rust/tests/codegen/issues/issue-45222.rs
2024-02-23 18:04:01 -05:00

63 lines
1.2 KiB
Rust

//@ compile-flags: -O
#![crate_type = "lib"]
// verify that LLVM recognizes a loop involving 0..=n and will const-fold it.
// Example from original issue #45222
fn foo2(n: u64) -> u64 {
let mut count = 0;
for _ in 0..n {
for j in (0..=n).rev() {
count += j;
}
}
count
}
// CHECK-LABEL: @check_foo2
#[no_mangle]
pub fn check_foo2() -> u64 {
// CHECK: ret i64 500005000000000
foo2(100000)
}
// Simplified example of #45222
//
// Temporarily disabled in #68835 to fix a soundness hole.
//
// fn triangle_inc(n: u64) -> u64 {
// let mut count = 0;
// for j in 0 ..= n {
// count += j;
// }
// count
// }
//
// // COMMENTEDCHECK-LABEL: @check_triangle_inc
// #[no_mangle]
// pub fn check_triangle_inc() -> u64 {
// // COMMENTEDCHECK: ret i64 5000050000
// triangle_inc(100000)
// }
// Demo in #48012
fn foo3r(n: u64) -> u64 {
let mut count = 0;
(0..n).for_each(|_| {
(0..=n).rev().for_each(|j| {
count += j;
})
});
count
}
// CHECK-LABEL: @check_foo3r
#[no_mangle]
pub fn check_foo3r() -> u64 {
// CHECK: ret i64 500050000000
foo3r(10000)
}