1 // Copyright 2023 The Go Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style
3 // license that can be found in the LICENSE file.
8 "cmd/compile/internal/base"
9 "cmd/compile/internal/ir"
10 "cmd/compile/internal/types"
13 "internal/goexperiment"
22 debugTraceFuncs = 1 << iota
26 debugTraceExprClassify
31 // propAnalyzer interface is used for defining one or more analyzer
32 // helper objects, each tasked with computing some specific subset of
33 // the properties we're interested in. The assumption is that
34 // properties are independent, so each new analyzer that implements
35 // this interface can operate entirely on its own. For a given analyzer
36 // there will be a sequence of calls to nodeVisitPre and nodeVisitPost
37 // as the nodes within a function are visited, then a followup call to
38 // setResults so that the analyzer can transfer its results into the
39 // final properties object.
40 type propAnalyzer interface {
41 nodeVisitPre(n ir.Node)
42 nodeVisitPost(n ir.Node)
43 setResults(funcProps *FuncProps)
46 // fnInlHeur contains inline heuristics state information about a
47 // specific Go function being analyzed/considered by the inliner. Note
48 // that in addition to constructing a fnInlHeur object by analyzing a
49 // specific *ir.Func, there is also code in the test harness
50 // (funcprops_test.go) that builds up fnInlHeur's by reading in and
51 // parsing a dump. This is the reason why we have file/fname/line
52 // fields below instead of just an *ir.Func field.
53 type fnInlHeur struct {
62 var fpmap = map[*ir.Func]fnInlHeur{}
64 func AnalyzeFunc(fn *ir.Func, canInline func(*ir.Func), inlineMaxBudget int32) *FuncProps {
65 if funcInlHeur, ok := fpmap[fn]; ok {
66 return funcInlHeur.props
68 funcProps, fcstab := computeFuncProps(fn, canInline, inlineMaxBudget)
69 file, line := fnFileLine(fn)
74 inlineMaxBudget: inlineMaxBudget,
78 fn.SetNeverReturns(entry.props.Flags&FuncPropNeverReturns != 0)
80 if fn.Inl != nil && fn.Inl.Properties == "" {
81 fn.Inl.Properties = entry.props.SerializeToString()
86 // computeFuncProps examines the Go function 'fn' and computes for it
87 // a function "properties" object, to be used to drive inlining
88 // heuristics. See comments on the FuncProps type for more info.
89 func computeFuncProps(fn *ir.Func, canInline func(*ir.Func), inlineMaxBudget int32) (*FuncProps, CallSiteTab) {
90 enableDebugTraceIfEnv()
91 if debugTrace&debugTraceFuncs != 0 {
92 fmt.Fprintf(os.Stderr, "=-= starting analysis of func %v:\n%+v\n",
95 ra := makeResultsAnalyzer(fn, canInline, inlineMaxBudget)
96 pa := makeParamsAnalyzer(fn)
97 ffa := makeFuncFlagsAnalyzer(fn)
98 analyzers := []propAnalyzer{ffa, ra, pa}
99 funcProps := new(FuncProps)
100 runAnalyzersOnFunction(fn, analyzers)
101 for _, a := range analyzers {
102 a.setResults(funcProps)
104 // Now build up a partial table of callsites for this func.
105 cstab := computeCallSiteTable(fn, ffa.panicPathTable())
107 return funcProps, cstab
110 func runAnalyzersOnFunction(fn *ir.Func, analyzers []propAnalyzer) {
111 var doNode func(ir.Node) bool
112 doNode = func(n ir.Node) bool {
113 for _, a := range analyzers {
116 ir.DoChildren(n, doNode)
117 for _, a := range analyzers {
125 func propsForFunc(fn *ir.Func) *FuncProps {
126 if funcInlHeur, ok := fpmap[fn]; ok {
127 return funcInlHeur.props
128 } else if fn.Inl != nil && fn.Inl.Properties != "" {
129 // FIXME: considering adding some sort of cache or table
130 // for deserialized properties of imported functions.
131 return DeserializeFromString(fn.Inl.Properties)
136 func fnFileLine(fn *ir.Func) (string, uint) {
137 p := base.Ctxt.InnermostPos(fn.Pos())
138 return filepath.Base(p.Filename()), p.Line()
141 func UnitTesting() bool {
142 return base.Debug.DumpInlFuncProps != ""
145 // DumpFuncProps computes and caches function properties for the func
146 // 'fn' and any closures it contains, or if fn is nil, it writes out the
147 // cached set of properties to the file given in 'dumpfile'. Used for
148 // the "-d=dumpinlfuncprops=..." command line flag, intended for use
149 // primarily in unit testing.
150 func DumpFuncProps(fn *ir.Func, dumpfile string, canInline func(*ir.Func), inlineMaxBudget int32) {
152 enableDebugTraceIfEnv()
153 dmp := func(fn *ir.Func) {
154 if !goexperiment.NewInliner {
157 captureFuncDumpEntry(fn, canInline, inlineMaxBudget)
160 ir.Visit(fn, func(n ir.Node) {
161 if clo, ok := n.(*ir.ClosureExpr); ok {
167 emitDumpToFile(dumpfile)
171 // emitDumpToFile writes out the buffer function property dump entries
172 // to a file, for unit testing. Dump entries need to be sorted by
173 // definition line, and due to generics we need to account for the
174 // possibility that several ir.Func's will have the same def line.
