n.Op])
+ return nil
+ }
+}
+
+// condBranch evaluates the boolean expression cond and branches to yes
+// if cond is true and no if cond is false.
+// This function is intended to handle && and || better than just calling
+// s.expr(cond) and branching on the result.
+func (s *state) condBranch(cond *Node, yes, no *ssa.Block, likely int8) {
+ if cond.Op == OANDAND {
+ mid := s.f.NewBlock(ssa.BlockPlain)
+ s.stmtList(cond.Ninit)
+ s.condBranch(cond.Left, mid, no, max8(likely, 0))
+ s.startBlock(mid)
+ s.condBranch(cond.Right, yes, no, likely)
+ return
+ // Note: if likely==1, then both recursive calls pass 1.
+ // If likely==-1, then we don't have enough information to decide
+ // whether the first branch is likely or not. So we pass 0 for
+ // the likeliness of the first branch.
+ // TODO: have the frontend give us branch prediction hints for
+ // OANDAND and OOROR nodes (if it ever has such info).
+ }
+ if cond.Op == OOROR {
+ mid := s.f.NewBlock(ssa.BlockPlain)
+ s.stmtList(cond.Ninit)
+ s.condBranch(cond.Left, yes, mid, min8(likely, 0))
+ s.startBlock(mid)
+ s.condBranch(cond.Right, yes, no, likely)
+ return
+ // Note: if likely==-1, then both recursive calls pass -1.
+ // If likely==1, then we don't have enough info to decide
+ // the likelihood of the first branch.
+ }
+ if cond.Op == ONOT {
+ s.stmtList(cond.Ninit)
+ s.condBranch(cond.Left, no, yes, -likely)
+ return
+ }
+ c := s.expr(cond)
+ b := s.endBlock()
+ b.Kind = ssa.BlockIf
+ b.Control = c
+ b.Likely = ssa.BranchPrediction(likely) // gc and ssa both use -1/0/+1 for likeliness
+ b.AddEdgeTo(yes)
+ b.AddEdgeTo(no)
+}
+
+// assign does left = right.
+// Right has already been evaluated to ssa, left has not.
+// If deref is true, then we do left = *right instead (and right has already been nil-checked).
+// If deref is true and right == nil, just do left = 0.
+// Include a write barrier if wb is true.
+func (s *state) assign(left *Node, right *ssa.Value, wb, deref bool, line int32) {
+ if left.Op == ONAME && isblank(left) {
+ return
+ }
+ t := left.Type
+ dowidth(t)
+ if s.canSSA(left) {
+ if deref {
+ s.Fatalf("can SSA LHS %s but not RHS %s", left, right)
+ }
+ if left.Op == ODOT {
+ // We're assigning to a field of an ssa-able value.
+ // We need to build a new structure with the new value for the
+ // field we're assigning and the old values for the other fields.
+ // For instance:
+ // type T struct {a, b, c int}
+ // var T x
+ // x.b = 5
+ // For the x.b = 5 assignment we want to generate x = T{x.a, 5, x.c}
+
+ // Grab information about the structure type.
+ t := left.Left.Type
+ nf := t.NumFields()
+ idx := fieldIdx(left)
+
+ // Grab old value of structure.
+ old := s.expr(left.Left)
+
+ // Make new structure.
+ new := s.newValue0(ssa.StructMakeOp(t.NumFields()), t)
+
+ // Add fields as args.
+ for i := int64(0); i < nf; i++ {
+ if i == idx {
+ new.AddArg(right)
+ } else {
+ new.AddArg(s.newValue1I(ssa.OpStructSelect, t.FieldType(i), i, old))
+ }
+ }
+
+ // Recursively assign the new value we've made to the base of the dot op.
+ s.assign(left.Left, new, false, false, line)
+ // TODO: do we need to update named values here?
+ return
+ }
+ // Update variable assignment.
+ s.vars[left] = right
+ s.addNamedValue(left, right)
+ return
+ }
+ // Left is not ssa-able. Compute its address.
+ addr := s.addr(left, false)
+ if left.Op == ONAME {
+ s.vars[&memVar] = s.newValue1A(ssa.OpVarDef, ssa.TypeMem, left, s.mem())
+ }
+ if deref {
+ // Treat as a mem->mem move.
+ if right == nil {
+ s.vars[&memVar] = s.newValue2I(ssa.OpZero, ssa.TypeMem, t.Size(), addr, s.mem())
+ return
+ }
+ if wb {
+ s.insertWBmove(t, addr, right, line)
+ return
+ }
+ s.vars[&memVar] = s.newValue3I(ssa.OpMove, ssa.TypeMem, t.Size(), addr, right, s.mem())
+ return
+ }
+ // Treat as a store.
+ if wb {
+ s.insertWBstore(t, addr, right, line)
+ return
+ }
+ s.vars[&memVar] = s.newValue3I(ssa.OpStore, ssa.TypeMem, t.Size(), addr, right, s.mem())
+}
+
+// zeroVal returns the zero value for type t.
+func (s *state) zeroVal(t *Type) *ssa.Value {
+ switch {
+ case t.IsInteger():
+ switch t.Size() {
+ case 1:
+ return s.constInt8(t, 0)
+ case 2:
+ return s.constInt16(t, 0)
+ case 4:
+ return s.constInt32(t, 0)
+ case 8:
+ return s.constInt64(t, 0)
+ default:
+ s.Fatalf("bad sized integer type %s", t)
+ }
+ case t.IsFloat():
+ switch t.Size() {
+ case 4:
+ return s.constFloat32(t, 0)
+ case 8:
+ return s.constFloat64(t, 0)
+ default:
+ s.Fatalf("bad sized float type %s", t)
+ }
+ case t.IsComplex():
+ switch t.Size() {
+ case 8:
+ z := s.constFloat32(Types[TFLOAT32], 0)
+ return s.entryNewValue2(ssa.OpComplexMake, t, z, z)
+ case 16:
+ z := s.constFloat64(Types[TFLOAT64], 0)
+ return s.entryNewValue2(ssa.OpComplexMake, t, z, z)
+ default:
+ s.Fatalf("bad sized complex type %s", t)
+ }
+
+ case t.IsString():
+ return s.entryNewValue0A(ssa.OpConstString, t, "")
+ case t.IsPtr():
+ return s.entryNewValue0(ssa.OpConstNil, t)
+ case t.IsBoolean():
+ return s.constBool(false)
+ case t.IsInterface():
+ return s.entryNewValue0(ssa.OpConstInterface, t)
+ case t.IsSlice():
+ return s.entryNewValue0(ssa.OpConstSlice, t)
+ case t.IsStruct():
+ n := t.NumFields()
+ v := s.entryNewValue0(ssa.StructMakeOp(t.NumFields()), t)
+ for i := int64(0); i < n; i++ {
+ v.AddArg(s.zeroVal(t.FieldType(i).(*Type)))
+ }
+ return v
+ }
+ s.Unimplementedf("zero for type %v not implemented", t)
+ return nil
+}
+
+type callKind int8
+
+const (
+ callNormal callKind = iota
+ callDefer
+ callGo
+)
+
+// Calls the function n using the specified call type.
+// Returns the address of the return value (or nil if none).
+func (s *state) call(n *Node, k callKind) *ssa.Value {
+ var sym *Sym // target symbol (if static)
+ var closure *ssa.Value // ptr to closure to run (if dynamic)
+ var codeptr *ssa.Value // ptr to target code (if dynamic)
+ var rcvr *ssa.Value // receiver to set
+ fn := n.Left
+ switch n.Op {
+ case OCALLFUNC:
+ if k == callNormal && fn.Op == ONAME && fn.Class == PFUNC {
+ sym = fn.Sym
+ break
+ }
+ closure = s.expr(fn)
+ case OCALLMETH:
+ if fn.Op != ODOTMETH {
+ Fatalf("OCALLMETH: n.Left not an ODOTMETH: %v", fn)
+ }
+ if fn.Right.Op != ONAME {
+ Fatalf("OCALLMETH: n.Left.Right not a ONAME: %v", fn.Right)
+ }
+ if k == callNormal {
+ sym = fn.Right.Sym
+ break
+ }
+ n2 := *fn.Right
+ n2.Class = PFUNC
+ closure = s.expr(&n2)
+ // Note: receiver is already assigned in n.List, so we don't
+ // want to set it here.
+ case OCALLINTER:
+ if fn.Op != ODOTINTER {
+ Fatalf("OCALLINTER: n.Left not an ODOTINTER: %v", Oconv(int(fn.Op), 0))
+ }
+ i := s.expr(fn.Left)
+ itab := s.newValue1(ssa.OpITab, Types[TUINTPTR], i)
+ itabidx := fn.Xoffset + 3*int64(Widthptr) + 8 // offset of fun field in runtime.itab
+ itab = s.newValue1I(ssa.OpOffPtr, Types[TUINTPTR], itabidx, itab)
+ if k == callNormal {
+ codeptr = s.newValue2(ssa.OpLoad, Types[TUINTPTR], itab, s.mem())
+ } else {
+ closure = itab
+ }
+ rcvr = s.newValue1(ssa.OpIData, Types[TUINTPTR], i)
+ }
+ dowidth(fn.Type)
+ stksize := fn.Type.Argwid // includes receiver
+
+ // Run all argument assignments. The arg slots have already
+ // been offset by the appropriate amount (+2*widthptr for go/defer,
+ // +widthptr for interface calls).
+ // For OCALLMETH, the receiver is set in these statements.
+ s.stmtList(n.List)
+
+ // Set receiver (for interface calls)
+ if rcvr != nil {
+ argStart := Ctxt.FixedFrameSize()
+ if k != callNormal {
+ argStart += int64(2 * Widthptr)
+ }
+ addr := s.entryNewValue1I(ssa.OpOffPtr, Types[TUINTPTR], argStart, s.sp)
+ s.vars[&memVar] = s.newValue3I(ssa.OpStore, ssa.TypeMem, int64(Widthptr), addr, rcvr, s.mem())
+ }
+
+ // Defer/go args
+ if k != callNormal {
+ // Write argsize and closure (args to Newproc/Deferproc).
+ argsize := s.constInt32(Types[TUINT32], int32(stksize))
+ s.vars[&memVar] = s.newValue3I(ssa.OpStore, ssa.TypeMem, 4, s.sp, argsize, s.mem())
+ addr := s.entryNewValue1I(ssa.OpOffPtr, Ptrto(Types[TUINTPTR]), int64(Widthptr), s.sp)
+ s.vars[&memVar] = s.newValue3I(ssa.OpStore, ssa.TypeMem, int64(Widthptr), addr, closure, s.mem())
+ stksize += 2 * int64(Widthptr)
+ }
+
+ // call target
+ bNext := s.f.NewBlock(ssa.BlockPlain)
+ var call *ssa.Value
+ switch {
+ case k == callDefer:
+ call = s.newValue1(ssa.OpDeferCall, ssa.TypeMem, s.mem())
+ case k == callGo:
+ call = s.newValue1(ssa.OpGoCall, ssa.TypeMem, s.mem())
+ case closure != nil:
+ codeptr = s.newValue2(ssa.OpLoad, Types[TUINTPTR], closure, s.mem())
+ call = s.newValue3(ssa.OpClosureCall, ssa.TypeMem, codeptr, closure, s.mem())
+ case codeptr != nil:
+ call = s.newValue2(ssa.OpInterCall, ssa.TypeMem, codeptr, s.mem())
+ case sym != nil:
+ call = s.newValue1A(ssa.OpStaticCall, ssa.TypeMem, sym, s.mem())
+ default:
+ Fatalf("bad call type %s %v", opnames[n.Op], n)
+ }
+ call.AuxInt = stksize // Call operations carry the argsize of the callee along with them
+
+ // Finish call block
+ s.vars[&memVar] = call
+ b := s.endBlock()
+ b.Kind = ssa.BlockCall
+ b.Control = call
+ b.AddEdgeTo(bNext)
+
+ // Start exit block, find address of result.
+ s.startBlock(bNext)
+ var titer Iter
+ fp := Structfirst(&titer, Getoutarg(n.Left.Type))
+ if fp == nil || k != callNormal {
+ // call has no return value. Continue with the next statement.
+ return nil
+ }
+ return s.entryNewValue1I(ssa.OpOffPtr, Ptrto(fp.Type), fp.Width, s.sp)
+}
+
+// etypesign returns the signed-ness of e, for integer/pointer etypes.
+// -1 means signed, +1 means unsigned, 0 means non-integer/non-pointer.
+func etypesign(e EType) int8 {
+ switch e {
+ case TINT8, TINT16, TINT32, TINT64, TINT:
+ return -1
+ case TUINT8, TUINT16, TUINT32, TUINT64, TUINT, TUINTPTR, TUNSAFEPTR:
+ return +1
+ }
+ return 0
+}
+
+// lookupSymbol is used to retrieve the symbol (Extern, Arg or Auto) used for a particular node.
+// This improves the effectiveness of cse by using the same Aux values for the
+// same symbols.
+func (s *state) lookupSymbol(n *Node, sym interface{}) interface{} {
+ switch sym.(type) {
+ default:
+ s.Fatalf("sym %v is of uknown type %T", sym, sym)
+ case *ssa.ExternSymbol, *ssa.ArgSymbol, *ssa.AutoSymbol:
+ // these are the only valid types
+ }
+
+ if lsym, ok := s.varsyms[n]; ok {
+ return lsym
+ } else {
+ s.varsyms[n] = sym
+ return sym
+ }
+}
+
+// addr converts the address of the expression n to SSA, adds it to s and returns the SSA result.
+// The value that the returned Value represents is guaranteed to be non-nil.
+// If bounded is true then this address does not require a nil check for its operand
+// even if that would otherwise be implied.
+func (s *state) addr(n *Node, bounded bool) *ssa.Value {
+ t := Ptrto(n.Type)
+ switch n.Op {
+ case ONAME:
+ switch n.Class {
+ case PEXTERN:
+ // global variable
+ aux := s.lookupSymbol(n, &ssa.ExternSymbol{n.Type, n.Sym})
+ v := s.entryNewValue1A(ssa.OpAddr, t, aux, s.sb)
+ // TODO: Make OpAddr use AuxInt as well as Aux.
+ if n.Xoffset != 0 {
+ v = s.entryNewValue1I(ssa.OpOffPtr, v.Type, n.Xoffset, v)
+ }
+ return v
+ case PPARAM:
+ // parameter slot
+ v := s.decladdrs[n]
+ if v != nil {
+ return v
+ }
+ if n.String() == ".fp" {
+ // Special arg that points to the frame pointer.
+ // (Used by the race detector, others?)
+ aux := s.lookupSymbol(n, &ssa.ArgSymbol{Typ: n.Type, Node: n})
+ return s.entryNewValue1A(ssa.OpAddr, t, aux, s.sp)
+ }
+ s.Fatalf("addr of undeclared ONAME %v. declared: %v", n, s.decladdrs)
+ return nil
+ case PAUTO:
+ // We need to regenerate the address of autos
+ // at every use. This prevents LEA instructions
+ // from occurring before the corresponding VarDef
+ // op and confusing the liveness analysis into thinking
+ // the variable is live at function entry.
+ // TODO: I'm not sure if this really works or we're just
+ // getting lucky. We might need a real dependency edge
+ // between vardef and addr ops.
+ aux := &ssa.AutoSymbol{Typ: n.Type, Node: n}
+ return s.newValue1A(ssa.OpAddr, t, aux, s.sp)
+ case PPARAMOUT: // Same as PAUTO -- cannot generate LEA early.
