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| author | Guillaume Gomez <guillaume1.gomez@gmail.com> | 2025-07-21 14:34:12 +0200 |
|---|---|---|
| committer | Guillaume Gomez <guillaume1.gomez@gmail.com> | 2025-07-22 14:28:48 +0200 |
| commit | a27f3e3fd1e4d16160f8885b6b06665b5319f56c (patch) | |
| tree | b033935392cbadf6f85d2dbddf433a88e323aeeb /tests/codegen-llvm/transmute-optimized.rs | |
| parent | ed93c1783b404d728d4809973a0550eb33cd293f (diff) | |
| download | rust-a27f3e3fd1e4d16160f8885b6b06665b5319f56c.tar.gz rust-a27f3e3fd1e4d16160f8885b6b06665b5319f56c.zip | |
Rename `tests/codegen` into `tests/codegen-llvm`
Diffstat (limited to 'tests/codegen-llvm/transmute-optimized.rs')
| -rw-r--r-- | tests/codegen-llvm/transmute-optimized.rs | 120 |
1 files changed, 120 insertions, 0 deletions
diff --git a/tests/codegen-llvm/transmute-optimized.rs b/tests/codegen-llvm/transmute-optimized.rs new file mode 100644 index 00000000000..477fdc6de90 --- /dev/null +++ b/tests/codegen-llvm/transmute-optimized.rs @@ -0,0 +1,120 @@ +//@ compile-flags: -Copt-level=3 -Z merge-functions=disabled +#![crate_type = "lib"] + +// This tests that LLVM can optimize based on the niches in the source or +// destination types for transmutes. + +#[repr(u32)] +pub enum AlwaysZero32 { + X = 0, +} + +// CHECK-LABEL: i32 @issue_109958(i32 +#[no_mangle] +pub fn issue_109958(x: AlwaysZero32) -> i32 { + // CHECK: ret i32 0 + unsafe { std::mem::transmute(x) } +} + +// CHECK-LABEL: i1 @reference_is_null(ptr +#[no_mangle] +pub fn reference_is_null(x: &i32) -> bool { + // CHECK: ret i1 false + let p: *const i32 = unsafe { std::mem::transmute(x) }; + p.is_null() +} + +// CHECK-LABEL: i1 @non_null_is_null(ptr +#[no_mangle] +pub fn non_null_is_null(x: std::ptr::NonNull<i32>) -> bool { + // CHECK: ret i1 false + let p: *const i32 = unsafe { std::mem::transmute(x) }; + p.is_null() +} + +// CHECK-LABEL: i1 @non_zero_is_null( +#[no_mangle] +pub fn non_zero_is_null(x: std::num::NonZero<usize>) -> bool { + // CHECK: ret i1 false + let p: *const i32 = unsafe { std::mem::transmute(x) }; + p.is_null() +} + +// CHECK-LABEL: i1 @non_null_is_zero(ptr +#[no_mangle] +pub fn non_null_is_zero(x: std::ptr::NonNull<i32>) -> bool { + // CHECK: ret i1 false + let a: isize = unsafe { std::mem::transmute(x) }; + a == 0 +} + +// CHECK-LABEL: i1 @bool_ordering_is_ge(i1 +#[no_mangle] +pub fn bool_ordering_is_ge(x: bool) -> bool { + // CHECK: ret i1 true + let y: std::cmp::Ordering = unsafe { std::mem::transmute(x) }; + y.is_ge() +} + +// CHECK-LABEL: i1 @ordering_is_ge_then_transmute_to_bool(i8 +#[no_mangle] +pub fn ordering_is_ge_then_transmute_to_bool(x: std::cmp::Ordering) -> bool { + let r = x.is_ge(); + let _: bool = unsafe { std::mem::transmute(x) }; + r +} + +// CHECK-LABEL: i32 @normal_div(i32 +#[no_mangle] +pub fn normal_div(a: u32, b: u32) -> u32 { + // CHECK: call core::panicking::panic + a / b +} + +// CHECK-LABEL: i32 @div_transmute_nonzero(i32 +#[no_mangle] +pub fn div_transmute_nonzero(a: u32, b: std::num::NonZero<i32>) -> u32 { + // CHECK-NOT: call core::panicking::panic + // CHECK: %[[R:.+]] = udiv i32 %a, %b + // CHECK-NEXT: ret i32 %[[R]] + // CHECK-NOT: call core::panicking::panic + let d: u32 = unsafe { std::mem::transmute(b) }; + a / d +} + +#[repr(i8)] +pub enum OneTwoThree { + One = 1, + Two = 2, + Three = 3, +} + +// CHECK-LABEL: i8 @ordering_transmute_onetwothree(i8 +#[no_mangle] +pub unsafe fn ordering_transmute_onetwothree(x: std::cmp::Ordering) -> OneTwoThree { + // CHECK: ret i8 1 + std::mem::transmute(x) +} + +// CHECK-LABEL: i8 @onetwothree_transmute_ordering(i8 +#[no_mangle] +pub unsafe fn onetwothree_transmute_ordering(x: OneTwoThree) -> std::cmp::Ordering { + // CHECK: ret i8 1 + std::mem::transmute(x) +} + +// CHECK-LABEL: i1 @char_is_negative(i32 +#[no_mangle] +pub fn char_is_negative(c: char) -> bool { + // CHECK: ret i1 false + let x: i32 = unsafe { std::mem::transmute(c) }; + x < 0 +} + +// CHECK-LABEL: i1 @transmute_to_char_is_negative(i32 +#[no_mangle] +pub fn transmute_to_char_is_negative(x: i32) -> bool { + // CHECK: ret i1 false + let _c: char = unsafe { std::mem::transmute(x) }; + x < 0 +} |
