rust/src/test/codegen/some-global-nonnull.rs
Nikita Popov 7e5c7cf8e3 Emit == null instead of <= null
When the niche maximum is zero, emit a "== zero" check instead of
a "<= zero" check. In particular, this avoid the awkward case of
"<= null". While LLVM does canonicalize this to "!= null", this
appently doesn't happen for constant expressions, leading to the
issue in #74425. While that can be addressed on the LLVM side, it
still seems prudent to emit sensible IR here, because this will
allow null checks to be optimized earlier in the pipeline.

Fixes #74425.
2020-08-08 10:45:15 +02:00

25 lines
361 B
Rust

// compile-flags: -O
#![crate_type = "lib"]
// CHECK-LABEL: @test
// CHECK-NEXT: start:
// CHECK-NEXT: tail call void @ext_fn0()
#[no_mangle]
pub fn test() {
test_inner(Some(inner0));
}
fn test_inner(f_maybe: Option<fn()>) {
if let Some(f) = f_maybe {
f();
}
}
fn inner0() {
unsafe { ext_fn0() };
}
extern "C" {
fn ext_fn0();
}