bjoernager/rust
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Copy 1-element arrays as scalars, not vectors

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For `[T; 1]` it's silly to copy as `<1 x T>` when we can just copy as `T`.
This commit is contained in:
Scott McMurray 2023-10-06 01:17:09 -07:00
parent 579be69de9
commit ae9cec5839
4 changed files with 80 additions and 1 deletions
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33
tests/codegen/array-optimized.rs Normal file
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// compile-flags: -O
#![crate_type = "lib"]
// CHECK-LABEL: @array_copy_1_element
#[no_mangle]
pub fn array_copy_1_element(a: &[u8; 1], p: &mut [u8; 1]) {
// CHECK-NOT: alloca
// CHECK: %[[TEMP:.+]] = load i8, ptr %a, align 1
// CHECK: store i8 %[[TEMP]], ptr %p, align 1
// CHECK: ret
*p = *a;
}
// CHECK-LABEL: @array_copy_2_elements
#[no_mangle]
pub fn array_copy_2_elements(a: &[u8; 2], p: &mut [u8; 2]) {
// CHECK-NOT: alloca
// CHECK: %[[TEMP:.+]] = load <2 x i8>, ptr %a, align 1
// CHECK: store <2 x i8> %[[TEMP]], ptr %p, align 1
// CHECK: ret
*p = *a;
}
// CHECK-LABEL: @array_copy_4_elements
#[no_mangle]
pub fn array_copy_4_elements(a: &[u8; 4], p: &mut [u8; 4]) {
// CHECK-NOT: alloca
// CHECK: %[[TEMP:.+]] = load <4 x i8>, ptr %a, align 1
// CHECK: store <4 x i8> %[[TEMP]], ptr %p, align 1
// CHECK: ret
*p = *a;
}