Re: kernel + gcc 4.1 = several problems

From: Segher Boessenkool
Date: Sun Jan 07 2007 - 10:13:17 EST


I want this:

char v[4];
...
memcmp(v, "abcd", 4) == 0

compile to single cmpl on i386. This (gcc 4.1.1) is ridiculous:

call memcmp

i686-linux-gcc (GCC) 4.2.0 20060410 (experimental)

movl $4, %ecx #, tmp65
cld
movl $v, %esi #, tmp63
movl $.LC0, %edi #, tmp64
repz
cmpsb
sete %al #, tmp68

Still not perfect, but better already. If you have any
specific examples that you'd like to have compiled to
better code, please report them in GCC bugzilla (with a
self-contained testcase, please).


Segher

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