Issue 6730029: [v8-dev] Improve code generation for DoAddI, DoSubI and DoBitI when the right hand...

Issue 6730029: [v8-dev] Improve code generation for DoAddI, DoSubI and DoBitI when the right hand... (Closed)

Created:
9 years, 9 months ago by Rodolph Perfetta

Modified:
9 years, 7 months ago

Reviewers:
Søren Thygesen Gjesse

CC:
v8-dev

Base URL:
http://v8.googlecode.com/svn/branches/bleeding_edge/

Visibility:
Public.

Description

Improve code generation for DoAddI, DoSubI and DoBitI when the right hand side is a constant. BUG=none TEST=none Committed: http://code.google.com/p/v8/source/detail?r=7358

Patch Set 1 #

Total comments: 5

Created: 9 years, 9 months ago

Download [raw] [tar.bz2]

		Unified diffs	Side-by-side diffs	Delta from patch set	Stats (+38 lines, -12 lines)			Patch
	M	src/arm/lithium-codegen-arm.cc	View		3 chunks	+38 lines, -12 lines	5 comments	Download

Messages

Total messages: 4 (0 generated)

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Søren Thygesen Gjesse

LGTM http://codereview.chromium.org/6730029/diff/1/src/arm/lithium-codegen-arm.cc File src/arm/lithium-codegen-arm.cc (right): http://codereview.chromium.org/6730029/diff/1/src/arm/lithium-codegen-arm.cc#newcode1178 src/arm/lithium-codegen-arm.cc:1178: bool can_overflow = instr->hydrogen()->CheckFlag(HValue::kCanOverflow); Can't we just use ...

9 years, 9 months ago (2011-03-24 20:32:24 UTC) #2

Rodolph Perfetta

http://codereview.chromium.org/6730029/diff/1/src/arm/lithium-codegen-arm.cc File src/arm/lithium-codegen-arm.cc (right): http://codereview.chromium.org/6730029/diff/1/src/arm/lithium-codegen-arm.cc#newcode1178 src/arm/lithium-codegen-arm.cc:1178: bool can_overflow = instr->hydrogen()->CheckFlag(HValue::kCanOverflow); On 2011/03/24 20:32:24, Søren Gjesse ...

9 years, 9 months ago (2011-03-25 00:23:09 UTC) #3

Søren Thygesen Gjesse

9 years, 9 months ago (2011-03-25 07:42:22 UTC) #4

LGTM

Committed: http://code.google.com/p/v8/source/detail?r=7358

http://codereview.chromium.org/6730029/diff/1/src/arm/lithium-codegen-arm.cc
File src/arm/lithium-codegen-arm.cc (right):

http://codereview.chromium.org/6730029/diff/1/src/arm/lithium-codegen-arm.cc#...
src/arm/lithium-codegen-arm.cc:1178: bool can_overflow =
instr->hydrogen()->CheckFlag(HValue::kCanOverflow);
On 2011/03/25 00:23:09, Rodolph Perfetta wrote:
> On 2011/03/24 20:32:24, Søren Gjesse wrote:
> > Can't we just use SetCC always?
> 
> We could, but on modern cores, setting the flags when not needed introduces a 
> dependency which tend to reduce the core efficiency. Admittedly the impact for
> one instruction is going to be very small. If you want I'll revert that. 

No, I am fine with that - I just wanted to know the reason.

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