| // Copyright 2011 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. |
| // |
| // The inlining facility makes 2 passes: first CanInline determines which |
| // functions are suitable for inlining, and for those that are it |
| // saves a copy of the body. Then InlineCalls walks each function body to |
| // expand calls to inlinable functions. |
| // |
| // The Debug.l flag controls the aggressiveness. Note that main() swaps level 0 and 1, |
| // making 1 the default and -l disable. Additional levels (beyond -l) may be buggy and |
| // are not supported. |
| // 0: disabled |
| // 1: 80-nodes leaf functions, oneliners, panic, lazy typechecking (default) |
| // 2: (unassigned) |
| // 3: (unassigned) |
| // 4: allow non-leaf functions |
| // |
| // At some point this may get another default and become switch-offable with -N. |
| // |
| // The -d typcheckinl flag enables early typechecking of all imported bodies, |
| // which is useful to flush out bugs. |
| // |
| // The Debug.m flag enables diagnostic output. a single -m is useful for verifying |
| // which calls get inlined or not, more is for debugging, and may go away at any point. |
| |
| package inline |
| |
| import ( |
| "fmt" |
| "go/constant" |
| "sort" |
| "strconv" |
| "strings" |
| |
| "cmd/compile/internal/base" |
| "cmd/compile/internal/ir" |
| "cmd/compile/internal/logopt" |
| "cmd/compile/internal/pgo" |
| "cmd/compile/internal/typecheck" |
| "cmd/compile/internal/types" |
| "cmd/internal/obj" |
| "cmd/internal/src" |
| ) |
| |
| // Inlining budget parameters, gathered in one place |
| const ( |
| inlineMaxBudget = 80 |
| inlineExtraAppendCost = 0 |
| // default is to inline if there's at most one call. -l=4 overrides this by using 1 instead. |
| inlineExtraCallCost = 57 // 57 was benchmarked to provided most benefit with no bad surprises; see https://github.com/golang/go/issues/19348#issuecomment-439370742 |
| inlineExtraPanicCost = 1 // do not penalize inlining panics. |
| inlineExtraThrowCost = inlineMaxBudget // with current (2018-05/1.11) code, inlining runtime.throw does not help. |
| |
| inlineBigFunctionNodes = 5000 // Functions with this many nodes are considered "big". |
| inlineBigFunctionMaxCost = 20 // Max cost of inlinee when inlining into a "big" function. |
| ) |
| |
| var ( |
| // List of all hot callee nodes. |
| // TODO(prattmic): Make this non-global. |
| candHotCalleeMap = make(map[*pgo.IRNode]struct{}) |
| |
| // List of all hot call sites. CallSiteInfo.Callee is always nil. |
| // TODO(prattmic): Make this non-global. |
| candHotEdgeMap = make(map[pgo.CallSiteInfo]struct{}) |
| |
| // List of inlined call sites. CallSiteInfo.Callee is always nil. |
| // TODO(prattmic): Make this non-global. |
| inlinedCallSites = make(map[pgo.CallSiteInfo]struct{}) |
| |
| // Threshold in percentage for hot callsite inlining. |
| inlineHotCallSiteThresholdPercent float64 |
| |
| // Threshold in CDF percentage for hot callsite inlining, |
| // that is, for a threshold of X the hottest callsites that |
| // make up the top X% of total edge weight will be |
| // considered hot for inlining candidates. |
| inlineCDFHotCallSiteThresholdPercent = float64(99) |
| |
| // Budget increased due to hotness. |
| inlineHotMaxBudget int32 = 2000 |
| ) |
| |
| // pgoInlinePrologue records the hot callsites from ir-graph. |
| func pgoInlinePrologue(p *pgo.Profile, decls []ir.Node) { |
| if base.Debug.PGOInlineCDFThreshold != "" { |
| if s, err := strconv.ParseFloat(base.Debug.PGOInlineCDFThreshold, 64); err == nil && s >= 0 && s <= 100 { |
| inlineCDFHotCallSiteThresholdPercent = s |
| } else { |
| base.Fatalf("invalid PGOInlineCDFThreshold, must be between 0 and 100") |
| } |
| } |
| var hotCallsites []pgo.NodeMapKey |
| inlineHotCallSiteThresholdPercent, hotCallsites = hotNodesFromCDF(p) |
| if base.Debug.PGOInline > 0 { |
| fmt.Printf("hot-callsite-thres-from-CDF=%v\n", inlineHotCallSiteThresholdPercent) |
| } |
| |
| if x := base.Debug.PGOInlineBudget; x != 0 { |
| inlineHotMaxBudget = int32(x) |
| } |
| |
| for _, n := range hotCallsites { |
| // mark inlineable callees from hot edges |
| if callee := p.WeightedCG.IRNodes[n.CalleeName]; callee != nil { |
| candHotCalleeMap[callee] = struct{}{} |
| } |
| // mark hot call sites |
| if caller := p.WeightedCG.IRNodes[n.CallerName]; caller != nil { |
| csi := pgo.CallSiteInfo{LineOffset: n.CallSiteOffset, Caller: caller.AST} |
| candHotEdgeMap[csi] = struct{}{} |
| } |
| } |
| |
| if base.Debug.PGOInline >= 2 { |
| fmt.Printf("hot-cg before inline in dot format:") |
| p.PrintWeightedCallGraphDOT(inlineHotCallSiteThresholdPercent) |
| } |
| } |
| |
| // hotNodesFromCDF computes an edge weight threshold and the list of hot |
| // nodes that make up the given percentage of the CDF. The threshold, as |
| // a percent, is the lower bound of weight for nodes to be considered hot |
| // (currently only used in debug prints) (in case of equal weights, |
| // comparing with the threshold may not accurately reflect which nodes are |
| // considiered hot). |
| func hotNodesFromCDF(p *pgo.Profile) (float64, []pgo.NodeMapKey) { |
| nodes := make([]pgo.NodeMapKey, len(p.NodeMap)) |
| i := 0 |
| for n := range p.NodeMap { |
| nodes[i] = n |
| i++ |
| } |
| sort.Slice(nodes, func(i, j int) bool { |
| ni, nj := nodes[i], nodes[j] |
| if wi, wj := p.NodeMap[ni].EWeight, p.NodeMap[nj].EWeight; wi != wj { |
| return wi > wj // want larger weight first |
| } |
| // same weight, order by name/line number |
| if ni.CallerName != nj.CallerName { |
| return ni.CallerName < nj.CallerName |
| } |
| if ni.CalleeName != nj.CalleeName { |
| return ni.CalleeName < nj.CalleeName |
| } |
| return ni.CallSiteOffset < nj.CallSiteOffset |
| }) |
| cum := int64(0) |
| for i, n := range nodes { |
| w := p.NodeMap[n].EWeight |
| cum += w |
| if pgo.WeightInPercentage(cum, p.TotalEdgeWeight) > inlineCDFHotCallSiteThresholdPercent { |
| // nodes[:i+1] to include the very last node that makes it to go over the threshold. |
| // (Say, if the CDF threshold is 50% and one hot node takes 60% of weight, we want to |
| // include that node instead of excluding it.) |
| return pgo.WeightInPercentage(w, p.TotalEdgeWeight), nodes[:i+1] |
| } |
| } |
| return 0, nodes |
| } |
| |
| // pgoInlineEpilogue updates IRGraph after inlining. |
| func pgoInlineEpilogue(p *pgo.Profile, decls []ir.Node) { |
| if base.Debug.PGOInline >= 2 { |
| ir.VisitFuncsBottomUp(decls, func(list []*ir.Func, recursive bool) { |
| for _, f := range list { |
| name := ir.PkgFuncName(f) |
| if n, ok := p.WeightedCG.IRNodes[name]; ok { |
| p.RedirectEdges(n, inlinedCallSites) |
| } |
| } |
| }) |
| // Print the call-graph after inlining. This is a debugging feature. |
| fmt.Printf("hot-cg after inline in dot:") |
| p.PrintWeightedCallGraphDOT(inlineHotCallSiteThresholdPercent) |
| } |
| } |
| |
| // InlinePackage finds functions that can be inlined and clones them before walk expands them. |
| func InlinePackage(p *pgo.Profile) { |
| InlineDecls(p, typecheck.Target.Decls, true) |
| } |
| |
| // InlineDecls applies inlining to the given batch of declarations. |
| func InlineDecls(p *pgo.Profile, decls []ir.Node, doInline bool) { |
| if p != nil { |
| pgoInlinePrologue(p, decls) |
| } |
| |
