rust/tests/mir-opt/const_prop/indirect_mutation.rs

42 lines
931 B
Rust

//@ test-mir-pass: GVN
// Check that we do not propagate past an indirect mutation.
#![feature(raw_ref_op)]
// EMIT_MIR indirect_mutation.foo.GVN.diff
fn foo() {
// CHECK-LABEL: fn foo(
// CHECK: debug u => _1;
// CHECK: debug y => _3;
// CHECK: _1 = const (1_i32,);
// CHECK: _2 = &mut (_1.0: i32);
// CHECK: (*_2) = const 5_i32;
// CHECK: _4 = (_1.0: i32);
// CHECK: _3 = Eq(move _4, const 5_i32);
let mut u = (1,);
*&mut u.0 = 5;
let y = { u.0 } == 5;
}
// EMIT_MIR indirect_mutation.bar.GVN.diff
fn bar() {
// CHECK-LABEL: fn bar(
// CHECK: debug v => _1;
// CHECK: debug y => _4;
// CHECK: _3 = &raw mut (_1.0: i32);
// CHECK: (*_3) = const 5_i32;
// CHECK: _5 = (_1.0: i32);
// CHECK: _4 = Eq(move _5, const 5_i32);
let mut v = (1,);
unsafe {
*&raw mut v.0 = 5;
}
let y = { v.0 } == 5;
}
fn main() {
foo();
bar();
}