+ // ensure that we reuse symbols for out parameters so
+ // that cse works on their addresses
+ aux := s.lookupSymbol(n, &ssa.ArgSymbol{Typ: n.Type, Node: n})
+ return s.newValue1A(ssa.OpAddr, t, aux, s.sp)
+ case PAUTO | PHEAP, PPARAM | PHEAP, PPARAMOUT | PHEAP, PPARAMREF:
+ return s.expr(n.Name.Heapaddr)
+ default:
+ s.Unimplementedf("variable address class %v not implemented", n.Class)
+ return nil
+ }
+ case OINDREG:
+ // indirect off a register
+ // used for storing/loading arguments/returns to/from callees
+ if int(n.Reg) != Thearch.REGSP {
+ s.Unimplementedf("OINDREG of non-SP register %s in addr: %v", obj.Rconv(int(n.Reg)), n)
+ return nil
+ }
+ return s.entryNewValue1I(ssa.OpOffPtr, t, n.Xoffset, s.sp)
+ case OINDEX:
+ if n.Left.Type.IsSlice() {
+ a := s.expr(n.Left)
+ i := s.expr(n.Right)
+ i = s.extendIndex(i)
+ len := s.newValue1(ssa.OpSliceLen, Types[TINT], a)
+ if !n.Bounded {
+ s.boundsCheck(i, len)
+ }
+ p := s.newValue1(ssa.OpSlicePtr, t, a)
+ return s.newValue2(ssa.OpPtrIndex, t, p, i)
+ } else { // array
+ a := s.addr(n.Left, bounded)
+ i := s.expr(n.Right)
+ i = s.extendIndex(i)
+ len := s.constInt(Types[TINT], n.Left.Type.Bound)
+ if !n.Bounded {
+ s.boundsCheck(i, len)
+ }
+ return s.newValue2(ssa.OpPtrIndex, Ptrto(n.Left.Type.Type), a, i)
+ }
+ case OIND:
+ p := s.expr(n.Left)
+ if !bounded {
+ s.nilCheck(p)
+ }
+ return p
+ case ODOT:
+ p := s.addr(n.Left, bounded)
+ return s.newValue2(ssa.OpAddPtr, t, p, s.constInt(Types[TINT], n.Xoffset))
+ case ODOTPTR:
+ p := s.expr(n.Left)
+ if !bounded {
+ s.nilCheck(p)
+ }
+ return s.newValue2(ssa.OpAddPtr, t, p, s.constInt(Types[TINT], n.Xoffset))
+ case OCLOSUREVAR:
+ return s.newValue2(ssa.OpAddPtr, t,
+ s.entryNewValue0(ssa.OpGetClosurePtr, Ptrto(Types[TUINT8])),
+ s.constInt(Types[TINT], n.Xoffset))
+ case OPARAM:
+ p := n.Left
+ if p.Op != ONAME || !(p.Class == PPARAM|PHEAP || p.Class == PPARAMOUT|PHEAP) {
+ s.Fatalf("OPARAM not of ONAME,{PPARAM,PPARAMOUT}|PHEAP, instead %s", nodedump(p, 0))
+ }
+
+ // Recover original offset to address passed-in param value.
+ original_p := *p
+ original_p.Xoffset = n.Xoffset
+ aux := &ssa.ArgSymbol{Typ: n.Type, Node: &original_p}
+ return s.entryNewValue1A(ssa.OpAddr, t, aux, s.sp)
+ case OCONVNOP:
+ addr := s.addr(n.Left, bounded)
+ return s.newValue1(ssa.OpCopy, t, addr) // ensure that addr has the right type
+ case OCALLFUNC, OCALLINTER, OCALLMETH:
+ return s.call(n, callNormal)
+
+ default:
+ s.Unimplementedf("unhandled addr %v", Oconv(int(n.Op), 0))
+ return nil
+ }
+}
+
+// canSSA reports whether n is SSA-able.
+// n must be an ONAME (or an ODOT sequence with an ONAME base).
+func (s *state) canSSA(n *Node) bool {
+ for n.Op == ODOT {
+ n = n.Left
+ }
+ if n.Op != ONAME {
+ return false
+ }
+ if n.Addrtaken {
+ return false
+ }
+ if n.Class&PHEAP != 0 {
+ return false
+ }
+ switch n.Class {
+ case PEXTERN, PPARAMREF:
+ // TODO: maybe treat PPARAMREF with an Arg-like op to read from closure?
+ return false
+ case PPARAMOUT:
+ if hasdefer {
+ // TODO: handle this case? Named return values must be
+ // in memory so that the deferred function can see them.
+ // Maybe do: if !strings.HasPrefix(n.String(), "~") { return false }
+ return false
+ }
+ if s.cgoUnsafeArgs {
+ // Cgo effectively takes the address of all result args,
+ // but the compiler can't see that.
+ return false
+ }
+ }
+ if n.Class == PPARAM && n.String() == ".this" {
+ // wrappers generated by genwrapper need to update
+ // the .this pointer in place.
+ // TODO: treat as a PPARMOUT?
+ return false
+ }
+ return canSSAType(n.Type)
+ // TODO: try to make more variables SSAable?
+}
+
+// canSSA reports whether variables of type t are SSA-able.
+func canSSAType(t *Type) bool {
+ dowidth(t)
+ if t.Width > int64(4*Widthptr) {
+ // 4*Widthptr is an arbitrary constant. We want it
+ // to be at least 3*Widthptr so slices can be registerized.
+ // Too big and we'll introduce too much register pressure.
+ return false
+ }
+ switch t.Etype {
+ case TARRAY:
+ if Isslice(t) {
+ return true
+ }
+ // We can't do arrays because dynamic indexing is
+ // not supported on SSA variables.
+ // TODO: maybe allow if length is <=1? All indexes
+ // are constant? Might be good for the arrays
+ // introduced by the compiler for variadic functions.
+ return false
+ case TSTRUCT:
+ if countfield(t) > ssa.MaxStruct {
+ return false
+ }
+ for t1 := t.Type; t1 != nil; t1 = t1.Down {
+ if !canSSAType(t1.Type) {
+ return false
+ }
+ }
+ return true
+ default:
+ return true
+ }
+}
+
+// nilCheck generates nil pointer checking code.
+// Starts a new block on return, unless nil checks are disabled.
+// Used only for automatically inserted nil checks,
+// not for user code like 'x != nil'.
+func (s *state) nilCheck(ptr *ssa.Value) {
+ if Disable_checknil != 0 {
+ return
+ }
+ chk := s.newValue2(ssa.OpNilCheck, ssa.TypeVoid, ptr, s.mem())
+ b := s.endBlock()
+ b.Kind = ssa.BlockCheck
+ b.Control = chk
+ bNext := s.f.NewBlock(ssa.BlockPlain)
+ b.AddEdgeTo(bNext)
+ s.startBlock(bNext)
+}
+
+// boundsCheck generates bounds checking code. Checks if 0 <= idx < len, branches to exit if not.
+// Starts a new block on return.
+func (s *state) boundsCheck(idx, len *ssa.Value) {
+ if Debug['B'] != 0 {
+ return
+ }
+ // TODO: convert index to full width?
+ // TODO: if index is 64-bit and we're compiling to 32-bit, check that high 32 bits are zero.
+
+ // bounds check
+ cmp := s.newValue2(ssa.OpIsInBounds, Types[TBOOL], idx, len)
+ s.check(cmp, Panicindex)
+}
+
+// sliceBoundsCheck generates slice bounds checking code. Checks if 0 <= idx <= len, branches to exit if not.
+// Starts a new block on return.
+func (s *state) sliceBoundsCheck(idx, len *ssa.Value) {
+ if Debug['B'] != 0 {
+ return
+ }
+ // TODO: convert index to full width?
+ // TODO: if index is 64-bit and we're compiling to 32-bit, check that high 32 bits are zero.
+
+ // bounds check
+ cmp := s.newValue2(ssa.OpIsSliceInBounds, Types[TBOOL], idx, len)
+ s.check(cmp, panicslice)
+}
+
+// If cmp (a bool) is true, panic using the given function.
+func (s *state) check(cmp *ssa.Value, fn *Node) {
+ b := s.endBlock()
+ b.Kind = ssa.BlockIf
+ b.Control = cmp
+ b.Likely = ssa.BranchLikely
+ bNext := s.f.NewBlock(ssa.BlockPlain)
+ line := s.peekLine()
+ bPanic := s.panics[funcLine{fn, line}]
+ if bPanic == nil {
+ bPanic = s.f.NewBlock(ssa.BlockPlain)
+ s.panics[funcLine{fn, line}] = bPanic
+ s.startBlock(bPanic)
+ // The panic call takes/returns memory to ensure that the right
+ // memory state is observed if the panic happens.
+ s.rtcall(fn, false, nil)
+ }
+ b.AddEdgeTo(bNext)
+ b.AddEdgeTo(bPanic)
+ s.startBlock(bNext)
+}
+
+// rtcall issues a call to the given runtime function fn with the listed args.
+// Returns a slice of results of the given result types.
+// The call is added to the end of the current block.
+// If returns is false, the block is marked as an exit block.
+// If returns is true, the block is marked as a call block. A new block
+// is started to load the return values.
+func (s *state) rtcall(fn *Node, returns bool, results []*Type, args ...*ssa.Value) []*ssa.Value {
+ // Write args to the stack
+ var off int64 // TODO: arch-dependent starting offset?
+ for _, arg := range args {
+ t := arg.Type
+ off = Rnd(off, t.Alignment())
+ ptr := s.sp
+ if off != 0 {
+ ptr = s.newValue1I(ssa.OpOffPtr, Types[TUINTPTR], off, s.sp)
+ }
+ size := t.Size()
+ s.vars[&memVar] = s.newValue3I(ssa.OpStore, ssa.TypeMem, size, ptr, arg, s.mem())
+ off += size
+ }
+ off = Rnd(off, int64(Widthptr))
+
+ // Issue call
+ call := s.newValue1A(ssa.OpStaticCall, ssa.TypeMem, fn.Sym, s.mem())
+ s.vars[&memVar] = call
+
+ // Finish block
+ b := s.endBlock()
+ if !returns {
+ b.Kind = ssa.BlockExit
+ b.Control = call
+ call.AuxInt = off
+ if len(results) > 0 {
+ Fatalf("panic call can't have results")
+ }
+ return nil
+ }
+ b.Kind = ssa.BlockCall
+ b.Control = call
+ bNext := s.f.NewBlock(ssa.BlockPlain)
+ b.AddEdgeTo(bNext)
+ s.startBlock(bNext)
+
+ // Load results
+ res := make([]*ssa.Value, len(results))
+ for i, t := range results {
+ off = Rnd(off, t.Alignment())
+ ptr := s.sp
+ if off != 0 {
+ ptr = s.newValue1I(ssa.OpOffPtr, Types[TUINTPTR], off, s.sp)
+ }
+ res[i] = s.newValue2(ssa.OpLoad, t, ptr, s.mem())
+ off += t.Size()
+ }
+ off = Rnd(off, int64(Widthptr))
+
+ // Remember how much callee stack space we needed.
+ call.AuxInt = off
+
+ return res
+}
+
+// insertWBmove inserts the assignment *left = *right including a write barrier.
+// t is the type being assigned.
+func (s *state) insertWBmove(t *Type, left, right *ssa.Value, line int32) {
+ // if writeBarrier.enabled {
+ // typedmemmove(&t, left, right)
+ // } else {
+ // *left = *right
+ // }
+ bThen := s.f.NewBlock(ssa.BlockPlain)
+ bElse := s.f.NewBlock(ssa.BlockPlain)
+ bEnd := s.f.NewBlock(ssa.BlockPlain)
+
+ aux := &ssa.ExternSymbol{Types[TBOOL], syslook("writeBarrier", 0).Sym}
+ flagaddr := s.newValue1A(ssa.OpAddr, Ptrto(Types[TUINT32]), aux, s.sb)
+ // TODO: select the .enabled field. It is currently first, so not needed for now.
+ // Load word, test byte, avoiding partial register write from load byte.
+ flag := s.newValue2(ssa.OpLoad, Types[TUINT32], flagaddr, s.mem())
+ flag = s.newValue1(ssa.OpTrunc64to8, Types[TBOOL], flag)
+ b := s.endBlock()
+ b.Kind = ssa.BlockIf
+ b.Likely = ssa.BranchUnlikely
+ b.Control = flag
+ b.AddEdgeTo(bThen)
+ b.AddEdgeTo(bElse)
+
+ s.startBlock(bThen)
+ taddr := s.newValue1A(ssa.OpAddr, Types[TUINTPTR], &ssa.ExternSymbol{Types[TUINTPTR], typenamesym(t)}, s.sb)
+ s.rtcall(typedmemmove, true, nil, taddr, left, right)
+ s.endBlock().AddEdgeTo(bEnd)
+
+ s.startBlock(bElse)
+ s.vars[&memVar] = s.newValue3I(ssa.OpMove, ssa.TypeMem, t.Size(), left, right, s.mem())
+ s.endBlock().AddEdgeTo(bEnd)
+
+ s.startBlock(bEnd)
+
+ if Debug_wb > 0 {
+ Warnl(int(line), "write barrier")
+ }
+}
+
+// insertWBstore inserts the assignment *left = right including a write barrier.
+// t is the type being assigned.
+func (s *state) insertWBstore(t *Type, left, right *ssa.Value, line int32) {
+ // store scalar fields
+ // if writeBarrier.enabled {
+ // writebarrierptr for pointer fields
+ // } else {
+ // store pointer fields
+ // }
+
+ s.storeTypeScalars(t, left, right)
+
+ bThen := s.f.NewBlock(ssa.BlockPlain)
+ bElse := s.f.NewBlock(ssa.BlockPlain)
+ bEnd := s.f.NewBlock(ssa.BlockPlain)
+
+ aux := &ssa.ExternSymbol{Types[TBOOL], syslook("writeBarrier", 0).Sym}
+ flagaddr := s.newValue1A(ssa.OpAddr, Ptrto(Types[TUINT32]), aux, s.sb)
+ // TODO: select the .enabled field. It is currently first, so not needed for now.
+ // Load word, test byte, avoiding partial register write from load byte.
+ flag := s.newValue2(ssa.OpLoad, Types[TUINT32], flagaddr, s.mem())
+ flag = s.newValue1(ssa.OpTrunc64to8, Types[TBOOL], flag)
+ b := s.endBlock()
+ b.Kind = ssa.BlockIf
+ b.Likely = ssa.BranchUnlikely
+ b.Control = flag
+ b.AddEdgeTo(bThen)
+ b.AddEdgeTo(bElse)
+
+ // Issue write barriers for pointer writes.
+ s.startBlock(bThen)
+ s.storeTypePtrsWB(t, left, right)
+ s.endBlock().AddEdgeTo(bEnd)
+
+ // Issue regular stores for pointer writes.
+ s.startBlock(bElse)
+ s.storeTypePtrs(t, left, right)
+ s.endBlock().AddEdgeTo(bEnd)
+
+ s.startBlock(bEnd)
+
+ if Debug_wb > 0 {
+ Warnl(int(line), "write barrier")
+ }
+}
+
+// do *left = right for all scalar (non-pointer) parts of t.
+func (s *state) storeTypeScalars(t *Type, left, right *ssa.Value) {
+ switch {
+ case t.IsBoolean() || t.IsInteger() || t.IsFloat() || t.IsComplex():
+ s.vars[&memVar] = s.newValue3I(ssa.OpStore, ssa.TypeMem, t.Size(), left, right, s.mem())
+ case t.IsPtr() || t.IsMap() || t.IsChan():
+ // no scalar fields.
+ case t.IsString():
+ len := s.newValue1(ssa.OpStringLen, Types[TINT], right)
+ lenAddr := s.newValue1I(ssa.OpOffPtr, Ptrto(Types[TINT]), s.config.IntSize, left)
+ s.vars[&memVar] = s.newValue3I(ssa.OpStore, ssa.TypeMem, s.config.IntSize, lenAddr, len, s.mem())
+ case t.IsSlice():
+ len := s.newValue1(ssa.OpSliceLen, Types[TINT], right)
+ cap := s.newValue1(ssa.OpSliceCap, Types[TINT], right)
+ lenAddr := s.newValue1I(ssa.OpOffPtr, Ptrto(Types[TINT]), s.config.IntSize, left)
+ s.vars[&memVar] = s.newValue3I(ssa.OpStore, ssa.TypeMem, s.config.IntSize, lenAddr, len, s.mem())
+ capAddr := s.newValue1I(ssa.OpOffPtr, Ptrto(Types[TINT]), 2*s.config.IntSize, left)
+ s.vars[&memVar] = s.newValue3I(ssa.OpStore, ssa.TypeMem, s.config.IntSize, capAddr, cap, s.mem())
+ case t.IsInterface():
+ // itab field doesn't need a write barrier (even though it is a pointer).
+ itab := s.newValue1(ssa.OpITab, Ptrto(Types[TUINT8]), right)
+ s.vars[&memVar] = s.newValue3I(ssa.OpStore, ssa.TypeMem, s.config.IntSize, left, itab, s.mem())
+ case t.IsStruct():
+ n := t.NumFields()
+ for i := int64(0); i < n; i++ {
+ ft := t.FieldType(i)
+ addr := s.newValue1I(ssa.OpOffPtr, ft.PtrTo(), t.FieldOff(i), left)
+ val := s.newValue1I(ssa.OpStructSelect, ft, i, right)
+ s.storeTypeScalars(ft.(*Type), addr, val)
+ }
+ default:
+ s.Fatalf("bad write barrier type %s", t)
+ }
+}
+
+// do *left = right for all pointer parts of t.
+func (s *state) storeTypePtrs(t *Type, left, right *ssa.Value) {
+ switch {
+ case t.IsPtr() || t.IsMap() || t.IsChan():
+ s.vars[&memVar] = s.newValue3I(ssa.OpStore, ssa.TypeMem, s.config.PtrSize, left, right, s.mem())
+ case t.IsString():
+ ptr := s.newValue1(ssa.OpStringPtr, Ptrto(Types[TUINT8]), right)
+ s.vars[&memVar] = s.newValue3I(ssa.OpStore, ssa.TypeMem, s.config.PtrSize, left, ptr, s.mem())
+ case t.IsSlice():
+ ptr := s.newValue1(ssa.OpSlicePtr, Ptrto(Types[TUINT8]), right)
+ s.vars[&memVar] = s.newValue3I(ssa.OpStore, ssa.TypeMem, s.config.PtrSize, left, ptr, s.mem())
+ case t.IsInterface():
+ // itab field is treated as a scalar.
