mirror of https://github.com/rust-lang/rust
38 lines
1.4 KiB
Rust
38 lines
1.4 KiB
Rust
// LLVM does not support some atomic RMW operations on pointers, so inside codegen we lower those
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// to integer atomics, surrounded by casts to and from integer type.
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// This test ensures that we do the round-trip correctly for AtomicPtr::fetch_byte_add, and also
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// ensures that we do not have such a round-trip for AtomicPtr::swap, because LLVM supports pointer
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// arguments to `atomicrmw xchg`.
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//@ compile-flags: -O -Cno-prepopulate-passes
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#![crate_type = "lib"]
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#![feature(strict_provenance)]
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#![feature(strict_provenance_atomic_ptr)]
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use std::ptr::without_provenance_mut;
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use std::sync::atomic::AtomicPtr;
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use std::sync::atomic::Ordering::Relaxed;
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// Portability hack so that we can say [[USIZE]] instead of i64/i32/i16 for usize.
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// CHECK: @helper([[USIZE:i[0-9]+]] noundef %_1)
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#[no_mangle]
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pub fn helper(_: usize) {}
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// CHECK-LABEL: @atomicptr_fetch_byte_add
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#[no_mangle]
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pub fn atomicptr_fetch_byte_add(a: &AtomicPtr<u8>, v: usize) -> *mut u8 {
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// CHECK: %[[INTPTR:.*]] = ptrtoint ptr %{{.*}} to [[USIZE]]
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// CHECK-NEXT: %[[RET:.*]] = atomicrmw add ptr %{{.*}}, [[USIZE]] %[[INTPTR]]
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// CHECK-NEXT: inttoptr [[USIZE]] %[[RET]] to ptr
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a.fetch_byte_add(v, Relaxed)
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}
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// CHECK-LABEL: @atomicptr_swap
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#[no_mangle]
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pub fn atomicptr_swap(a: &AtomicPtr<u8>, ptr: *mut u8) -> *mut u8 {
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// CHECK-NOT: ptrtoint
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// CHECK: atomicrmw xchg ptr %{{.*}}, ptr %{{.*}} monotonic
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// CHECK-NOT: inttoptr
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a.swap(ptr, Relaxed)
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}
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