rust/tests/codegen/constant-branch.rs

52 lines
1.0 KiB
Rust

//@ compile-flags: -Zmir-opt-level=0 -C no-prepopulate-passes -Copt-level=0
// make sure that branching on a constant does not emit a conditional
// branch or a switch
#![crate_type = "lib"]
// CHECK-LABEL: @if_bool
#[no_mangle]
pub fn if_bool() {
// CHECK: br label %{{.+}}
_ = if true { 0 } else { 1 };
// CHECK: br label %{{.+}}
_ = if false { 0 } else { 1 };
}
// CHECK-LABEL: @if_constant_int_eq
#[no_mangle]
pub fn if_constant_int_eq() {
let val = 0;
// CHECK: br label %{{.+}}
_ = if val == 0 { 0 } else { 1 };
// CHECK: br label %{{.+}}
_ = if val == 1 { 0 } else { 1 };
}
// CHECK-LABEL: @if_constant_match
#[no_mangle]
pub fn if_constant_match() {
// CHECK: br label %{{.+}}
_ = match 1 {
1 => 2,
2 => 3,
_ => 4,
};
// CHECK: br label %{{.+}}
_ = match 1 {
2 => 3,
_ => 4,
};
// CHECK: br label %[[MINUS1:.+]]
_ = match -1 {
// CHECK: [[MINUS1]]:
// CHECK: store i32 1
-1 => 1,
_ => 0,
}
}