cmd/compile: Enables PGO in Go and performs profile-guided inlining

For #55022

Change-Id: I51f1ba166d5a66dcaf4b280756be4a6bf9545c5e
Reviewed-on: https://go-review.googlesource.com/c/go/+/429863
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
Run-TryBot: Cherry Mui <cherryyz@google.com>

1 files changed, 11 insertions, 5 deletions

diff --git a/src/internal/profile/legacy_profile.go b/src/internal/profile/legacy_profile.go
index 0ac350a888..b102c95904 100644
--- a/src/internal/profile/legacy_profile.go
+++ b/src/internal/profile/legacy_profile.go
@@ -722,7 +722,7 @@ func parseCppContention(r *bytes.Buffer) (*Profile, error) {
 	var l string
 	var err error
 	// Parse text of the form "attribute = value" before the samples.
-	const delimiter = "="
+	const delimiter = '='
 	for {
 		l, err = r.ReadString('\n')
 		if err != nil {
@@ -746,10 +746,13 @@ func parseCppContention(r *bytes.Buffer) (*Profile, error) {
 			break
 		}
 
-		key, val, ok := strings.Cut(l, delimiter)
-		if !ok {
+		index := strings.IndexByte(l, delimiter)
+		if index < 0 {
 			break
 		}
+		key := l[:index]
+		val := l[index+1:]
+
 		key, val = strings.TrimSpace(key), strings.TrimSpace(val)
 		var err error
 		switch key {
@@ -1023,7 +1026,7 @@ func (p *Profile) ParseMemoryMap(rd io.Reader) error {
 
 	var attrs []string
 	var r *strings.Replacer
-	const delimiter = "="
+	const delimiter = '='
 	for {
 		l, err := b.ReadString('\n')
 		if err != nil {
@@ -1046,7 +1049,10 @@ func (p *Profile) ParseMemoryMap(rd io.Reader) error {
 			if err == errUnrecognized {
 				// Recognize assignments of the form: attr=value, and replace
 				// $attr with value on subsequent mappings.
-				if attr, value, ok := strings.Cut(l, delimiter); ok {
+				idx := strings.IndexByte(l, delimiter)
+				if idx >= 0 {
+					attr := l[:idx]
+					value := l[idx+1:]
 					attrs = append(attrs, "$"+strings.TrimSpace(attr), strings.TrimSpace(value))
 					r = strings.NewReplacer(attrs...)
 				}