src/cmd/compile/internal/test/inl_test.go

   1 // Copyright 2017 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.
   4
   5 package test
   6
   7 import (
   8         "bufio"
   9         "internal/testenv"
  10         "io"
  11         "math/bits"
  12         "os/exec"
  13         "regexp"
  14         "runtime"
  15         "strings"
  16         "testing"
  17 )
  18
  19 // TestIntendedInlining tests that specific functions are inlined.
  20 // This allows refactoring for code clarity and re-use without fear that
  21 // changes to the compiler will cause silent performance regressions.
  22 func TestIntendedInlining(t *testing.T) {
  23         if testing.Short() && testenv.Builder() == "" {
  24                 t.Skip("skipping in short mode")
  25         }
  26         testenv.MustHaveGoRun(t)
  27         t.Parallel()
  28
  29         // want is the list of function names (by package) that should
  30         // be inlinable. If they have no callers in their packages, they
  31         // might not actually be inlined anywhere.
  32         want := map[string][]string{
  33                 "runtime": {
  34                         "add",
  35                         "acquirem",
  36                         "add1",
  37                         "addb",
  38                         "adjustpanics",
  39                         "adjustpointer",
  40                         "alignDown",
  41                         "alignUp",
  42                         "bucketMask",
  43                         "bucketShift",
  44                         "chanbuf",
  45                         "evacuated",
  46                         "fastlog2",
  47                         "fastrand",
  48                         "float64bits",
  49                         "getArgInfoFast",
  50                         "getm",
  51                         "getMCache",
  52                         "isDirectIface",
  53                         "itabHashFunc",
  54                         "noescape",
  55                         "pcvalueCacheKey",
  56                         "readUnaligned32",
  57                         "readUnaligned64",
  58                         "releasem",
  59                         "roundupsize",
  60                         "stackmapdata",
  61                         "stringStructOf",
  62                         "subtract1",
  63                         "subtractb",
  64                         "tophash",
  65                         "(*bmap).keys",
  66                         "(*bmap).overflow",
  67                         "(*waitq).enqueue",
  68
  69                         // GC-related ones
  70                         "cgoInRange",
  71                         "gclinkptr.ptr",
  72                         "guintptr.ptr",
  73                         "heapBits.bits",
  74                         "heapBits.isPointer",
  75                         "heapBits.morePointers",
  76                         "heapBits.next",
  77                         "heapBitsForAddr",
  78                         "markBits.isMarked",
  79                         "muintptr.ptr",
  80                         "puintptr.ptr",
  81                         "spanOf",
  82                         "spanOfUnchecked",
  83                         "(*gcWork).putFast",
  84                         "(*gcWork).tryGetFast",
  85                         "(*guintptr).set",
  86                         "(*markBits).advance",
  87                         "(*mspan).allocBitsForIndex",
  88                         "(*mspan).base",
  89                         "(*mspan).markBitsForBase",
  90                         "(*mspan).markBitsForIndex",
  91                         "(*muintptr).set",
  92                         "(*puintptr).set",
  93                 },
  94                 "runtime/internal/sys": {},
  95                 "runtime/internal/math": {
  96                         "MulUintptr",
  97                 },
  98                 "bytes": {
  99                         "(*Buffer).Bytes",
 100                         "(*Buffer).Cap",
 101                         "(*Buffer).Len",
 102                         "(*Buffer).Grow",
 103                         "(*Buffer).Next",
 104                         "(*Buffer).Read",
 105                         "(*Buffer).ReadByte",
 106                         "(*Buffer).Reset",
 107                         "(*Buffer).String",
 108                         "(*Buffer).UnreadByte",
 109                         "(*Buffer).tryGrowByReslice",
 110                 },
 111                 "compress/flate": {
 112                         "byLiteral.Len",
 113                         "byLiteral.Less",
 114                         "byLiteral.Swap",
 115                         "(*dictDecoder).tryWriteCopy",
 116                 },
 117                 "encoding/base64": {
 118                         "assemble32",
 119                         "assemble64",
 120                 },
 121                 "unicode/utf8": {
 122                         "FullRune",
 123                         "FullRuneInString",
 124                         "RuneLen",
 125                         "AppendRune",
 126                         "ValidRune",
 127                 },
 128                 "reflect": {
 129                         "Value.CanAddr",
 130                         "Value.CanSet",
 131                         "Value.CanInterface",
 132                         "Value.IsValid",
 133                         "Value.pointer",
 134                         "add",
 135                         "align",
 136                         "flag.mustBe",
 137                         "flag.mustBeAssignable",
 138                         "flag.mustBeExported",
 139                         "flag.kind",
 140                         "flag.ro",
 141                 },
 142                 "regexp": {
 143                         "(*bitState).push",
 144                 },
 145                 "math/big": {
 146                         "bigEndianWord",
 147                         // The following functions require the math_big_pure_go build tag.