+ idata := s.newValue1(ssa.OpIData, Ptrto(Types[TUINT8]), right)
+ idataAddr := s.newValue1I(ssa.OpOffPtr, Ptrto(Types[TUINT8]), s.config.PtrSize, left)
+ s.vars[&memVar] = s.newValue3I(ssa.OpStore, ssa.TypeMem, s.config.PtrSize, idataAddr, idata, s.mem())
+ case t.IsStruct():
+ n := t.NumFields()
+ for i := int64(0); i < n; i++ {
+ ft := t.FieldType(i)
+ if !haspointers(ft.(*Type)) {
+ continue
+ }
+ addr := s.newValue1I(ssa.OpOffPtr, ft.PtrTo(), t.FieldOff(i), left)
+ val := s.newValue1I(ssa.OpStructSelect, ft, i, right)
+ s.storeTypePtrs(ft.(*Type), addr, val)
+ }
+ default:
+ s.Fatalf("bad write barrier type %s", t)
+ }
+}
+
+// do *left = right with a write barrier for all pointer parts of t.
+func (s *state) storeTypePtrsWB(t *Type, left, right *ssa.Value) {
+ switch {
+ case t.IsPtr() || t.IsMap() || t.IsChan():
+ s.rtcall(writebarrierptr, true, nil, left, right)
+ case t.IsString():
+ ptr := s.newValue1(ssa.OpStringPtr, Ptrto(Types[TUINT8]), right)
+ s.rtcall(writebarrierptr, true, nil, left, ptr)
+ case t.IsSlice():
+ ptr := s.newValue1(ssa.OpSlicePtr, Ptrto(Types[TUINT8]), right)
+ s.rtcall(writebarrierptr, true, nil, left, ptr)
+ case t.IsInterface():
+ idata := s.newValue1(ssa.OpIData, Ptrto(Types[TUINT8]), right)
+ idataAddr := s.newValue1I(ssa.OpOffPtr, Ptrto(Types[TUINT8]), s.config.PtrSize, left)
+ s.rtcall(writebarrierptr, true, nil, idataAddr, idata)
+ case t.IsStruct():
+ n := t.NumFields()
+ for i := int64(0); i < n; i++ {
+ ft := t.FieldType(i)
+ if !haspointers(ft.(*Type)) {
+ continue
+ }
+ addr := s.newValue1I(ssa.OpOffPtr, ft.PtrTo(), t.FieldOff(i), left)
+ val := s.newValue1I(ssa.OpStructSelect, ft, i, right)
+ s.storeTypePtrsWB(ft.(*Type), addr, val)
+ }
+ default:
+ s.Fatalf("bad write barrier type %s", t)
+ }
+}
+
+// slice computes the slice v[i:j:k] and returns ptr, len, and cap of result.
+// i,j,k may be nil, in which case they are set to their default value.
+// t is a slice, ptr to array, or string type.
+func (s *state) slice(t *Type, v, i, j, k *ssa.Value) (p, l, c *ssa.Value) {
+ var elemtype *Type
+ var ptrtype *Type
+ var ptr *ssa.Value
+ var len *ssa.Value
+ var cap *ssa.Value
+ zero := s.constInt(Types[TINT], 0)
+ switch {
+ case t.IsSlice():
+ elemtype = t.Type
+ ptrtype = Ptrto(elemtype)
+ ptr = s.newValue1(ssa.OpSlicePtr, ptrtype, v)
+ len = s.newValue1(ssa.OpSliceLen, Types[TINT], v)
+ cap = s.newValue1(ssa.OpSliceCap, Types[TINT], v)
+ case t.IsString():
+ elemtype = Types[TUINT8]
+ ptrtype = Ptrto(elemtype)
+ ptr = s.newValue1(ssa.OpStringPtr, ptrtype, v)
+ len = s.newValue1(ssa.OpStringLen, Types[TINT], v)
+ cap = len
+ case t.IsPtr():
+ if !t.Type.IsArray() {
+ s.Fatalf("bad ptr to array in slice %v\n", t)
+ }
+ elemtype = t.Type.Type
+ ptrtype = Ptrto(elemtype)
+ s.nilCheck(v)
+ ptr = v
+ len = s.constInt(Types[TINT], t.Type.Bound)
+ cap = len
+ default:
+ s.Fatalf("bad type in slice %v\n", t)
+ }
+
+ // Set default values
+ if i == nil {
+ i = zero
+ }
+ if j == nil {
+ j = len
+ }
+ if k == nil {
+ k = cap
+ }
+
+ // Panic if slice indices are not in bounds.
+ s.sliceBoundsCheck(i, j)
+ if j != k {
+ s.sliceBoundsCheck(j, k)
+ }
+ if k != cap {
+ s.sliceBoundsCheck(k, cap)
+ }
+
+ // Generate the following code assuming that indexes are in bounds.
+ // The conditional is to make sure that we don't generate a slice
+ // that points to the next object in memory.
+ // rlen = (Sub64 j i)
+ // rcap = (Sub64 k i)
+ // p = ptr
+ // if rcap != 0 {
+ // p = (AddPtr ptr (Mul64 low (Const64 size)))
+ // }
+ // result = (SliceMake p size)
+ subOp := s.ssaOp(OSUB, Types[TINT])
+ neqOp := s.ssaOp(ONE, Types[TINT])
+ mulOp := s.ssaOp(OMUL, Types[TINT])
+ rlen := s.newValue2(subOp, Types[TINT], j, i)
+ var rcap *ssa.Value
+ switch {
+ case t.IsString():
+ // Capacity of the result is unimportant. However, we use
+ // rcap to test if we've generated a zero-length slice.
+ // Use length of strings for that.
+ rcap = rlen
+ case j == k:
+ rcap = rlen
+ default:
+ rcap = s.newValue2(subOp, Types[TINT], k, i)
+ }
+
+ s.vars[&ptrVar] = ptr
+
+ // Generate code to test the resulting slice length.
+ cmp := s.newValue2(neqOp, Types[TBOOL], rcap, s.constInt(Types[TINT], 0))
+
+ b := s.endBlock()
+ b.Kind = ssa.BlockIf
+ b.Likely = ssa.BranchLikely
+ b.Control = cmp
+
+ // Generate code for non-zero length slice case.
+ nz := s.f.NewBlock(ssa.BlockPlain)
+ b.AddEdgeTo(nz)
+ s.startBlock(nz)
+ var inc *ssa.Value
+ if elemtype.Width == 1 {
+ inc = i
+ } else {
+ inc = s.newValue2(mulOp, Types[TINT], i, s.constInt(Types[TINT], elemtype.Width))
+ }
+ s.vars[&ptrVar] = s.newValue2(ssa.OpAddPtr, ptrtype, ptr, inc)
+ s.endBlock()
+
+ // All done.
+ merge := s.f.NewBlock(ssa.BlockPlain)
+ b.AddEdgeTo(merge)
+ nz.AddEdgeTo(merge)
+ s.startBlock(merge)
+ rptr := s.variable(&ptrVar, ptrtype)
+ delete(s.vars, &ptrVar)
+ return rptr, rlen, rcap
+}
+
+type u2fcvtTab struct {
+ geq, cvt2F, and, rsh, or, add ssa.Op
+ one func(*state, ssa.Type, int64) *ssa.Value
+}
+
+var u64_f64 u2fcvtTab = u2fcvtTab{
+ geq: ssa.OpGeq64,
+ cvt2F: ssa.OpCvt64to64F,
+ and: ssa.OpAnd64,
+ rsh: ssa.OpRsh64Ux64,
+ or: ssa.OpOr64,
+ add: ssa.OpAdd64F,
+ one: (*state).constInt64,
+}
+
+var u64_f32 u2fcvtTab = u2fcvtTab{
+ geq: ssa.OpGeq64,
+ cvt2F: ssa.OpCvt64to32F,
+ and: ssa.OpAnd64,
+ rsh: ssa.OpRsh64Ux64,
+ or: ssa.OpOr64,
+ add: ssa.OpAdd32F,
+ one: (*state).constInt64,
+}
+
+// Excess generality on a machine with 64-bit integer registers.
+// Not used on AMD64.
+var u32_f32 u2fcvtTab = u2fcvtTab{
+ geq: ssa.OpGeq32,
+ cvt2F: ssa.OpCvt32to32F,
+ and: ssa.OpAnd32,
+ rsh: ssa.OpRsh32Ux32,
+ or: ssa.OpOr32,
+ add: ssa.OpAdd32F,
+ one: func(s *state, t ssa.Type, x int64) *ssa.Value {
+ return s.constInt32(t, int32(x))
+ },
+}
+
+func (s *state) uint64Tofloat64(n *Node, x *ssa.Value, ft, tt *Type) *ssa.Value {
+ return s.uintTofloat(&u64_f64, n, x, ft, tt)
+}
+
+func (s *state) uint64Tofloat32(n *Node, x *ssa.Value, ft, tt *Type) *ssa.Value {
+ return s.uintTofloat(&u64_f32, n, x, ft, tt)
+}
+
+func (s *state) uintTofloat(cvttab *u2fcvtTab, n *Node, x *ssa.Value, ft, tt *Type) *ssa.Value {
+ // if x >= 0 {
+ // result = (floatY) x
+ // } else {
+ // y = uintX(x) ; y = x & 1
+ // z = uintX(x) ; z = z >> 1
+ // z = z >> 1
+ // z = z | y
+ // result = floatY(z)
+ // result = result + result
+ // }
+ //
+ // Code borrowed from old code generator.
+ // What's going on: large 64-bit "unsigned" looks like
+ // negative number to hardware's integer-to-float
+ // conversion. However, because the mantissa is only
+ // 63 bits, we don't need the LSB, so instead we do an
+ // unsigned right shift (divide by two), convert, and
+ // double. However, before we do that, we need to be
+ // sure that we do not lose a "1" if that made the
+ // difference in the resulting rounding. Therefore, we
+ // preserve it, and OR (not ADD) it back in. The case
+ // that matters is when the eleven discarded bits are
+ // equal to 10000000001; that rounds up, and the 1 cannot
+ // be lost else it would round down if the LSB of the
+ // candidate mantissa is 0.
+ cmp := s.newValue2(cvttab.geq, Types[TBOOL], x, s.zeroVal(ft))
+ b := s.endBlock()
+ b.Kind = ssa.BlockIf
+ b.Control = cmp
+ b.Likely = ssa.BranchLikely
+
+ bThen := s.f.NewBlock(ssa.BlockPlain)
+ bElse := s.f.NewBlock(ssa.BlockPlain)
+ bAfter := s.f.NewBlock(ssa.BlockPlain)
+
+ b.AddEdgeTo(bThen)
+ s.startBlock(bThen)
+ a0 := s.newValue1(cvttab.cvt2F, tt, x)
+ s.vars[n] = a0
+ s.endBlock()
+ bThen.AddEdgeTo(bAfter)
+
+ b.AddEdgeTo(bElse)
+ s.startBlock(bElse)
+ one := cvttab.one(s, ft, 1)
+ y := s.newValue2(cvttab.and, ft, x, one)
+ z := s.newValue2(cvttab.rsh, ft, x, one)
+ z = s.newValue2(cvttab.or, ft, z, y)
+ a := s.newValue1(cvttab.cvt2F, tt, z)
+ a1 := s.newValue2(cvttab.add, tt, a, a)
+ s.vars[n] = a1
+ s.endBlock()
+ bElse.AddEdgeTo(bAfter)
+
+ s.startBlock(bAfter)
+ return s.variable(n, n.Type)
+}
+
+// referenceTypeBuiltin generates code for the len/cap builtins for maps and channels.
+func (s *state) referenceTypeBuiltin(n *Node, x *ssa.Value) *ssa.Value {
+ if !n.Left.Type.IsMap() && !n.Left.Type.IsChan() {
+ s.Fatalf("node must be a map or a channel")
+ }
+ // if n == nil {
+ // return 0
+ // } else {
+ // // len
+ // return *((*int)n)
+ // // cap
+ // return *(((*int)n)+1)
+ // }
+ lenType := n.Type
+ nilValue := s.newValue0(ssa.OpConstNil, Types[TUINTPTR])
+ cmp := s.newValue2(ssa.OpEqPtr, Types[TBOOL], x, nilValue)
+ b := s.endBlock()
+ b.Kind = ssa.BlockIf
+ b.Control = cmp
+ b.Likely = ssa.BranchUnlikely
+
+ bThen := s.f.NewBlock(ssa.BlockPlain)
+ bElse := s.f.NewBlock(ssa.BlockPlain)
+ bAfter := s.f.NewBlock(ssa.BlockPlain)
+
+ // length/capacity of a nil map/chan is zero
+ b.AddEdgeTo(bThen)
+ s.startBlock(bThen)
+ s.vars[n] = s.zeroVal(lenType)
+ s.endBlock()
+ bThen.AddEdgeTo(bAfter)
+
+ b.AddEdgeTo(bElse)
+ s.startBlock(bElse)
+ if n.Op == OLEN {
+ // length is stored in the first word for map/chan
+ s.vars[n] = s.newValue2(ssa.OpLoad, lenType, x, s.mem())
+ } else if n.Op == OCAP {
+ // capacity is stored in the second word for chan
+ sw := s.newValue1I(ssa.OpOffPtr, lenType.PtrTo(), lenType.Width, x)
+ s.vars[n] = s.newValue2(ssa.OpLoad, lenType, sw, s.mem())
+ } else {
+ s.Fatalf("op must be OLEN or OCAP")
+ }
+ s.endBlock()
+ bElse.AddEdgeTo(bAfter)
+
+ s.startBlock(bAfter)
+ return s.variable(n, lenType)
+}
+
+type f2uCvtTab struct {
+ ltf, cvt2U, subf ssa.Op
+ value func(*state, ssa.Type, float64) *ssa.Value
+}
+
+var f32_u64 f2uCvtTab = f2uCvtTab{
+ ltf: ssa.OpLess32F,
+ cvt2U: ssa.OpCvt32Fto64,
+ subf: ssa.OpSub32F,
+ value: (*state).constFloat32,
+}
+
+var f64_u64 f2uCvtTab = f2uCvtTab{
+ ltf: ssa.OpLess64F,
+ cvt2U: ssa.OpCvt64Fto64,
+ subf: ssa.OpSub64F,
+ value: (*state).constFloat64,
+}
+
+func (s *state) float32ToUint64(n *Node, x *ssa.Value, ft, tt *Type) *ssa.Value {
+ return s.floatToUint(&f32_u64, n, x, ft, tt)
+}
+func (s *state) float64ToUint64(n *Node, x *ssa.Value, ft, tt *Type) *ssa.Value {
+ return s.floatToUint(&f64_u64, n, x, ft, tt)
+}
+
+func (s *state) floatToUint(cvttab *f2uCvtTab, n *Node, x *ssa.Value, ft, tt *Type) *ssa.Value {
+ // if x < 9223372036854775808.0 {
+ // result = uintY(x)
+ // } else {
+ // y = x - 9223372036854775808.0
+ // z = uintY(y)
+ // result = z | -9223372036854775808
+ // }
+ twoToThe63 := cvttab.value(s, ft, 9223372036854775808.0)
+ cmp := s.newValue2(cvttab.ltf, Types[TBOOL], x, twoToThe63)
+ b := s.endBlock()
+ b.Kind = ssa.BlockIf
+ b.Control = cmp
+ b.Likely = ssa.BranchLikely
+
+ bThen := s.f.NewBlock(ssa.BlockPlain)
+ bElse := s.f.NewBlock(ssa.BlockPlain)
+ bAfter := s.f.NewBlock(ssa.BlockPlain)
+
+ b.AddEdgeTo(bThen)
+ s.startBlock(bThen)
+ a0 := s.newValue1(cvttab.cvt2U, tt, x)
+ s.vars[n] = a0
+ s.endBlock()
+ bThen.AddEdgeTo(bAfter)
+
+ b.AddEdgeTo(bElse)
+ s.startBlock(bElse)
+ y := s.newValue2(cvttab.subf, ft, x, twoToThe63)
+ y = s.newValue1(cvttab.cvt2U, tt, y)
+ z := s.constInt64(tt, -9223372036854775808)
+ a1 := s.newValue2(ssa.OpOr64, tt, y, z)
+ s.vars[n] = a1
+ s.endBlock()
+ bElse.AddEdgeTo(bAfter)
+
+ s.startBlock(bAfter)
+ return s.variable(n, n.Type)
+}
+
+// ifaceType returns the value for the word containing the type.
