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// Copyright 2017 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 (
"bufio"
"internal/testenv"
"io"
"math/bits"
"os/exec"
"regexp"
"runtime"
"strings"
"testing"
)
// TestIntendedInlining tests that specific runtime functions are inlined.
// This allows refactoring for code clarity and re-use without fear that
// changes to the compiler will cause silent performance regressions.
func TestIntendedInlining(t *testing.T) {
if testing.Short() && testenv.Builder() == "" {
t.Skip("skipping in short mode")
}
testenv.MustHaveGoRun(t)
t.Parallel()
// want is the list of function names (by package) that should
// be inlinable. If they have no callers in their packages, they
// might not actually be inlined anywhere.
want := map[string][]string{
"runtime": {
// TODO(mvdan): enable these once mid-stack
// inlining is available
// "adjustctxt",
"add",
"acquirem",
"add1",
"addb",
"adjustpanics",
"adjustpointer",
"bucketMask",
"bucketShift",
"chanbuf",
"deferArgs",
"deferclass",
"evacuated",
"fastlog2",
"fastrand",
"float64bits",
"funcPC",
"getArgInfoFast",
"getm",
"isDirectIface",
"itabHashFunc",
"noescape",
"pcvalueCacheKey",
"readUnaligned32",
"readUnaligned64",
"releasem",
"round",
"roundupsize",
"stackmapdata",
"stringStructOf",
"subtract1",
"subtractb",
"tophash",
"totaldefersize",
"(*bmap).keys",
"(*bmap).overflow",
"(*waitq).enqueue",
// GC-related ones
"cgoInRange",
"gclinkptr.ptr",
"guintptr.ptr",
"heapBits.bits",
"heapBits.isPointer",
"heapBits.morePointers",
"heapBits.next",
"heapBitsForAddr",
"markBits.isMarked",
"muintptr.ptr",
"puintptr.ptr",
"spanOf",
"spanOfUnchecked",
//"(*gcWork).putFast", // TODO(austin): For debugging #27993
"(*gcWork).tryGetFast",
"(*guintptr).set",
"(*markBits).advance",
"(*mspan).allocBitsForIndex",
"(*mspan).base",
"(*mspan).markBitsForBase",
"(*mspan).markBitsForIndex",
"(*muintptr).set",
"(*puintptr).set",
},
"runtime/internal/sys": {},
"runtime/internal/math": {
"MulUintptr",
},
"bytes": {
"(*Buffer).Bytes",
"(*Buffer).Cap",
"(*Buffer).Len",
"(*Buffer).Grow",
"(*Buffer).Next",
"(*Buffer).Read",
"(*Buffer).ReadByte",
"(*Buffer).Reset",
"(*Buffer).String",
"(*Buffer).UnreadByte",
"(*Buffer).tryGrowByReslice",
},
"compress/flate": {
"byLiteral.Len",
"byLiteral.Less",
"byLiteral.Swap",
},
"encoding/base64": {
"assemble32",
"assemble64",
},
"unicode/utf8": {
"FullRune",
"FullRuneInString",
"RuneLen",
"ValidRune",
},
"reflect": {
"Value.CanAddr",
"Value.CanSet",
"Value.CanInterface",
"Value.IsValid",
"Value.pointer",
"add",
"align",
"flag.mustBe",
"flag.mustBeAssignable",
"flag.mustBeExported",
"flag.kind",
"flag.ro",
},
"regexp": {
"(*bitState).push",
},
"math/big": {
"bigEndianWord",
// The following functions require the math_big_pure_go build tag.
"addVW",
"subVW",
},
}
if runtime.GOARCH != "386" && runtime.GOARCH != "mips64" && runtime.GOARCH != "mips64le" {
// nextFreeFast calls sys.Ctz64, which on 386 is implemented in asm and is not inlinable.
// We currently don't have midstack inlining so nextFreeFast is also not inlinable on 386.
// On MIPS64x, Ctz64 is not intrinsified and causes nextFreeFast too expensive to inline
// (Issue 22239).
want["runtime"] = append(want["runtime"], "nextFreeFast")
}
if runtime.GOARCH != "386" {
// As explained above, Ctz64 and Ctz32 are not Go code on 386.
// The same applies to Bswap32.
want["runtime/internal/sys"] = append(want["runtime/internal/sys"], "Ctz64")
want["runtime/internal/sys"] = append(want["runtime/internal/sys"], "Ctz32")
want["runtime/internal/sys"] = append(want["runtime/internal/sys"], "Bswap32")
}
if bits.UintSize == 64 {
// rotl_31 is only defined on 64-bit architectures
want["runtime"] = append(want["runtime"], "rotl_31")
}
switch runtime.GOARCH {
case "nacl", "386", "wasm", "arm":
default:
// TODO(mvdan): As explained in /test/inline_sync.go, some
// architectures don't have atomic intrinsics, so these go over
// the inlining budget. Move back to the main table once that
// problem is solved.
want["sync"] = []string{
"(*Mutex).Lock",
"(*Mutex).Unlock",
"(*RWMutex).RLock",
"(*RWMutex).RUnlock",
"(*Once).Do",
}
}
// Functions that must actually be inlined; they must have actual callers.
must := map[string]bool{
"compress/flate.byLiteral.Len": true,
"compress/flate.byLiteral.Less": true,
"compress/flate.byLiteral.Swap": true,
}
notInlinedReason := make(map[string]string)
pkgs := make([]string, 0, len(want))
for pname, fnames := range want {
pkgs = append(pkgs, pname)
for _, fname := range fnames {
fullName := pname + "." + fname
if _, ok := notInlinedReason[fullName]; ok {
t.Errorf("duplicate func: %s", fullName)
}
notInlinedReason[fullName] = "unknown reason"
}
}
args := append([]string{"build", "-a", "-gcflags=all=-m -m", "-tags=math_big_pure_go"}, pkgs...)
cmd := testenv.CleanCmdEnv(exec.Command(testenv.GoToolPath(t), args...))
pr, pw := io.Pipe()
cmd.Stdout = pw
cmd.Stderr = pw
cmdErr := make(chan error, 1)
go func() {
cmdErr <- cmd.Run()
pw.Close()
}()
scanner := bufio.NewScanner(pr)
curPkg := ""
canInline := regexp.MustCompile(`: can inline ([^ ]*)`)
haveInlined := regexp.MustCompile(`: inlining call to ([^ ]*)`)
cannotInline := regexp.MustCompile(`: cannot inline ([^ ]*): (.*)`)
for scanner.Scan() {
line := scanner.Text()
if strings.HasPrefix(line, "# ") {
curPkg = line[2:]
continue
}
if m := haveInlined.FindStringSubmatch(line); m != nil {
fname := m[1]
delete(notInlinedReason, curPkg+"."+fname)
continue
}
if m := canInline.FindStringSubmatch(line); m != nil {
fname := m[1]
fullname := curPkg + "." + fname
// If function must be inlined somewhere, being inlinable is not enough
if _, ok := must[fullname]; !ok {
delete(notInlinedReason, fullname)
continue
}
}
if m := cannotInline.FindStringSubmatch(line); m != nil {
fname, reason := m[1], m[2]
fullName := curPkg + "." + fname
if _, ok := notInlinedReason[fullName]; ok {
// cmd/compile gave us a reason why
notInlinedReason[fullName] = reason
}
continue
}
}
if err := <-cmdErr; err != nil {
t.Fatal(err)
}
if err := scanner.Err(); err != nil {
t.Fatal(err)
}
for fullName, reason := range notInlinedReason {
t.Errorf("%s was not inlined: %s", fullName, reason)
}
}