mirror of https://github.com/rust-lang/rust
107 lines
2.8 KiB
Rust
107 lines
2.8 KiB
Rust
//@ compile-flags: -O -Z merge-functions=disabled
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#![crate_type = "lib"]
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// This tests that LLVM can optimize based on the niches in the source or
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// destination types for transmutes.
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#[repr(u32)]
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pub enum AlwaysZero32 { X = 0 }
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// CHECK-LABEL: i32 @issue_109958(i32
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#[no_mangle]
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pub fn issue_109958(x: AlwaysZero32) -> i32 {
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// CHECK: ret i32 0
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unsafe { std::mem::transmute(x) }
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}
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// CHECK-LABEL: i1 @reference_is_null(ptr
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#[no_mangle]
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pub fn reference_is_null(x: &i32) -> bool {
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// CHECK: ret i1 false
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let p: *const i32 = unsafe { std::mem::transmute(x) };
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p.is_null()
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}
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// CHECK-LABEL: i1 @non_null_is_null(ptr
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#[no_mangle]
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pub fn non_null_is_null(x: std::ptr::NonNull<i32>) -> bool {
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// CHECK: ret i1 false
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let p: *const i32 = unsafe { std::mem::transmute(x) };
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p.is_null()
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}
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// CHECK-LABEL: i1 @non_zero_is_null(
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#[no_mangle]
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pub fn non_zero_is_null(x: std::num::NonZero<usize>) -> bool {
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// CHECK: ret i1 false
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let p: *const i32 = unsafe { std::mem::transmute(x) };
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p.is_null()
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}
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// CHECK-LABEL: i1 @non_null_is_zero(ptr
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#[no_mangle]
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pub fn non_null_is_zero(x: std::ptr::NonNull<i32>) -> bool {
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// CHECK: ret i1 false
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let a: isize = unsafe { std::mem::transmute(x) };
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a == 0
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}
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// CHECK-LABEL: i1 @bool_ordering_is_ge(i1
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#[no_mangle]
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pub fn bool_ordering_is_ge(x: bool) -> bool {
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// CHECK: ret i1 true
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let y: std::cmp::Ordering = unsafe { std::mem::transmute(x) };
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y.is_ge()
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}
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// CHECK-LABEL: i1 @ordering_is_ge_then_transmute_to_bool(i8
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#[no_mangle]
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pub fn ordering_is_ge_then_transmute_to_bool(x: std::cmp::Ordering) -> bool {
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let r = x.is_ge();
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let _: bool = unsafe { std::mem::transmute(x) };
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r
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}
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// CHECK-LABEL: i32 @normal_div(i32
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#[no_mangle]
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pub fn normal_div(a: u32, b: u32) -> u32 {
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// CHECK: call core::panicking::panic
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a / b
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}
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// CHECK-LABEL: i32 @div_transmute_nonzero(i32
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#[no_mangle]
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pub fn div_transmute_nonzero(a: u32, b: std::num::NonZero<i32>) -> u32 {
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// CHECK-NOT: call core::panicking::panic
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// CHECK: %[[R:.+]] = udiv i32 %a, %b
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// CHECK-NEXT: ret i32 %[[R]]
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// CHECK-NOT: call core::panicking::panic
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let d: u32 = unsafe { std::mem::transmute(b) };
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a / d
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}
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#[repr(i8)]
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pub enum OneTwoThree { One = 1, Two = 2, Three = 3 }
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// CHECK-LABEL: i8 @ordering_transmute_onetwothree(i8
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#[no_mangle]
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pub unsafe fn ordering_transmute_onetwothree(x: std::cmp::Ordering) -> OneTwoThree {
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// CHECK: ret i8 1
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std::mem::transmute(x)
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}
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// CHECK-LABEL: i8 @onetwothree_transmute_ordering(i8
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#[no_mangle]
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pub unsafe fn onetwothree_transmute_ordering(x: OneTwoThree) -> std::cmp::Ordering {
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// CHECK: ret i8 1
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std::mem::transmute(x)
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}
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// CHECK-LABEL: i1 @char_is_negative(i32
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#[no_mangle]
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pub fn char_is_negative(c: char) -> bool {
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// CHECK: ret i1 false
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let x: i32 = unsafe { std::mem::transmute(c) };
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x < 0
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}
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