| ir.VisitFuncsBottomUp(decls, func(list []*ir.Func, recursive bool) { |
| numfns := numNonClosures(list) |
| for _, n := range list { |
| if !recursive || numfns > 1 { |
| // We allow inlining if there is no |
| // recursion, or the recursion cycle is |
| // across more than one function. |
| CanInline(n, p) |
| } else { |
| if base.Flag.LowerM > 1 { |
| fmt.Printf("%v: cannot inline %v: recursive\n", ir.Line(n), n.Nname) |
| } |
| } |
| if doInline { |
| InlineCalls(n, p) |
| } |
| } |
| }) |
| |
| if p != nil { |
| pgoInlineEpilogue(p, decls) |
| } |
| } |
| |
| // CanInline determines whether fn is inlineable. |
| // If so, CanInline saves copies of fn.Body and fn.Dcl in fn.Inl. |
| // fn and fn.Body will already have been typechecked. |
| func CanInline(fn *ir.Func, profile *pgo.Profile) { |
| if fn.Nname == nil { |
| base.Fatalf("CanInline no nname %+v", fn) |
| } |
| |
| var reason string // reason, if any, that the function was not inlined |
| if base.Flag.LowerM > 1 || logopt.Enabled() { |
| defer func() { |
| if reason != "" { |
| if base.Flag.LowerM > 1 { |
| fmt.Printf("%v: cannot inline %v: %s\n", ir.Line(fn), fn.Nname, reason) |
| } |
| if logopt.Enabled() { |
| logopt.LogOpt(fn.Pos(), "cannotInlineFunction", "inline", ir.FuncName(fn), reason) |
| } |
| } |
| }() |
| } |
| |
| // If marked "go:noinline", don't inline |
| if fn.Pragma&ir.Noinline != 0 { |
| reason = "marked go:noinline" |
| return |
| } |
| |
| // If marked "go:norace" and -race compilation, don't inline. |
| if base.Flag.Race && fn.Pragma&ir.Norace != 0 { |
| reason = "marked go:norace with -race compilation" |
| return |
| } |
| |
| // If marked "go:nocheckptr" and -d checkptr compilation, don't inline. |
| if base.Debug.Checkptr != 0 && fn.Pragma&ir.NoCheckPtr != 0 { |
| reason = "marked go:nocheckptr" |
| return |
| } |
| |
| // If marked "go:cgo_unsafe_args", don't inline, since the |
| // function makes assumptions about its argument frame layout. |
| if fn.Pragma&ir.CgoUnsafeArgs != 0 { |
| reason = "marked go:cgo_unsafe_args" |
| return |
| } |
| |
| // If marked as "go:uintptrkeepalive", don't inline, since the |
| // keep alive information is lost during inlining. |
| // |
| // TODO(prattmic): This is handled on calls during escape analysis, |
| // which is after inlining. Move prior to inlining so the keep-alive is |
| // maintained after inlining. |
| if fn.Pragma&ir.UintptrKeepAlive != 0 { |
| reason = "marked as having a keep-alive uintptr argument" |
| return |
| } |
| |
| // If marked as "go:uintptrescapes", don't inline, since the |
| // escape information is lost during inlining. |
| if fn.Pragma&ir.UintptrEscapes != 0 { |
| reason = "marked as having an escaping uintptr argument" |
| return |
| } |
| |
| // The nowritebarrierrec checker currently works at function |
| // granularity, so inlining yeswritebarrierrec functions can |
| // confuse it (#22342). As a workaround, disallow inlining |
| // them for now. |
| if fn.Pragma&ir.Yeswritebarrierrec != 0 { |
| reason = "marked go:yeswritebarrierrec" |
| return |
| } |
| |
| // If fn has no body (is defined outside of Go), cannot inline it. |
| if len(fn.Body) == 0 { |
| reason = "no function body" |
| return |
| } |
| |
| if fn.Typecheck() == 0 { |
| base.Fatalf("CanInline on non-typechecked function %v", fn) |
| } |
| |
| n := fn.Nname |
| if n.Func.InlinabilityChecked() { |
| return |
| } |
| defer n.Func.SetInlinabilityChecked(true) |
| |
| cc := int32(inlineExtraCallCost) |
| if base.Flag.LowerL == 4 { |
| cc = 1 // this appears to yield better performance than 0. |
| } |
| |
| // Update the budget for profile-guided inlining. |
| budget := int32(inlineMaxBudget) |
| if profile != nil { |
| if n, ok := profile.WeightedCG.IRNodes[ir.PkgFuncName(fn)]; ok { |
| if _, ok := candHotCalleeMap[n]; ok { |
| budget = int32(inlineHotMaxBudget) |
| if base.Debug.PGOInline > 0 { |
| fmt.Printf("hot-node enabled increased budget=%v for func=%v\n", budget, ir.PkgFuncName(fn)) |
| } |
| } |
| } |
| } |
| |
| // At this point in the game the function we're looking at may |
| // have "stale" autos, vars that still appear in the Dcl list, but |
| // which no longer have any uses in the function body (due to |
| // elimination by deadcode). We'd like to exclude these dead vars |
| // when creating the "Inline.Dcl" field below; to accomplish this, |
| // the hairyVisitor below builds up a map of used/referenced |
| // locals, and we use this map to produce a pruned Inline.Dcl |
| // list. See issue 25249 for more context. |
| |
| visitor := hairyVisitor{ |
| curFunc: fn, |
| budget: budget, |
| maxBudget: budget, |
| extraCallCost: cc, |
| profile: profile, |
| } |
| if visitor.tooHairy(fn) { |
| reason = visitor.reason |
| return |
| } |
| |
| n.Func.Inl = &ir.Inline{ |
| Cost: budget - visitor.budget, |
| Dcl: pruneUnusedAutos(n.Defn.(*ir.Func).Dcl, &visitor), |
| Body: inlcopylist(fn.Body), |
| |
| CanDelayResults: canDelayResults(fn), |
| } |
| |
| if base.Flag.LowerM > 1 { |
| fmt.Printf("%v: can inline %v with cost %d as: %v { %v }\n", ir.Line(fn), n, budget-visitor.budget, fn.Type(), ir.Nodes(n.Func.Inl.Body)) |
| } else if base.Flag.LowerM != 0 { |
| fmt.Printf("%v: can inline %v\n", ir.Line(fn), n) |
| } |
| if logopt.Enabled() { |
| logopt.LogOpt(fn.Pos(), "canInlineFunction", "inline", ir.FuncName(fn), fmt.Sprintf("cost: %d", budget-visitor.budget)) |
| } |
| } |
| |
| // canDelayResults reports whether inlined calls to fn can delay |
| // declaring the result parameter until the "return" statement. |
| func canDelayResults(fn *ir.Func) bool { |
| // We can delay declaring+initializing result parameters if: |
| // (1) there's exactly one "return" statement in the inlined function; |
| // (2) it's not an empty return statement (#44355); and |
| // (3) the result parameters aren't named. |
| |
| nreturns := 0 |
| ir.VisitList(fn.Body, func(n ir.Node) { |
| if n, ok := n.(*ir.ReturnStmt); ok { |
| nreturns++ |
| if len(n.Results) == 0 { |
| nreturns++ // empty return statement (case 2) |
| } |
| } |
| }) |
| |
| if nreturns != 1 { |
| return false // not exactly one return statement (case 1) |
| } |
| |
| // temporaries for return values. |
| for _, param := range fn.Type().Results().FieldSlice() { |
| if sym := types.OrigSym(param.Sym); sym != nil && !sym.IsBlank() { |
| return false // found a named result parameter (case 3) |
| } |
| } |
| |
| return true |
| } |
| |
| // hairyVisitor visits a function body to determine its inlining |
| // hairiness and whether or not it can be inlined. |
| type hairyVisitor struct { |
| // This is needed to access the current caller in the doNode function. |
| curFunc *ir.Func |
| budget int32 |
| maxBudget int32 |
| reason string |
| extraCallCost int32 |
| usedLocals ir.NameSet |
| do func(ir.Node) bool |
| profile *pgo.Profile |
| } |
| |
| func (v *hairyVisitor) tooHairy(fn *ir.Func) bool { |
| v.do = v.doNode // cache closure |
| if ir.DoChildren(fn, v.do) { |
| return true |
| } |
| if v.budget < 0 { |
| v.reason = fmt.Sprintf("function too complex: cost %d exceeds budget %d", v.maxBudget-v.budget, v.maxBudget) |
| return true |
| } |
| return false |
| } |
| |
| func (v *hairyVisitor) doNode(n ir.Node) bool { |
| if n == nil { |
| return false |
| } |
| switch n.Op() { |
