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

RESOLVED FIXED in mozilla37

Status

()

Product:
Core
Component:
JavaScript Engine: JIT
Type:
defect
Status:
RESOLVED FIXED
Opened:
5 years ago
Updated:
5 years ago

People

(Reporter: bzbarsky, Assigned: bzbarsky)

Tracking

Version:
unspecified
Target:
mozilla37
Platform:
x86
macOS
Points:
---

Firefox Tracking Flags

(Not tracked)

Details

Attachments

(1 attachment)

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: 5 years ago
Resolution: --- → FIXED
You need to log in before you can comment on or make changes to this bug.