| Issue |
131824
|
| Summary |
InstCombine misses freeze of i1 select fold which appears in X86ISelLowering
|
| Labels |
llvm:instcombine,
missed-optimization
|
| Assignees |
|
| Reporter |
arsenm
|
```
define i1 @src(i8 range(i8 0, 2) noundef %i, i8 range(i8 0, 2) noundef %i1) {
bb:
%loadedv.i.i2.i = trunc nuw i8 %i to i1
%loadedv.i1.i.i = trunc nuw i8 %i1 to i1
%i2 = select i1 %loadedv.i.i2.i, i1 %loadedv.i1.i.i, i1 false
%cond.fr13 = freeze i1 %i2
ret i1 %cond.fr13
}
define i1 @tgt(i8 range(i8 0, 2) noundef %i, i8 range(i8 0, 2) noundef %i1) {
bb:
%i21 = and i8 %i1, %i
%i2 = trunc nuw i8 %i21 to i1
ret i1 %i2
}
```
https://alive2.llvm.org/ce/z/HRpvwJ
I noticed this while looking at random IR samples in X86ISelLowering.cpp's output.
![]()
_______________________________________________
llvm-bugs mailing list
llvm-bugs@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-bugs