| // Call is okay if inlinable and we have the budget for the body. |
| case ir.OCALLFUNC: |
| n := n.(*ir.CallExpr) |
| // Functions that call runtime.getcaller{pc,sp} can not be inlined |
| // because getcaller{pc,sp} expect a pointer to the caller's first argument. |
| // |
| // runtime.throw is a "cheap call" like panic in normal code. |
| if n.X.Op() == ir.ONAME { |
| name := n.X.(*ir.Name) |
| if name.Class == ir.PFUNC && types.IsRuntimePkg(name.Sym().Pkg) { |
| fn := name.Sym().Name |
| if fn == "getcallerpc" || fn == "getcallersp" { |
| v.reason = "call to " + fn |
| return true |
| } |
| if fn == "throw" { |
| v.budget -= inlineExtraThrowCost |
| break |
| } |
| } |
| // Special case for coverage counter updates; although |
| // these correspond to real operations, we treat them as |
| // zero cost for the moment. This is due to the existence |
| // of tests that are sensitive to inlining-- if the |
| // insertion of coverage instrumentation happens to tip a |
| // given function over the threshold and move it from |
| // "inlinable" to "not-inlinable", this can cause changes |
| // in allocation behavior, which can then result in test |
| // failures (a good example is the TestAllocations in |
| // crypto/ed25519). |
| if isAtomicCoverageCounterUpdate(n) { |
| return false |
| } |
| } |
| if n.X.Op() == ir.OMETHEXPR { |
| if meth := ir.MethodExprName(n.X); meth != nil { |
| if fn := meth.Func; fn != nil { |
| s := fn.Sym() |
| var cheap bool |
| if types.IsRuntimePkg(s.Pkg) && s.Name == "heapBits.nextArena" { |
| // Special case: explicitly allow mid-stack inlining of |
| // runtime.heapBits.next even though it calls slow-path |
| // runtime.heapBits.nextArena. |
| cheap = true |
| } |
| // Special case: on architectures that can do unaligned loads, |
| // explicitly mark encoding/binary methods as cheap, |
| // because in practice they are, even though our inlining |
| // budgeting system does not see that. See issue 42958. |
| if base.Ctxt.Arch.CanMergeLoads && s.Pkg.Path == "encoding/binary" { |
| switch s.Name { |
| case "littleEndian.Uint64", "littleEndian.Uint32", "littleEndian.Uint16", |
| "bigEndian.Uint64", "bigEndian.Uint32", "bigEndian.Uint16", |
| "littleEndian.PutUint64", "littleEndian.PutUint32", "littleEndian.PutUint16", |
| "bigEndian.PutUint64", "bigEndian.PutUint32", "bigEndian.PutUint16", |
| "littleEndian.AppendUint64", "littleEndian.AppendUint32", "littleEndian.AppendUint16", |
| "bigEndian.AppendUint64", "bigEndian.AppendUint32", "bigEndian.AppendUint16": |
| cheap = true |
| } |
| } |
| if cheap { |
| break // treat like any other node, that is, cost of 1 |
| } |
| } |
| } |
| } |
| |
| // Determine if the callee edge is for an inlinable hot callee or not. |
| if v.profile != nil && v.curFunc != nil { |
| if fn := inlCallee(n.X, v.profile); fn != nil && typecheck.HaveInlineBody(fn) { |
| lineOffset := pgo.NodeLineOffset(n, fn) |
| csi := pgo.CallSiteInfo{LineOffset: lineOffset, Caller: v.curFunc} |
| if _, o := candHotEdgeMap[csi]; o { |
| if base.Debug.PGOInline > 0 { |
| fmt.Printf("hot-callsite identified at line=%v for func=%v\n", ir.Line(n), ir.PkgFuncName(v.curFunc)) |
| } |
| } |
| } |
| } |
| |
| if ir.IsIntrinsicCall(n) { |
| // Treat like any other node. |
| break |
| } |
| |
| if fn := inlCallee(n.X, v.profile); fn != nil && typecheck.HaveInlineBody(fn) { |
| v.budget -= fn.Inl.Cost |
| break |
| } |
| |
| // Call cost for non-leaf inlining. |
| v.budget -= v.extraCallCost |
| |
| case ir.OCALLMETH: |
| base.FatalfAt(n.Pos(), "OCALLMETH missed by typecheck") |
| |
| // Things that are too hairy, irrespective of the budget |
| case ir.OCALL, ir.OCALLINTER: |
| // Call cost for non-leaf inlining. |
| v.budget -= v.extraCallCost |
| |
| case ir.OPANIC: |
| n := n.(*ir.UnaryExpr) |
| if n.X.Op() == ir.OCONVIFACE && n.X.(*ir.ConvExpr).Implicit() { |
| // Hack to keep reflect.flag.mustBe inlinable for TestIntendedInlining. |
| // Before CL 284412, these conversions were introduced later in the |
| // compiler, so they didn't count against inlining budget. |
| v.budget++ |
| } |
| v.budget -= inlineExtraPanicCost |
| |
| case ir.ORECOVER: |
| // recover matches the argument frame pointer to find |
| // the right panic value, so it needs an argument frame. |
| v.reason = "call to recover" |
| return true |
| |
| case ir.OCLOSURE: |
| if base.Debug.InlFuncsWithClosures == 0 { |
| v.reason = "not inlining functions with closures" |
| return true |
| } |
| |
| // TODO(danscales): Maybe make budget proportional to number of closure |
| // variables, e.g.: |
| //v.budget -= int32(len(n.(*ir.ClosureExpr).Func.ClosureVars) * 3) |
| v.budget -= 15 |
| // Scan body of closure (which DoChildren doesn't automatically |
| // do) to check for disallowed ops in the body and include the |
| // body in the budget. |
| if doList(n.(*ir.ClosureExpr).Func.Body, v.do) { |
| return true |
| } |
| |
| case ir.OGO, |
| ir.ODEFER, |
| ir.ODCLTYPE, // can't print yet |
| ir.OTAILCALL: |
| v.reason = "unhandled op " + n.Op().String() |
| return true |
| |
| case ir.OAPPEND: |
| v.budget -= inlineExtraAppendCost |
| |
| case ir.OADDR: |
| n := n.(*ir.AddrExpr) |
| // Make "&s.f" cost 0 when f's offset is zero. |
| if dot, ok := n.X.(*ir.SelectorExpr); ok && (dot.Op() == ir.ODOT || dot.Op() == ir.ODOTPTR) { |
| if _, ok := dot.X.(*ir.Name); ok && dot.Selection.Offset == 0 { |
| v.budget += 2 // undo ir.OADDR+ir.ODOT/ir.ODOTPTR |
| } |
| } |
| |
| case ir.ODEREF: |
| // *(*X)(unsafe.Pointer(&x)) is low-cost |
| n := n.(*ir.StarExpr) |
| |
| ptr := n.X |
| for ptr.Op() == ir.OCONVNOP { |
| ptr = ptr.(*ir.ConvExpr).X |
| } |
| if ptr.Op() == ir.OADDR { |
| v.budget += 1 // undo half of default cost of ir.ODEREF+ir.OADDR |
| } |
| |
| case ir.OCONVNOP: |
| // This doesn't produce code, but the children might. |
| v.budget++ // undo default cost |
| |
| case ir.ODCLCONST, ir.OFALL: |
| // These nodes don't produce code; omit from inlining budget. |
| return false |
| |
| case ir.OIF: |
| n := n.(*ir.IfStmt) |
| if ir.IsConst(n.Cond, constant.Bool) { |
| // This if and the condition cost nothing. |
| if doList(n.Init(), v.do) { |
| return true |
| } |
| if ir.BoolVal(n.Cond) { |
| return doList(n.Body, v.do) |
| } else { |
| return doList(n.Else, v.do) |
| } |
| } |
| |
| case ir.ONAME: |
| n := n.(*ir.Name) |
| if n.Class == ir.PAUTO { |
| v.usedLocals.Add(n) |
| } |
| |
| case ir.OBLOCK: |
| // The only OBLOCK we should see at this point is an empty one. |
| // In any event, let the visitList(n.List()) below take care of the statements, |
| // and don't charge for the OBLOCK itself. The ++ undoes the -- below. |
| v.budget++ |
| |
| case ir.OMETHVALUE, ir.OSLICELIT: |
| v.budget-- // Hack for toolstash -cmp. |
| |
| case ir.OMETHEXPR: |
| v.budget++ // Hack for toolstash -cmp. |
| |
| case ir.OAS2: |
| n := n.(*ir.AssignListStmt) |
| |
| // Unified IR unconditionally rewrites: |
| // |
| // a, b = f() |
| // |
| // into: |
| // |
| // DCL tmp1 |
| // DCL tmp2 |
| // tmp1, tmp2 = f() |
| // a, b = tmp1, tmp2 |
| // |
| // so that it can insert implicit conversions as necessary. To |
| // minimize impact to the existing inlining heuristics (in |
| // particular, to avoid breaking the existing inlinability regress |
| // tests), we need to compensate for this here. |
