| // unit-test: InstSimplify |
| // compile-flags: -C panic=abort |
| |
| #![crate_type = "lib"] |
| #![feature(core_intrinsics)] |
| #![feature(custom_mir)] |
| |
| use std::intrinsics::mir::*; |
| use std::mem::{MaybeUninit, ManuallyDrop, transmute}; |
| |
| // EMIT_MIR combine_transmutes.identity_transmutes.InstSimplify.diff |
| pub unsafe fn identity_transmutes() { |
| // These are nops and should be removed |
| let _a = transmute::<i32, i32>(1); |
| let _a = transmute::<Vec<i32>, Vec<i32>>(Vec::new()); |
| } |
| |
| #[custom_mir(dialect = "runtime", phase = "initial")] |
| // EMIT_MIR combine_transmutes.integer_transmutes.InstSimplify.diff |
| pub unsafe fn integer_transmutes() { |
| mir! { |
| { |
| let A = CastTransmute::<i32, u32>(1); // Can be a cast |
| let B = CastTransmute::<i32, i64>(1); // UB |
| let C = CastTransmute::<u64, i64>(1); // Can be a cast |
| let D = CastTransmute::<u64, u32>(1); // UB |
| let E = CastTransmute::<isize, usize>(1); // Can be a cast |
| Return() |
| } |
| } |
| } |
| |
| // EMIT_MIR combine_transmutes.adt_transmutes.InstSimplify.diff |
| pub unsafe fn adt_transmutes() { |
| let _a: u8 = transmute(Some(std::num::NonZeroU8::MAX)); |
| let _a: i16 = transmute(std::num::Wrapping(0_i16)); |
| let _a: u16 = transmute(std::num::Wrapping(0_i16)); |
| let _a: u32 = transmute(Union32 { i32: 0 }); |
| let _a: i32 = transmute(Union32 { u32: 0 }); |
| let _a: ManuallyDrop<String> = transmute(MaybeUninit::<String>::uninit()); |
| } |
| |
| pub union Union32 { u32: u32, i32: i32 } |