rust/tests/mir-opt/copy-prop/borrowed_local.rs

42 lines
940 B
Rust

// skip-filecheck
// EMIT_MIR_FOR_EACH_PANIC_STRATEGY
//@ unit-test: CopyProp
#![feature(custom_mir, core_intrinsics)]
#![allow(unused_assignments)]
extern crate core;
use core::intrinsics::mir::*;
fn opaque(_: impl Sized) -> bool { true }
fn cmp_ref(a: &u8, b: &u8) -> bool {
std::ptr::eq(a as *const u8, b as *const u8)
}
#[custom_mir(dialect = "analysis", phase = "post-cleanup")]
fn f() -> bool {
mir!(
{
let a = 5_u8;
let r1 = &a;
let b = a;
// We cannot propagate the place `a`.
let r2 = &b;
Call(RET = cmp_ref(r1, r2), ReturnTo(next), UnwindContinue())
}
next = {
// But we can propagate the value `a`.
Call(RET = opaque(b), ReturnTo(ret), UnwindContinue())
}
ret = {
Return()
}
)
}
fn main() {
assert!(!f());
}
// EMIT_MIR borrowed_local.f.CopyProp.diff