| if base.Debug.Unified != 0 { |
| if init := n.Rhs[0].Init(); len(init) == 1 { |
| if _, ok := init[0].(*ir.AssignListStmt); ok { |
| // 4 for each value, because each temporary variable now |
| // appears 3 times (DCL, LHS, RHS), plus an extra DCL node. |
| // |
| // 1 for the extra "tmp1, tmp2 = f()" assignment statement. |
| v.budget += 4*int32(len(n.Lhs)) + 1 |
| } |
| } |
| } |
| |
| case ir.OAS: |
| // Special case for coverage counter updates and coverage |
| // function registrations. Although these correspond to real |
| // operations, we treat them as zero cost for the moment. This |
| // is primarily due to the existence of tests that are |
| // sensitive to inlining-- if the insertion of coverage |
| // instrumentation happens to tip a given function over the |
| // threshold and move it from "inlinable" to "not-inlinable", |
| // this can cause changes in allocation behavior, which can |
| // then result in test failures (a good example is the |
| // TestAllocations in crypto/ed25519). |
| n := n.(*ir.AssignStmt) |
| if n.X.Op() == ir.OINDEX && isIndexingCoverageCounter(n.X) { |
| return false |
| } |
| } |
| |
| v.budget-- |
| |
| // When debugging, don't stop early, to get full cost of inlining this function |
| if v.budget < 0 && base.Flag.LowerM < 2 && !logopt.Enabled() { |
| v.reason = "too expensive" |
| return true |
| } |
| |
| return ir.DoChildren(n, v.do) |
| } |
| |
| func isBigFunc(fn *ir.Func) bool { |
| budget := inlineBigFunctionNodes |
| return ir.Any(fn, func(n ir.Node) bool { |
| budget-- |
| return budget <= 0 |
| }) |
| } |
| |
| // inlcopylist (together with inlcopy) recursively copies a list of nodes, except |
| // that it keeps the same ONAME, OTYPE, and OLITERAL nodes. It is used for copying |
| // the body and dcls of an inlineable function. |
| func inlcopylist(ll []ir.Node) []ir.Node { |
| s := make([]ir.Node, len(ll)) |
| for i, n := range ll { |
| s[i] = inlcopy(n) |
| } |
| return s |
| } |
| |
| // inlcopy is like DeepCopy(), but does extra work to copy closures. |
| func inlcopy(n ir.Node) ir.Node { |
| var edit func(ir.Node) ir.Node |
| edit = func(x ir.Node) ir.Node { |
| switch x.Op() { |
| case ir.ONAME, ir.OTYPE, ir.OLITERAL, ir.ONIL: |
| return x |
| } |
| m := ir.Copy(x) |
| ir.EditChildren(m, edit) |
| if x.Op() == ir.OCLOSURE { |
| x := x.(*ir.ClosureExpr) |
| // Need to save/duplicate x.Func.Nname, |
| // x.Func.Nname.Ntype, x.Func.Dcl, x.Func.ClosureVars, and |
| // x.Func.Body for iexport and local inlining. |
| oldfn := x.Func |
| newfn := ir.NewFunc(oldfn.Pos()) |
| m.(*ir.ClosureExpr).Func = newfn |
| newfn.Nname = ir.NewNameAt(oldfn.Nname.Pos(), oldfn.Nname.Sym()) |
| // XXX OK to share fn.Type() ?? |
| newfn.Nname.SetType(oldfn.Nname.Type()) |
| newfn.Body = inlcopylist(oldfn.Body) |
| // Make shallow copy of the Dcl and ClosureVar slices |
| newfn.Dcl = append([]*ir.Name(nil), oldfn.Dcl...) |
| newfn.ClosureVars = append([]*ir.Name(nil), oldfn.ClosureVars...) |
| } |
| return m |
| } |
| return edit(n) |
| } |
| |
| // InlineCalls/inlnode walks fn's statements and expressions and substitutes any |
| // calls made to inlineable functions. This is the external entry point. |
| func InlineCalls(fn *ir.Func, profile *pgo.Profile) { |
| savefn := ir.CurFunc |
| ir.CurFunc = fn |
| maxCost := int32(inlineMaxBudget) |
| if isBigFunc(fn) { |
| maxCost = inlineBigFunctionMaxCost |
| } |
| var inlCalls []*ir.InlinedCallExpr |
| var edit func(ir.Node) ir.Node |
| edit = func(n ir.Node) ir.Node { |
| return inlnode(n, maxCost, &inlCalls, edit, profile) |
| } |
| ir.EditChildren(fn, edit) |
| |
| // If we inlined any calls, we want to recursively visit their |
| // bodies for further inlining. However, we need to wait until |
| // *after* the original function body has been expanded, or else |
| // inlCallee can have false positives (e.g., #54632). |
| for len(inlCalls) > 0 { |
| call := inlCalls[0] |
| inlCalls = inlCalls[1:] |
| ir.EditChildren(call, edit) |
| } |
| |
| ir.CurFunc = savefn |
| } |
| |
| // inlnode recurses over the tree to find inlineable calls, which will |
| // be turned into OINLCALLs by mkinlcall. When the recursion comes |
| // back up will examine left, right, list, rlist, ninit, ntest, nincr, |
| // nbody and nelse and use one of the 4 inlconv/glue functions above |
| // to turn the OINLCALL into an expression, a statement, or patch it |
| // in to this nodes list or rlist as appropriate. |
| // NOTE it makes no sense to pass the glue functions down the |
| // recursion to the level where the OINLCALL gets created because they |
| // have to edit /this/ n, so you'd have to push that one down as well, |
| // but then you may as well do it here. so this is cleaner and |
| // shorter and less complicated. |
| // The result of inlnode MUST be assigned back to n, e.g. |
| // |
| // n.Left = inlnode(n.Left) |
| func inlnode(n ir.Node, maxCost int32, inlCalls *[]*ir.InlinedCallExpr, edit func(ir.Node) ir.Node, profile *pgo.Profile) ir.Node { |
| if n == nil { |
| return n |
| } |
| |
| switch n.Op() { |
| case ir.ODEFER, ir.OGO: |
| n := n.(*ir.GoDeferStmt) |
| switch call := n.Call; call.Op() { |
| case ir.OCALLMETH: |
| base.FatalfAt(call.Pos(), "OCALLMETH missed by typecheck") |
| case ir.OCALLFUNC: |
| call := call.(*ir.CallExpr) |
| call.NoInline = true |
| } |
| case ir.OTAILCALL: |
| n := n.(*ir.TailCallStmt) |
| n.Call.NoInline = true // Not inline a tail call for now. Maybe we could inline it just like RETURN fn(arg)? |
| |
| // TODO do them here (or earlier), |
| // so escape analysis can avoid more heapmoves. |
| case ir.OCLOSURE: |
| return n |
| case ir.OCALLMETH: |
| base.FatalfAt(n.Pos(), "OCALLMETH missed by typecheck") |
| case ir.OCALLFUNC: |
| n := n.(*ir.CallExpr) |
| if n.X.Op() == ir.OMETHEXPR { |
| // Prevent inlining some reflect.Value methods when using checkptr, |
| // even when package reflect was compiled without it (#35073). |
| if meth := ir.MethodExprName(n.X); meth != nil { |
| s := meth.Sym() |
| if base.Debug.Checkptr != 0 && types.IsReflectPkg(s.Pkg) && (s.Name == "Value.UnsafeAddr" || s.Name == "Value.Pointer") { |
| return n |
| } |
| } |
| } |
| } |
| |
| lno := ir.SetPos(n) |
| |
| ir.EditChildren(n, edit) |
| |
| // with all the branches out of the way, it is now time to |
| // transmogrify this node itself unless inhibited by the |
| // switch at the top of this function. |
| switch n.Op() { |
| case ir.OCALLMETH: |
| base.FatalfAt(n.Pos(), "OCALLMETH missed by typecheck") |
| |
| case ir.OCALLFUNC: |
| call := n.(*ir.CallExpr) |
| if call.NoInline { |
| break |
| } |
| if base.Flag.LowerM > 3 { |
| fmt.Printf("%v:call to func %+v\n", ir.Line(n), call.X) |
| } |
| if ir.IsIntrinsicCall(call) { |
| break |
| } |
| if fn := inlCallee(call.X, profile); fn != nil && typecheck.HaveInlineBody(fn) { |
| n = mkinlcall(call, fn, maxCost, inlCalls, edit) |
| } |
| } |
| |
| base.Pos = lno |
| |
| return n |
| } |
| |
| // inlCallee takes a function-typed expression and returns the underlying function ONAME |
| // that it refers to if statically known. Otherwise, it returns nil. |
| func inlCallee(fn ir.Node, profile *pgo.Profile) *ir.Func { |
| fn = ir.StaticValue(fn) |
| switch fn.Op() { |
| case ir.OMETHEXPR: |
| fn := fn.(*ir.SelectorExpr) |