+// n is the node for the interface expression.
+// v is the corresponding value.
+func (s *state) ifaceType(n *Node, v *ssa.Value) *ssa.Value {
+ byteptr := Ptrto(Types[TUINT8]) // type used in runtime prototypes for runtime type (*byte)
+
+ if isnilinter(n.Type) {
+ // Have *eface. The type is the first word in the struct.
+ return s.newValue1(ssa.OpITab, byteptr, v)
+ }
+
+ // Have *iface.
+ // The first word in the struct is the *itab.
+ // If the *itab is nil, return 0.
+ // Otherwise, the second word in the *itab is the type.
+
+ tab := s.newValue1(ssa.OpITab, byteptr, v)
+ s.vars[&typVar] = tab
+ isnonnil := s.newValue2(ssa.OpNeqPtr, Types[TBOOL], tab, s.entryNewValue0(ssa.OpConstNil, byteptr))
+ b := s.endBlock()
+ b.Kind = ssa.BlockIf
+ b.Control = isnonnil
+ b.Likely = ssa.BranchLikely
+
+ bLoad := s.f.NewBlock(ssa.BlockPlain)
+ bEnd := s.f.NewBlock(ssa.BlockPlain)
+
+ b.AddEdgeTo(bLoad)
+ b.AddEdgeTo(bEnd)
+ bLoad.AddEdgeTo(bEnd)
+
+ s.startBlock(bLoad)
+ off := s.newValue1I(ssa.OpOffPtr, byteptr, int64(Widthptr), tab)
+ s.vars[&typVar] = s.newValue2(ssa.OpLoad, byteptr, off, s.mem())
+ s.endBlock()
+
+ s.startBlock(bEnd)
+ typ := s.variable(&typVar, byteptr)
+ delete(s.vars, &typVar)
+ return typ
+}
+
+// dottype generates SSA for a type assertion node.
+// commaok indicates whether to panic or return a bool.
+// If commaok is false, resok will be nil.
+func (s *state) dottype(n *Node, commaok bool) (res, resok *ssa.Value) {
+ iface := s.expr(n.Left)
+ typ := s.ifaceType(n.Left, iface) // actual concrete type
+ target := s.expr(typename(n.Type)) // target type
+ if !isdirectiface(n.Type) {
+ // walk rewrites ODOTTYPE/OAS2DOTTYPE into runtime calls except for this case.
+ Fatalf("dottype needs a direct iface type %s", n.Type)
+ }
+
+ if Debug_typeassert > 0 {
+ Warnl(int(n.Lineno), "type assertion inlined")
+ }
+
+ // TODO: If we have a nonempty interface and its itab field is nil,
+ // then this test is redundant and ifaceType should just branch directly to bFail.
+ cond := s.newValue2(ssa.OpEqPtr, Types[TBOOL], typ, target)
+ b := s.endBlock()
+ b.Kind = ssa.BlockIf
+ b.Control = cond
+ b.Likely = ssa.BranchLikely
+
+ byteptr := Ptrto(Types[TUINT8])
+
+ bOk := s.f.NewBlock(ssa.BlockPlain)
+ bFail := s.f.NewBlock(ssa.BlockPlain)
+ b.AddEdgeTo(bOk)
+ b.AddEdgeTo(bFail)
+
+ if !commaok {
+ // on failure, panic by calling panicdottype
+ s.startBlock(bFail)
+ taddr := s.newValue1A(ssa.OpAddr, byteptr, &ssa.ExternSymbol{byteptr, typenamesym(n.Left.Type)}, s.sb)
+ s.rtcall(panicdottype, false, nil, typ, target, taddr)
+
+ // on success, return idata field
+ s.startBlock(bOk)
+ return s.newValue1(ssa.OpIData, n.Type, iface), nil
+ }
+
+ // commaok is the more complicated case because we have
+ // a control flow merge point.
+ bEnd := s.f.NewBlock(ssa.BlockPlain)
+
+ // type assertion succeeded
+ s.startBlock(bOk)
+ s.vars[&idataVar] = s.newValue1(ssa.OpIData, n.Type, iface)
+ s.vars[&okVar] = s.constBool(true)
+ s.endBlock()
+ bOk.AddEdgeTo(bEnd)
+
+ // type assertion failed
+ s.startBlock(bFail)
+ s.vars[&idataVar] = s.entryNewValue0(ssa.OpConstNil, byteptr)
+ s.vars[&okVar] = s.constBool(false)
+ s.endBlock()
+ bFail.AddEdgeTo(bEnd)
+
+ // merge point
+ s.startBlock(bEnd)
+ res = s.variable(&idataVar, byteptr)
+ resok = s.variable(&okVar, Types[TBOOL])
+ delete(s.vars, &idataVar)
+ delete(s.vars, &okVar)
+ return res, resok
+}
+
+// checkgoto checks that a goto from from to to does not
+// jump into a block or jump over variable declarations.
+// It is a copy of checkgoto in the pre-SSA backend,
+// modified only for line number handling.
+// TODO: document how this works and why it is designed the way it is.
+func (s *state) checkgoto(from *Node, to *Node) {
+ if from.Sym == to.Sym {
+ return
+ }
+
+ nf := 0
+ for fs := from.Sym; fs != nil; fs = fs.Link {
+ nf++
+ }
+ nt := 0
+ for fs := to.Sym; fs != nil; fs = fs.Link {
+ nt++
+ }
+ fs := from.Sym
+ for ; nf > nt; nf-- {
+ fs = fs.Link
+ }
+ if fs != to.Sym {
+ // decide what to complain about.
+ // prefer to complain about 'into block' over declarations,
+ // so scan backward to find most recent block or else dcl.
+ var block *Sym
+
+ var dcl *Sym
+ ts := to.Sym
+ for ; nt > nf; nt-- {
+ if ts.Pkg == nil {
+ block = ts
+ } else {
+ dcl = ts
+ }
+ ts = ts.Link
+ }
+
+ for ts != fs {
+ if ts.Pkg == nil {
+ block = ts
+ } else {
+ dcl = ts
+ }
+ ts = ts.Link
+ fs = fs.Link
+ }
+
+ lno := int(from.Left.Lineno)
+ if block != nil {
+ yyerrorl(lno, "goto %v jumps into block starting at %v", from.Left.Sym, Ctxt.Line(int(block.Lastlineno)))
+ } else {
+ yyerrorl(lno, "goto %v jumps over declaration of %v at %v", from.Left.Sym, dcl, Ctxt.Line(int(dcl.Lastlineno)))
+ }
+ }
+}
+
+// variable returns the value of a variable at the current location.
+func (s *state) variable(name *Node, t ssa.Type) *ssa.Value {
+ v := s.vars[name]
+ if v == nil {
+ v = s.newValue0A(ssa.OpFwdRef, t, name)
+ s.fwdRefs = append(s.fwdRefs, v)
+ s.vars[name] = v
+ s.addNamedValue(name, v)
+ }
+ return v
+}
+
+func (s *state) mem() *ssa.Value {
+ return s.variable(&memVar, ssa.TypeMem)
+}
+
+func (s *state) linkForwardReferences() {
+ // Build SSA graph. Each variable on its first use in a basic block
+ // leaves a FwdRef in that block representing the incoming value
+ // of that variable. This function links that ref up with possible definitions,
+ // inserting Phi values as needed. This is essentially the algorithm
+ // described by Braun, Buchwald, Hack, Leißa, Mallon, and Zwinkau:
+ // http://pp.info.uni-karlsruhe.de/uploads/publikationen/braun13cc.pdf
+ // Differences:
+ // - We use FwdRef nodes to postpone phi building until the CFG is
+ // completely built. That way we can avoid the notion of "sealed"
+ // blocks.
+ // - Phi optimization is a separate pass (in ../ssa/phielim.go).
+ for len(s.fwdRefs) > 0 {
+ v := s.fwdRefs[len(s.fwdRefs)-1]
+ s.fwdRefs = s.fwdRefs[:len(s.fwdRefs)-1]
+ s.resolveFwdRef(v)
+ }
+}
+
+// resolveFwdRef modifies v to be the variable's value at the start of its block.
+// v must be a FwdRef op.
+func (s *state) resolveFwdRef(v *ssa.Value) {
+ b := v.Block
+ name := v.Aux.(*Node)
+ v.Aux = nil
+ if b == s.f.Entry {
+ // Live variable at start of function.
+ if s.canSSA(name) {
+ v.Op = ssa.OpArg
+ v.Aux = name
+ return
+ }
+ // Not SSAable. Load it.
+ addr := s.decladdrs[name]
+ if addr == nil {
+ // TODO: closure args reach here.
+ s.Unimplementedf("unhandled closure arg %s at entry to function %s", name, b.Func.Name)
+ }
+ if _, ok := addr.Aux.(*ssa.ArgSymbol); !ok {
+ s.Fatalf("variable live at start of function %s is not an argument %s", b.Func.Name, name)
+ }
+ v.Op = ssa.OpLoad
+ v.AddArgs(addr, s.startmem)
+ return
+ }
+ if len(b.Preds) == 0 {
+ // This block is dead; we have no predecessors and we're not the entry block.
+ // It doesn't matter what we use here as long as it is well-formed.
+ v.Op = ssa.OpUnknown
+ return
+ }
+ // Find variable value on each predecessor.
+ var argstore [4]*ssa.Value
+ args := argstore[:0]
+ for _, p := range b.Preds {
+ args = append(args, s.lookupVarOutgoing(p, v.Type, name, v.Line))
+ }
+
+ // Decide if we need a phi or not. We need a phi if there
+ // are two different args (which are both not v).
+ var w *ssa.Value
+ for _, a := range args {
+ if a == v {
+ continue // self-reference
+ }
+ if a == w {
+ continue // already have this witness
+ }
+ if w != nil {
+ // two witnesses, need a phi value
+ v.Op = ssa.OpPhi
+ v.AddArgs(args...)
+ return
+ }
+ w = a // save witness
+ }
+ if w == nil {
+ s.Fatalf("no witness for reachable phi %s", v)
+ }
+ // One witness. Make v a copy of w.
+ v.Op = ssa.OpCopy
+ v.AddArg(w)
+}
+
+// lookupVarOutgoing finds the variable's value at the end of block b.
+func (s *state) lookupVarOutgoing(b *ssa.Block, t ssa.Type, name *Node, line int32) *ssa.Value {
+ m := s.defvars[b.ID]
+ if v, ok := m[name]; ok {
+ return v
+ }
+ // The variable is not defined by b and we haven't
+ // looked it up yet. Generate a FwdRef for the variable and return that.
+ v := b.NewValue0A(line, ssa.OpFwdRef, t, name)
+ s.fwdRefs = append(s.fwdRefs, v)
+ m[name] = v
+ s.addNamedValue(name, v)
+ return v
+}
+
+func (s *state) addNamedValue(n *Node, v *ssa.Value) {
+ if n.Class == Pxxx {
+ // Don't track our dummy nodes (&memVar etc.).
+ return
+ }
+ if strings.HasPrefix(n.Sym.Name, "autotmp_") {
+ // Don't track autotmp_ variables.
+ return
+ }
+ if n.Class == PAUTO && (v.Type.IsString() || v.Type.IsSlice() || v.Type.IsInterface()) {
+ // TODO: can't handle auto compound objects with pointers yet.
+ // The live variable analysis barfs because we don't put VARDEF
+ // pseudos in the right place when we spill to these nodes.
+ return
+ }
+ if n.Class == PAUTO && n.Xoffset != 0 {
+ s.Fatalf("AUTO var with offset %s %d", n, n.Xoffset)
+ }
+ loc := ssa.LocalSlot{N: n, Type: n.Type, Off: 0}
+ values, ok := s.f.NamedValues[loc]
+ if !ok {
+ s.f.Names = append(s.f.Names, loc)
+ }
+ s.f.NamedValues[loc] = append(values, v)
+}
+
+// an unresolved branch
+type branch struct {
+ p *obj.Prog // branch instruction
+ b *ssa.Block // target
+}
+
+type genState struct {
+ // branches remembers all the branch instructions we've seen
+ // and where they would like to go.
+ branches []branch
+
+ // bstart remembers where each block starts (indexed by block ID)
+ bstart []*obj.Prog
+
+ // deferBranches remembers all the defer branches we've seen.
+ deferBranches []*obj.Prog
+
+ // deferTarget remembers the (last) deferreturn call site.
+ deferTarget *obj.Prog
+}
+
+// genssa appends entries to ptxt for each instruction in f.
+// gcargs and gclocals are filled in with pointer maps for the frame.
+func genssa(f *ssa.Func, ptxt *obj.Prog, gcargs, gclocals *Sym) {
+ var s genState
+
+ e := f.Config.Frontend().(*ssaExport)
+ // We're about to emit a bunch of Progs.
+ // Since the only way to get here is to explicitly request it,
+ // just fail on unimplemented instead of trying to unwind our mess.
+ e.mustImplement = true
+
+ // Remember where each block starts.
+ s.bstart = make([]*obj.Prog, f.NumBlocks())
+
+ var valueProgs map[*obj.Prog]*ssa.Value
+ var blockProgs map[*obj.Prog]*ssa.Block
+ const logProgs = true
+ if logProgs {
+ valueProgs = make(map[*obj.Prog]*ssa.Value, f.NumValues())
+ blockProgs = make(map[*obj.Prog]*ssa.Block, f.NumBlocks())
+ f.Logf("genssa %s\n", f.Name)
+ blockProgs[Pc] = f.Blocks[0]
+ }
+
+ // Emit basic blocks
+ for i, b := range f.Blocks {
+ s.bstart[b.ID] = Pc
+ // Emit values in block
+ s.markMoves(b)
+ for _, v := range b.Values {
+ x := Pc
+ s.genValue(v)
+ if logProgs {
+ for ; x != Pc; x = x.Link {
+ valueProgs[x] = v
+ }
+ }
+ }
+ // Emit control flow instructions for block
+ var next *ssa.Block
+ if i < len(f.Blocks)-1 && (Debug['N'] == 0 || b.Kind == ssa.BlockCall) {
+ // If -N, leave next==nil so every block with successors
+ // ends in a JMP (except call blocks - plive doesn't like
+ // select{send,recv} followed by a JMP call). Helps keep
+ // line numbers for otherwise empty blocks.
+ next = f.Blocks[i+1]
+ }
+ x := Pc
+ s.genBlock(b, next)
+ if logProgs {
+ for ; x != Pc; x = x.Link {
+ blockProgs[x] = b
+ }
+ }
+ }
+
+ // Resolve branches
+ for _, br := range s.branches {
+ br.p.To.Val = s.bstart[br.b.ID]
+ }
+ if s.deferBranches != nil && s.deferTarget == nil {
+ // This can happen when the function has a defer but
+ // no return (because it has an infinite loop).
+ s.deferReturn()
+ Prog(obj.ARET)
+ }
+ for _, p := range s.deferBranches {
+ p.To.Val = s.deferTarget
+ }
+
+ if logProgs {
+ for p := ptxt; p != nil; p = p.Link {
+ var s string
+ if v, ok := valueProgs[p]; ok {
+ s = v.String()
+ } else if b, ok := blockProgs[p]; ok {
+ s = b.String()
+ } else {
+ s = " " // most value and branch strings are 2-3 characters long
+ }
+ f.Logf("%s\t%s\n", s, p)
+ }
+ if f.Config.HTML != nil {
+ saved := ptxt.Ctxt.LineHist.PrintFilenameOnly
+ ptxt.Ctxt.LineHist.PrintFilenameOnly = true
+ var buf bytes.Buffer
+ buf.WriteString("<code>")
+ buf.WriteString("<dl class=\"ssa-gen\">")
+ for p := ptxt; p != nil; p = p.Link {
+ buf.WriteString("<dt class=\"ssa-prog-src\">")
+ if v, ok := valueProgs[p]; ok {
+ buf.WriteString(v.HTML())
+ } else if b, ok := blockProgs[p]; ok {
+ buf.WriteString(b.HTML())
+ }
+ buf.WriteString("</dt>")
+ buf.WriteString("<dd class=\"ssa-prog\">")
+ buf.WriteString(html.EscapeString(p.String()))
+ buf.WriteString("</dd>")
+ buf.WriteString("</li>")
+ }
+ buf.WriteString("</dl>")
+ buf.WriteString("</code>")
+ f.Config.HTML.WriteColumn("genssa", buf.String())
+ ptxt.Ctxt.LineHist.PrintFilenameOnly = saved
+ }
+ }
+
+ // Emit static data
+ if f.StaticData != nil {
+ for _, n := range f.StaticData.([]*Node) {
+ if !gen_as_init(n, false) {
+ Fatalf("non-static data marked as static: %v\n\n", n, f)
+ }
+ }
+ }
+
+ // Allocate stack frame
+ allocauto(ptxt)
+
+ // Generate gc bitmaps.
