rust/tests/mir-opt/simplify_dead_blocks.rs

53 lines
1.5 KiB
Rust

//@ test-mir-pass: SimplifyCfg-after-unreachable-enum-branching
#![feature(custom_mir, core_intrinsics)]
#![crate_type = "lib"]
use std::intrinsics::mir::*;
// Check that we correctly cleaned up the dead BB.
// EMIT_MIR simplify_dead_blocks.assert_nonzero_nonmax.SimplifyCfg-after-unreachable-enum-branching.diff
#[custom_mir(dialect = "runtime", phase = "post-cleanup")]
pub unsafe fn assert_nonzero_nonmax(x: u8) -> u8 {
// CHECK-LABEL: fn assert_nonzero_nonmax(
// CHECK: bb0: {
// CHECK-NEXT: switchInt(copy {{_[0-9]+}}) -> [0: [[unreachable:bb.*]], 1: [[retblock2:bb.*]], 255: [[unreachable:bb.*]], otherwise: [[retblock:bb.*]]];
// CHECK-NEXT: }
// CHECK-NOT: _0 = const 1_u8;
// CHECK: [[retblock2]]: {
// CHECK-NEXT: _0 = const 2_u8;
// CHECK-NEXT: return;
// CHECK-NEXT: }
// CHECK: [[unreachable]]: {
// CHECK-NEXT: unreachable;
// CHECK-NEXT: }
// CHECK: [[retblock]]: {
// CHECK-NEXT: _0 = copy _1;
// CHECK-NEXT: return;
// CHECK-NEXT: }
mir! {
{
match x {
0 => unreachable,
1 => retblock2,
u8::MAX => unreachable,
_ => retblock,
}
}
deadRetblock1 = {
RET = 1;
Return()
}
retblock2 = {
RET = 2;
Return()
}
unreachable = {
Unreachable()
}
retblock = {
RET = x;
Return()
}
}
}