| n := ir.MethodExprName(fn) |
| // Check that receiver type matches fn.X. |
| // TODO(mdempsky): Handle implicit dereference |
| // of pointer receiver argument? |
| if n == nil || !types.Identical(n.Type().Recv().Type, fn.X.Type()) { |
| return nil |
| } |
| return n.Func |
| case ir.ONAME: |
| fn := fn.(*ir.Name) |
| if fn.Class == ir.PFUNC { |
| return fn.Func |
| } |
| case ir.OCLOSURE: |
| fn := fn.(*ir.ClosureExpr) |
| c := fn.Func |
| CanInline(c, profile) |
| return c |
| } |
| return nil |
| } |
| |
| func inlParam(t *types.Field, as ir.InitNode, inlvars map[*ir.Name]*ir.Name) ir.Node { |
| if t.Nname == nil { |
| return ir.BlankNode |
| } |
| n := t.Nname.(*ir.Name) |
| if ir.IsBlank(n) { |
| return ir.BlankNode |
| } |
| inlvar := inlvars[n] |
| if inlvar == nil { |
| base.Fatalf("missing inlvar for %v", n) |
| } |
| as.PtrInit().Append(ir.NewDecl(base.Pos, ir.ODCL, inlvar)) |
| inlvar.Name().Defn = as |
| return inlvar |
| } |
| |
| var inlgen int |
| |
| // SSADumpInline gives the SSA back end a chance to dump the function |
| // when producing output for debugging the compiler itself. |
| var SSADumpInline = func(*ir.Func) {} |
| |
| // InlineCall allows the inliner implementation to be overridden. |
| // If it returns nil, the function will not be inlined. |
| var InlineCall = oldInlineCall |
| |
| // If n is a OCALLFUNC node, and fn is an ONAME node for a |
| // function with an inlinable body, return an OINLCALL node that can replace n. |
| // The returned node's Ninit has the parameter assignments, the Nbody is the |
| // inlined function body, and (List, Rlist) contain the (input, output) |
| // parameters. |
| // The result of mkinlcall MUST be assigned back to n, e.g. |
| // |
| // n.Left = mkinlcall(n.Left, fn, isddd) |
| func mkinlcall(n *ir.CallExpr, fn *ir.Func, maxCost int32, inlCalls *[]*ir.InlinedCallExpr, edit func(ir.Node) ir.Node) ir.Node { |
| if fn.Inl == nil { |
| if logopt.Enabled() { |
| logopt.LogOpt(n.Pos(), "cannotInlineCall", "inline", ir.FuncName(ir.CurFunc), |
| fmt.Sprintf("%s cannot be inlined", ir.PkgFuncName(fn))) |
| } |
| return n |
| } |
| if fn.Inl.Cost > maxCost { |
| // If the callsite is hot and it is under the inlineHotMaxBudget budget, then try to inline it, or else bail. |
| lineOffset := pgo.NodeLineOffset(n, ir.CurFunc) |
| csi := pgo.CallSiteInfo{LineOffset: lineOffset, Caller: ir.CurFunc} |
| if _, ok := candHotEdgeMap[csi]; ok { |
| if fn.Inl.Cost > inlineHotMaxBudget { |
| if logopt.Enabled() { |
| logopt.LogOpt(n.Pos(), "cannotInlineCall", "inline", ir.FuncName(ir.CurFunc), |
| fmt.Sprintf("cost %d of %s exceeds max large caller cost %d", fn.Inl.Cost, ir.PkgFuncName(fn), inlineHotMaxBudget)) |
| } |
| return n |
| } |
| if base.Debug.PGOInline > 0 { |
| fmt.Printf("hot-budget check allows inlining for call %s at %v\n", ir.PkgFuncName(fn), ir.Line(n)) |
| } |
| } else { |
| // The inlined function body is too big. Typically we use this check to restrict |
| // inlining into very big functions. See issue 26546 and 17566. |
| if logopt.Enabled() { |
| logopt.LogOpt(n.Pos(), "cannotInlineCall", "inline", ir.FuncName(ir.CurFunc), |
| fmt.Sprintf("cost %d of %s exceeds max large caller cost %d", fn.Inl.Cost, ir.PkgFuncName(fn), maxCost)) |
| } |
| return n |
| } |
| } |
| |
| if fn == ir.CurFunc { |
| // Can't recursively inline a function into itself. |
| if logopt.Enabled() { |
| logopt.LogOpt(n.Pos(), "cannotInlineCall", "inline", fmt.Sprintf("recursive call to %s", ir.FuncName(ir.CurFunc))) |
| } |
| return n |
| } |
| |
| // The non-unified frontend has issues with inlining and shape parameters. |
| if base.Debug.Unified == 0 { |
| // Don't inline a function fn that has no shape parameters, but is passed at |
| // least one shape arg. This means we must be inlining a non-generic function |
| // fn that was passed into a generic function, and can be called with a shape |
| // arg because it matches an appropriate type parameters. But fn may include |
| // an interface conversion (that may be applied to a shape arg) that was not |
| // apparent when we first created the instantiation of the generic function. |
| // We can't handle this if we actually do the inlining, since we want to know |
| // all interface conversions immediately after stenciling. So, we avoid |
| // inlining in this case, see issue #49309. (1) |
| // |
| // See discussion on go.dev/cl/406475 for more background. |
| if !fn.Type().Params().HasShape() { |
| for _, arg := range n.Args { |
| if arg.Type().HasShape() { |
| if logopt.Enabled() { |
| logopt.LogOpt(n.Pos(), "cannotInlineCall", "inline", ir.FuncName(ir.CurFunc), |
| fmt.Sprintf("inlining function %v has no-shape params with shape args", ir.FuncName(fn))) |
| } |
| return n |
| } |
| } |
| } else { |
| // Don't inline a function fn that has shape parameters, but is passed no shape arg. |
| // See comments (1) above, and issue #51909. |
| inlineable := len(n.Args) == 0 // Function has shape in type, with no arguments can always be inlined. |
| for _, arg := range n.Args { |
| if arg.Type().HasShape() { |
| inlineable = true |
| break |
| } |
| } |
| if !inlineable { |
| if logopt.Enabled() { |
| logopt.LogOpt(n.Pos(), "cannotInlineCall", "inline", ir.FuncName(ir.CurFunc), |
| fmt.Sprintf("inlining function %v has shape params with no-shape args", ir.FuncName(fn))) |
| } |
| return n |
| } |
| } |
| } |
| |
| if base.Flag.Cfg.Instrumenting && types.IsRuntimePkg(fn.Sym().Pkg) { |
| // Runtime package must not be instrumented. |
| // Instrument skips runtime package. However, some runtime code can be |
| // inlined into other packages and instrumented there. To avoid this, |
| // we disable inlining of runtime functions when instrumenting. |
| // The example that we observed is inlining of LockOSThread, |
| // which lead to false race reports on m contents. |
| return n |
| } |
| |
| parent := base.Ctxt.PosTable.Pos(n.Pos()).Base().InliningIndex() |
| sym := fn.Linksym() |
| |
| // Check if we've already inlined this function at this particular |
| // call site, in order to stop inlining when we reach the beginning |
| // of a recursion cycle again. We don't inline immediately recursive |
| // functions, but allow inlining if there is a recursion cycle of |
| // many functions. Most likely, the inlining will stop before we |
| // even hit the beginning of the cycle again, but this catches the |
| // unusual case. |
| for inlIndex := parent; inlIndex >= 0; inlIndex = base.Ctxt.InlTree.Parent(inlIndex) { |
| if base.Ctxt.InlTree.InlinedFunction(inlIndex) == sym { |
| if base.Flag.LowerM > 1 { |
| fmt.Printf("%v: cannot inline %v into %v: repeated recursive cycle\n", ir.Line(n), fn, ir.FuncName(ir.CurFunc)) |
| } |
| return n |
| } |
| } |
| |
| typecheck.FixVariadicCall(n) |
| |
| inlIndex := base.Ctxt.InlTree.Add(parent, n.Pos(), sym) |
| |
| closureInitLSym := func(n *ir.CallExpr, fn *ir.Func) { |
| // The linker needs FuncInfo metadata for all inlined |
| // functions. This is typically handled by gc.enqueueFunc |
| // calling ir.InitLSym for all function declarations in |
| // typecheck.Target.Decls (ir.UseClosure adds all closures to |
| // Decls). |
| // |
| // However, non-trivial closures in Decls are ignored, and are |
| // insteaded enqueued when walk of the calling function |
