[AArch64] Avoid going through GPRs for across-vector instructions.
This adds new node types for each intrinsic.
For instance, for addv, we have AArch64ISD::UADDV, such that:
(v4i32 (uaddv ...))
is the same as
(v4i32 (scalar_to_vector (i32 (int_aarch64_neon_uaddv ...))))
that is,
(v4i32 (INSERT_SUBREG (v4i32 (IMPLICIT_DEF)),
(i32 (int_aarch64_neon_uaddv ...)), ssub)
In a combine, we transform all such across-vector-lanes intrinsics to:
(i32 (extract_vector_elt (uaddv ...), 0))
This has one big advantage: by making the extract_element explicit, we
enable the existing patterns for lane-aware instructions to fire.
This lets us avoid needlessly going through the GPRs. Consider:
uint32x4_t test_mul(uint32x4_t a, uint32x4_t b) {
return vmulq_n_u32(a, vaddvq_u32(b));
}
We now generate:
addv.4s s1, v1
mul.4s v0, v0, v1[0]
instead of the previous:
addv.4s s1, v1
fmov w8, s1
dup.4s v1, w8
mul.4s v0, v1, v0
rdar://
20044838
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231840
91177308-0d34-0410-b5e6-
96231b3b80d8