Add target specific rules for combining vselect dag nodes into movss/movsd
when possible.
If the vector type of the vselect dag node in input is either MVT::v4i13 or
MVT::v4f32, then try to fold according to rules:
1) fold (vselect (build_vector (0, -1, -1, -1)), A, B) -> (movss A, B)
2) fold (vselect (build_vector (-1, 0, 0, 0)), A, B) -> (movss B, A)
If the vector type of the vselect dag node in input is either MVT::v2i64 or
MVT::v2f64 (and we have SSE2), then try to fold according to rules:
3) fold (vselect (build_vector (0, -1)), A, B) -> (movsd A, B)
4) fold (vselect (build_vector (-1, 0)), A, B) -> (movsd B, A)
llvm-svn: 199683
a vector packed single/double fp operation followed by a vector insert.
The effect is that the backend coverts the packed fp instruction
followed by a vectro insert into a SSE or AVX scalar fp instruction.
For example, given the following code:
__m128 foo(__m128 A, __m128 B) {
__m128 C = A + B;
return (__m128) {c[0], a[1], a[2], a[3]};
}
previously we generated:
addps %xmm0, %xmm1
movss %xmm1, %xmm0
we now generate:
addss %xmm1, %xmm0
llvm-svn: 197145
Andrea Di Biagio