+ liveness(Curfn, ptxt, gcargs, gclocals)
+ gcsymdup(gcargs)
+ gcsymdup(gclocals)
+
+ // Add frame prologue. Zero ambiguously live variables.
+ Thearch.Defframe(ptxt)
+ if Debug['f'] != 0 {
+ frame(0)
+ }
+
+ // Remove leftover instrumentation from the instruction stream.
+ removevardef(ptxt)
+
+ f.Config.HTML.Close()
+}
+
+// opregreg emits instructions for
+// dest := dest(To) op src(From)
+// and also returns the created obj.Prog so it
+// may be further adjusted (offset, scale, etc).
+func opregreg(op int, dest, src int16) *obj.Prog {
+ p := Prog(op)
+ p.From.Type = obj.TYPE_REG
+ p.To.Type = obj.TYPE_REG
+ p.To.Reg = dest
+ p.From.Reg = src
+ return p
+}
+
+func (s *genState) genValue(v *ssa.Value) {
+ lineno = v.Line
+ switch v.Op {
+ case ssa.OpAMD64ADDQ, ssa.OpAMD64ADDL, ssa.OpAMD64ADDW:
+ r := regnum(v)
+ r1 := regnum(v.Args[0])
+ r2 := regnum(v.Args[1])
+ switch {
+ case r == r1:
+ p := Prog(v.Op.Asm())
+ p.From.Type = obj.TYPE_REG
+ p.From.Reg = r2
+ p.To.Type = obj.TYPE_REG
+ p.To.Reg = r
+ case r == r2:
+ p := Prog(v.Op.Asm())
+ p.From.Type = obj.TYPE_REG
+ p.From.Reg = r1
+ p.To.Type = obj.TYPE_REG
+ p.To.Reg = r
+ default:
+ var asm int
+ switch v.Op {
+ case ssa.OpAMD64ADDQ:
+ asm = x86.ALEAQ
+ case ssa.OpAMD64ADDL:
+ asm = x86.ALEAL
+ case ssa.OpAMD64ADDW:
+ asm = x86.ALEAL
+ }
+ p := Prog(asm)
+ p.From.Type = obj.TYPE_MEM
+ p.From.Reg = r1
+ p.From.Scale = 1
+ p.From.Index = r2
+ p.To.Type = obj.TYPE_REG
+ p.To.Reg = r
+ }
+ // 2-address opcode arithmetic, symmetric
+ case ssa.OpAMD64ADDB, ssa.OpAMD64ADDSS, ssa.OpAMD64ADDSD,
+ ssa.OpAMD64ANDQ, ssa.OpAMD64ANDL, ssa.OpAMD64ANDW, ssa.OpAMD64ANDB,
+ ssa.OpAMD64ORQ, ssa.OpAMD64ORL, ssa.OpAMD64ORW, ssa.OpAMD64ORB,
+ ssa.OpAMD64XORQ, ssa.OpAMD64XORL, ssa.OpAMD64XORW, ssa.OpAMD64XORB,
+ ssa.OpAMD64MULQ, ssa.OpAMD64MULL, ssa.OpAMD64MULW, ssa.OpAMD64MULB,
+ ssa.OpAMD64MULSS, ssa.OpAMD64MULSD, ssa.OpAMD64PXOR:
+ r := regnum(v)
+ x := regnum(v.Args[0])
+ y := regnum(v.Args[1])
+ if x != r && y != r {
+ opregreg(moveByType(v.Type), r, x)
+ x = r
+ }
+ p := Prog(v.Op.Asm())
+ p.From.Type = obj.TYPE_REG
+ p.To.Type = obj.TYPE_REG
+ p.To.Reg = r
+ if x == r {
+ p.From.Reg = y
+ } else {
+ p.From.Reg = x
+ }
+ // 2-address opcode arithmetic, not symmetric
+ case ssa.OpAMD64SUBQ, ssa.OpAMD64SUBL, ssa.OpAMD64SUBW, ssa.OpAMD64SUBB:
+ r := regnum(v)
+ x := regnum(v.Args[0])
+ y := regnum(v.Args[1])
+ var neg bool
+ if y == r {
+ // compute -(y-x) instead
+ x, y = y, x
+ neg = true
+ }
+ if x != r {
+ opregreg(moveByType(v.Type), r, x)
+ }
+ opregreg(v.Op.Asm(), r, y)
+
+ if neg {
+ if v.Op == ssa.OpAMD64SUBQ {
+ p := Prog(x86.ANEGQ)
+ p.To.Type = obj.TYPE_REG
+ p.To.Reg = r
+ } else { // Avoids partial registers write
+ p := Prog(x86.ANEGL)
+ p.To.Type = obj.TYPE_REG
+ p.To.Reg = r
+ }
+ }
+ case ssa.OpAMD64SUBSS, ssa.OpAMD64SUBSD, ssa.OpAMD64DIVSS, ssa.OpAMD64DIVSD:
+ r := regnum(v)
+ x := regnum(v.Args[0])
+ y := regnum(v.Args[1])
+ if y == r && x != r {
+ // r/y := x op r/y, need to preserve x and rewrite to
+ // r/y := r/y op x15
+ x15 := int16(x86.REG_X15)
+ // register move y to x15
+ // register move x to y
+ // rename y with x15
+ opregreg(moveByType(v.Type), x15, y)
+ opregreg(moveByType(v.Type), r, x)
+ y = x15
+ } else if x != r {
+ opregreg(moveByType(v.Type), r, x)
+ }
+ opregreg(v.Op.Asm(), r, y)
+
+ case ssa.OpAMD64DIVQ, ssa.OpAMD64DIVL, ssa.OpAMD64DIVW,
+ ssa.OpAMD64DIVQU, ssa.OpAMD64DIVLU, ssa.OpAMD64DIVWU,
+ ssa.OpAMD64MODQ, ssa.OpAMD64MODL, ssa.OpAMD64MODW,
+ ssa.OpAMD64MODQU, ssa.OpAMD64MODLU, ssa.OpAMD64MODWU:
+
+ // Arg[0] is already in AX as it's the only register we allow
+ // and AX is the only output
+ x := regnum(v.Args[1])
+
+ // CPU faults upon signed overflow, which occurs when most
+ // negative int is divided by -1.
+ var j *obj.Prog
+ if v.Op == ssa.OpAMD64DIVQ || v.Op == ssa.OpAMD64DIVL ||
+ v.Op == ssa.OpAMD64DIVW || v.Op == ssa.OpAMD64MODQ ||
+ v.Op == ssa.OpAMD64MODL || v.Op == ssa.OpAMD64MODW {
+
+ var c *obj.Prog
+ switch v.Op {
+ case ssa.OpAMD64DIVQ, ssa.OpAMD64MODQ:
+ c = Prog(x86.ACMPQ)
+ j = Prog(x86.AJEQ)
+ // go ahead and sign extend to save doing it later
+ Prog(x86.ACQO)
+
+ case ssa.OpAMD64DIVL, ssa.OpAMD64MODL:
+ c = Prog(x86.ACMPL)
+ j = Prog(x86.AJEQ)
+ Prog(x86.ACDQ)
+
+ case ssa.OpAMD64DIVW, ssa.OpAMD64MODW:
+ c = Prog(x86.ACMPW)
+ j = Prog(x86.AJEQ)
+ Prog(x86.ACWD)
+ }
+ c.From.Type = obj.TYPE_REG
+ c.From.Reg = x
+ c.To.Type = obj.TYPE_CONST
+ c.To.Offset = -1
+
+ j.To.Type = obj.TYPE_BRANCH
+
+ }
+
+ // for unsigned ints, we sign extend by setting DX = 0
+ // signed ints were sign extended above
+ if v.Op == ssa.OpAMD64DIVQU || v.Op == ssa.OpAMD64MODQU ||
+ v.Op == ssa.OpAMD64DIVLU || v.Op == ssa.OpAMD64MODLU ||
+ v.Op == ssa.OpAMD64DIVWU || v.Op == ssa.OpAMD64MODWU {
+ c := Prog(x86.AXORQ)
+ c.From.Type = obj.TYPE_REG
+ c.From.Reg = x86.REG_DX
+ c.To.Type = obj.TYPE_REG
+ c.To.Reg = x86.REG_DX
+ }
+
+ p := Prog(v.Op.Asm())
+ p.From.Type = obj.TYPE_REG
+ p.From.Reg = x
+
+ // signed division, rest of the check for -1 case
+ if j != nil {
+ j2 := Prog(obj.AJMP)
+ j2.To.Type = obj.TYPE_BRANCH
+
+ var n *obj.Prog
+ if v.Op == ssa.OpAMD64DIVQ || v.Op == ssa.OpAMD64DIVL ||
+ v.Op == ssa.OpAMD64DIVW {
+ // n * -1 = -n
+ n = Prog(x86.ANEGQ)
+ n.To.Type = obj.TYPE_REG
+ n.To.Reg = x86.REG_AX
+ } else {
+ // n % -1 == 0
+ n = Prog(x86.AXORQ)
+ n.From.Type = obj.TYPE_REG
+ n.From.Reg = x86.REG_DX
+ n.To.Type = obj.TYPE_REG
+ n.To.Reg = x86.REG_DX
+ }
+
+ j.To.Val = n
+ j2.To.Val = Pc
+ }
+
+ case ssa.OpAMD64HMULQ, ssa.OpAMD64HMULL, ssa.OpAMD64HMULW, ssa.OpAMD64HMULB,
+ ssa.OpAMD64HMULQU, ssa.OpAMD64HMULLU, ssa.OpAMD64HMULWU, ssa.OpAMD64HMULBU:
+ // the frontend rewrites constant division by 8/16/32 bit integers into
+ // HMUL by a constant
+ // SSA rewrites generate the 64 bit versions
+
+ // Arg[0] is already in AX as it's the only register we allow
+ // and DX is the only output we care about (the high bits)
+ p := Prog(v.Op.Asm())
+ p.From.Type = obj.TYPE_REG
+ p.From.Reg = regnum(v.Args[1])
+
+ // IMULB puts the high portion in AH instead of DL,
+ // so move it to DL for consistency
+ if v.Type.Size() == 1 {
+ m := Prog(x86.AMOVB)
+ m.From.Type = obj.TYPE_REG
+ m.From.Reg = x86.REG_AH
+ m.To.Type = obj.TYPE_REG
+ m.To.Reg = x86.REG_DX
+ }
+
+ case ssa.OpAMD64AVGQU:
+ // compute (x+y)/2 unsigned.
+ // Do a 64-bit add, the overflow goes into the carry.
+ // Shift right once and pull the carry back into the 63rd bit.
+ r := regnum(v)
+ x := regnum(v.Args[0])
+ y := regnum(v.Args[1])
+ if x != r && y != r {
+ opregreg(moveByType(v.Type), r, x)
+ x = r
+ }
+ p := Prog(x86.AADDQ)
+ p.From.Type = obj.TYPE_REG
+ p.To.Type = obj.TYPE_REG
+ p.To.Reg = r
+ if x == r {
+ p.From.Reg = y
+ } else {
+ p.From.Reg = x
+ }
+ p = Prog(x86.ARCRQ)
+ p.From.Type = obj.TYPE_CONST
+ p.From.Offset = 1
+ p.To.Type = obj.TYPE_REG
+ p.To.Reg = r
+
+ case ssa.OpAMD64SHLQ, ssa.OpAMD64SHLL, ssa.OpAMD64SHLW, ssa.OpAMD64SHLB,
+ ssa.OpAMD64SHRQ, ssa.OpAMD64SHRL, ssa.OpAMD64SHRW, ssa.OpAMD64SHRB,
+ ssa.OpAMD64SARQ, ssa.OpAMD64SARL, ssa.OpAMD64SARW, ssa.OpAMD64SARB:
+ x := regnum(v.Args[0])
+ r := regnum(v)
+ if x != r {
+ if r == x86.REG_CX {
+ v.Fatalf("can't implement %s, target and shift both in CX", v.LongString())
+ }
+ p := Prog(moveByType(v.Type))
+ p.From.Type = obj.TYPE_REG
+ p.From.Reg = x
+ p.To.Type = obj.TYPE_REG
+ p.To.Reg = r
+ }
+ p := Prog(v.Op.Asm())
+ p.From.Type = obj.TYPE_REG
+ p.From.Reg = regnum(v.Args[1]) // should be CX
+ p.To.Type = obj.TYPE_REG
+ p.To.Reg = r
+ case ssa.OpAMD64ADDQconst, ssa.OpAMD64ADDLconst, ssa.OpAMD64ADDWconst:
+ r := regnum(v)
+ a := regnum(v.Args[0])
+ if r == a {
+ if v.AuxInt2Int64() == 1 {
+ var asm int
+ switch v.Op {
+ // Software optimization manual recommends add $1,reg.
+ // But inc/dec is 1 byte smaller. ICC always uses inc
+ // Clang/GCC choose depending on flags, but prefer add.
+ // Experiments show that inc/dec is both a little faster
+ // and make a binary a little smaller.
+ case ssa.OpAMD64ADDQconst:
+ asm = x86.AINCQ
+ case ssa.OpAMD64ADDLconst:
+ asm = x86.AINCL
+ case ssa.OpAMD64ADDWconst:
+ asm = x86.AINCL
+ }
+ p := Prog(asm)
+ p.To.Type = obj.TYPE_REG
+ p.To.Reg = r
+ return
+ } else if v.AuxInt2Int64() == -1 {
+ var asm int
+ switch v.Op {
+ case ssa.OpAMD64ADDQconst:
+ asm = x86.ADECQ
+ case ssa.OpAMD64ADDLconst:
+ asm = x86.ADECL
+ case ssa.OpAMD64ADDWconst:
+ asm = x86.ADECL
+ }
+ p := Prog(asm)
+ p.To.Type = obj.TYPE_REG
+ p.To.Reg = r
+ return
+ } else {
+ p := Prog(v.Op.Asm())
+ p.From.Type = obj.TYPE_CONST
+ p.From.Offset = v.AuxInt2Int64()
+ p.To.Type = obj.TYPE_REG
+ p.To.Reg = r
+ return
+ }
+ }
+ var asm int
+ switch v.Op {
+ case ssa.OpAMD64ADDQconst:
+ asm = x86.ALEAQ
+ case ssa.OpAMD64ADDLconst:
+ asm = x86.ALEAL
+ case ssa.OpAMD64ADDWconst:
+ asm = x86.ALEAL
+ }
+ p := Prog(asm)
+ p.From.Type = obj.TYPE_MEM
+ p.From.Reg = a
+ p.From.Offset = v.AuxInt2Int64()
+ p.To.Type = obj.TYPE_REG
+ p.To.Reg = r
+ case ssa.OpAMD64MULQconst, ssa.OpAMD64MULLconst, ssa.OpAMD64MULWconst, ssa.OpAMD64MULBconst:
+ r := regnum(v)
+ x := regnum(v.Args[0])
+ if r != x {
+ p := Prog(moveByType(v.Type))
+ p.From.Type = obj.TYPE_REG
+ p.From.Reg = x
+ p.To.Type = obj.TYPE_REG
+ p.To.Reg = r
+ }
+ p := Prog(v.Op.Asm())
+ p.From.Type = obj.TYPE_CONST
+ p.From.Offset = v.AuxInt2Int64()
+ p.To.Type = obj.TYPE_REG
+ p.To.Reg = r
+ // TODO: Teach doasm to compile the three-address multiply imul $c, r1, r2
+ // instead of using the MOVQ above.
+ //p.From3 = new(obj.Addr)
+ //p.From3.Type = obj.TYPE_REG
+ //p.From3.Reg = regnum(v.Args[0])
+ case ssa.OpAMD64SUBQconst, ssa.OpAMD64SUBLconst, ssa.OpAMD64SUBWconst:
+ x := regnum(v.Args[0])
+ r := regnum(v)
+ // We have 3-op add (lea), so transforming a = b - const into
+ // a = b + (- const), saves us 1 instruction. We can't fit
+ // - (-1 << 31) into 4 bytes offset in lea.
+ // We handle 2-address just fine below.
+ if v.AuxInt2Int64() == -1<<31 || x == r {
+ if x != r {
+ // This code compensates for the fact that the register allocator
+ // doesn't understand 2-address instructions yet. TODO: fix that.
