Issue 6594115: Optimize loads from root-array in X64.

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Issue 6594115: Optimize loads from root-array in X64. (Closed)

Created:
9 years, 9 months ago by Lasse Reichstein

Modified:
9 years, 6 months ago

Reviewers:
William Hesse, Rico

CC:
v8-dev

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

Visibility:
Public.

Description

Optimize loads from root-array in X64. Move the value of the root-array register to offset 128 from the start of the root array. This allows indices 16..31 to be reached using only an 8-bit displacement, saving three bytes per access. Committed: http://code.google.com/p/v8/source/detail?r=7069

Patch Set 1 #

Patch Set 2 : Reordered the root-array slightly. Should have no effect on ia32, but help slightly on x64. #

Created: 9 years, 9 months ago

Download [raw] [tar.bz2]

	Unified diffs	Side-by-side diffs	Delta from patch set	Stats (+52 lines, -28 lines)			Patch
M	src/heap.h	View	1	5 chunks	+11 lines, -12 lines	0 comments	Download
M	src/x64/code-stubs-x64.cc	View	1	1 chunk	+1 line, -2 lines	0 comments	Download
M	src/x64/codegen-x64.cc	View	1	2 chunks	+4 lines, -2 lines	0 comments	Download
M	src/x64/deoptimizer-x64.cc	View	1	1 chunk	+2 lines, -5 lines	0 comments	Download
M	src/x64/lithium-codegen-x64.cc	View	1	2 chunks	+2 lines, -3 lines	0 comments	Download
M	src/x64/macro-assembler-x64.h	View	1	3 chunks	+15 lines, -0 lines	0 comments	Download
M	src/x64/macro-assembler-x64.cc	View	1	1 chunk	+17 lines, -4 lines	0 comments	Download

Messages

Total messages: 3 (0 generated)

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William Hesse

9 years, 9 months ago (2011-03-07 17:08:01 UTC) #3

Isn't there one element that is loaded with a zero displacement?  Shouldn't it
be the stack limit?

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