| // discovers them. |
| // |
| // This presents a problem for direct calls to closures. |
| // Inlining will replace the entire closure definition with its |
| // body, which hides the closure from walk and thus suppresses |
| // symbol creation. |
| // |
| // Explicitly create a symbol early in this edge case to ensure |
| // we keep this metadata. |
| // |
| // TODO: Refactor to keep a reference so this can all be done |
| // by enqueueFunc. |
| |
| if n.Op() != ir.OCALLFUNC { |
| // Not a standard call. |
| return |
| } |
| if n.X.Op() != ir.OCLOSURE { |
| // Not a direct closure call. |
| return |
| } |
| |
| clo := n.X.(*ir.ClosureExpr) |
| if ir.IsTrivialClosure(clo) { |
| // enqueueFunc will handle trivial closures anyways. |
| return |
| } |
| |
| ir.InitLSym(fn, true) |
| } |
| |
| closureInitLSym(n, fn) |
| |
| if base.Flag.GenDwarfInl > 0 { |
| if !sym.WasInlined() { |
| base.Ctxt.DwFixups.SetPrecursorFunc(sym, fn) |
| sym.Set(obj.AttrWasInlined, true) |
| } |
| } |
| |
| if base.Flag.LowerM != 0 { |
| fmt.Printf("%v: inlining call to %v\n", ir.Line(n), fn) |
| } |
| if base.Flag.LowerM > 2 { |
| fmt.Printf("%v: Before inlining: %+v\n", ir.Line(n), n) |
| } |
| |
| if base.Debug.PGOInline > 0 { |
| csi := pgo.CallSiteInfo{LineOffset: pgo.NodeLineOffset(n, fn), Caller: ir.CurFunc} |
| if _, ok := inlinedCallSites[csi]; !ok { |
| inlinedCallSites[csi] = struct{}{} |
| } |
| } |
| |
| res := InlineCall(n, fn, inlIndex) |
| |
| if res == nil { |
| base.FatalfAt(n.Pos(), "inlining call to %v failed", fn) |
| } |
| |
| if base.Flag.LowerM > 2 { |
| fmt.Printf("%v: After inlining %+v\n\n", ir.Line(res), res) |
| } |
| |
| *inlCalls = append(*inlCalls, res) |
| |
| return res |
| } |
| |
| // CalleeEffects appends any side effects from evaluating callee to init. |
| func CalleeEffects(init *ir.Nodes, callee ir.Node) { |
| for { |
| init.Append(ir.TakeInit(callee)...) |
| |
| switch callee.Op() { |
| case ir.ONAME, ir.OCLOSURE, ir.OMETHEXPR: |
| return // done |
| |
| case ir.OCONVNOP: |
| conv := callee.(*ir.ConvExpr) |
| callee = conv.X |
| |
| case ir.OINLCALL: |
| ic := callee.(*ir.InlinedCallExpr) |
| init.Append(ic.Body.Take()...) |
| callee = ic.SingleResult() |
| |
| default: |
| base.FatalfAt(callee.Pos(), "unexpected callee expression: %v", callee) |
| } |
| } |
| } |
| |
| // oldInlineCall creates an InlinedCallExpr to replace the given call |
| // expression. fn is the callee function to be inlined. inlIndex is |
| // the inlining tree position index, for use with src.NewInliningBase |
| // when rewriting positions. |
| func oldInlineCall(call *ir.CallExpr, fn *ir.Func, inlIndex int) *ir.InlinedCallExpr { |
| if base.Debug.TypecheckInl == 0 { |
| typecheck.ImportedBody(fn) |
| } |
| |
| SSADumpInline(fn) |
| |
| ninit := call.Init() |
| |
| // For normal function calls, the function callee expression |
| // may contain side effects. Make sure to preserve these, |
| // if necessary (#42703). |
| if call.Op() == ir.OCALLFUNC { |
| CalleeEffects(&ninit, call.X) |
| } |
| |
| // Make temp names to use instead of the originals. |
| inlvars := make(map[*ir.Name]*ir.Name) |
| |
| // record formals/locals for later post-processing |
| var inlfvars []*ir.Name |
| |
| for _, ln := range fn.Inl.Dcl { |
| if ln.Op() != ir.ONAME { |
| continue |
| } |
| if ln.Class == ir.PPARAMOUT { // return values handled below. |
| continue |
| } |
| inlf := typecheck.Expr(inlvar(ln)).(*ir.Name) |
| inlvars[ln] = inlf |
| if base.Flag.GenDwarfInl > 0 { |
| if ln.Class == ir.PPARAM { |
| inlf.Name().SetInlFormal(true) |
| } else { |
| inlf.Name().SetInlLocal(true) |
| } |
| inlf.SetPos(ln.Pos()) |
| inlfvars = append(inlfvars, inlf) |
| } |
| } |
| |
| // We can delay declaring+initializing result parameters if: |
| // temporaries for return values. |
| var retvars []ir.Node |
| for i, t := range fn.Type().Results().Fields().Slice() { |
| var m *ir.Name |
| if nn := t.Nname; nn != nil && !ir.IsBlank(nn.(*ir.Name)) && !strings.HasPrefix(nn.Sym().Name, "~r") { |
| n := nn.(*ir.Name) |
| m = inlvar(n) |
| m = typecheck.Expr(m).(*ir.Name) |
| inlvars[n] = m |
| } else { |
| // anonymous return values, synthesize names for use in assignment that replaces return |
| m = retvar(t, i) |
| } |
| |
| if base.Flag.GenDwarfInl > 0 { |
| // Don't update the src.Pos on a return variable if it |
| // was manufactured by the inliner (e.g. "~R2"); such vars |
| // were not part of the original callee. |
| if !strings.HasPrefix(m.Sym().Name, "~R") { |
| m.Name().SetInlFormal(true) |
| m.SetPos(t.Pos) |
| inlfvars = append(inlfvars, m) |
| } |
| } |
| |
| retvars = append(retvars, m) |
| } |
| |
| // Assign arguments to the parameters' temp names. |
| as := ir.NewAssignListStmt(base.Pos, ir.OAS2, nil, nil) |
| as.Def = true |
| if call.Op() == ir.OCALLMETH { |
| base.FatalfAt(call.Pos(), "OCALLMETH missed by typecheck") |
| } |
| as.Rhs.Append(call.Args...) |
| |
| if recv := fn.Type().Recv(); recv != nil { |
| as.Lhs.Append(inlParam(recv, as, inlvars)) |
| } |
| for _, param := range fn.Type().Params().Fields().Slice() { |
| as.Lhs.Append(inlParam(param, as, inlvars)) |
| } |
| |
| if len(as.Rhs) != 0 { |
| ninit.Append(typecheck.Stmt(as)) |
| } |
| |
| if !fn.Inl.CanDelayResults { |
| // Zero the return parameters. |
| for _, n := range retvars { |
| ninit.Append(ir.NewDecl(base.Pos, ir.ODCL, n.(*ir.Name))) |
| ras := ir.NewAssignStmt(base.Pos, n, nil) |
| ninit.Append(typecheck.Stmt(ras)) |
| } |
| } |
| |
| retlabel := typecheck.AutoLabel(".i") |
| |
| inlgen++ |
| |
| // Add an inline mark just before the inlined body. |
| // This mark is inline in the code so that it's a reasonable spot |
| // to put a breakpoint. Not sure if that's really necessary or not |
| // (in which case it could go at the end of the function instead). |
| // Note issue 28603. |
| ninit.Append(ir.NewInlineMarkStmt(call.Pos().WithIsStmt(), int64(inlIndex))) |
| |
| subst := inlsubst{ |
| retlabel: retlabel, |
| retvars: retvars, |
| inlvars: inlvars, |
| defnMarker: ir.NilExpr{}, |
| bases: make(map[*src.PosBase]*src.PosBase), |
| newInlIndex: inlIndex, |
| fn: fn, |
| } |
| subst.edit = subst.node |
| |
| body := subst.list(ir.Nodes(fn.Inl.Body)) |
| |
| lab := ir.NewLabelStmt(base.Pos, retlabel) |
| body = append(body, lab) |
| |
| if base.Flag.GenDwarfInl > 0 { |
| for _, v := range inlfvars { |
| v.SetPos(subst.updatedPos(v.Pos())) |
| } |
| } |
| |
| //dumplist("ninit post", ninit); |
| |
| res := ir.NewInlinedCallExpr(base.Pos, body, retvars) |
| res.SetInit(ninit) |
| res.SetType(call.Type()) |
| res.SetTypecheck(1) |
| return res |
| } |
| |
| // Every time we expand a function we generate a new set of tmpnames, |
| // PAUTO's in the calling functions, and link them off of the |
| // PPARAM's, PAUTOS and PPARAMOUTs of the called function. |
| func inlvar(var_ *ir.Name) *ir.Name { |
| if base.Flag.LowerM > 3 { |
| fmt.Printf("inlvar %+v\n", var_) |
| } |
| |
| n := typecheck.NewName(var_.Sym()) |
| n.SetType(var_.Type()) |
| n.SetTypecheck(1) |
| n.Class = ir.PAUTO |
| n.SetUsed(true) |
| n.SetAutoTemp(var_.AutoTemp()) |
| n.Curfn = ir.CurFunc // the calling function, not the called one |
| n.SetAddrtaken(var_.Addrtaken()) |
| |
| ir.CurFunc.Dcl = append(ir.CurFunc.Dcl, n) |
