[LLVMdev] Turning on/off instruction extensions

[Pablo Barrio López-Cortijo]

Hi everybody,

I'm trying to run some examples with different backend options (turning
on/off SSE, 3dnow, or MMX instructions). However, I don't see any
difference in terms of execution time. Does anybody know which language
constructs (in C/C++ preferably) should I try to make these instructions
generated (and thus make a difference between a backend that enables
them or not) ?

I tried generating vector instructions with loops but it's not
happening. Perhaps Polly can generate vector instructions?

Thanks ahead,

Pablo
DIE-UPM
Madrid