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| author | Sanjay Patel <spatel@rotateright.com> | 2019-04-17 22:38:51 +0000 |
|---|---|---|
| committer | Sanjay Patel <spatel@rotateright.com> | 2019-04-17 22:38:51 +0000 |
| commit | fb363a778fd72e1db89f8b8910582664b2d579fa (patch) | |
| tree | f283e715e617469b2f29d51de21b7a91ce2b3247 /lldb/scripts/Python/prepare_binding_Python.py | |
| parent | 4c177038e096dad3646fe8fc33682e6ef2f590fa (diff) | |
| download | bcm5719-llvm-fb363a778fd72e1db89f8b8910582664b2d579fa.tar.gz bcm5719-llvm-fb363a778fd72e1db89f8b8910582664b2d579fa.zip | |
[x86] try to widen 'shl' as part of LEA formation
The test file has pairs of tests that are logically equivalent:
https://rise4fun.com/Alive/2zQ
%t4 = and i8 %t1, 8
%t5 = zext i8 %t4 to i16
%sh = shl i16 %t5, 2
%t6 = add i16 %sh, %t0
=>
%t4 = and i8 %t1, 8
%sh2 = shl i8 %t4, 2
%z5 = zext i8 %sh2 to i16
%t6 = add i16 %z5, %t0
...so if we can fold the shift op into LEA in the 1st pattern, then we
should be able to do the same in the 2nd pattern (unnecessary 'movzbl'
is a separate bug I think).
We don't want to do this any sooner though because that would conflict
with generic transforms that try to narrow the width of the shift.
Differential Revision: https://reviews.llvm.org/D60789
llvm-svn: 358622
Diffstat (limited to 'lldb/scripts/Python/prepare_binding_Python.py')
0 files changed, 0 insertions, 0 deletions
