overmighty wrote:
Maybe the semantic analysis and docs should have been changed to match GCC's
better.
GCC's docs say their `__builtin_popcountg` takes a "type-generic unsigned
integer" but that "No integral argument promotions are performed on the
argument." Our builtin accepts signed integers too, but the argument goes
through integer promotion, so the builtin can return an incorrect value if we
give it a signed integer.
For example, this program will output 32 with Clang on
`x86_64-unknown-linux-gnu`:
```c
#include <stdio.h>
int main(void) {
char foo = -1;
int pop = __builtin_popcountg(foo);
printf("%d\n", pop);
}
```
GCC refuses to compile it: https://godbolt.org/z/chh4WGT4v.
Should I open a new issue?
https://github.com/llvm/llvm-project/pull/82359
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