+ p := Prog(moveByType(v.Type))
+ p.From.Type = obj.TYPE_REG
+ p.From.Reg = x
+ p.To.Type = obj.TYPE_REG
+ p.To.Reg = r
+ }
+ p := Prog(v.Op.Asm())
+ p.From.Type = obj.TYPE_CONST
+ p.From.Offset = v.AuxInt2Int64()
+ p.To.Type = obj.TYPE_REG
+ p.To.Reg = r
+ } else if x == r && v.AuxInt2Int64() == -1 {
+ var asm int
+ // x = x - (-1) is the same as x++
+ // See OpAMD64ADDQconst comments about inc vs add $1,reg
+ switch v.Op {
+ case ssa.OpAMD64SUBQconst:
+ asm = x86.AINCQ
+ case ssa.OpAMD64SUBLconst:
+ asm = x86.AINCL
+ case ssa.OpAMD64SUBWconst:
+ asm = x86.AINCL
+ }
+ p := Prog(asm)
+ p.To.Type = obj.TYPE_REG
+ p.To.Reg = r
+ } else if x == r && v.AuxInt2Int64() == 1 {
+ var asm int
+ switch v.Op {
+ case ssa.OpAMD64SUBQconst:
+ asm = x86.ADECQ
+ case ssa.OpAMD64SUBLconst:
+ asm = x86.ADECL
+ case ssa.OpAMD64SUBWconst:
+ asm = x86.ADECL
+ }
+ p := Prog(asm)
+ p.To.Type = obj.TYPE_REG
+ p.To.Reg = r
+ } else {
+ var asm int
+ switch v.Op {
+ case ssa.OpAMD64SUBQconst:
+ asm = x86.ALEAQ
+ case ssa.OpAMD64SUBLconst:
+ asm = x86.ALEAL
+ case ssa.OpAMD64SUBWconst:
+ asm = x86.ALEAL
+ }
+ p := Prog(asm)
+ p.From.Type = obj.TYPE_MEM
+ p.From.Reg = x
+ p.From.Offset = -v.AuxInt2Int64()
+ p.To.Type = obj.TYPE_REG
+ p.To.Reg = r
+ }
+
+ case ssa.OpAMD64ADDBconst,
+ ssa.OpAMD64ANDQconst, ssa.OpAMD64ANDLconst, ssa.OpAMD64ANDWconst, ssa.OpAMD64ANDBconst,
+ ssa.OpAMD64ORQconst, ssa.OpAMD64ORLconst, ssa.OpAMD64ORWconst, ssa.OpAMD64ORBconst,
+ ssa.OpAMD64XORQconst, ssa.OpAMD64XORLconst, ssa.OpAMD64XORWconst, ssa.OpAMD64XORBconst,
+ ssa.OpAMD64SUBBconst, ssa.OpAMD64SHLQconst, ssa.OpAMD64SHLLconst, ssa.OpAMD64SHLWconst,
+ ssa.OpAMD64SHLBconst, ssa.OpAMD64SHRQconst, ssa.OpAMD64SHRLconst, ssa.OpAMD64SHRWconst,
+ ssa.OpAMD64SHRBconst, ssa.OpAMD64SARQconst, ssa.OpAMD64SARLconst, ssa.OpAMD64SARWconst,
+ ssa.OpAMD64SARBconst, ssa.OpAMD64ROLQconst, ssa.OpAMD64ROLLconst, ssa.OpAMD64ROLWconst,
+ ssa.OpAMD64ROLBconst:
+ // This code compensates for the fact that the register allocator
+ // doesn't understand 2-address instructions yet. TODO: fix that.
+ x := regnum(v.Args[0])
+ r := regnum(v)
+ if x != r {
+ p := Prog(moveByType(v.Type))
+ p.From.Type = obj.TYPE_REG
+ p.From.Reg = x
+ p.To.Type = obj.TYPE_REG
+ p.To.Reg = r
+ }
+ p := Prog(v.Op.Asm())
+ p.From.Type = obj.TYPE_CONST
+ p.From.Offset = v.AuxInt2Int64()
+ p.To.Type = obj.TYPE_REG
+ p.To.Reg = r
+ case ssa.OpAMD64SBBQcarrymask, ssa.OpAMD64SBBLcarrymask:
+ r := regnum(v)
+ p := Prog(v.Op.Asm())
+ p.From.Type = obj.TYPE_REG
+ p.From.Reg = r
+ p.To.Type = obj.TYPE_REG
+ p.To.Reg = r
+ case ssa.OpAMD64LEAQ1, ssa.OpAMD64LEAQ2, ssa.OpAMD64LEAQ4, ssa.OpAMD64LEAQ8:
+ p := Prog(x86.ALEAQ)
+ p.From.Type = obj.TYPE_MEM
+ p.From.Reg = regnum(v.Args[0])
+ switch v.Op {
+ case ssa.OpAMD64LEAQ1:
+ p.From.Scale = 1
+ case ssa.OpAMD64LEAQ2:
+ p.From.Scale = 2
+ case ssa.OpAMD64LEAQ4:
+ p.From.Scale = 4
+ case ssa.OpAMD64LEAQ8:
+ p.From.Scale = 8
+ }
+ p.From.Index = regnum(v.Args[1])
+ addAux(&p.From, v)
+ p.To.Type = obj.TYPE_REG
+ p.To.Reg = regnum(v)
+ case ssa.OpAMD64LEAQ:
+ p := Prog(x86.ALEAQ)
+ p.From.Type = obj.TYPE_MEM
+ p.From.Reg = regnum(v.Args[0])
+ addAux(&p.From, v)
+ p.To.Type = obj.TYPE_REG
+ p.To.Reg = regnum(v)
+ case ssa.OpAMD64CMPQ, ssa.OpAMD64CMPL, ssa.OpAMD64CMPW, ssa.OpAMD64CMPB,
+ ssa.OpAMD64TESTQ, ssa.OpAMD64TESTL, ssa.OpAMD64TESTW, ssa.OpAMD64TESTB:
+ opregreg(v.Op.Asm(), regnum(v.Args[1]), regnum(v.Args[0]))
+ case ssa.OpAMD64UCOMISS, ssa.OpAMD64UCOMISD:
+ // Go assembler has swapped operands for UCOMISx relative to CMP,
+ // must account for that right here.
+ opregreg(v.Op.Asm(), regnum(v.Args[0]), regnum(v.Args[1]))
+ case ssa.OpAMD64CMPQconst, ssa.OpAMD64CMPLconst, ssa.OpAMD64CMPWconst, ssa.OpAMD64CMPBconst:
+ p := Prog(v.Op.Asm())
+ p.From.Type = obj.TYPE_REG
+ p.From.Reg = regnum(v.Args[0])
+ p.To.Type = obj.TYPE_CONST
+ p.To.Offset = v.AuxInt2Int64()
+ case ssa.OpAMD64TESTQconst, ssa.OpAMD64TESTLconst, ssa.OpAMD64TESTWconst, ssa.OpAMD64TESTBconst:
+ p := Prog(v.Op.Asm())
+ p.From.Type = obj.TYPE_CONST
+ p.From.Offset = v.AuxInt2Int64()
+ p.To.Type = obj.TYPE_REG
+ p.To.Reg = regnum(v.Args[0])
+ case ssa.OpAMD64MOVBconst, ssa.OpAMD64MOVWconst, ssa.OpAMD64MOVLconst, ssa.OpAMD64MOVQconst:
+ x := regnum(v)
+ p := Prog(v.Op.Asm())
+ p.From.Type = obj.TYPE_CONST
+ p.From.Offset = v.AuxInt2Int64()
+ p.To.Type = obj.TYPE_REG
+ p.To.Reg = x
+ // If flags are live at this instruction, suppress the
+ // MOV $0,AX -> XOR AX,AX optimization.
+ if v.Aux != nil {
+ p.Mark |= x86.PRESERVEFLAGS
+ }
+ case ssa.OpAMD64MOVSSconst, ssa.OpAMD64MOVSDconst:
+ x := regnum(v)
+ p := Prog(v.Op.Asm())
+ p.From.Type = obj.TYPE_FCONST
+ p.From.Val = math.Float64frombits(uint64(v.AuxInt))
+ p.To.Type = obj.TYPE_REG
+ p.To.Reg = x
+ case ssa.OpAMD64MOVQload, ssa.OpAMD64MOVSSload, ssa.OpAMD64MOVSDload, ssa.OpAMD64MOVLload, ssa.OpAMD64MOVWload, ssa.OpAMD64MOVBload, ssa.OpAMD64MOVBQSXload, ssa.OpAMD64MOVBQZXload, ssa.OpAMD64MOVWQSXload, ssa.OpAMD64MOVWQZXload, ssa.OpAMD64MOVLQSXload, ssa.OpAMD64MOVLQZXload, ssa.OpAMD64MOVOload:
+ p := Prog(v.Op.Asm())
+ p.From.Type = obj.TYPE_MEM
+ p.From.Reg = regnum(v.Args[0])
+ addAux(&p.From, v)
+ p.To.Type = obj.TYPE_REG
+ p.To.Reg = regnum(v)
+ case ssa.OpAMD64MOVQloadidx8, ssa.OpAMD64MOVSDloadidx8:
+ p := Prog(v.Op.Asm())
+ p.From.Type = obj.TYPE_MEM
+ p.From.Reg = regnum(v.Args[0])
+ addAux(&p.From, v)
+ p.From.Scale = 8
+ p.From.Index = regnum(v.Args[1])
+ p.To.Type = obj.TYPE_REG
+ p.To.Reg = regnum(v)
+ case ssa.OpAMD64MOVLloadidx4, ssa.OpAMD64MOVSSloadidx4:
+ p := Prog(v.Op.Asm())
+ p.From.Type = obj.TYPE_MEM
+ p.From.Reg = regnum(v.Args[0])
+ addAux(&p.From, v)
+ p.From.Scale = 4
+ p.From.Index = regnum(v.Args[1])
+ p.To.Type = obj.TYPE_REG
+ p.To.Reg = regnum(v)
+ case ssa.OpAMD64MOVWloadidx2:
+ p := Prog(v.Op.Asm())
+ p.From.Type = obj.TYPE_MEM
+ p.From.Reg = regnum(v.Args[0])
+ addAux(&p.From, v)
+ p.From.Scale = 2
+ p.From.Index = regnum(v.Args[1])
+ p.To.Type = obj.TYPE_REG
+ p.To.Reg = regnum(v)
+ case ssa.OpAMD64MOVBloadidx1:
+ p := Prog(v.Op.Asm())
+ p.From.Type = obj.TYPE_MEM
+ p.From.Reg = regnum(v.Args[0])
+ addAux(&p.From, v)
+ p.From.Scale = 1
+ p.From.Index = regnum(v.Args[1])
+ p.To.Type = obj.TYPE_REG
+ p.To.Reg = regnum(v)
+ case ssa.OpAMD64MOVQstore, ssa.OpAMD64MOVSSstore, ssa.OpAMD64MOVSDstore, ssa.OpAMD64MOVLstore, ssa.OpAMD64MOVWstore, ssa.OpAMD64MOVBstore, ssa.OpAMD64MOVOstore:
+ p := Prog(v.Op.Asm())
+ p.From.Type = obj.TYPE_REG
+ p.From.Reg = regnum(v.Args[1])
+ p.To.Type = obj.TYPE_MEM
+ p.To.Reg = regnum(v.Args[0])
+ addAux(&p.To, v)
+ case ssa.OpAMD64MOVQstoreidx8, ssa.OpAMD64MOVSDstoreidx8:
+ p := Prog(v.Op.Asm())
+ p.From.Type = obj.TYPE_REG
+ p.From.Reg = regnum(v.Args[2])
+ p.To.Type = obj.TYPE_MEM
+ p.To.Reg = regnum(v.Args[0])
+ p.To.Scale = 8
+ p.To.Index = regnum(v.Args[1])
+ addAux(&p.To, v)
+ case ssa.OpAMD64MOVSSstoreidx4, ssa.OpAMD64MOVLstoreidx4:
+ p := Prog(v.Op.Asm())
+ p.From.Type = obj.TYPE_REG
+ p.From.Reg = regnum(v.Args[2])
+ p.To.Type = obj.TYPE_MEM
+ p.To.Reg = regnum(v.Args[0])
+ p.To.Scale = 4
+ p.To.Index = regnum(v.Args[1])
+ addAux(&p.To, v)
+ case ssa.OpAMD64MOVWstoreidx2:
+ p := Prog(v.Op.Asm())
+ p.From.Type = obj.TYPE_REG
+ p.From.Reg = regnum(v.Args[2])
+ p.To.Type = obj.TYPE_MEM
+ p.To.Reg = regnum(v.Args[0])
+ p.To.Scale = 2
+ p.To.Index = regnum(v.Args[1])
+ addAux(&p.To, v)
+ case ssa.OpAMD64MOVBstoreidx1:
+ p := Prog(v.Op.Asm())
+ p.From.Type = obj.TYPE_REG
+ p.From.Reg = regnum(v.Args[2])
+ p.To.Type = obj.TYPE_MEM
+ p.To.Reg = regnum(v.Args[0])
+ p.To.Scale = 1
+ p.To.Index = regnum(v.Args[1])
+ addAux(&p.To, v)
+ case ssa.OpAMD64MOVQstoreconst, ssa.OpAMD64MOVLstoreconst, ssa.OpAMD64MOVWstoreconst, ssa.OpAMD64MOVBstoreconst:
+ p := Prog(v.Op.Asm())
+ p.From.Type = obj.TYPE_CONST
+ sc := v.AuxValAndOff()
+ i := sc.Val()
+ switch v.Op {
+ case ssa.OpAMD64MOVBstoreconst:
+ i = int64(int8(i))
+ case ssa.OpAMD64MOVWstoreconst:
+ i = int64(int16(i))
+ case ssa.OpAMD64MOVLstoreconst:
+ i = int64(int32(i))
+ case ssa.OpAMD64MOVQstoreconst:
+ }
+ p.From.Offset = i
+ p.To.Type = obj.TYPE_MEM
+ p.To.Reg = regnum(v.Args[0])
+ addAux2(&p.To, v, sc.Off())
+ case ssa.OpAMD64MOVQstoreconstidx8, ssa.OpAMD64MOVLstoreconstidx4, ssa.OpAMD64MOVWstoreconstidx2, ssa.OpAMD64MOVBstoreconstidx1:
+ p := Prog(v.Op.Asm())
+ p.From.Type = obj.TYPE_CONST
+ sc := v.AuxValAndOff()
+ switch v.Op {
+ case ssa.OpAMD64MOVBstoreconstidx1:
+ p.From.Offset = int64(int8(sc.Val()))
+ p.To.Scale = 1
+ case ssa.OpAMD64MOVWstoreconstidx2:
+ p.From.Offset = int64(int16(sc.Val()))
+ p.To.Scale = 2
+ case ssa.OpAMD64MOVLstoreconstidx4:
+ p.From.Offset = int64(int32(sc.Val()))
+ p.To.Scale = 4
+ case ssa.OpAMD64MOVQstoreconstidx8:
+ p.From.Offset = sc.Val()
+ p.To.Scale = 8
+ }
+ p.To.Type = obj.TYPE_MEM
+ p.To.Reg = regnum(v.Args[0])
+ p.To.Index = regnum(v.Args[1])
+ addAux2(&p.To, v, sc.Off())
+ case ssa.OpAMD64MOVLQSX, ssa.OpAMD64MOVWQSX, ssa.OpAMD64MOVBQSX, ssa.OpAMD64MOVLQZX, ssa.OpAMD64MOVWQZX, ssa.OpAMD64MOVBQZX,
+ ssa.OpAMD64CVTSL2SS, ssa.OpAMD64CVTSL2SD, ssa.OpAMD64CVTSQ2SS, ssa.OpAMD64CVTSQ2SD,
+ ssa.OpAMD64CVTTSS2SL, ssa.OpAMD64CVTTSD2SL, ssa.OpAMD64CVTTSS2SQ, ssa.OpAMD64CVTTSD2SQ,
+ ssa.OpAMD64CVTSS2SD, ssa.OpAMD64CVTSD2SS:
+ opregreg(v.Op.Asm(), regnum(v), regnum(v.Args[0]))
+ case ssa.OpAMD64DUFFZERO:
+ p := Prog(obj.ADUFFZERO)
+ p.To.Type = obj.TYPE_ADDR
+ p.To.Sym = Linksym(Pkglookup("duffzero", Runtimepkg))
+ p.To.Offset = v.AuxInt
+ case ssa.OpAMD64MOVOconst:
+ if v.AuxInt != 0 {
+ v.Unimplementedf("MOVOconst can only do constant=0")
+ }
+ r := regnum(v)
+ opregreg(x86.AXORPS, r, r)
+ case ssa.OpAMD64DUFFCOPY:
+ p := Prog(obj.ADUFFCOPY)
+ p.To.Type = obj.TYPE_ADDR
+ p.To.Sym = Linksym(Pkglookup("duffcopy", Runtimepkg))
+ p.To.Offset = v.AuxInt
+
+ case ssa.OpCopy, ssa.OpAMD64MOVQconvert: // TODO: use MOVQreg for reg->reg copies instead of OpCopy?
