On v8-raytrace JM calls stubs::ValueToBoolean more than 400.000 times. This may be caused by these lines: -------- this.x = (x ? x : 0); this.y = (y ? y : 0); this.z = (z ? z : 0); -------- We should add (stub-)paths for int32/double in BooleanJumpScript to eliminate them. Should win at least some % on v8-raytrace and could help other benchmarks/websites. Note that JSC also has fast paths for these cases in emit_op_jtrue.

A double stub path removes 400.000 stub calls to ValueToBoolean but wins just a few ms. IIRC this helped more on my P4, which I used to measure the numbers in comment 0. It makes the code more complicated though and type inference will subsume this anyway, so marking WONTFIX for now. Will reopen if some other benchmark requires it.