Ilya Enkovich <enkovich....@gmail.com> writes: > Silvermont processors have penalty for instructions having 4+ bytes of > prefixes (including escape bytes in opcode). This situation happens > when REX prefix is used in SSE4 instructions. This patch tries to > avoid such situation by preferring xmm0-xmm7 usage over xmm8-xmm15 in > those instructions. I achieved it by adding new tuning flag and new > alternatives affected by tuning.
Why make it a tuning flag? Shouldn't this help unconditionally for code size everywhere? Or is there some drawback? -Andi -- a...@linux.intel.com -- Speaking for myself only
