| Issue |
161140
|
| Summary |
slp-vectorizer miscompile
|
| Labels |
new issue
|
| Assignees |
|
| Reporter |
mikaelholmen
|
llvm commit: ab5bba580c5
Reproduce with:
```
opt -passes=slp-vectorizer bbi-110973_2.ll -S -o - -slp-threshold=-100
```
which results in
```
define i1 @foo(i1 %v) {
entry:
%0 = insertelement <2 x i1> poison, i1 %v, i32 0
%1 = shufflevector <2 x i1> %0, <2 x i1> poison, <2 x i32> zeroinitializer
%2 = mul <2 x i1> <i1 false, i1 true>, %1
%3 = extractelement <2 x i1> %2, i32 0
%4 = extractelement <2 x i1> %2, i32 1
%sub = sub i1 %3, %4
ret i1 %sub
}
```
If you e.g. calculate the result for input value %v == 1 you see the the input and output results are different.
See also
[alive2](https://alive2.llvm.org/ce/#g:!((g:!((g:!((h:codeEditor,i:(fontScale:14,j:1,lang:llvm,selection:(endColumn:14,endLineNumber:7,positionColumn:14,positionLineNumber:7,selectionStartColumn:14,selectionStartLineNumber:7,startColumn:14,startLineNumber:7),source:'define+i1+@src(i1+%25v)+%7B%0Aentry:%0A++%25not+%3D+xor+i1+%25v,+1%0A++%25not1+%3D+xor+i1+%25not,+1%0A++%25mul+%3D+mul+i1+%25v,+1%0A++%25sub+%3D+sub+i1+%25not1,+%25mul%0A++ret+i1+%25sub%0A%7D%0A%0Adefine+i1+@tgt(i1+%25v)+%7B%0Aentry:%0A++%250+%3D+insertelement+%3C2+x+i1%3E+poison,+i1+%25v,+i32+0%0A++%251+%3D+shufflevector+%3C2+x+i1%3E+%250,+%3C2+x+i1%3E+poison,+%3C2+x+i32%3E+zeroinitializer%0A++%252+%3D+mul+%3C2+x+i1%3E+%3Ci1+false,+i1+true%3E,+%251%0A++%253+%3D+extractelement+%3C2+x+i1%3E+%252,+i32+0%0A++%254+%3D+extractelement+%3C2+x+i1%3E+%252,+i32+1%0A++%25sub+%3D+sub+i1+%253,+%254%0A++ret+i1+%25sub%0A%7D%0A'),l:'5',n:'0',o:'LLVM+IR+source+%231',t:'0')),k:43.15667262669051,l:'4',n:'0',o:'',s:0,t:'0'),(g:!((h:compiler,i:(compiler:alive,filters:(b:'0',binary:'1',commentOnly:'0',demangle:'0',directives:'0',execute:'1',intel:'0',libraryCode:'1',trim:'1'),fontScale:14,j:1,lang:llvm,libs:!(),options:'--disable-undef-input',selection:(endColumn:1,endLineNumber:1,positionColumn:1,positionLineNumber:1,selectionStartColumn:1,selectionStartLineNumber:1,startColumn:1,startLineNumber:1),source:1),l:'5',n:'0',o:'alive-tv+(Editor+%231,+Compiler+%231)+LLVM+IR',t:'0')),k:56.8433273733095,l:'4',n:'0',o:'',s:0,t:'0')),l:'2',n:'0',o:'',t:'0')),version:4)
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