[Vorbis-dev] [patch] libvorbis + gcc4

[j at v2v.cc]

http://trac.xiph.org/cgi-bin/trac.cgi/ticket/583

looking at why gcc4 could increase vorbis so much, i first had a look at
the compiler options, and i saw -O20, as far as i know there is 
-O0, .. -O3 and -Os but no -O20. changing that to -O2 (patch attached)
one gets close to the result of gcc-3.4.

gcc3.4-O20.ogg  20423 

gcc4-O20.ogg    54623
gcc4-O3.ogg     54623

gcc4-O2.ogg     20423

looking at the hexdump of gcc4-02.ogg and gcc3.4-020.ogg, 
they differ slightly, things like:
-0000000 674f 5367 0200 0000 0000 0000 0000 0e8a
-0000010 25e5 0000 0000 5b97 0de7 1e01 7601 726f
+0000000 674f 5367 0200 0000 0000 0000 0000 fb5f
+0000010 0bb0 0000 0000 6e2e af20 1e01 7601 726f

luckily the wav files i get from oggdec do not differ.

the question is now which part of -O3(which -O20 is in the end) 
causes this increase in vorbis and is it a bug in vorbis or 
in gcc4?

j
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