Closed Bug 579466 Opened 11 years ago Closed 11 years ago

JM: fast path for JSOP_MOD on int operands

Categories

(Core :: JavaScript Engine, defect)

defect
Not set
normal

Tracking

()

RESOLVED FIXED

People

(Reporter: dmandelin, Unassigned)

References

Details

We do 223331 of these in SunSpider. 

JM wanted SS win: 9 ms
Integer mod should be done using idiv. Since this requires clobbering %eax and %edx, mod should not be implemented within jsop_binary(), even though its constant-folding function can be used.

This is highly non-trivial to implement in the current state if you want fast-paths for (int, double) and (double, int), like jsop_binary() has.
(In reply to comment #1)
> This is highly non-trivial to implement in the current state if you want
> fast-paths for (int, double) and (double, int), like jsop_binary() has.

We only need mod for ints for now.
this path ends up being pretty gross, lots of guards. down to ~11,000 calls to slow::Mod now.

looks like a 5.5ms win, though it's not totally clear where this went. the biggest deltas are in users of MOD, though.

http://hg.mozilla.org/users/danderson_mozilla.com/moo/rev/4997d6d1141d
Status: NEW → RESOLVED
Closed: 11 years ago
Resolution: --- → FIXED
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