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| author | Zvi Rackover <zvi.rackover@intel.com> | 2017-04-30 06:25:04 +0000 |
|---|---|---|
| committer | Zvi Rackover <zvi.rackover@intel.com> | 2017-04-30 06:25:04 +0000 |
| commit | 9d8cd821e690e4bcb2d5277423a1f807ed45a4c8 (patch) | |
| tree | 7445a3b0b0bcca9a6fca0c7e0c94fa26a9cfdfa7 /llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp | |
| parent | 0411e46fff0aec936263fc34fb435653334f79c8 (diff) | |
| download | bcm5719-llvm-9d8cd821e690e4bcb2d5277423a1f807ed45a4c8.tar.gz bcm5719-llvm-9d8cd821e690e4bcb2d5277423a1f807ed45a4c8.zip | |
InstructionSimplify: Canonicalize shuffle operands. NFC-ish.
Summary:
Apply canonicalization rules:
1. Input vectors with no elements selected from can be replaced with undef.
2. If only one input vector is constant it shall be the second one.
This allows constant-folding to cover more ad-hoc simplifications that
were in place and avoid duplication for RHS and LHS checks.
There are more rules we may want to add in the future when we see a
justification. e.g. mask elements that select undef elements can be
replaced with undef.
Reviewers: spatel, RKSimon, andreadb, davide
Reviewed By: spatel, RKSimon
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D32338
llvm-svn: 301766
Diffstat (limited to 'llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp')
0 files changed, 0 insertions, 0 deletions
