cmd/compile: pull ssa OAPPEND expression handing into its own function
Pure code movement.
Change-Id: Ia07ee0b0041c931b08adf090f262a6f74a6fdb01
Reviewed-on: https://go-review.googlesource.com/21546
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
diff --git a/src/cmd/compile/internal/gc/ssa.go b/src/cmd/compile/internal/gc/ssa.go
index bfac175..359f4b2 100644
--- a/src/cmd/compile/internal/gc/ssa.go
+++ b/src/cmd/compile/internal/gc/ssa.go
@@ -2066,98 +2066,7 @@
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.Elem()
- pt := Ptrto(et)
-
- // Evaluate slice
- slice := s.expr(n.List.First())
-
- // Allocate new blocks
- grow := s.f.NewBlock(ssa.BlockPlain)
- assign := s.f.NewBlock(ssa.BlockPlain)
-
- // Decide if we need to grow
- nargs := int64(n.List.Len() - 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.SetControl(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 _, n := range n.List.Slice()[1:] {
- if canSSAType(n.Type) {
- args = append(args, s.expr(n))
- store = append(store, true)
- } else {
- args = append(args, s.addr(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, 0)
- } 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)
+ return s.exprAppend(n)
default:
s.Unimplementedf("unhandled expr %s", opnames[n.Op])
@@ -2165,6 +2074,102 @@
}
}
+// exprAppend converts an OAPPEND node n to an ssa.Value, adds it to s, and returns the Value.
+func (s *state) exprAppend(n *Node) *ssa.Value {
+ // 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.Elem()
+ pt := Ptrto(et)
+
+ // Evaluate slice
+ slice := s.expr(n.List.First())
+
+ // Allocate new blocks
+ grow := s.f.NewBlock(ssa.BlockPlain)
+ assign := s.f.NewBlock(ssa.BlockPlain)
+
+ // Decide if we need to grow
+ nargs := int64(n.List.Len() - 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.SetControl(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 _, n := range n.List.Slice()[1:] {
+ if canSSAType(n.Type) {
+ args = append(args, s.expr(n))
+ store = append(store, true)
+ } else {
+ args = append(args, s.addr(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, 0)
+ } 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)
+}
+
// 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
