On 20.07.2022 15:33, Andrew Cooper wrote: > On 20/07/2022 14:30, Jan Beulich wrote: >> Passing -mno-sse alone is not enough: The compiler may still find >> (questionable) reasons to use MMX insns. In particular with gcc12 use >> of MOVD+PUNPCKLDQ+MOVQ was observed in an apparent attempt to auto- >> vectorize the storing of two adjacent zeroes, 32 bits each. >> >> Reported-by: ChrisD <[email protected]> >> Signed-off-by: Jan Beulich <[email protected]> > > Acked-by: Andrew Cooper <[email protected]>
Thanks. > But while we're at it, what else might we have to clobber to stop > nonsense like this? x87 and avx come to mind. AVX is taking SSE as a prereq (with -mno-sse %xmm etc registers simply are unavailable). And with -msoft-float I would very much hope we have clearly indicated to the compiler that we want no x87 insns whatsoever. Jan
