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645c0fddd2
Previously, it was only put on scalars with range validity invariants like bool, was uninit was obviously invalid for those. Since then, we have normatively declared all uninit primitives to be undefined behavior and can therefore put `noundef` on them. The remaining concern was the `mem::uninitialized` function, which cause quite a lot of UB in the older parts of the ecosystem. This function now doesn't return uninit values anymore, making users of it safe from this change. The only real sources of UB where people could encounter uninit primitives are `MaybeUninit::uninit().assume_init()`, which has always be clear in the docs about being UB and from heap allocations (like reading from the spare capacity of a vec. This is hopefully rare enough to not break anything.
46 lines
1.3 KiB
Rust
46 lines
1.3 KiB
Rust
// compile-flags: -O
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#![crate_type = "lib"]
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// CHECK: define{{.*}}{ i8, i8 } @pair_bool_bool(i1 noundef zeroext %pair.0, i1 noundef zeroext %pair.1)
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#[no_mangle]
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pub fn pair_bool_bool(pair: (bool, bool)) -> (bool, bool) {
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pair
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}
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// CHECK: define{{.*}}{ i8, i32 } @pair_bool_i32(i1 noundef zeroext %pair.0, i32 noundef %pair.1)
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#[no_mangle]
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pub fn pair_bool_i32(pair: (bool, i32)) -> (bool, i32) {
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pair
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}
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// CHECK: define{{.*}}{ i32, i8 } @pair_i32_bool(i32 noundef %pair.0, i1 noundef zeroext %pair.1)
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#[no_mangle]
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pub fn pair_i32_bool(pair: (i32, bool)) -> (i32, bool) {
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pair
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}
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// CHECK: define{{.*}}{ i8, i8 } @pair_and_or(i1 noundef zeroext %_1.0, i1 noundef zeroext %_1.1)
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#[no_mangle]
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pub fn pair_and_or((a, b): (bool, bool)) -> (bool, bool) {
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// Make sure it can operate directly on the unpacked args
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// (but it might not be using simple and/or instructions)
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// CHECK-DAG: %_1.0
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// CHECK-DAG: %_1.1
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(a && b, a || b)
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}
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// CHECK: define{{.*}}void @pair_branches(i1 noundef zeroext %_1.0, i1 noundef zeroext %_1.1)
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#[no_mangle]
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pub fn pair_branches((a, b): (bool, bool)) {
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// Make sure it can branch directly on the unpacked bool args
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// CHECK: br i1 %_1.0
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if a {
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println!("Hello!");
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}
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// CHECK: br i1 %_1.1
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if b {
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println!("Goodbye!");
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}
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}
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