+ if v.Type.IsMemory() {
+ return
+ }
+ x := regnum(v.Args[0])
+ y := regnum(v)
+ if x != y {
+ opregreg(moveByType(v.Type), y, x)
+ }
+ case ssa.OpLoadReg:
+ if v.Type.IsFlags() {
+ v.Unimplementedf("load flags not implemented: %v", v.LongString())
+ return
+ }
+ p := Prog(loadByType(v.Type))
+ n, off := autoVar(v.Args[0])
+ p.From.Type = obj.TYPE_MEM
+ p.From.Node = n
+ p.From.Sym = Linksym(n.Sym)
+ p.From.Offset = off
+ if n.Class == PPARAM || n.Class == PPARAMOUT {
+ p.From.Name = obj.NAME_PARAM
+ p.From.Offset += n.Xoffset
+ } else {
+ p.From.Name = obj.NAME_AUTO
+ }
+ p.To.Type = obj.TYPE_REG
+ p.To.Reg = regnum(v)
+
+ case ssa.OpStoreReg:
+ if v.Type.IsFlags() {
+ v.Unimplementedf("store flags not implemented: %v", v.LongString())
+ return
+ }
+ p := Prog(storeByType(v.Type))
+ p.From.Type = obj.TYPE_REG
+ p.From.Reg = regnum(v.Args[0])
+ n, off := autoVar(v)
+ p.To.Type = obj.TYPE_MEM
+ p.To.Node = n
+ p.To.Sym = Linksym(n.Sym)
+ p.To.Offset = off
+ if n.Class == PPARAM || n.Class == PPARAMOUT {
+ p.To.Name = obj.NAME_PARAM
+ p.To.Offset += n.Xoffset
+ } else {
+ p.To.Name = obj.NAME_AUTO
+ }
+ case ssa.OpPhi:
+ // just check to make sure regalloc and stackalloc did it right
+ if v.Type.IsMemory() {
+ return
+ }
+ f := v.Block.Func
+ loc := f.RegAlloc[v.ID]
+ for _, a := range v.Args {
+ if aloc := f.RegAlloc[a.ID]; aloc != loc { // TODO: .Equal() instead?
+ v.Fatalf("phi arg at different location than phi: %v @ %v, but arg %v @ %v\n%s\n", v, loc, a, aloc, v.Block.Func)
+ }
+ }
+ case ssa.OpInitMem:
+ // memory arg needs no code
+ case ssa.OpArg:
+ // input args need no code
+ case ssa.OpAMD64LoweredGetClosurePtr:
+ // Output is hardwired to DX only,
+ // and DX contains the closure pointer on
+ // closure entry, and this "instruction"
+ // is scheduled to the very beginning
+ // of the entry block.
+ case ssa.OpAMD64LoweredGetG:
+ r := regnum(v)
+ // See the comments in cmd/internal/obj/x86/obj6.go
+ // near CanUse1InsnTLS for a detailed explanation of these instructions.
+ if x86.CanUse1InsnTLS(Ctxt) {
+ // MOVQ (TLS), r
+ p := Prog(x86.AMOVQ)
+ p.From.Type = obj.TYPE_MEM
+ p.From.Reg = x86.REG_TLS
+ p.To.Type = obj.TYPE_REG
+ p.To.Reg = r
+ } else {
+ // MOVQ TLS, r
+ // MOVQ (r)(TLS*1), r
+ p := Prog(x86.AMOVQ)
+ p.From.Type = obj.TYPE_REG
+ p.From.Reg = x86.REG_TLS
+ p.To.Type = obj.TYPE_REG
+ p.To.Reg = r
+ q := Prog(x86.AMOVQ)
+ q.From.Type = obj.TYPE_MEM
+ q.From.Reg = r
+ q.From.Index = x86.REG_TLS
+ q.From.Scale = 1
+ q.To.Type = obj.TYPE_REG
+ q.To.Reg = r
+ }
+ case ssa.OpAMD64CALLstatic:
+ p := Prog(obj.ACALL)
+ p.To.Type = obj.TYPE_MEM
+ p.To.Name = obj.NAME_EXTERN
+ p.To.Sym = Linksym(v.Aux.(*Sym))
+ if Maxarg < v.AuxInt {
+ Maxarg = v.AuxInt
+ }
+ case ssa.OpAMD64CALLclosure:
+ p := Prog(obj.ACALL)
+ p.To.Type = obj.TYPE_REG
+ p.To.Reg = regnum(v.Args[0])
+ if Maxarg < v.AuxInt {
+ Maxarg = v.AuxInt
+ }
+ case ssa.OpAMD64CALLdefer:
+ p := Prog(obj.ACALL)
+ p.To.Type = obj.TYPE_MEM
+ p.To.Name = obj.NAME_EXTERN
+ p.To.Sym = Linksym(Deferproc.Sym)
+ if Maxarg < v.AuxInt {
+ Maxarg = v.AuxInt
+ }
+ // defer returns in rax:
+ // 0 if we should continue executing
+ // 1 if we should jump to deferreturn call
+ p = Prog(x86.ATESTL)
+ p.From.Type = obj.TYPE_REG
+ p.From.Reg = x86.REG_AX
+ p.To.Type = obj.TYPE_REG
+ p.To.Reg = x86.REG_AX
+ p = Prog(x86.AJNE)
+ p.To.Type = obj.TYPE_BRANCH
+ s.deferBranches = append(s.deferBranches, p)
+ case ssa.OpAMD64CALLgo:
+ p := Prog(obj.ACALL)
+ p.To.Type = obj.TYPE_MEM
+ p.To.Name = obj.NAME_EXTERN
+ p.To.Sym = Linksym(Newproc.Sym)
+ if Maxarg < v.AuxInt {
+ Maxarg = v.AuxInt
+ }
+ case ssa.OpAMD64CALLinter:
+ p := Prog(obj.ACALL)
+ p.To.Type = obj.TYPE_REG
+ p.To.Reg = regnum(v.Args[0])
+ if Maxarg < v.AuxInt {
+ Maxarg = v.AuxInt
+ }
+ case ssa.OpAMD64NEGQ, ssa.OpAMD64NEGL, ssa.OpAMD64NEGW, ssa.OpAMD64NEGB,
+ ssa.OpAMD64NOTQ, ssa.OpAMD64NOTL, ssa.OpAMD64NOTW, ssa.OpAMD64NOTB:
+ x := regnum(v.Args[0])
+ r := regnum(v)
+ if x != r {
+ p := Prog(moveByType(v.Type))
+ p.From.Type = obj.TYPE_REG
+ p.From.Reg = x
+ p.To.Type = obj.TYPE_REG
+ p.To.Reg = r
+ }
+ p := Prog(v.Op.Asm())
+ p.To.Type = obj.TYPE_REG
+ p.To.Reg = r
+ case ssa.OpAMD64SQRTSD:
+ p := Prog(v.Op.Asm())
+ p.From.Type = obj.TYPE_REG
+ p.From.Reg = regnum(v.Args[0])
+ p.To.Type = obj.TYPE_REG
+ p.To.Reg = regnum(v)
+ case ssa.OpSP, ssa.OpSB:
+ // nothing to do
+ case ssa.OpAMD64SETEQ, ssa.OpAMD64SETNE,
+ ssa.OpAMD64SETL, ssa.OpAMD64SETLE,
+ ssa.OpAMD64SETG, ssa.OpAMD64SETGE,
+ ssa.OpAMD64SETGF, ssa.OpAMD64SETGEF,
+ ssa.OpAMD64SETB, ssa.OpAMD64SETBE,
+ ssa.OpAMD64SETORD, ssa.OpAMD64SETNAN,
+ ssa.OpAMD64SETA, ssa.OpAMD64SETAE:
+ p := Prog(v.Op.Asm())
+ p.To.Type = obj.TYPE_REG
+ p.To.Reg = regnum(v)
+
+ case ssa.OpAMD64SETNEF:
+ p := Prog(v.Op.Asm())
+ p.To.Type = obj.TYPE_REG
+ p.To.Reg = regnum(v)
+ q := Prog(x86.ASETPS)
+ q.To.Type = obj.TYPE_REG
+ q.To.Reg = x86.REG_AX
+ // ORL avoids partial register write and is smaller than ORQ, used by old compiler
+ opregreg(x86.AORL, regnum(v), x86.REG_AX)
+
+ case ssa.OpAMD64SETEQF:
+ p := Prog(v.Op.Asm())
+ p.To.Type = obj.TYPE_REG
+ p.To.Reg = regnum(v)
+ q := Prog(x86.ASETPC)
+ q.To.Type = obj.TYPE_REG
+ q.To.Reg = x86.REG_AX
+ // ANDL avoids partial register write and is smaller than ANDQ, used by old compiler
+ opregreg(x86.AANDL, regnum(v), x86.REG_AX)
+
+ case ssa.OpAMD64InvertFlags:
+ v.Fatalf("InvertFlags should never make it to codegen %v", v)
+ case ssa.OpAMD64FlagEQ, ssa.OpAMD64FlagLT_ULT, ssa.OpAMD64FlagLT_UGT, ssa.OpAMD64FlagGT_ULT, ssa.OpAMD64FlagGT_UGT:
+ v.Fatalf("Flag* ops should never make it to codegen %v", v)
+ case ssa.OpAMD64REPSTOSQ:
+ Prog(x86.AREP)
+ Prog(x86.ASTOSQ)
+ case ssa.OpAMD64REPMOVSQ:
+ Prog(x86.AREP)
+ Prog(x86.AMOVSQ)
+ case ssa.OpVarDef:
+ Gvardef(v.Aux.(*Node))
+ case ssa.OpVarKill:
+ gvarkill(v.Aux.(*Node))
+ case ssa.OpVarLive:
+ gvarlive(v.Aux.(*Node))
+ case ssa.OpAMD64LoweredNilCheck:
+ // Optimization - if the subsequent block has a load or store
+ // at the same address, we don't need to issue this instruction.
+ mem := v.Args[1]
+ for _, w := range v.Block.Succs[0].Values {
+ if w.Op == ssa.OpPhi {
+ if w.Type.IsMemory() {
+ mem = w
+ }
+ continue
+ }
+ if len(w.Args) == 0 || !w.Args[len(w.Args)-1].Type.IsMemory() {
+ // w doesn't use a store - can't be a memory op.
+ continue
+ }
+ if w.Args[len(w.Args)-1] != mem {
+ v.Fatalf("wrong store after nilcheck v=%s w=%s", v, w)
+ }
+ switch w.Op {
+ case ssa.OpAMD64MOVQload, ssa.OpAMD64MOVLload, ssa.OpAMD64MOVWload, ssa.OpAMD64MOVBload,
+ ssa.OpAMD64MOVQstore, ssa.OpAMD64MOVLstore, ssa.OpAMD64MOVWstore, ssa.OpAMD64MOVBstore,
+ ssa.OpAMD64MOVBQSXload, ssa.OpAMD64MOVBQZXload, ssa.OpAMD64MOVWQSXload,
+ ssa.OpAMD64MOVWQZXload, ssa.OpAMD64MOVLQSXload, ssa.OpAMD64MOVLQZXload,
+ ssa.OpAMD64MOVSSload, ssa.OpAMD64MOVSDload, ssa.OpAMD64MOVOload,
+ ssa.OpAMD64MOVSSstore, ssa.OpAMD64MOVSDstore, ssa.OpAMD64MOVOstore:
+ if w.Args[0] == v.Args[0] && w.Aux == nil && w.AuxInt >= 0 && w.AuxInt < minZeroPage {
+ if Debug_checknil != 0 && int(v.Line) > 1 {
+ Warnl(int(v.Line), "removed nil check")
+ }
+ return
+ }
+ case ssa.OpAMD64MOVQstoreconst, ssa.OpAMD64MOVLstoreconst, ssa.OpAMD64MOVWstoreconst, ssa.OpAMD64MOVBstoreconst:
+ off := ssa.ValAndOff(v.AuxInt).Off()
+ if w.Args[0] == v.Args[0] && w.Aux == nil && off >= 0 && off < minZeroPage {
+ if Debug_checknil != 0 && int(v.Line) > 1 {
+ Warnl(int(v.Line), "removed nil check")
+ }
+ return
+ }
+ }
+ if w.Type.IsMemory() {
+ if w.Op == ssa.OpVarDef || w.Op == ssa.OpVarKill || w.Op == ssa.OpVarLive {
+ // these ops are OK
+ mem = w
+ continue
+ }
+ // We can't delay the nil check past the next store.
+ break
+ }
+ }
+ // Issue a load which will fault if the input is nil.
+ // TODO: We currently use the 2-byte instruction TESTB AX, (reg).
+ // Should we use the 3-byte TESTB $0, (reg) instead? It is larger
+ // but it doesn't have false dependency on AX.
+ // Or maybe allocate an output register and use MOVL (reg),reg2 ?
+ // That trades clobbering flags for clobbering a register.
+ p := Prog(x86.ATESTB)
+ p.From.Type = obj.TYPE_REG
+ p.From.Reg = x86.REG_AX
+ p.To.Type = obj.TYPE_MEM
+ p.To.Reg = regnum(v.Args[0])
+ addAux(&p.To, v)
+ if Debug_checknil != 0 && v.Line > 1 { // v.Line==1 in generated wrappers
+ Warnl(int(v.Line), "generated nil check")
+ }
+ default:
+ v.Unimplementedf("genValue not implemented: %s", v.LongString())
+ }
+}
+
+// markMoves marks any MOVXconst ops that need to avoid clobbering flags.
+func (s *genState) markMoves(b *ssa.Block) {
+ flive := b.FlagsLiveAtEnd
+ if b.Control != nil && b.Control.Type.IsFlags() {
+ flive = true
+ }
+ for i := len(b.Values) - 1; i >= 0; i-- {
+ v := b.Values[i]
+ if flive && (v.Op == ssa.OpAMD64MOVBconst || v.Op == ssa.OpAMD64MOVWconst || v.Op == ssa.OpAMD64MOVLconst || v.Op == ssa.OpAMD64MOVQconst) {
+ // The "mark" is any non-nil Aux value.
+ v.Aux = v
+ }
+ if v.Type.IsFlags() {
+ flive = false
+ }
+ for _, a := range v.Args {
+ if a.Type.IsFlags() {
+ flive = true
+ }
+ }
+ }
+}
+
+// movZero generates a register indirect move with a 0 immediate and keeps track of bytes left and next offset
+func movZero(as int, width int64, nbytes int64, offset int64, regnum int16) (nleft int64, noff int64) {
+ p := Prog(as)
+ // TODO: use zero register on archs that support it.
+ p.From.Type = obj.TYPE_CONST
+ p.From.Offset = 0
+ p.To.Type = obj.TYPE_MEM
+ p.To.Reg = regnum
+ p.To.Offset = offset
+ offset += width
+ nleft = nbytes - width
+ return nleft, offset
+}
+
+var blockJump = [...]struct {
+ asm, invasm int
+}{
+ ssa.BlockAMD64EQ: {x86.AJEQ, x86.AJNE},
+ ssa.BlockAMD64NE: {x86.AJNE, x86.AJEQ},
+ ssa.BlockAMD64LT: {x86.AJLT, x86.AJGE},
+ ssa.BlockAMD64GE: {x86.AJGE, x86.AJLT},
+ ssa.BlockAMD64LE: {x86.AJLE, x86.AJGT},
+ ssa.BlockAMD64GT: {x86.AJGT, x86.AJLE},
+ ssa.BlockAMD64ULT: {x86.AJCS, x86.AJCC},
+ ssa.BlockAMD64UGE: {x86.AJCC, x86.AJCS},
+ ssa.BlockAMD64UGT: {x86.AJHI, x86.AJLS},
+ ssa.BlockAMD64ULE: {x86.AJLS, x86.AJHI},
+ ssa.BlockAMD64ORD: {x86.AJPC, x86.AJPS},
+ ssa.BlockAMD64NAN: {x86.AJPS, x86.AJPC},
+}
+
+type floatingEQNEJump struct {
+ jump, index int
+}
+
+var eqfJumps = [2][2]floatingEQNEJump{
+ {{x86.AJNE, 1}, {x86.AJPS, 1}}, // next == b.Succs[0]
+ {{x86.AJNE, 1}, {x86.AJPC, 0}}, // next == b.Succs[1]
+}
+var nefJumps = [2][2]floatingEQNEJump{
+ {{x86.AJNE, 0}, {x86.AJPC, 1}}, // next == b.Succs[0]
+ {{x86.AJNE, 0}, {x86.AJPS, 0}}, // next == b.Succs[1]
+}
+
+func oneFPJump(b *ssa.Block, jumps *floatingEQNEJump, likely ssa.BranchPrediction, branches []branch) []branch {
+ p := Prog(jumps.jump)
+ p.To.Type = obj.TYPE_BRANCH
+ to := jumps.index
+ branches = append(branches, branch{p, b.Succs[to]})
+ if to == 1 {
+ likely = -likely
+ }
+ // liblink reorders the instruction stream as it sees fit.
+ // Pass along what we know so liblink can make use of it.
+ // TODO: Once we've fully switched to SSA,
+ // make liblink leave our output alone.
