| //@ only-64bit llvm appears to use stores instead of memset on 32bit | |
| //@ compile-flags: -C opt-level=3 -Z merge-functions=disabled | |
| //@ needs-deterministic-layouts | |
| // The below two functions ensure that both `String::new()` and `"".to_string()` | |
| // produce the identical code. | |
| #![crate_type = "lib"] | |
| // CHECK-LABEL: define {{(dso_local )?}}void @string_new | |
| #[no_mangle] | |
| pub fn string_new() -> String { | |
| // CHECK-NOT: load i8 | |
| // CHECK: store i{{32|64}} | |
| // CHECK-NEXT: getelementptr | |
| // CHECK-NEXT: store ptr | |
| // CHECK-NEXT: getelementptr | |
| // CHECK-NEXT: store i{{32|64}} | |
| // CHECK-NEXT: ret void | |
| String::new() | |
| } | |
| // CHECK-LABEL: define {{(dso_local )?}}void @empty_to_string | |
| #[no_mangle] | |
| pub fn empty_to_string() -> String { | |
| // CHECK-NOT: load i8 | |
| // CHECK: store i{{32|64}} | |
| // CHECK-NEXT: getelementptr | |
| // CHECK-NEXT: store ptr | |
| // CHECK-NEXT: getelementptr | |
| // CHECK-NEXT: store i{{32|64}} | |
| // CHECK-NEXT: ret void | |
| "".to_string() | |
| } | |
| // The below two functions ensure that both `vec![]` and `vec![].clone()` | |
| // produce the identical code. | |
| // CHECK-LABEL: @empty_vec | |
| #[no_mangle] | |
| pub fn empty_vec() -> Vec<u8> { | |
| // CHECK: store i{{32|64}} | |
| // CHECK-NOT: load i8 | |
| // CHECK-NEXT: getelementptr | |
| // CHECK-NEXT: store ptr | |
| // CHECK-NEXT: getelementptr | |
| // CHECK-NEXT: store i{{32|64}} | |
| // CHECK-NEXT: ret void | |
| vec![] | |
| } | |
| // CHECK-LABEL: @empty_vec_clone | |
| #[no_mangle] | |
| pub fn empty_vec_clone() -> Vec<u8> { | |
| // CHECK: store i{{32|64}} | |
| // CHECK-NOT: load i8 | |
| // CHECK-NEXT: getelementptr | |
| // CHECK-NEXT: store ptr | |
| // CHECK-NEXT: getelementptr | |
| // CHECK-NEXT: store i{{32|64}} | |
| // CHECK-NEXT: ret void | |
| vec![].clone() | |
| } |