[Ffmpeg-devel] int vs. float profiler, take 2

[Attila Kinali]

On Fri, 20 May 2005 17:05:30 -0600
Mike Melanson <mike at multimedia.cx> wrote:

> The ASM code has ITERATIONS set to 1 right now. I would be interested to 
> know the results from varying CPUs using 1, 10, and 100 iterations.

Here again my PentiumM:

  warming up with 1000 cycles...
integer_adder(), 1 adds, 43 cycles used (overhead = 43)
float_adder(), 1 adds, 199 cycles used (overhead = 43)
integer_mult(), 1 mults, 43 cycles used (overhead = 43)
float_mult(), 1 mults, 200 cycles used (overhead = 43)

  warming up with 1000 cycles...
integer_adder(), 10 adds, 46 cycles used (overhead = 43)
float_adder(), 10 adds, 1596 cycles used (overhead = 43)
integer_mult(), 10 mults, 87 cycles used (overhead = 43)
float_mult(), 10 mults, 1618 cycles used (overhead = 43)

 warming up with 1000 cycles...
integer_adder(), 100 adds, 136 cycles used (overhead = 43)
float_adder(), 100 adds, 15579 cycles used (overhead = 43)
integer_mult(), 100 mults, 539 cycles used (overhead = 43)
float_mult(), 100 mults, 15780 cycles used (overhead = 43)

And here the result with Gabriel Gerhardsson math.asm:

  warming up with 1000 cycles...
integer_adder(), 1 adds, 291 cycles used (overhead = 291)
float_adder(), 1 adds, 447 cycles used (overhead = 290)
integer_mult(), 1 mults, 295 cycles used (overhead = 291)
float_mult(), 1 mults, 448 cycles used (overhead = 291)

  warming up with 1000 cycles...
integer_adder(), 10 adds, 301 cycles used (overhead = 291)
float_adder(), 10 adds, 1844 cycles used (overhead = 291)
integer_mult(), 10 mults, 340 cycles used (overhead = 290)
float_mult(), 10 mults, 1865 cycles used (overhead = 290)

  warming up with 1000 cycles...
integer_adder(), 100 adds, 397 cycles used (overhead = 291)
float_adder(), 100 adds, 15827 cycles used (overhead = 290)
integer_mult(), 100 mults, 792 cycles used (overhead = 290)
float_mult(), 100 mults, 16027 cycles used (overhead = 291)

Any explanation why float performs so much worse than integer
compared to the first version of this benchmark ?

			Attila Kinali
-- 
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