+ switch likely {
+ case ssa.BranchUnlikely:
+ p.From.Type = obj.TYPE_CONST
+ p.From.Offset = 0
+ case ssa.BranchLikely:
+ p.From.Type = obj.TYPE_CONST
+ p.From.Offset = 1
+ }
+ return branches
+}
+
+func genFPJump(s *genState, b, next *ssa.Block, jumps *[2][2]floatingEQNEJump) {
+ likely := b.Likely
+ switch next {
+ case b.Succs[0]:
+ s.branches = oneFPJump(b, &jumps[0][0], likely, s.branches)
+ s.branches = oneFPJump(b, &jumps[0][1], likely, s.branches)
+ case b.Succs[1]:
+ s.branches = oneFPJump(b, &jumps[1][0], likely, s.branches)
+ s.branches = oneFPJump(b, &jumps[1][1], likely, s.branches)
+ default:
+ s.branches = oneFPJump(b, &jumps[1][0], likely, s.branches)
+ s.branches = oneFPJump(b, &jumps[1][1], likely, s.branches)
+ q := Prog(obj.AJMP)
+ q.To.Type = obj.TYPE_BRANCH
+ s.branches = append(s.branches, branch{q, b.Succs[1]})
+ }
+}
+
+func (s *genState) genBlock(b, next *ssa.Block) {
+ lineno = b.Line
+
+ switch b.Kind {
+ case ssa.BlockPlain, ssa.BlockCall, ssa.BlockCheck:
+ if b.Succs[0] != next {
+ p := Prog(obj.AJMP)
+ p.To.Type = obj.TYPE_BRANCH
+ s.branches = append(s.branches, branch{p, b.Succs[0]})
+ }
+ case ssa.BlockExit:
+ Prog(obj.AUNDEF) // tell plive.go that we never reach here
+ case ssa.BlockRet:
+ if hasdefer {
+ s.deferReturn()
+ }
+ Prog(obj.ARET)
+ case ssa.BlockRetJmp:
+ p := Prog(obj.AJMP)
+ p.To.Type = obj.TYPE_MEM
+ p.To.Name = obj.NAME_EXTERN
+ p.To.Sym = Linksym(b.Aux.(*Sym))
+
+ case ssa.BlockAMD64EQF:
+ genFPJump(s, b, next, &eqfJumps)
+
+ case ssa.BlockAMD64NEF:
+ genFPJump(s, b, next, &nefJumps)
+
+ case ssa.BlockAMD64EQ, ssa.BlockAMD64NE,
+ ssa.BlockAMD64LT, ssa.BlockAMD64GE,
+ ssa.BlockAMD64LE, ssa.BlockAMD64GT,
+ ssa.BlockAMD64ULT, ssa.BlockAMD64UGT,
+ ssa.BlockAMD64ULE, ssa.BlockAMD64UGE:
+ jmp := blockJump[b.Kind]
+ likely := b.Likely
+ var p *obj.Prog
+ switch next {
+ case b.Succs[0]:
+ p = Prog(jmp.invasm)
+ likely *= -1
+ p.To.Type = obj.TYPE_BRANCH
+ s.branches = append(s.branches, branch{p, b.Succs[1]})
+ case b.Succs[1]:
+ p = Prog(jmp.asm)
+ p.To.Type = obj.TYPE_BRANCH
+ s.branches = append(s.branches, branch{p, b.Succs[0]})
+ default:
+ p = Prog(jmp.asm)
+ p.To.Type = obj.TYPE_BRANCH
+ s.branches = append(s.branches, branch{p, b.Succs[0]})
+ q := Prog(obj.AJMP)
+ q.To.Type = obj.TYPE_BRANCH
+ s.branches = append(s.branches, branch{q, b.Succs[1]})
+ }
+
+ // liblink reorders the instruction stream as it sees fit.
+ // Pass along what we know so liblink can make use of it.
+ // TODO: Once we've fully switched to SSA,
+ // make liblink leave our output alone.
+ switch likely {
+ case ssa.BranchUnlikely:
+ p.From.Type = obj.TYPE_CONST
+ p.From.Offset = 0
+ case ssa.BranchLikely:
+ p.From.Type = obj.TYPE_CONST
+ p.From.Offset = 1
+ }
+
+ default:
+ b.Unimplementedf("branch not implemented: %s. Control: %s", b.LongString(), b.Control.LongString())
+ }
+}
+
+func (s *genState) deferReturn() {
+ // Deferred calls will appear to be returning to
+ // the CALL deferreturn(SB) that we are about to emit.
+ // However, the stack trace code will show the line
+ // of the instruction byte before the return PC.
+ // To avoid that being an unrelated instruction,
+ // insert an actual hardware NOP that will have the right line number.
+ // This is different from obj.ANOP, which is a virtual no-op
+ // that doesn't make it into the instruction stream.
+ s.deferTarget = Pc
+ Thearch.Ginsnop()
+ p := Prog(obj.ACALL)
+ p.To.Type = obj.TYPE_MEM
+ p.To.Name = obj.NAME_EXTERN
+ p.To.Sym = Linksym(Deferreturn.Sym)
+}
+
+// addAux adds the offset in the aux fields (AuxInt and Aux) of v to a.
+func addAux(a *obj.Addr, v *ssa.Value) {
+ addAux2(a, v, v.AuxInt)
+}
+func addAux2(a *obj.Addr, v *ssa.Value, offset int64) {
+ if a.Type != obj.TYPE_MEM {
+ v.Fatalf("bad addAux addr %s", a)
+ }
+ // add integer offset
+ a.Offset += offset
+
+ // If no additional symbol offset, we're done.
+ if v.Aux == nil {
+ return
+ }
+ // Add symbol's offset from its base register.
+ switch sym := v.Aux.(type) {
+ case *ssa.ExternSymbol:
+ a.Name = obj.NAME_EXTERN
+ a.Sym = Linksym(sym.Sym.(*Sym))
+ case *ssa.ArgSymbol:
+ n := sym.Node.(*Node)
+ a.Name = obj.NAME_PARAM
+ a.Node = n
+ a.Sym = Linksym(n.Orig.Sym)
+ a.Offset += n.Xoffset // TODO: why do I have to add this here? I don't for auto variables.
+ case *ssa.AutoSymbol:
+ n := sym.Node.(*Node)
+ a.Name = obj.NAME_AUTO
+ a.Node = n
+ a.Sym = Linksym(n.Sym)
+ default:
+ v.Fatalf("aux in %s not implemented %#v", v, v.Aux)
+ }
+}
+
+// extendIndex extends v to a full int width.
+func (s *state) extendIndex(v *ssa.Value) *ssa.Value {
+ size := v.Type.Size()
+ if size == s.config.IntSize {
+ return v
+ }
+ if size > s.config.IntSize {
+ // TODO: truncate 64-bit indexes on 32-bit pointer archs. We'd need to test
+ // the high word and branch to out-of-bounds failure if it is not 0.
+ s.Unimplementedf("64->32 index truncation not implemented")
+ return v
+ }
+
+ // Extend value to the required size
+ var op ssa.Op
+ if v.Type.IsSigned() {
+ switch 10*size + s.config.IntSize {
+ case 14:
+ op = ssa.OpSignExt8to32
+ case 18:
+ op = ssa.OpSignExt8to64
+ case 24:
+ op = ssa.OpSignExt16to32
+ case 28:
+ op = ssa.OpSignExt16to64
+ case 48:
+ op = ssa.OpSignExt32to64
+ default:
+ s.Fatalf("bad signed index extension %s", v.Type)
+ }
+ } else {
+ switch 10*size + s.config.IntSize {
+ case 14:
+ op = ssa.OpZeroExt8to32
+ case 18:
+ op = ssa.OpZeroExt8to64
+ case 24:
+ op = ssa.OpZeroExt16to32
+ case 28:
+ op = ssa.OpZeroExt16to64
+ case 48:
+ op = ssa.OpZeroExt32to64
+ default:
+ s.Fatalf("bad unsigned index extension %s", v.Type)
+ }
+ }
+ return s.newValue1(op, Types[TINT], v)
+}
+
+// ssaRegToReg maps ssa register numbers to obj register numbers.
+var ssaRegToReg = [...]int16{
+ x86.REG_AX,
+ x86.REG_CX,
+ x86.REG_DX,
+ x86.REG_BX,
+ x86.REG_SP,
+ x86.REG_BP,
+ x86.REG_SI,
+ x86.REG_DI,
+ x86.REG_R8,
+ x86.REG_R9,
+ x86.REG_R10,
+ x86.REG_R11,
+ x86.REG_R12,
+ x86.REG_R13,
+ x86.REG_R14,
+ x86.REG_R15,
+ x86.REG_X0,
+ x86.REG_X1,
+ x86.REG_X2,
+ x86.REG_X3,
+ x86.REG_X4,
+ x86.REG_X5,
+ x86.REG_X6,
+ x86.REG_X7,
+ x86.REG_X8,
+ x86.REG_X9,
+ x86.REG_X10,
+ x86.REG_X11,
+ x86.REG_X12,
+ x86.REG_X13,
+ x86.REG_X14,
+ x86.REG_X15,
+ 0, // SB isn't a real register. We fill an Addr.Reg field with 0 in this case.
+ // TODO: arch-dependent
+}
+
+// loadByType returns the load instruction of the given type.
+func loadByType(t ssa.Type) int {
+ // Avoid partial register write
+ if !t.IsFloat() && t.Size() <= 2 {
+ if t.Size() == 1 {
+ return x86.AMOVBLZX
+ } else {
+ return x86.AMOVWLZX
+ }
+ }
+ // Otherwise, there's no difference between load and store opcodes.
+ return storeByType(t)
+}
+
+// storeByType returns the store instruction of the given type.
+func storeByType(t ssa.Type) int {
+ width := t.Size()
+ if t.IsFloat() {
+ switch width {
+ case 4:
+ return x86.AMOVSS
+ case 8:
+ return x86.AMOVSD
+ }
+ } else {
+ switch width {
+ case 1:
+ return x86.AMOVB
+ case 2:
+ return x86.AMOVW
+ case 4:
+ return x86.AMOVL
+ case 8:
+ return x86.AMOVQ
+ }
+ }
+ panic("bad store type")
+}
+
+// moveByType returns the reg->reg move instruction of the given type.
+func moveByType(t ssa.Type) int {
+ if t.IsFloat() {
+ // Moving the whole sse2 register is faster
+ // than moving just the correct low portion of it.
+ // There is no xmm->xmm move with 1 byte opcode,
+ // so use movups, which has 2 byte opcode.
+ return x86.AMOVUPS
+ } else {
+ switch t.Size() {
+ case 1:
+ // Avoids partial register write
+ return x86.AMOVL
+ case 2:
+ return x86.AMOVL
+ case 4:
+ return x86.AMOVL
+ case 8:
+ return x86.AMOVQ
+ default:
+ panic("bad int register width")
+ }
+ }
+ panic("bad register type")
+}
+
+// regnum returns the register (in cmd/internal/obj numbering) to
+// which v has been allocated. Panics if v is not assigned to a
+// register.
+// TODO: Make this panic again once it stops happening routinely.
+func regnum(v *ssa.Value) int16 {
+ reg := v.Block.Func.RegAlloc[v.ID]
+ if reg == nil {
+ v.Unimplementedf("nil regnum for value: %s\n%s\n", v.LongString(), v.Block.Func)
+ return 0
+ }
+ return ssaRegToReg[reg.(*ssa.Register).Num]
+}
+
+// autoVar returns a *Node and int64 representing the auto variable and offset within it
+// where v should be spilled.
+func autoVar(v *ssa.Value) (*Node, int64) {
+ loc := v.Block.Func.RegAlloc[v.ID].(ssa.LocalSlot)
+ if v.Type.Size() > loc.Type.Size() {
+ v.Fatalf("spill/restore type %s doesn't fit in slot type %s", v.Type, loc.Type)
+ }
+ return loc.N.(*Node), loc.Off
+}
+
+// fieldIdx finds the index of the field referred to by the ODOT node n.
+func fieldIdx(n *Node) int64 {
+ t := n.Left.Type
+ f := n.Right
+ if t.Etype != TSTRUCT {
+ panic("ODOT's LHS is not a struct")
+ }
+
+ var i int64
+ for t1 := t.Type; t1 != nil; t1 = t1.Down {
+ if t1.Etype != TFIELD {
+ panic("non-TFIELD in TSTRUCT")
+ }
+ if t1.Sym != f.Sym {
+ i++
+ continue
+ }
+ if t1.Width != n.Xoffset {
+ panic("field offset doesn't match")
+ }
+ return i
+ }
+ panic(fmt.Sprintf("can't find field in expr %s\n", n))
+
+ // TODO: keep the result of this fucntion somewhere in the ODOT Node
+ // so we don't have to recompute it each time we need it.
+}
+
+// ssaExport exports a bunch of compiler services for the ssa backend.
+type ssaExport struct {
+ log bool
+ unimplemented bool
+ mustImplement bool
+}
+
+func (s *ssaExport) TypeBool() ssa.Type { return Types[TBOOL] }
+func (s *ssaExport) TypeInt8() ssa.Type { return Types[TINT8] }
+func (s *ssaExport) TypeInt16() ssa.Type { return Types[TINT16] }
+func (s *ssaExport) TypeInt32() ssa.Type { return Types[TINT32] }
+func (s *ssaExport) TypeInt64() ssa.Type { return Types[TINT64] }
+func (s *ssaExport) TypeUInt8() ssa.Type { return Types[TUINT8] }
+func (s *ssaExport) TypeUInt16() ssa.Type { return Types[TUINT16] }
+func (s *ssaExport) TypeUInt32() ssa.Type { return Types[TUINT32] }
+func (s *ssaExport) TypeUInt64() ssa.Type { return Types[TUINT64] }
+func (s *ssaExport) TypeFloat32() ssa.Type { return Types[TFLOAT32] }
+func (s *ssaExport) TypeFloat64() ssa.Type { return Types[TFLOAT64] }
+func (s *ssaExport) TypeInt() ssa.Type { return Types[TINT] }
+func (s *ssaExport) TypeUintptr() ssa.Type { return Types[TUINTPTR] }
+func (s *ssaExport) TypeString() ssa.Type { return Types[TSTRING] }
+func (s *ssaExport) TypeBytePtr() ssa.Type { return Ptrto(Types[TUINT8]) }
+
+// StringData returns a symbol (a *Sym wrapped in an interface) which
+// is the data component of a global string constant containing s.
+func (*ssaExport) StringData(s string) interface{} {
+ // TODO: is idealstring correct? It might not matter...
+ _, data := stringsym(s)
+ return &ssa.ExternSymbol{Typ: idealstring, Sym: data}
+}
+
+func (e *ssaExport) Auto(t ssa.Type) ssa.GCNode {
+ n := temp(t.(*Type)) // Note: adds new auto to Curfn.Func.Dcl list
+ e.mustImplement = true // This modifies the input to SSA, so we want to make sure we succeed from here!
+ return n
+}
+
+func (e *ssaExport) CanSSA(t ssa.Type) bool {
+ return canSSAType(t.(*Type))
+}
+
+func (e *ssaExport) Line(line int32) string {
+ return Ctxt.Line(int(line))
+}
+
+// Log logs a message from the compiler.
+func (e *ssaExport) Logf(msg string, args ...interface{}) {
+ // If e was marked as unimplemented, anything could happen. Ignore.
+ if e.log && !e.unimplemented {
+ fmt.Printf(msg, args...)
+ }
+}
+
+func (e *ssaExport) Log() bool {
+ return e.log
+}
+
+// Fatal reports a compiler error and exits.
+func (e *ssaExport) Fatalf(line int32, msg string, args ...interface{}) {
+ // If e was marked as unimplemented, anything could happen. Ignore.
+ if !e.unimplemented {
+ lineno = line
+ Fatalf(msg, args...)
+ }
+}
+
+// Unimplemented reports that the function cannot be compiled.
+// It will be removed once SSA work is complete.
+func (e *ssaExport) Unimplementedf(line int32, msg string, args ...interface{}) {
+ if e.mustImplement {
+ lineno = line
+ Fatalf(msg, args...)
+ }
+ const alwaysLog = false // enable to calculate top unimplemented features
+ if !e.unimplemented && (e.log || alwaysLog) {
+ // first implementation failure, print explanation
+ fmt.Printf("SSA unimplemented: "+msg+"\n", args...)
+ }
+ e.unimplemented = true
+}
+
+// Warnl reports a "warning", which is usually flag-triggered
+// logging output for the benefit of tests.
+func (e *ssaExport) Warnl(line int, fmt_ string, args ...interface{}) {
+ Warnl(line, fmt_, args...)
+}
+
+func (e *ssaExport) Debug_checknil() bool {
+ return Debug_checknil != 0
+}
+
+func (n *Node) Typ() ssa.Type {
+ return n.Type
+}
