Displaying 1 result from an estimated 1 matches for "_mm_fmadd_ss".
2016 Sep 12
4
[X86] FMA transformation restrictions
I noticed that the operand commuting code in X86InstrInfo.cpp treats
scalar FMA intrinsics specially. It prevents operand commuting on these
scalar instructions because the scalar FMA instructions preserve the
upper bits of the vector. Presumably, the restrictions are there
because commuting operands potentially changes the result upper bits.
However, AFAIK the Intel and GNU FMA intrinsics