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66 lines
2.0 KiB
Rust
66 lines
2.0 KiB
Rust
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// unit-test: InstCombine
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// compile-flags: -C panic=abort
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#![crate_type = "lib"]
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#![feature(core_intrinsics)]
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#![feature(custom_mir)]
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use std::intrinsics::mir::*;
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use std::mem::{MaybeUninit, ManuallyDrop, transmute};
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// EMIT_MIR combine_transmutes.identity_transmutes.InstCombine.diff
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pub unsafe fn identity_transmutes() {
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// These are nops and should be removed
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let _a = transmute::<i32, i32>(1);
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let _a = transmute::<Vec<i32>, Vec<i32>>(Vec::new());
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}
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#[custom_mir(dialect = "runtime", phase = "initial")]
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// EMIT_MIR combine_transmutes.integer_transmutes.InstCombine.diff
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pub unsafe fn integer_transmutes() {
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mir! {
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{
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let A = CastTransmute::<i32, u32>(1); // Can be a cast
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let B = CastTransmute::<i32, i64>(1); // UB
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let C = CastTransmute::<u64, i64>(1); // Can be a cast
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let D = CastTransmute::<u64, u32>(1); // UB
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let E = CastTransmute::<isize, usize>(1); // Can be a cast
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Return()
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}
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}
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}
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// EMIT_MIR combine_transmutes.adt_transmutes.InstCombine.diff
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pub unsafe fn adt_transmutes() {
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let _a: u8 = transmute(EnumNoRepr::A);
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let _a: i8 = transmute(EnumNoRepr::B);
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let _a: usize = transmute(EnumReprIsize::A);
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let _a: isize = transmute(EnumReprIsize::B);
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let _a: u8 = transmute(std::cmp::Ordering::Less);
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let _a: i8 = transmute(std::cmp::Ordering::Less);
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let _a: u8 = transmute(Some(std::num::NonZeroU8::MAX));
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let _a: i16 = transmute(std::num::Wrapping(0_i16));
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let _a: u16 = transmute(std::num::Wrapping(0_i16));
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let _a: u32 = transmute(Union32 { i32: 0 });
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let _a: i32 = transmute(Union32 { u32: 0 });
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let _a: ManuallyDrop<String> = transmute(MaybeUninit::<String>::uninit());
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}
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#[inline(always)]
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#[custom_mir(dialect = "runtime", phase = "initial")]
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const unsafe fn mir_transmute<T, U>(x: T) -> U {
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mir!{
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{
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RET = CastTransmute(x);
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Return()
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}
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}
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}
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pub enum EnumNoRepr { A, B, C }
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#[repr(isize)]
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pub enum EnumReprIsize { A, B, C }
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pub union Union32 { u32: u32, i32: i32 }
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