Subject: gcc de-optimisations
To: None <>
From: David Laight <>
List: tech-toolchain
Date: 10/23/2005 20:24:27
How do we stop gcc (i386) converting:
    if (memcmp(a, b, 16))
    movl  %ecx, #16
    repeq cmpsb

Since any moderm x86 processor takes more cycles getting a repeated
string operation started than I've had hot dinners recently...

It is probably faster to call a C compare function than to use the
inlined code that gcc generates.  Certainly I sped up (a hacked version of)
the dynamic linker that way.


David Laight: