rust/tests/mir-opt/gvn_copy_aggregate.all_copy_ret_2.GVN.diff
DianQK c16c22cc9c
Simplify the canonical clone method to copy
The optimized clone method ends up as the following MIR:

```
_2 = copy ((*_1).0: i32);
_3 = copy ((*_1).1: u64);
_4 = copy ((*_1).2: [i8; 3]);
_0 = Foo { a: move _2, b: move _3, c: move _4 };
```

We can transform this to:

```
_0 = copy (*_1);
```
2024-09-14 13:30:35 +08:00

78 lines
1.9 KiB
Diff

- // MIR for `all_copy_ret_2` before GVN
+ // MIR for `all_copy_ret_2` after GVN
fn all_copy_ret_2(_1: &AllCopy) -> (AllCopy, AllCopy) {
debug v => _1;
let mut _0: (AllCopy, AllCopy);
let _2: i32;
let mut _5: AllCopy;
let mut _6: i32;
let mut _7: u64;
let mut _8: [i8; 3];
let mut _9: AllCopy;
let mut _10: i32;
let mut _11: u64;
let mut _12: [i8; 3];
scope 1 {
debug a => _2;
let _3: u64;
scope 2 {
debug b => _3;
let _4: [i8; 3];
scope 3 {
debug c => _4;
}
}
}
bb0: {
- StorageLive(_2);
+ nop;
_2 = copy ((*_1).0: i32);
- StorageLive(_3);
+ nop;
_3 = copy ((*_1).1: u64);
- StorageLive(_4);
+ nop;
_4 = copy ((*_1).2: [i8; 3]);
- StorageLive(_5);
+ nop;
StorageLive(_6);
_6 = copy _2;
StorageLive(_7);
_7 = copy _3;
StorageLive(_8);
_8 = copy _4;
- _5 = AllCopy { a: move _6, b: move _7, c: move _8 };
+ _5 = copy (*_1);
StorageDead(_8);
StorageDead(_7);
StorageDead(_6);
StorageLive(_9);
StorageLive(_10);
_10 = copy _2;
StorageLive(_11);
_11 = copy _3;
StorageLive(_12);
_12 = copy _4;
- _9 = AllCopy { a: move _10, b: move _11, c: move _12 };
+ _9 = copy _5;
StorageDead(_12);
StorageDead(_11);
StorageDead(_10);
- _0 = (move _5, move _9);
+ _0 = (copy _5, copy _5);
StorageDead(_9);
- StorageDead(_5);
- StorageDead(_4);
- StorageDead(_3);
- StorageDead(_2);
+ nop;
+ nop;
+ nop;
+ nop;
return;
}
}