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Re: [PATCH] speedup timevar pushing/poping

Andrew Pinski <> writes:

>> This is probably OK, but could you post a compiler speed and binary
>> size comparison?
> Okay I did some speed and size comparison on i686 (because my PPC
> laptop's battery ran out and I had forgot to take my power supply
> to school today).
> Here is the results.
> test			before		after		percent
> Speed, PR8361 -O3	57.27s		57.19		.10%
> cc1 size		11278673	11287701	.09%
> cc1plus		14245041	14258105	.08%

I'm not surprised it's more of a win on PPC, which has a much more
expensive calling convention.  However, .1% performance improvements
are tiny enough that I worry about the noise floor.  How did you
arrive at that number?

Could you repeat the test with the timevar_push/pop macros modified

#define timevar_pop(TV) do { if (__builtin_expect (timevar_enable, 0)) timevar_pop_1 (TV); }while(0)
#define timevar_push(TV) do { if (__builtin_expect (timevar_enable, 0)) timevar_push_1 (TV); }while(0)

as I suspect GCC is not clever enough to predict the conditional.
(This will probably be both more of a speed improvement and more of a
size increase.)


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