175 func emitDumpToFile(dumpfile string) {
176 mode := os.O_WRONLY | os.O_CREATE | os.O_TRUNC
177 if dumpfile[0] == '+' {
178 dumpfile = dumpfile[1:]
179 mode = os.O_WRONLY | os.O_APPEND | os.O_CREATE
181 if dumpfile[0] == '%' {
182 dumpfile = dumpfile[1:]
183 d, b := filepath.Dir(dumpfile), filepath.Base(dumpfile)
184 ptag := strings.ReplaceAll(types.LocalPkg.Path, "/", ":")
185 dumpfile = d + "/" + ptag + "." + b
187 outf, err := os.OpenFile(dumpfile, mode, 0644)
189 base.Fatalf("opening function props dump file %q: %v\n", dumpfile, err)
192 dumpFilePreamble(outf)
194 atline := map[uint]uint{}
195 sl := make([]fnInlHeur, 0, len(dumpBuffer))
196 for _, e := range dumpBuffer {
198 atline[e.line] = atline[e.line] + 1
200 sl = sortFnInlHeurSlice(sl)
203 for _, entry := range sl {
205 if prevline == entry.line {
208 prevline = entry.line
209 atl := atline[entry.line]
210 if err := dumpFnPreamble(outf, &entry, nil, idx, atl); err != nil {
211 base.Fatalf("function props dump: %v\n", err)
217 // captureFuncDumpEntry grabs the function properties object for 'fn'
218 // and enqueues it for later dumping. Used for the
219 // "-d=dumpinlfuncprops=..." command line flag, intended for use
220 // primarily in unit testing.
221 func captureFuncDumpEntry(fn *ir.Func, canInline func(*ir.Func), inlineMaxBudget int32) {
222 // avoid capturing compiler-generated equality funcs.
223 if strings.HasPrefix(fn.Sym().Name, ".eq.") {
226 funcInlHeur, ok := fpmap[fn]
227 // Props object should already be present, unless this is a
228 // directly recursive routine.
230 AnalyzeFunc(fn, canInline, inlineMaxBudget)
231 funcInlHeur = fpmap[fn]
232 if fn.Inl != nil && fn.Inl.Properties == "" {
233 fn.Inl.Properties = funcInlHeur.props.SerializeToString()
236 if dumpBuffer == nil {
237 dumpBuffer = make(map[*ir.Func]fnInlHeur)
239 if _, ok := dumpBuffer[fn]; ok {
240 // we can wind up seeing closures multiple times here,
241 // so don't add them more than once.
244 if debugTrace&debugTraceFuncs != 0 {
245 fmt.Fprintf(os.Stderr, "=-= capturing dump for %v:\n", fn)
247 dumpBuffer[fn] = funcInlHeur
250 // dumpFilePreamble writes out a file-level preamble for a given
251 // Go function as part of a function properties dump.
252 func dumpFilePreamble(w io.Writer) {
253 fmt.Fprintf(w, "// DO NOT EDIT (use 'go test -v -update-expected' instead.)\n")
254 fmt.Fprintf(w, "// See cmd/compile/internal/inline/inlheur/testdata/props/README.txt\n")
255 fmt.Fprintf(w, "// for more information on the format of this file.\n")
256 fmt.Fprintf(w, "// %s\n", preambleDelimiter)
259 // dumpFnPreamble writes out a function-level preamble for a given
260 // Go function as part of a function properties dump. See the
261 // README.txt file in testdata/props for more on the format of
263 func dumpFnPreamble(w io.Writer, funcInlHeur *fnInlHeur, ecst encodedCallSiteTab, idx, atl uint) error {
264 fmt.Fprintf(w, "// %s %s %d %d %d\n",
265 funcInlHeur.file, funcInlHeur.fname, funcInlHeur.line, idx, atl)
266 // emit props as comments, followed by delimiter
267 fmt.Fprintf(w, "%s// %s\n", funcInlHeur.props.ToString("// "), comDelimiter)
268 data, err := json.Marshal(funcInlHeur.props)
270 return fmt.Errorf("marshall error %v\n", err)
272 fmt.Fprintf(w, "// %s\n", string(data))
273 dumpCallSiteComments(w, funcInlHeur.cstab, ecst)
274 fmt.Fprintf(w, "// %s\n", fnDelimiter)
278 // sortFnInlHeurSlice sorts a slice of fnInlHeur based on
279 // the starting line of the function definition, then by name.
280 func sortFnInlHeurSlice(sl []fnInlHeur) []fnInlHeur {
281 sort.SliceStable(sl, func(i, j int) bool {
282 if sl[i].line != sl[j].line {
283 return sl[i].line < sl[j].line
285 return sl[i].fname < sl[j].fname
290 // delimiters written to various preambles to make parsing of
292 const preambleDelimiter = "<endfilepreamble>"
293 const fnDelimiter = "<endfuncpreamble>"
294 const comDelimiter = "<endpropsdump>"
295 const csDelimiter = "<endcallsites>"
297 // dumpBuffer stores up function properties dumps when
298 // "-d=dumpinlfuncprops=..." is in effect.
299 var dumpBuffer map[*ir.Func]fnInlHeur