| return n |
| } |
| |
| // Synthesize a variable to store the inlined function's results in. |
| func retvar(t *types.Field, i int) *ir.Name { |
| n := typecheck.NewName(typecheck.LookupNum("~R", i)) |
| n.SetType(t.Type) |
| n.SetTypecheck(1) |
| n.Class = ir.PAUTO |
| n.SetUsed(true) |
| n.Curfn = ir.CurFunc // the calling function, not the called one |
| ir.CurFunc.Dcl = append(ir.CurFunc.Dcl, n) |
| return n |
| } |
| |
| // The inlsubst type implements the actual inlining of a single |
| // function call. |
| type inlsubst struct { |
| // Target of the goto substituted in place of a return. |
| retlabel *types.Sym |
| |
| // Temporary result variables. |
| retvars []ir.Node |
| |
| inlvars map[*ir.Name]*ir.Name |
| // defnMarker is used to mark a Node for reassignment. |
| // inlsubst.clovar set this during creating new ONAME. |
| // inlsubst.node will set the correct Defn for inlvar. |
| defnMarker ir.NilExpr |
| |
| // bases maps from original PosBase to PosBase with an extra |
| // inlined call frame. |
| bases map[*src.PosBase]*src.PosBase |
| |
| // newInlIndex is the index of the inlined call frame to |
| // insert for inlined nodes. |
| newInlIndex int |
| |
| edit func(ir.Node) ir.Node // cached copy of subst.node method value closure |
| |
| // If non-nil, we are inside a closure inside the inlined function, and |
| // newclofn is the Func of the new inlined closure. |
| newclofn *ir.Func |
| |
| fn *ir.Func // For debug -- the func that is being inlined |
| |
| // If true, then don't update source positions during substitution |
| // (retain old source positions). |
| noPosUpdate bool |
| } |
| |
| // list inlines a list of nodes. |
| func (subst *inlsubst) list(ll ir.Nodes) []ir.Node { |
| s := make([]ir.Node, 0, len(ll)) |
| for _, n := range ll { |
| s = append(s, subst.node(n)) |
| } |
| return s |
| } |
| |
| // fields returns a list of the fields of a struct type representing receiver, |
| // params, or results, after duplicating the field nodes and substituting the |
| // Nname nodes inside the field nodes. |
| func (subst *inlsubst) fields(oldt *types.Type) []*types.Field { |
| oldfields := oldt.FieldSlice() |
| newfields := make([]*types.Field, len(oldfields)) |
| for i := range oldfields { |
| newfields[i] = oldfields[i].Copy() |
| if oldfields[i].Nname != nil { |
| newfields[i].Nname = subst.node(oldfields[i].Nname.(*ir.Name)) |
| } |
| } |
| return newfields |
| } |
| |
| // clovar creates a new ONAME node for a local variable or param of a closure |
| // inside a function being inlined. |
| func (subst *inlsubst) clovar(n *ir.Name) *ir.Name { |
| m := ir.NewNameAt(n.Pos(), n.Sym()) |
| m.Class = n.Class |
| m.SetType(n.Type()) |
| m.SetTypecheck(1) |
| if n.IsClosureVar() { |
| m.SetIsClosureVar(true) |
| } |
| if n.Addrtaken() { |
| m.SetAddrtaken(true) |
| } |
| if n.Used() { |
| m.SetUsed(true) |
| } |
| m.Defn = n.Defn |
| |
| m.Curfn = subst.newclofn |
| |
| switch defn := n.Defn.(type) { |
| case nil: |
| // ok |
| case *ir.Name: |
| if !n.IsClosureVar() { |
| base.FatalfAt(n.Pos(), "want closure variable, got: %+v", n) |
| } |
| if n.Sym().Pkg != types.LocalPkg { |
| // If the closure came from inlining a function from |
| // another package, must change package of captured |
| // variable to localpkg, so that the fields of the closure |
| // struct are local package and can be accessed even if |
| // name is not exported. If you disable this code, you can |
| // reproduce the problem by running 'go test |
| // go/internal/srcimporter'. TODO(mdempsky) - maybe change |
| // how we create closure structs? |
| m.SetSym(types.LocalPkg.Lookup(n.Sym().Name)) |
| } |
| // Make sure any inlvar which is the Defn |
| // of an ONAME closure var is rewritten |
| // during inlining. Don't substitute |
| // if Defn node is outside inlined function. |
| if subst.inlvars[n.Defn.(*ir.Name)] != nil { |
| m.Defn = subst.node(n.Defn) |
| } |
| case *ir.AssignStmt, *ir.AssignListStmt: |
| // Mark node for reassignment at the end of inlsubst.node. |
| m.Defn = &subst.defnMarker |
| case *ir.TypeSwitchGuard: |
| // TODO(mdempsky): Set m.Defn properly. See discussion on #45743. |
| case *ir.RangeStmt: |
| // TODO: Set m.Defn properly if we support inlining range statement in the future. |
| default: |
| base.FatalfAt(n.Pos(), "unexpected Defn: %+v", defn) |
| } |
| |
| if n.Outer != nil { |
| // Either the outer variable is defined in function being inlined, |
| // and we will replace it with the substituted variable, or it is |
| // defined outside the function being inlined, and we should just |
| // skip the outer variable (the closure variable of the function |
| // being inlined). |
| s := subst.node(n.Outer).(*ir.Name) |
| if s == n.Outer { |
| s = n.Outer.Outer |
| } |
| m.Outer = s |
| } |
| return m |
| } |
| |
| // closure does the necessary substitions for a ClosureExpr n and returns the new |
| // closure node. |
| func (subst *inlsubst) closure(n *ir.ClosureExpr) ir.Node { |
| // Prior to the subst edit, set a flag in the inlsubst to indicate |
| // that we don't want to update the source positions in the new |
| // closure function. If we do this, it will appear that the |
| // closure itself has things inlined into it, which is not the |
| // case. See issue #46234 for more details. At the same time, we |
| // do want to update the position in the new ClosureExpr (which is |
| // part of the function we're working on). See #49171 for an |
| // example of what happens if we miss that update. |
| newClosurePos := subst.updatedPos(n.Pos()) |
| defer func(prev bool) { subst.noPosUpdate = prev }(subst.noPosUpdate) |
| subst.noPosUpdate = true |
| |
| //fmt.Printf("Inlining func %v with closure into %v\n", subst.fn, ir.FuncName(ir.CurFunc)) |
| |
| oldfn := n.Func |
| newfn := ir.NewClosureFunc(oldfn.Pos(), true) |
| |
| if subst.newclofn != nil { |
| //fmt.Printf("Inlining a closure with a nested closure\n") |
| } |
| prevxfunc := subst.newclofn |
| |
| // Mark that we are now substituting within a closure (within the |
| // inlined function), and create new nodes for all the local |
| // vars/params inside this closure. |
| subst.newclofn = newfn |
| newfn.Dcl = nil |
| newfn.ClosureVars = nil |
| for _, oldv := range oldfn.Dcl { |
| newv := subst.clovar(oldv) |
| subst.inlvars[oldv] = newv |
| newfn.Dcl = append(newfn.Dcl, newv) |
| } |
| for _, oldv := range oldfn.ClosureVars { |
| newv := subst.clovar(oldv) |
| subst.inlvars[oldv] = newv |
| newfn.ClosureVars = append(newfn.ClosureVars, newv) |
| } |
| |
| // Need to replace ONAME nodes in |
| // newfn.Type().FuncType().Receiver/Params/Results.FieldSlice().Nname |
| oldt := oldfn.Type() |
| newrecvs := subst.fields(oldt.Recvs()) |
| var newrecv *types.Field |
| if len(newrecvs) > 0 { |
| newrecv = newrecvs[0] |
| } |
| newt := types.NewSignature(oldt.Pkg(), newrecv, |
| nil, subst.fields(oldt.Params()), subst.fields(oldt.Results())) |
| |
| newfn.Nname.SetType(newt) |
| newfn.Body = subst.list(oldfn.Body) |
| |
| // Remove the nodes for the current closure from subst.inlvars |
| for _, oldv := range oldfn.Dcl { |
| delete(subst.inlvars, oldv) |
| } |
| for _, oldv := range oldfn.ClosureVars { |
| delete(subst.inlvars, oldv) |
| } |
| // Go back to previous closure func |
