On 02/05/15 14:37, Volker Armin Hemmann wrote:
Am 02.05.2015 um 13:25 schrieb Nikos Chantziaras:
The kernel uses -O2 and several -march variants (e.g. -march=core2).
Several other options are used to prevent GCC from generating
unsuitable code.
Specifying another -march variant does not affect the optimizer
though. It only affects the code generator. If you don't modify the
other CFLAGS and only change -march, you will not get FP instructions
unless you use FP in the code.
http://www.agner.org/optimize/calling_conventions.pdf
Not sure what you're trying to say.
that simd is not save in kernel if not carefully guarded.
Really people, just don't fuck around with the cflags.
I still fail to see the relevance. Unless you mean using a different -O
level. In that case, yes. You shouldn't. But I was talking about -march.