 148                         "addVW",
 149                         "subVW",
 150                 },
 151                 "math/rand": {
 152                         "(*rngSource).Int63",
 153                         "(*rngSource).Uint64",
 154                 },
 155                 "net": {
 156                         "(*UDPConn).ReadFromUDP",
 157                 },
 158         }
 159
 160         if runtime.GOARCH != "386" && runtime.GOARCH != "mips64" && runtime.GOARCH != "mips64le" && runtime.GOARCH != "riscv64" {
 161                 // nextFreeFast calls sys.Ctz64, which on 386 is implemented in asm and is not inlinable.
 162                 // We currently don't have midstack inlining so nextFreeFast is also not inlinable on 386.
 163                 // On mips64x and riscv64, Ctz64 is not intrinsified and causes nextFreeFast too expensive
 164                 // to inline (Issue 22239).
 165                 want["runtime"] = append(want["runtime"], "nextFreeFast")
 166         }
 167         if runtime.GOARCH != "386" {
 168                 // As explained above, Ctz64 and Ctz32 are not Go code on 386.
 169                 // The same applies to Bswap32.
 170                 want["runtime/internal/sys"] = append(want["runtime/internal/sys"], "Ctz64")
 171                 want["runtime/internal/sys"] = append(want["runtime/internal/sys"], "Ctz32")
 172                 want["runtime/internal/sys"] = append(want["runtime/internal/sys"], "Bswap32")
 173         }
 174         if bits.UintSize == 64 {
 175                 // mix is only defined on 64-bit architectures
 176                 want["runtime"] = append(want["runtime"], "mix")
 177         }
 178
 179         switch runtime.GOARCH {
 180         case "386", "wasm", "arm":
 181         default:
 182                 // TODO(mvdan): As explained in /test/inline_sync.go, some
 183                 // architectures don't have atomic intrinsics, so these go over
 184                 // the inlining budget. Move back to the main table once that
 185                 // problem is solved.
 186                 want["sync"] = []string{
 187                         "(*Mutex).Lock",
 188                         "(*Mutex).Unlock",
 189                         "(*RWMutex).RLock",
 190                         "(*RWMutex).RUnlock",
 191                         "(*Once).Do",
 192                 }
 193         }
 194
 195         // Functions that must actually be inlined; they must have actual callers.
 196         must := map[string]bool{
 197                 "compress/flate.byLiteral.Len":  true,
 198                 "compress/flate.byLiteral.Less": true,
 199                 "compress/flate.byLiteral.Swap": true,
 200         }
 201
 202         notInlinedReason := make(map[string]string)
 203         pkgs := make([]string, 0, len(want))
 204         for pname, fnames := range want {
 205                 pkgs = append(pkgs, pname)
 206                 for _, fname := range fnames {
 207                         fullName := pname + "." + fname
 208                         if _, ok := notInlinedReason[fullName]; ok {
 209                                 t.Errorf("duplicate func: %s", fullName)
 210                         }
 211                         notInlinedReason[fullName] = "unknown reason"
 212                 }
 213         }
 214
 215         args := append([]string{"build", "-a", "-gcflags=all=-m -m", "-tags=math_big_pure_go"}, pkgs...)
 216         cmd := testenv.CleanCmdEnv(exec.Command(testenv.GoToolPath(t), args...))
 217         pr, pw := io.Pipe()
 218         cmd.Stdout = pw
 219         cmd.Stderr = pw
 220         cmdErr := make(chan error, 1)
 221         go func() {
 222                 cmdErr <- cmd.Run()
 223                 pw.Close()
 224         }()
 225         scanner := bufio.NewScanner(pr)
 226         curPkg := ""
 227         canInline := regexp.MustCompile(`: can inline ([^ ]*)`)
 228         haveInlined := regexp.MustCompile(`: inlining call to ([^ ]*)`)
 229         cannotInline := regexp.MustCompile(`: cannot inline ([^ ]*): (.*)`)
 230         for scanner.Scan() {
 231                 line := scanner.Text()
 232                 if strings.HasPrefix(line, "# ") {
 233                         curPkg = line[2:]
 234                         continue
 235                 }
 236                 if m := haveInlined.FindStringSubmatch(line); m != nil {
 237                         fname := m[1]
 238                         delete(notInlinedReason, curPkg+"."+fname)
 239                         continue
 240                 }
 241                 if m := canInline.FindStringSubmatch(line); m != nil {
 242                         fname := m[1]
 243                         fullname := curPkg + "." + fname
 244                         // If function must be inlined somewhere, being inlinable is not enough
 245                         if _, ok := must[fullname]; !ok {
 246                                 delete(notInlinedReason, fullname)
 247                                 continue
 248                         }
 249                 }
 250                 if m := cannotInline.FindStringSubmatch(line); m != nil {
 251                         fname, reason := m[1], m[2]
 252                         fullName := curPkg + "." + fname
 253                         if _, ok := notInlinedReason[fullName]; ok {
 254                                 // cmd/compile gave us a reason why
 255                                 notInlinedReason[fullName] = reason
 256                         }
 257                         continue
 258                 }
 259         }
 260         if err := <-cmdErr; err != nil {
 261                 t.Fatal(err)
 262         }
 263         if err := scanner.Err(); err != nil {
 264                 t.Fatal(err)
 265         }
 266         for fullName, reason := range notInlinedReason {
 267                 t.Errorf("%s was not inlined: %s", fullName, reason)
 268         }
 269 }