| subst.newclofn = prevxfunc |
| |
| // Actually create the named function for the closure, now that |
| // the closure is inlined in a specific function. |
| newclo := newfn.OClosure |
| newclo.SetPos(newClosurePos) |
| newclo.SetInit(subst.list(n.Init())) |
| return typecheck.Expr(newclo) |
| } |
| |
| // node recursively copies a node from the saved pristine body of the |
| // inlined function, substituting references to input/output |
| // parameters with ones to the tmpnames, and substituting returns with |
| // assignments to the output. |
| func (subst *inlsubst) node(n ir.Node) ir.Node { |
| if n == nil { |
| return nil |
| } |
| |
| switch n.Op() { |
| case ir.ONAME: |
| n := n.(*ir.Name) |
| |
| // Handle captured variables when inlining closures. |
| if n.IsClosureVar() && subst.newclofn == nil { |
| o := n.Outer |
| |
| // Deal with case where sequence of closures are inlined. |
| // TODO(danscales) - write test case to see if we need to |
| // go up multiple levels. |
| if o.Curfn != ir.CurFunc { |
| o = o.Outer |
| } |
| |
| // make sure the outer param matches the inlining location |
| if o == nil || o.Curfn != ir.CurFunc { |
| base.Fatalf("%v: unresolvable capture %v\n", ir.Line(n), n) |
| } |
| |
| if base.Flag.LowerM > 2 { |
| fmt.Printf("substituting captured name %+v -> %+v\n", n, o) |
| } |
| return o |
| } |
| |
| if inlvar := subst.inlvars[n]; inlvar != nil { // These will be set during inlnode |
| if base.Flag.LowerM > 2 { |
| fmt.Printf("substituting name %+v -> %+v\n", n, inlvar) |
| } |
| return inlvar |
| } |
| |
| if base.Flag.LowerM > 2 { |
| fmt.Printf("not substituting name %+v\n", n) |
| } |
| return n |
| |
| case ir.OMETHEXPR: |
| n := n.(*ir.SelectorExpr) |
| return n |
| |
| case ir.OLITERAL, ir.ONIL, ir.OTYPE: |
| // If n is a named constant or type, we can continue |
| // using it in the inline copy. Otherwise, make a copy |
| // so we can update the line number. |
| if n.Sym() != nil { |
| return n |
| } |
| |
| case ir.ORETURN: |
| if subst.newclofn != nil { |
| // Don't do special substitutions if inside a closure |
| break |
| } |
| // Because of the above test for subst.newclofn, |
| // this return is guaranteed to belong to the current inlined function. |
| n := n.(*ir.ReturnStmt) |
| init := subst.list(n.Init()) |
| if len(subst.retvars) != 0 && len(n.Results) != 0 { |
| as := ir.NewAssignListStmt(base.Pos, ir.OAS2, nil, nil) |
| |
| // Make a shallow copy of retvars. |
| // Otherwise OINLCALL.Rlist will be the same list, |
| // and later walk and typecheck may clobber it. |
| for _, n := range subst.retvars { |
| as.Lhs.Append(n) |
| } |
| as.Rhs = subst.list(n.Results) |
| |
| if subst.fn.Inl.CanDelayResults { |
| for _, n := range as.Lhs { |
| as.PtrInit().Append(ir.NewDecl(base.Pos, ir.ODCL, n.(*ir.Name))) |
| n.Name().Defn = as |
| } |
| } |
| |
| init = append(init, typecheck.Stmt(as)) |
| } |
| init = append(init, ir.NewBranchStmt(base.Pos, ir.OGOTO, subst.retlabel)) |
| typecheck.Stmts(init) |
| return ir.NewBlockStmt(base.Pos, init) |
| |
| case ir.OGOTO, ir.OBREAK, ir.OCONTINUE: |
| if subst.newclofn != nil { |
| // Don't do special substitutions if inside a closure |
| break |
| } |
| n := n.(*ir.BranchStmt) |
| m := ir.Copy(n).(*ir.BranchStmt) |
| m.SetPos(subst.updatedPos(m.Pos())) |
| m.SetInit(nil) |
| m.Label = translateLabel(n.Label) |
| return m |
| |
| case ir.OLABEL: |
| if subst.newclofn != nil { |
| // Don't do special substitutions if inside a closure |
| break |
| } |
| n := n.(*ir.LabelStmt) |
| m := ir.Copy(n).(*ir.LabelStmt) |
| m.SetPos(subst.updatedPos(m.Pos())) |
| m.SetInit(nil) |
| m.Label = translateLabel(n.Label) |
| return m |
| |
| case ir.OCLOSURE: |
| return subst.closure(n.(*ir.ClosureExpr)) |
| |
| } |
| |
| m := ir.Copy(n) |
| m.SetPos(subst.updatedPos(m.Pos())) |
| ir.EditChildren(m, subst.edit) |
| |
| if subst.newclofn == nil { |
| // Translate any label on FOR, RANGE loops, SWITCH or SELECT |
| switch m.Op() { |
| case ir.OFOR: |
| m := m.(*ir.ForStmt) |
| m.Label = translateLabel(m.Label) |
| return m |
| |
| case ir.ORANGE: |
| m := m.(*ir.RangeStmt) |
| m.Label = translateLabel(m.Label) |
| return m |
| |
| case ir.OSWITCH: |
| m := m.(*ir.SwitchStmt) |
| m.Label = translateLabel(m.Label) |
| return m |
| |
| case ir.OSELECT: |
| m := m.(*ir.SelectStmt) |
| m.Label = translateLabel(m.Label) |
| return m |
| } |
| } |
| |
| switch m := m.(type) { |
| case *ir.AssignStmt: |
| if lhs, ok := m.X.(*ir.Name); ok && lhs.Defn == &subst.defnMarker { |
| lhs.Defn = m |
| } |
| case *ir.AssignListStmt: |
| for _, lhs := range m.Lhs { |
| if lhs, ok := lhs.(*ir.Name); ok && lhs.Defn == &subst.defnMarker { |
| lhs.Defn = m |
| } |
| } |
| } |
| |
| return m |
| } |
| |
| // translateLabel makes a label from an inlined function (if non-nil) be unique by |
| // adding "·inlgen". |
| func translateLabel(l *types.Sym) *types.Sym { |
| if l == nil { |
| return nil |
| } |
| p := fmt.Sprintf("%s·%d", l.Name, inlgen) |
| return typecheck.Lookup(p) |
| } |
| |
| func (subst *inlsubst) updatedPos(xpos src.XPos) src.XPos { |
| if subst.noPosUpdate { |
| return xpos |
| } |
| pos := base.Ctxt.PosTable.Pos(xpos) |
| oldbase := pos.Base() // can be nil |
| newbase := subst.bases[oldbase] |
| if newbase == nil { |
| newbase = src.NewInliningBase(oldbase, subst.newInlIndex) |
| subst.bases[oldbase] = newbase |
| } |
| pos.SetBase(newbase) |
| return base.Ctxt.PosTable.XPos(pos) |
| } |
| |
| func pruneUnusedAutos(ll []*ir.Name, vis *hairyVisitor) []*ir.Name { |
| s := make([]*ir.Name, 0, len(ll)) |
| for _, n := range ll { |
| if n.Class == ir.PAUTO { |
| if !vis.usedLocals.Has(n) { |
| continue |
| } |
| } |
| s = append(s, n) |
| } |
| return s |
| } |
| |
| // numNonClosures returns the number of functions in list which are not closures. |
| func numNonClosures(list []*ir.Func) int { |
| count := 0 |
| for _, fn := range list { |
| if fn.OClosure == nil { |
| count++ |
| } |
| } |
| return count |
| } |
| |
| func doList(list []ir.Node, do func(ir.Node) bool) bool { |
| for _, x := range list { |
| if x != nil { |
| if do(x) { |
| return true |
| } |
| } |
| } |
| return false |
| } |
| |
| // isIndexingCoverageCounter returns true if the specified node 'n' is indexing |
| // into a coverage counter array. |
| func isIndexingCoverageCounter(n ir.Node) bool { |
| if n.Op() != ir.OINDEX { |
| return false |
| } |
| ixn := n.(*ir.IndexExpr) |
| if ixn.X.Op() != ir.ONAME || !ixn.X.Type().IsArray() { |
| return false |
| } |
| nn := ixn.X.(*ir.Name) |
| return nn.CoverageCounter() |
| } |
| |
| // isAtomicCoverageCounterUpdate examines the specified node to |
| // determine whether it represents a call to sync/atomic.AddUint32 to |
| // increment a coverage counter. |
| func isAtomicCoverageCounterUpdate(cn *ir.CallExpr) bool { |
| if cn.X.Op() != ir.ONAME { |
| return false |
| } |
| name := cn.X.(*ir.Name) |
| if name.Class != ir.PFUNC { |
| return false |
| } |
| fn := name.Sym().Name |
| if name.Sym().Pkg.Path != "sync/atomic" || |
| (fn != "AddUint32" && fn != "StoreUint32") { |
| return false |
| } |
| if len(cn.Args) != 2 || cn.Args[0].Op() != ir.OADDR { |
| return false |
| } |
| adn := cn.Args[0].(*ir.AddrExpr) |
| v := isIndexingCoverageCounter(adn.X) |
| return v |
| } |