Closed Bug 1113018 Opened 6 years ago Closed 6 years ago

x86-64 masm.extractObject does what looks like an unnecessary mov

Categories

(Core :: JavaScript Engine: JIT, defect)

Product:
Core
Component:
JavaScript Engine: JIT
Platform:
x86
macOS
Type:
defect
Priority:
Not set
Severity:
normal

Tracking

()

Status:
RESOLVED FIXED
Milestone:
mozilla37

People

(Reporter: bzbarsky, Assigned: bzbarsky)

Details

Attachments

(1 file)

Stop manually moving things into ScratchReg in the x86-64 version of extractObject; just rely on unboxNonDouble doing the right thing as needed
2.44 KB, patch
sunfish
: review+
Details | Diff | Splinter Review 
Here's the codegen I see for the masm.extractObject call in CallDOMNative:

    movq       0x0(%rsp), %r11
    movabsq    $0x7fffffffffff, %rsi
    andq       %r11, %rsi

With the patch I'm about to attach this becomes:

    movabsq    $0x7fffffffffff, %rsi
    andq       0x0(%rsp), %rsi
Comment on attachment 8538290 [details] [diff] [review]
Stop manually moving things into ScratchReg in the x86-64 version of extractObject; just rely on unboxNonDouble doing the right thing as needed

Review of attachment 8538290 [details] [diff] [review]:
-----------------------------------------------------------------

Nice, that eliminates an ugly coupling at the same time!
Attachment #8538290 - Flags: review?(sunfish) → review+
https://hg.mozilla.org/mozilla-central/rev/936b4df54580
Status: NEW → RESOLVED
Closed: 6 years ago
Resolution: --- → FIXED
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