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| author | Dávid Bolvanský <david.bolvansky@gmail.com> | 2021-01-17 17:06:06 +0100 |
|---|---|---|
| committer | Dávid Bolvanský <david.bolvansky@gmail.com> | 2021-01-17 17:06:14 +0100 |
| commit | ed396212da41feed9bffb8cc1ca6518ab031a3c7 (patch) | |
| tree | 7ca7dbabe3c673b61d302b3d1c6815b9ca6f18cc /llvm/lib/FileCheck/FileCheck.cpp | |
| parent | 469ceaf53892d26f7b68f86f1feb38fe7057815e (diff) | |
| download | llvm-ed396212da41feed9bffb8cc1ca6518ab031a3c7.zip llvm-ed396212da41feed9bffb8cc1ca6518ab031a3c7.tar.gz llvm-ed396212da41feed9bffb8cc1ca6518ab031a3c7.tar.bz2 | |
[InstCombine] Transform abs pattern using multiplication to abs intrinsic (PR45691)
```
unsigned r(int v)
{
return (1 | -(v < 0)) * v;
}
`r` is equivalent to `abs(v)`.
```
```
define <4 x i8> @src(<4 x i8> %0) {
%1:
%2 = ashr <4 x i8> %0, { 31, undef, 31, 31 }
%3 = or <4 x i8> %2, { 1, 1, 1, undef }
%4 = mul nsw <4 x i8> %3, %0
ret <4 x i8> %4
}
=>
define <4 x i8> @tgt(<4 x i8> %0) {
%1:
%2 = icmp slt <4 x i8> %0, { 0, 0, 0, 0 }
%3 = sub nsw <4 x i8> { 0, 0, 0, 0 }, %0
%4 = select <4 x i1> %2, <4 x i8> %3, <4 x i8> %0
ret <4 x i8> %4
}
Transformation seems to be correct!
```
Reviewed By: nikic
Differential Revision: https://reviews.llvm.org/D94874
Diffstat (limited to 'llvm/lib/FileCheck/FileCheck.cpp')
0 files changed, 0 insertions, 0 deletions