[Webkit-unassigned] [Bug 130638] [Win64] ASM LLINT is not enabled.

[bugzilla-daemon at webkit.org]

https://bugs.webkit.org/show_bug.cgi?id=130638





--- Comment #18 from Mark Lam <mark.lam at apple.com>  2014-04-10 17:52:05 PST ---
(From update of attachment 227778)
View in context: https://bugs.webkit.org/attachment.cgi?id=227778&action=review

> Source/JavaScriptCore/jit/Repatch.cpp:836
> -    stubJit.store32(MacroAssembler::TrustedImm32(reinterpret_cast<uint32_t>(structure->id())), MacroAssembler::Address(baseGPR, JSCell::structureIDOffset()));
> +#if USE(JSVALUE64)
> +    uint32_t val = structure->id();
> +#else
> +    uint32_t val = reinterpret_cast<uint32_t>(structure->id());
> +#endif
> +    stubJit.store32(MacroAssembler::TrustedImm32(val), MacroAssembler::Address(baseGPR, JSCell::structureIDOffset()));

Can you please clarify why is this change needed?  Your ChangeLog mentioned a "compile fix".  Can you please provide some details?  Thanks.

> Source/JavaScriptCore/llint/LowLevelInterpreter64.asm:387
> +# The signature of a slow path call is extern "C" SlowPathReturnType slowpathfunction(ExecState* exec, Instruction* pc).
> +# The size of the SlowPathReturnType is 16 bytes.
> +# On Win64, when the return type is larger than 8 bytes, we need to allocate space on the stack for the return value.
> +# On entry rcx (t2), should contain a pointer to this stack space. The other parameters are shifted to the right,
> +# rdx (t1) should contain the first argument, and r8 (t6) should contain the second argument.
> +# On return, rax contains a pointer to this stack value, and we then need to copy the 16 byte return value into rax (t0) and rdx (t1)
> +# since the return value is expected to be split between the two.
> +# See http://msdn.microsoft.com/en-us/library/7572ztz4.aspx
> +macro callSlowPathWin64(slowPath, arg1, arg2)
> +    move arg1, t1
> +    move arg2, t6
> +    subp 80, sp
> +    move sp, t2
> +    addp 48, t2
> +    call slowPath
> +    addp 80, sp
> +    move 8[t0], t1
> +    move [t0], t0
> +end

I suggest moving this into the cCall2() macro as a X86_64_WIN target instead of having a separate function like this.

> Source/JavaScriptCore/llint/LowLevelInterpreter64.asm:395
> -    cCall2(slowPath, cfr, PC)
> +    if X86_64_WIN
> +        callSlowPathWin64(slowPath, cfr, PC)
> +    else
> +        cCall2(slowPath, cfr, PC)
> +    end

Instead of adding this condition everywhere, is there any reason why you can't just add a case to cCall2() to handle X86_64_WIN?

Same with all the uses of cCall2() below.

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