| //@ 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) |
| } |
