Invalid codegen for wasm at opt-level=0 #51986
Description
I've reported an upstream LLVM bug for this but I want to track it on our side as well to track pulling in the fix. The gist of the issue is that this code:
extern {
fn return_one() -> u32;
fn panic() -> !;
}
#[no_mangle]
pub unsafe extern fn test() {
let tmp: bool = !(return_one() == 1);
if tmp { panic() }
if !tmp { panic() }
}will execute successfully when compiled at O0:
<html>
<head>
<script>
const imports = {
env: {
return_one: function() { return 1; },
panic: function() { throw 'bad'; }
}
};
fetch('foo.wasm')
.then(r => r.arrayBuffer())
.then(r => WebAssembly.instantiate(r, imports))
.then(m => {
console.log('start');
m.instance.exports.test()
console.log('end');
})
.catch(e => console.error(e));
</script>
</head>
<body>
</body>
</html>And it should certainly panic!
I'm currently hoping we can fix this upstream in LLVM before we need to work around it in rustc!
