[webkit-reviews] review denied: [Bug 123182] Change local variable register allocation to start at offset -1 : [Attachment 215080] Patch

[bugzilla-daemon at webkit.org]

Geoffrey Garen <ggaren at apple.com> has denied Michael Saboff
<msaboff at apple.com>'s request for review:
Bug 123182: Change local variable register allocation to start at offset -1
https://bugs.webkit.org/show_bug.cgi?id=123182

Attachment 215080: Patch
https://bugs.webkit.org/attachment.cgi?id=215080&action=review

------- Additional Comments from Geoffrey Garen <ggaren at apple.com>
View in context: https://bugs.webkit.org/attachment.cgi?id=215080&action=review


> Source/JavaScriptCore/bytecode/CodeBlock.h:350
> +    int numCalleeRegistersIncludingSkippedSlot0() { return
m_numCalleeRegisters + 1; }

We want the call frame pointer to point to the first call frame header slot,
with the first local below it. This skipped slot 0 design logically points the
call frame header at the first local slot, and then avoids allocating a virtual
register to the first local slot. That's not quite what we want.

Instead, you should adjust the call frame pointer to point to the first call
frame header slot.

> Source/JavaScriptCore/bytecode/VirtualRegister.h:77
> +    static int localToOperand(int local) { return -1-local; }
> +    static int operandToLocal(int operand) { return -1-operand; }

Spaces around "-" please.