Bug 14602
| Summary: | JSC/WTF: fastMalloc doesn't use bsr under VC | ||
|---|---|---|---|
| Product: | WebKit | Reporter: | 808caaa4.8ce9.9cd6c799e9f6 |
| Component: | JavaScriptCore | Assignee: | Nobody <webkit-unassigned> |
| Status: | RESOLVED WONTFIX | ||
| Severity: | Trivial | CC: | ap, barraclough |
| Priority: | P4 | Keywords: | InRadar, PlatformOnly |
| Version: | 523.x (Safari 3) | ||
| Hardware: | PC | ||
| OS: | Windows XP | ||
808caaa4.8ce9.9cd6c799e9f6
With VC, fastMalloc.cpp doesn't use inline assembly for LgFloor().
#if defined(_MSC_VER) && !defined(_68K_) && !defined(_MPPC_) && !defined(_X86_) && !defined(_IA64_) && !defined(_AMD64_) && defined(_M_IX86)
static inline int LgFloor(size_t n) {
__asm xor eax,eax
__asm not eax
__asm bsr eax,n
}
#endif
p.s.
In WebKit.dll, do_malloc() and do_free() expands as ALWAYS_INLINE everywhere and costs binary sizes.
Is this intended?
| Attachments | ||
|---|---|---|
| Add attachment proposed patch, testcase, etc. |
David Kilzer (:ddkilzer)
<rdar://problem/5335830>
Maciej Stachowiak
Yes, we don't have all the inline assembly implemented for Windows yet. It could be a small performance boost once done.
Maciej Stachowiak
Why are the xor and the not needed in the inline assembly here? They don't seem to be needed in the gcc version.
Robert Blaut
P5 is not used for WebKit bugs. [http://webkit.org/quality/bugpriorities.html]
Gavin Barraclough
I don't think this method has shown up under recent profiling, and this bug has sat idle for 5 years. I don't think this is a change we intend to make. Please reopen if you intend to work on this bug.