I am trying to run various benchmark tests using CPU2006 to see what various optimizations do in terms of speed on gcc. I am familiar with -O1, -O2, and -O3, but have heard that -msse is a decent optimization. What exactly is -msse? I've also seen that -msse is default on a 64 bit architecture, so how do I disable it to compare the difference between using it and not using it?
http://www.justskins.com/forums/gcc-option-msse-and-128289.html
SSE (http://it.wikipedia.org/wiki/Streaming_SIMD_Extensions) as the name says are the SSE instructions present in processors since Pentium 3. They are fast for some kind of vectorial and floating point computation. They are available in all 64 bit processors, so why should we disable them?
You can choose between -msse and -msse2. SSE2 are another instruction set built over SSE that add other powerful and very fast vectorial instructions.
Pentium 3 did have SSE, and is a 32 bit processor. SSE2 is more modern instead, Pentium 4, that is still a 32 bit processor, have SSE2.