Revert "cmd/compile/internal/pgo: fix hard-coded PGO sample data position"

This reverts CL 465135.

Reason for revert: This broke cmd/go.TestScript/build_pgo on the linux-amd64-longtest builder: https://build.golang.org/log/8f8ed7bf576f891a06d295c4a5bca987c6e941d6

Change-Id: Ie2f2cc2731099eb28eda6b94dded4dfc34e29441
Reviewed-on: https://go-review.googlesource.com/c/go/+/466439
Run-TryBot: Michael Pratt <mpratt@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
Auto-Submit: Michael Pratt <mpratt@google.com>

diff --git a/src/cmd/compile/internal/pgo/irgraph.go b/src/cmd/compile/internal/pgo/irgraph.go
index a0319f3962b2f388c87056b4bade45d59da42794..ca9e2f3b5adde3917c91d84e390594c5bcc410c9 100644 (file)
--- a/src/cmd/compile/internal/pgo/irgraph.go
+++ b/src/cmd/compile/internal/pgo/irgraph.go
@@ -140,25 +140,9 @@ func New(profileFile string) *Profile {
                return nil
        }
 
-       samplesCountIndex := -1
-       for i, s := range profile.SampleType {
-               // Samples count is the raw data collected, and CPU nanoseconds is just
-               // a scaled version of it, so either one we can find is fine.
-               if (s.Type == "samples" && s.Unit == "count") ||
-                       (s.Type == "cpu" && s.Unit == "nanoseconds") {
-                       samplesCountIndex = i
-                       break
-               }
-       }
-
-       if samplesCountIndex == -1 {
-               log.Fatal("failed to find CPU samples count or CPU nanoseconds value-types in profile.")
-               return nil
-       }
-
        g := newGraph(profile, &Options{
                CallTree:    false,
-               SampleValue: func(v []int64) int64 { return v[samplesCountIndex] },
+               SampleValue: func(v []int64) int64 { return v[1] },
        })
 
        p := &Profile{

diff --git a/src/cmd/compile/internal/test/pgo_inl_test.go b/src/cmd/compile/internal/test/pgo_inl_test.go
index 4d6b5a134a0e2808ae25da3f2f06bece30b50a19..2f6391fded265dddc4fd4464ad3d6441b86aa196 100644 (file)
--- a/src/cmd/compile/internal/test/pgo_inl_test.go
+++ b/src/cmd/compile/internal/test/pgo_inl_test.go
@@ -7,7 +7,6 @@ package test
 import (
        "bufio"
        "fmt"
-       "internal/profile"
        "internal/testenv"
        "io"
        "os"
@@ -214,73 +213,6 @@ func TestPGOIntendedInliningShiftedLines(t *testing.T) {
        testPGOIntendedInlining(t, dir)
 }
 
-// TestPGOSingleIndex tests that the sample index can not be 1 and compilation
-// will not fail. All it should care about is that the sample type is either
-// CPU nanoseconds or samples count, whichever it finds first.
-func TestPGOSingleIndex(t *testing.T) {
-       for _, tc := range []struct {
-               originalIndex int
-       }{{
-               // The `testdata/pgo/inline/inline_hot.pprof` file is a standard CPU
-               // profile as the runtime would generate. The 0 index contains the
-               // value-type samples and value-unit count. The 1 index contains the
-               // value-type cpu and value-unit nanoseconds. These tests ensure that
-               // the compiler can work with profiles that only have a single index,
-               // but are either samples count or CPU nanoseconds.
-               originalIndex: 0,
-       }, {
-               originalIndex: 1,
-       }} {
-               t.Run(fmt.Sprintf("originalIndex=%d", tc.originalIndex), func(t *testing.T) {
-                       wd, err := os.Getwd()
-                       if err != nil {
-                               t.Fatalf("error getting wd: %v", err)
-                       }
-                       srcDir := filepath.Join(wd, "testdata/pgo/inline")
-
-                       // Copy the module to a scratch location so we can add a go.mod.
-                       dir := t.TempDir()
-
-                       originalPprofFile, err := os.Open(filepath.Join(srcDir, "inline_hot.pprof"))
-                       if err != nil {
-                               t.Fatalf("error opening inline_hot.pprof: %v", err)
-                       }
-                       defer originalPprofFile.Close()
-
-                       p, err := profile.Parse(originalPprofFile)
-                       if err != nil {
-                               t.Fatalf("error parsing inline_hot.pprof: %v", err)
-                       }
-
-                       // Move the samples count value-type to the 0 index.
-                       p.SampleType = []*profile.ValueType{p.SampleType[tc.originalIndex]}
-
-                       // Ensure we only have a single set of sample values.
-                       for _, s := range p.Sample {
-                               s.Value = []int64{s.Value[tc.originalIndex]}
-                       }
-
-                       modifiedPprofFile, err := os.Create(filepath.Join(dir, "inline_hot.pprof"))
-                       if err != nil {
-                               t.Fatalf("error creating inline_hot.pprof: %v", err)
-                       }
-                       defer modifiedPprofFile.Close()
-
-                       if err := p.Write(modifiedPprofFile); err != nil {
-                               t.Fatalf("error writing inline_hot.pprof: %v", err)
-                       }
-
-                       for _, file := range []string{"inline_hot.go", "inline_hot_test.go"} {
-                               if err := copyFile(filepath.Join(dir, file), filepath.Join(srcDir, file)); err != nil {
-                                       t.Fatalf("error copying %s: %v", file, err)
-                               }
-                       }
-
-                       testPGOIntendedInlining(t, dir)
-               })
-       }
-}
-
 func copyFile(dst, src string) error {
        s, err := os.Open(src)
        if err != nil {