Issue 597059: Added optimization for div/mod by constant power of 2.

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Issue 597059: Added optimization for div/mod by constant power of 2. (Closed)

Created:
10 years, 10 months ago by Lasse Reichstein

Modified:
9 years, 6 months ago

Reviewers:
Lasse Reichstein, William Hesse, Kevin Millikin (Chromium), fschneider

CC:
v8-dev

Visibility:
Public.

Description

Added optimization for div/mod by constant power of 2.

Patch Set 1 #

Patch Set 2 : Moved div code, removed mod code, only div by 2. #

Total comments: 1

Created: 10 years, 10 months ago

Download [raw] [tar.bz2]

		Unified diffs	Side-by-side diffs	Delta from patch set	Stats (+48 lines, -1 line)			Patch
	M	src/ia32/codegen-ia32.cc	View	1	1 chunk	+33 lines, -0 lines	1 comment	Download
	M	test/mjsunit/div-mod.js	View		1 chunk	+15 lines, -1 line	0 comments	Download

Messages

Total messages: 4 (0 generated)

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fschneider

Drive-by comment: It seems there is already an optimization for MOD power-of-2 in CodeGenerator::ConstantSmiOperation. You ...

10 years, 10 months ago (2010-02-12 12:39:57 UTC) #2

William Hesse

10 years, 7 months ago (2010-05-10 14:10:43 UTC) #4

Just an idea, on division by a power of 2.

http://codereview.chromium.org/597059/diff/4001/4002
File src/ia32/codegen-ia32.cc (right):

http://codereview.chromium.org/597059/diff/4001/4002#newcode1854
src/ia32/codegen-ia32.cc:1854: frame_->Spill(operand->reg());
If we know that we are in a to-int32 context, where the result will be converted
to int32, then we should be able to handle odd numbers divided by 2!

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