711763 - IonMonkey: Simplify the greedy allocator

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[David Anderson [:dvander] - inactive, e-mail if emergency]

Attachment: WIP v0

I'm still not sure whether this allocator is useful, but it's really complex (arguably, moreso than LSRA) and has lots of bugs. This patch simplifies it by removing all the control flow handling code and instead spilling the register state at the top of basic blocks. It still gets good allocation inside a basic block.

(Note, this patch is totally untested.)

Comment 1

[David Anderson [:dvander] - inactive, e-mail if emergency]

Attachment: patch

7 files changed, 212 insertions(+), 624 deletions(-)

This also fixes a bunch of test failures, so I guess the old implementation was actually pretty buggy.

Comment 2

[David Anderson [:dvander] - inactive, e-mail if emergency]

Attachment: v2

This version is a little less aggressive. It keeps FindNaturalLoops which makes safepoint integration much easier.

Comment 5

[Sean Stangl [:sstangl]]

Comment on attachment 583331 [details] [diff] [review]
v2

Review of attachment 583331 [details] [diff] [review]:
-----------------------------------------------------------------

This looks great. It's significantly simpler. Haven't found any issues.

::: js/src/ion/C1Spewer.cpp
@@ +55,5 @@
>  
>  bool
>  C1Spewer::init(const char *path)
>  {
> +    spewout_ = NULL; //fopen(path, "w");

Hm.

::: js/src/ion/MIRGraph.h
@@ +406,5 @@
>          JS_ASSERT(isLoopHeader());
>          return containedInLoop_.append(block);
>      }
>  
> +	void setLoopDepth(uint32 loopDepth) {

One indentation level back

Comment 6

[David Anderson [:dvander] - inactive, e-mail if emergency]

http://hg.mozilla.org/projects/ionmonkey/rev/3725545a3e35