Issue 6922049: code review 6922049: cmd/6g, cmd/8g: simplify integer division code.

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Issue 6922049: code review 6922049: cmd/6g, cmd/8g: simplify integer division code. (Closed)

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Created:
12 years, 3 months ago by remyoudompheng

Modified:
12 years, 3 months ago

Reviewers:

CC:
golang-dev, rsc

Visibility:
Public.

Description

cmd/6g, cmd/8g: simplify integer division code. Change suggested by iant. The compiler generates special code for a/b when a is -0x80...0 and b = -1. A single instruction can cover the case where b is -1, so only one comparison is needed. Fixes issue 3551.

Patch Set 1 #

Patch Set 2 : diff -r ec3ae5b98922 https://go.googlecode.com/hg/ #

Patch Set 3 : diff -r ec3ae5b98922 https://go.googlecode.com/hg/ #

Patch Set 4 : diff -r ec3ae5b98922 https://go.googlecode.com/hg/ #

Created: 12 years, 3 months ago

Download [raw] [tar.bz2]

		Unified diffs	Side-by-side diffs	Delta from patch set	Stats (+21 lines, -30 lines)			Patch
	M	src/cmd/6g/ggen.c	View	1	3 chunks	+11 lines, -19 lines	0 comments	Download
	M	src/cmd/8g/ggen.c	View	1	3 chunks	+10 lines, -11 lines	0 comments	Download

Messages

Total messages: 3

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remyoudompheng

Hello golang-dev@googlegroups.com (cc: golang-dev@googlegroups.com), I'd like you to review this change to https://go.googlecode.com/hg/

12 years, 3 months ago (2012-12-11 23:46:41 UTC) #1

remyoudompheng

12 years, 3 months ago (2012-12-12 07:35:59 UTC) #3

*** Submitted as https://code.google.com/p/go/source/detail?r=a3a847781593 ***

cmd/6g, cmd/8g: simplify integer division code.

Change suggested by iant. The compiler generates
special code for a/b when a is -0x80...0 and b = -1.
A single instruction can cover the case where b is -1,
so only one comparison is needed.

Fixes issue 3551.

R=golang-dev, rsc
CC=golang-dev
https://codereview.appspot.com/6922049

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