From: Brad Fitzpatrick <bradfitz@golang.org>
Date: Mon, 30 Jan 2012 19:42:09 +0000 (-0800)
Subject: json: remove old optimization that inlining covers now
X-Git-Tag: weekly.2012-02-07~212
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=25c96cba2e6e9729ffda9e05da05f121ce9077f4;p=gostls13.git

json: remove old optimization that inlining covers now

Benchmarks look the same.

R=golang-dev, dsymonds, rsc
CC=golang-dev
https://golang.org/cl/5572080
---

diff --git a/src/pkg/encoding/json/scanner.go b/src/pkg/encoding/json/scanner.go
index 2661f410e0..054b6b3d56 100644
--- a/src/pkg/encoding/json/scanner.go
+++ b/src/pkg/encoding/json/scanner.go
@@ -185,18 +185,9 @@ func isSpace(c rune) bool {
 	return c == ' ' || c == '\t' || c == '\r' || c == '\n'
 }
 
-// NOTE(rsc): The various instances of
-//
-//	if c <= ' ' && (c == ' ' || c == '\t' || c == '\r' || c == '\n')
-//
-// below should all be if c <= ' ' && isSpace(c), but inlining
-// the checks makes a significant difference (>10%) in tight loops
-// such as nextValue.  These should be rewritten with the clearer
-// function call once 6g knows to inline the call.
-
 // stateBeginValueOrEmpty is the state after reading `[`.
 func stateBeginValueOrEmpty(s *scanner, c int) int {
-	if c <= ' ' && (c == ' ' || c == '\t' || c == '\r' || c == '\n') {
+	if c <= ' ' && isSpace(rune(c)) {
 		return scanSkipSpace
 	}
 	if c == ']' {
@@ -207,7 +198,7 @@ func stateBeginValueOrEmpty(s *scanner, c int) int {
 
 // stateBeginValue is the state at the beginning of the input.
 func stateBeginValue(s *scanner, c int) int {
-	if c <= ' ' && (c == ' ' || c == '\t' || c == '\r' || c == '\n') {
+	if c <= ' ' && isSpace(rune(c)) {
 		return scanSkipSpace
 	}
 	switch c {
@@ -247,7 +238,7 @@ func stateBeginValue(s *scanner, c int) int {
 
 // stateBeginStringOrEmpty is the state after reading `{`.
 func stateBeginStringOrEmpty(s *scanner, c int) int {
-	if c <= ' ' && (c == ' ' || c == '\t' || c == '\r' || c == '\n') {
+	if c <= ' ' && isSpace(rune(c)) {
 		return scanSkipSpace
 	}
 	if c == '}' {
@@ -260,7 +251,7 @@ func stateBeginStringOrEmpty(s *scanner, c int) int {
 
 // stateBeginString is the state after reading `{"key": value,`.
 func stateBeginString(s *scanner, c int) int {
-	if c <= ' ' && (c == ' ' || c == '\t' || c == '\r' || c == '\n') {
+	if c <= ' ' && isSpace(rune(c)) {
 		return scanSkipSpace
 	}
 	if c == '"' {
@@ -280,7 +271,7 @@ func stateEndValue(s *scanner, c int) int {
 		s.endTop = true
 		return stateEndTop(s, c)
 	}
-	if c <= ' ' && (c == ' ' || c == '\t' || c == '\r' || c == '\n') {
+	if c <= ' ' && isSpace(rune(c)) {
 		s.step = stateEndValue
 		return scanSkipSpace
 	}