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| author | Sanjay Patel <spatel@rotateright.com> | 2017-06-12 14:23:43 +0000 |
|---|---|---|
| committer | Sanjay Patel <spatel@rotateright.com> | 2017-06-12 14:23:43 +0000 |
| commit | 2e33bbaff0904a8568eac4c9329a39834edf2c68 (patch) | |
| tree | 079dc7754c09115ac2d102f63911871b20118f2f /lldb/packages/Python/lldbsuite/test/expression_command | |
| parent | c0112ae8dacc969b828e7ca17251126413bcc8cc (diff) | |
| download | bcm5719-llvm-2e33bbaff0904a8568eac4c9329a39834edf2c68.tar.gz bcm5719-llvm-2e33bbaff0904a8568eac4c9329a39834edf2c68.zip | |
[InstCombine] lshr (sext iM X to iN), N-M --> zext (ashr X, min(N-M, M-1)) to iN
This is a follow-up to https://reviews.llvm.org/D33879 / https://reviews.llvm.org/rL304939 ,
and was discussed in https://reviews.llvm.org/D33338.
We prefer this form because a narrower shift may be cheaper, and we can more easily fold a
zext than a sext.
http://rise4fun.com/Alive/slVe
Name: shz
%s = sext i8 %x to i12
%r = lshr i12 %s, 4
=>
%a = ashr i8 %x, 4
%r = zext i8 %a to i12
llvm-svn: 305190
Diffstat (limited to 'lldb/packages/Python/lldbsuite/test/expression_command')
0 files changed, 0 insertions, 0 deletions
