840569 - BaselineCompiler: Inline caches for comparing numbers with undefined

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[Brian Hackett [Laid off!]]

Attachment: patch

Some SS tests use this pattern heavily.  Adding a cache for this reduces the number of fallback stubs taken in SS by about 3%.  This also adds a bool<->bool comparison stub, which is colder.

Comment 1

[Kannan Vijayan [:djvj]]

Comment on attachment 712952 [details] [diff] [review]
patch

Review of attachment 712952 [details] [diff] [review]:
-----------------------------------------------------------------

::: js/src/ion/BaselineIC.cpp
@@ +1244,5 @@
> +        ICCompare_Boolean::Compiler compiler(cx, op);
> +        ICStub *booleanStub = compiler.getStub(ICStubSpace::StubSpaceFor(script));
> +        if (!booleanStub)
> +            return false;
> +        

Nit: trailing whitespace above.

::: js/src/ion/BaselineIC.h
@@ +1512,5 @@
>          }
>      };
>  };
>  
> +class ICCompare_DoubleWithUndefined : public ICStub

This should be ICCompare_NumberWithUndefined, to reflect its operation.  Name currently suggests it gets attached strictly for double/undefined compares.

Comment 2

[Tom S [:evilpie]]

Comment on attachment 712952 [details] [diff] [review]
patch

Review of attachment 712952 [details] [diff] [review]:
-----------------------------------------------------------------

::: js/src/ion/BaselineIC.cpp
@@ +1347,5 @@
> +
> +    Label result, success;
> +
> +    // Compare payload regs of R0 and R1.
> +    Assembler::Condition cond = JSOpToCondition(op);

I recently moved emitSet into MacroAssembler.

@@ +1366,5 @@
> +    return true;
> +}
> +
> +//
> +// Compare_Boolean

Compare_DoubleWithUndefined

Comment 3

[Brian Hackett [Laid off!]]

https://hg.mozilla.org/projects/ionmonkey/rev/9a755b1e97a4