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| author | Sanjay Patel <spatel@rotateright.com> | 2018-08-26 18:20:41 +0000 |
|---|---|---|
| committer | Sanjay Patel <spatel@rotateright.com> | 2018-08-26 18:20:41 +0000 |
| commit | 113cac3b159214cb6ac28d527075eb1c250bca9f (patch) | |
| tree | 534c32b57423b767e7fa5ab3ed69f0760e861498 /llvm/lib/Demangle | |
| parent | 5fdb81755f28fe69234454ca4b1158862ced56a7 (diff) | |
| download | bcm5719-llvm-113cac3b159214cb6ac28d527075eb1c250bca9f.tar.gz bcm5719-llvm-113cac3b159214cb6ac28d527075eb1c250bca9f.zip | |
[SelectionDAG][x86] turn insertelement into undef with variable index into splat
I noticed this along with the patterns in D51125, but when the index is variable,
we don't convert insertelement into a build_vector.
For x86, that means these get expanded at legalization time into the loading/spilling
code that we see in the tests. I think it's always better to avoid going to memory on
these, and we get the optimal 'broadcast' if it's available.
I suspect other targets may want to look at enabling the hook. AArch64 and AMDGPU have
regression tests that would be affected (although I did not check what would happen in
those cases). In the most basic cases shown here, AArch64 would probably do much
better with a splat.
Differential Revision: https://reviews.llvm.org/D51186
llvm-svn: 340705
Diffstat (limited to 'llvm/lib/Demangle')
0 files changed, 0 insertions, 0 deletions
