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

45 lines
1005 B
Rust

// skip-filecheck
// Check that CopyProp does propagate return values of call terminators.
//@ unit-test: CopyProp
//@ needs-unwind
#![feature(custom_mir, core_intrinsics)]
use std::intrinsics::mir::*;
#[inline(never)]
fn dummy(x: u8) -> u8 {
x
}
// EMIT_MIR calls.nrvo.CopyProp.diff
fn nrvo() -> u8 {
let y = dummy(5); // this should get NRVO
y
}
// EMIT_MIR calls.multiple_edges.CopyProp.diff
#[custom_mir(dialect = "runtime", phase = "initial")]
fn multiple_edges(t: bool) -> u8 {
mir! {
let x: u8;
{
match t { true => bbt, _ => ret }
}
bbt = {
Call(x = dummy(13), ReturnTo(ret), UnwindContinue())
}
ret = {
// `x` is not assigned on the `bb0 -> ret` edge,
// so should not be marked as SSA for merging with `_0`.
RET = x;
Return()
}
}
}
fn main() {
// Make sure the function actually gets instantiated.
nrvo();
multiple_edges(false);
}