Mail Archives: pgcc/1998/09/02/12:29:05
At 11:44 AM 9/2/98, Krzysztof Strasburger wrote:
>Hi!
>I just downloaded and compiled pgcc-1.1a and did a simple comparison
>with the older pgcc-1.0.3a (my own FPU-intensive program).
>Compilation options:
>-march=pentium -mcpu=pentium -On -ffast-math -frerun-loop-opt
>-malign-double -mstack-align-double -malign-jumps=0 -malign-loops=0
>-malign-functions=0,
>where n=2,3,4 or s
>The first thing I noticed is code bloat :-(, but this is rather egcs
>related problem. Here are file sizes (in bytes):
>pgcc-1.0.3a: -O2 -O3 -O4
> 46600 46920 48024
>pgcc-1.1a: -O2 -O3 -O4 -Os
> 47880 48296 49224 46888
>The second thing I noticed is no speed improvement on Pentium :-(((
>(this is valid for tested program only, of course).
>And now the good news. The optimization on Pentium Pro is better than before.
>Here are execution times (only -mcpu=pentiumpro -march=pentiumpro different
>than in previous example) averaged over 9 runs:
>pgcc-1.0.3a: -O2 -O3
> 28.24s 28.95s
>pgcc-1.1a -O2 -O3 -Os
> 28.45s 27.97s 28.12s
>The performance win is not very big, but higher optimization options
>improve the performance for newer pgcc instead of degrading it.
>The code optimized for size performs surprisingly well.
>Krzysztof
Cool i'll try at DIEP whether there is speed improvement.
Greetings,
Vincent
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