| Issue |
98244
|
| Summary |
[X86] Function multiversioning doesn't consistently handle features with priority=0
|
| Labels |
new issue
|
| Assignees |
|
| Reporter |
DanShaders
|
The following code produces a correctly constructed ifunc resolver:
```cpp
[[gnu::target("sha")]] int f() { return 2; }
[[gnu::target("default")]] int f() { return 1; }
int main() { return f(); }
```
While in the snippet below, Clang either silently ignores the "sha" overload without assertions or ICEs with assertions.
```cpp
[[gnu::target("default")]] int f() { return 1; }
[[gnu::target("sha")]] int f() { return 2; }
int main() { return f(); }
```
CE link: https://godbolt.org/z/Ghzb6KzGf
The buggy behavior arises because "sha" has PRIORITY=0 as defined here:
https://github.com/llvm/llvm-project/blob/7bfb98c34687d9784f36937c3ff3e735698b498a/llvm/include/llvm/TargetParser/X86TargetParser.def#L214
Obviously, this is one of the manifestations of a long-standing issue with `__attribute__((target))` and "unorderable" features, so I'm not sure what the expected behavior is here. However, at the very least, issuing a diagnostic in the cases above will greatly improve DX.
![]()
_______________________________________________
llvm-bugs mailing list
llvm-bugs@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-bugs
