Issue 6842045: code review 6842045: cmd/5g: avoid temporary during OMINUS

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Issue 6842045: code review 6842045: cmd/5g: avoid temporary during OMINUS (Closed)

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Created:
12 years, 11 months ago by dave

Modified:
12 years, 10 months ago

Reviewers:

CC:
rsc, golang-dev

Visibility:
Public.

Description

cmd/5g: avoid temporary during OMINUS Saves one MOVW and one register during the fast div/mod introduced in CL 6819123. linux/arm (armv5) benchmark old ns/op new ns/op delta BenchmarkInt64Mod1 12 12 +7.50% BenchmarkUint16Mod2 7 7 +0.28% BenchmarkUint16Mod4 7 7 -0.28% BenchmarkUint64Mod1 15 11 -23.72% BenchmarkInt8Neg 8 7 -17.66% BenchmarkInt16Neg 8 7 -17.66% BenchmarkInt32Neg 5 5 -9.04% BenchmarkUint8Neg 7 6 -14.35% BenchmarkUint16Neg 8 7 -17.66% BenchmarkUint32Neg 5 5 -9.04%

Patch Set 1 #

Patch Set 2 : diff -r 9b31d3f52fff https://code.google.com/p/go #

Patch Set 3 : diff -r 6b602ab487d6 https://code.google.com/p/go #

Patch Set 4 : diff -r 6b602ab487d6 https://code.google.com/p/go #

Patch Set 5 : diff -r f593af463c17 https://go.googlecode.com/hg/ #

Created: 12 years, 10 months ago

Download [raw] [tar.bz2]

		Unified diffs	Side-by-side diffs	Delta from patch set	Stats (+14 lines, -7 lines)			Patch
	M	src/cmd/5g/cgen.c	View	1	2 chunks	+4 lines, -7 lines	0 comments	Download
	M	src/cmd/5g/gsubr.c	View	1	1 chunk	+10 lines, -0 lines	0 comments	Download

Messages

Total messages: 5

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dave_cheney.net

Hello minux.ma@gmail.com, remyoudompheng@gmail.com (cc: golang-dev@googlegroups.com), I'd like you to review this change to https://code.google.com/p/go

12 years, 10 months ago (2012-12-09 05:36:24 UTC) #1

dave_cheney.net

On 2012/12/09 05:36:24, dfc wrote: > Hello mailto:minux.ma@gmail.com, mailto:remyoudompheng@gmail.com (cc: > mailto:golang-dev@googlegroups.com), > > I'd ...

12 years, 10 months ago (2012-12-11 23:52:06 UTC) #2

dave_cheney.net

On 2012/12/12 04:09:15, rsc wrote: > LGTM Thanks. One day soon I will finish the ...

12 years, 10 months ago (2012-12-12 04:09:53 UTC) #4

dave_cheney.net

12 years, 10 months ago (2012-12-12 08:25:39 UTC) #5

*** Submitted as https://code.google.com/p/go/source/detail?r=3b81a777b3a1 ***

cmd/5g: avoid temporary during OMINUS

Saves one MOVW and one register during the fast div/mod introduced in CL
6819123.

linux/arm (armv5)

benchmark               old ns/op    new ns/op    delta
BenchmarkInt64Mod1             12           12   +7.50%
BenchmarkUint16Mod2             7            7   +0.28%
BenchmarkUint16Mod4             7            7   -0.28%
BenchmarkUint64Mod1            15           11  -23.72%
BenchmarkInt8Neg                8            7  -17.66%
BenchmarkInt16Neg               8            7  -17.66%
BenchmarkInt32Neg               5            5   -9.04%
BenchmarkUint8Neg               7            6  -14.35%
BenchmarkUint16Neg              8            7  -17.66%
BenchmarkUint32Neg              5            5   -9.04%

R=rsc
CC=golang-dev
https://codereview.appspot.com/6842045

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