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author | Manman Ren <manman.ren@gmail.com> | 2014-01-31 01:10:35 +0000 |
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committer | Manman Ren <manman.ren@gmail.com> | 2014-01-31 01:10:35 +0000 |
commit | 05324ab01567f5b7a90f587ec36f54c1bef53c99 (patch) | |
tree | 11d1c18363f5ba6c053fc05df449d5b7ebb2e578 /include | |
parent | 45b07e157c0a22fec8148e0cc7243a029d4a061e (diff) | |
download | llvm-05324ab01567f5b7a90f587ec36f54c1bef53c99.tar.gz llvm-05324ab01567f5b7a90f587ec36f54c1bef53c99.tar.bz2 llvm-05324ab01567f5b7a90f587ec36f54c1bef53c99.tar.xz |
This patch teaches the DAGCombiner how to fold insert_subvector nodes
when the input is a concat_vectors and the insert replaces one of the
concat halves:
Lower half: fold (insert_subvector (concat_vectors X, Y), Z) ->
(concat_vectors Z, Y)
Upper half: fold (insert_subvector (concat_vectors X, Y), Z) ->
(concat_vectors X, Z)
This can be seen with the following IR:
define <8 x float> @lower_half(<4 x float> %v1, <4 x float> %v2, <4 x
float> %v3) {
%1 = shufflevector <4 x float> %v1, <4 x float> %v2, <8 x i32> <i32
0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7>
%2 = tail call <8 x float> @llvm.x86.avx.vinsertf128.ps.256(<8 x
float> %1, <4 x float> %v3, i8 0)
The vinsertf128 intrinsic is converted into an insert_subvector node
in SelectionDAGBuilder.cpp.
Using AVX, without the patch this generates two vinsertf128 instructions:
vinsertf128 $1, %xmm1, %ymm0, %ymm0
vinsertf128 $0, %xmm2, %ymm0, %ymm0
With the patch this is optimized into:
vinsertf128 $1, %xmm1, %ymm2, %ymm0
Patch by Robert Lougher.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200506 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'include')
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