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-fpic no optimization...


Happy 2006!

I was compiling LZMA SDK (http://www.7-zip.org/, LzmaDecode.c) and just
for curiosity I looked at output assembler. I noted that when PIC is
enabled (-fpic, Linux Intel) ebx is reserved to global pointer. However
LzmaDecode do not access any global data and do not call other functions
(no relocations at all) so why not use ebx register? -fpic make compiler
just not use ebx. I tried using different versions (gcc 3.4.4 from
Fedora Core 3 and 4.0.2 from Fedora Core 4) with same result.

Frediano Ziglio (aka freddy77)




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