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| author | Sanjay Patel <spatel@rotateright.com> | 2020-01-07 09:47:50 -0500 |
|---|---|---|
| committer | Sanjay Patel <spatel@rotateright.com> | 2020-01-07 09:48:59 -0500 |
| commit | 58e2e92a57fcc3c628fd03ae33698fcc9aabedb9 (patch) | |
| tree | a868bd918c4f06b22ab4b9d2d385a6ba55ebc438 /clang/lib/Frontend/CompilerInvocation.cpp | |
| parent | 3f2e3dc44b42fab2e991222e74248b7006f1091e (diff) | |
| download | llvm-58e2e92a57fcc3c628fd03ae33698fcc9aabedb9.zip llvm-58e2e92a57fcc3c628fd03ae33698fcc9aabedb9.tar.gz llvm-58e2e92a57fcc3c628fd03ae33698fcc9aabedb9.tar.bz2 | |
[DAGCombiner] reduce shuffle of concat of same vector
This is possibly a small part towards solving PR42024:
https://bugs.llvm.org/show_bug.cgi?id=42024
The vectorizer is creating shuffles of concat like this:
%63 = shufflevector <4 x i64> %x, <4 x i64> undef, <8 x i32> <i32 0, i32 1, i32 2, i32 3, i32 0, i32 1, i32 2, i32 3>
%64 = shufflevector <8 x i64> %63, <8 x i64> undef, <8 x i32> <i32 0, i32 4, i32 1, i32 5, i32 2, i32 6, i32 3, i32 7>
That might be fixable in the vectorizers, but we're not allowed to fold that into a single shuffle in instcombine,
so we should have a backend backstop to convert that into the likely simpler form:
%64 = shufflevector <4 x i64> %x, <4 x i64> undef, <8 x i32> <i32 0, i32 0, i32 1, i32 1, i32 2, i32 2, i32 3, i32 3>
Differential Revision: https://reviews.llvm.org/D72300
Diffstat (limited to 'clang/lib/Frontend/CompilerInvocation.cpp')
0 files changed, 0 insertions, 0 deletions