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be5d6c5425
We cannot transform `*elem` to `array[idx1]` in the following code,
as `idx1` has already been modified.
```rust
mir! {
let array;
let elem;
{
array = [*val; 5];
elem = &array[idx1];
idx1 = idx2;
RET = *elem;
Return()
}
}
```
50 lines
1.1 KiB
Rust
50 lines
1.1 KiB
Rust
//@ test-mir-pass: GVN
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#![feature(custom_mir, core_intrinsics)]
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// Check that we do not introduce out-of-bounds access.
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use std::intrinsics::mir::*;
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// EMIT_MIR gvn_repeat.repeat_place.GVN.diff
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#[custom_mir(dialect = "runtime")]
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pub fn repeat_place(mut idx1: usize, idx2: usize, val: &i32) -> i32 {
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// CHECK-LABEL: fn repeat_place(
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// CHECK: let mut [[ELEM:.*]]: &i32;
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// CHECK: _0 = copy (*[[ELEM]])
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mir! {
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let array;
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let elem;
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{
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array = [*val; 5];
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elem = &array[idx1];
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idx1 = idx2;
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RET = *elem;
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Return()
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}
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}
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}
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// EMIT_MIR gvn_repeat.repeat_local.GVN.diff
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#[custom_mir(dialect = "runtime")]
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pub fn repeat_local(mut idx1: usize, idx2: usize, val: i32) -> i32 {
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// CHECK-LABEL: fn repeat_local(
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// CHECK: _0 = copy _3
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mir! {
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let array;
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let elem;
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{
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array = [val; 5];
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elem = &array[idx1];
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idx1 = idx2;
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RET = *elem;
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Return()
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}
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}
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}
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fn main() {
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assert_eq!(repeat_place(0, 5, &0), 0);
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assert_eq!(repeat_local(0, 5, 0), 0);
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}
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