Bug 159612 – Inline store loop for CopyRest in DFG and FTL for certain array modes

• Status: RESOLVED
• Resolution: FIXED
• Component: JavaScriptCore

[Saam Barati]

...

[Saam Barati]

Created attachment 283294 [details]
WIP

This makes trivial test programs like 50% faster.
It makes Fil's air.js benchmark ~7% faster.

[WebKit Commit Bot]

Attachment 283294 [details] did not pass style-queue:


ERROR: Source/JavaScriptCore/ftl/FTLLowerDFGToB3.cpp:3804:  Missing space after ,  [whitespace/comma] [3]
Total errors found: 1 in 3 files


If any of these errors are false positives, please file a bug against check-webkit-style.

[Saam Barati]

Created attachment 285788 [details]
patch

[WebKit Commit Bot]

Attachment 285788 [details] did not pass style-queue:


ERROR: Source/JavaScriptCore/ftl/FTLLowerDFGToB3.cpp:3889:  Place brace on its own line for function definitions.  [whitespace/braces] [4]
Total errors found: 1 in 8 files


If any of these errors are false positives, please file a bug against check-webkit-style.

[Filip Pizlo]

Comment on attachment 285788 [details]
patch

View in context: https://bugs.webkit.org/attachment.cgi?id=285788&action=review

> Source/JavaScriptCore/dfg/DFGAbstractInterpreterInlines.h:2871
> +        IndexingType indexingType = node->child1()->indexingType();

This is really bad.  You're requiring that the child of CopyRest is NewArray.

A property of any good IR is that this:

a: Foo()
b: Bar(@a)

Must always behave the same as:

a: Foo()
x: Identity(@a)
b: Bar(@x)

Or even:

a: Foo()
Upsilon(@a, ^p)
...
p: Phi()
b: Bar(@p)

Clearly, any of these transformations would break your patch here and in other places.  Therefore, I believe your change is not sound.

[Saam Barati]

After speaking with Filip in person, I'm going to change
CopyRest and copy_rest to produce the array itself
instead of consuming it as an argument.

[Saam Barati]

Created attachment 285811 [details]
WIP

Might be the patch. I just need to see if it's possible to end up with an array larger
than MIN_ARRAY_STORAGE_LENGTH and what to do in such a situation.

[Saam Barati]

Created attachment 285882 [details]
WIP

Just about done. Just going to write a changelog and do a once over of the code, and write 32-bit DFG support.

[WebKit Commit Bot]

Attachment 285882 [details] did not pass style-queue:


ERROR: Source/JavaScriptCore/runtime/CommonSlowPaths.cpp:856:  Extra space between Structure* and structure  [whitespace/declaration] [3]
ERROR: Source/JavaScriptCore/bytecode/BytecodeUseDef.h:94:  Weird number of spaces at line-start.  Are you using a 4-space indent?  [whitespace/indent] [3]
ERROR: Source/JavaScriptCore/dfg/DFGCallArrayAllocatorSlowPathGenerator.h:87:  Wrong number of spaces before statement. (expected: 12)  [whitespace/indent] [4]
ERROR: Source/JavaScriptCore/dfg/DFGSpeculativeJIT.cpp:6510:  Should have a space between // and comment  [whitespace/comments] [4]
ERROR: Source/JavaScriptCore/dfg/DFGSpeculativeJIT.cpp:6514:  Should have a space between // and comment  [whitespace/comments] [4]
ERROR: Source/JavaScriptCore/dfg/DFGSpeculativeJIT.h:764:  The parameter name "indexingType" adds no information, so it should be removed.  [readability/parameter_name] [5]
ERROR: Source/JavaScriptCore/dfg/DFGSpeculativeJIT64.cpp:5507:  When wrapping a line, only indent 4 spaces.  [whitespace/indent] [3]
Total errors found: 7 in 35 files


If any of these errors are false positives, please file a bug against check-webkit-style.

[Saam Barati]

Created attachment 285930 [details]
patch

[WebKit Commit Bot]

Attachment 285930 [details] did not pass style-queue:


ERROR: Source/JavaScriptCore/dfg/DFGSpeculativeJIT32_64.cpp:5442:  When wrapping a line, only indent 4 spaces.  [whitespace/indent] [3]
ERROR: Source/JavaScriptCore/bytecode/BytecodeUseDef.h:94:  Weird number of spaces at line-start.  Are you using a 4-space indent?  [whitespace/indent] [3]
ERROR: Source/JavaScriptCore/dfg/DFGCallArrayAllocatorSlowPathGenerator.h:87:  Wrong number of spaces before statement. (expected: 12)  [whitespace/indent] [4]
ERROR: Source/JavaScriptCore/dfg/DFGSpeculativeJIT.h:764:  The parameter name "indexingType" adds no information, so it should be removed.  [readability/parameter_name] [5]
ERROR: Source/JavaScriptCore/dfg/DFGSpeculativeJIT64.cpp:5507:  When wrapping a line, only indent 4 spaces.  [whitespace/indent] [3]
Total errors found: 5 in 37 files


If any of these errors are false positives, please file a bug against check-webkit-style.

[Saam Barati]

Created attachment 285962 [details]
patch for landing

[WebKit Commit Bot]

Attachment 285962 [details] did not pass style-queue:


ERROR: Source/JavaScriptCore/dfg/DFGCallArrayAllocatorSlowPathGenerator.h:87:  Wrong number of spaces before statement. (expected: 12)  [whitespace/indent] [4]
Total errors found: 1 in 41 files


If any of these errors are false positives, please file a bug against check-webkit-style.

[WebKit Commit Bot]

Comment on attachment 285962 [details]
patch for landing

Clearing flags on attachment: 285962

Committed r204439: <http://trac.webkit.org/changeset/204439>

[WebKit Commit Bot]

All reviewed patches have been landed.  Closing bug.