AuroraMiddleware/v8
1
0
Fork 0
Code Issues 2 Pull Requests Releases Wiki Activity

[ptr-compr][arm64] Set kRootRegisterBias to zero

Browse Source 
... in order to improve performance of decompression code on C++ side
(because computation of isolate root from isolate pointer becomes a trivial
reinterpret cast) and measure the impact separately from other ptr-compr
changes.

Bug: v8:9353
Change-Id: I36906cef2968355411ee944d97625ecd2652646b
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1835550
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#64115}
This commit is contained in:
Igor Sheludko 2019-10-02 16:32:56 +02:00 committed by Commit Bot
parent 3aeadaac22
commit a1e73fd6af
1 changed files with 2 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
src/codegen/arm64/constants-arm64.h
View File

@ -147,7 +147,8 @@ const unsigned kFloat16ExponentBias = 15;
// Actual value of root register is offset from the root array's start
// to take advantage of negative displacement values.
// TODO(sigurds): Choose best value.
constexpr int kRootRegisterBias = 256;
// TODO(ishell): Choose best value for ptr-compr.
constexpr int kRootRegisterBias = kSystemPointerSize == kTaggedSize ? 256 : 0;
using float16 = uint16_t;