tests/assembly-llvm/x86_64-typed-swap.rs

//@ revisions: WIN LIN
//@ [WIN] only-windows
//@ [LIN] only-linux
//@ only-x86_64
//@ assembly-output: emit-asm
//@ compile-flags: --crate-type=lib -Copt-level=3

use std::arch::x86_64::__m128;
use std::mem::swap;

// CHECK-LABEL: swap_i32:
#[no_mangle]
pub fn swap_i32(x: &mut i32, y: &mut i32) {
    // CHECK: movl (%[[ARG1:.+]]), %[[T1:.+]]
    // CHECK-NEXT: movl (%[[ARG2:.+]]), %[[T2:.+]]
    // CHECK-DAG: movl %[[T2]], (%[[ARG1]])
    // CHECK-DAG: movl %[[T1]], (%[[ARG2]])
    // CHECK-NEXT: retq
    swap(x, y)
}

// CHECK-LABEL: swap_pair:
#[no_mangle]
pub fn swap_pair(x: &mut (i32, u32), y: &mut (i32, u32)) {
    // CHECK: movq (%[[ARG1:r..?]]), %[[T1:.+]]
    // CHECK-NEXT: movq (%[[ARG2:r..?]]), %[[T2:.+]]
    // CHECK-DAG: movq %[[T2]], (%[[ARG1]])
    // CHECK-DAG: movq %[[T1]], (%[[ARG2]])
    // CHECK-NEXT: retq
    swap(x, y)
}

// CHECK-LABEL: swap_str:
#[no_mangle]
pub fn swap_str<'a>(x: &mut &'a str, y: &mut &'a str) {
    // CHECK: movups (%[[ARG1:r..?]]), %[[T1:xmm.]]
    // CHECK-NEXT: movups (%[[ARG2:r..?]]), %[[T2:xmm.]]
    // CHECK-DAG: movups %[[T2]], (%[[ARG1]])
    // CHECK-DAG: movups %[[T1]], (%[[ARG2]])
    // CHECK-NEXT: retq
    swap(x, y)
}

// CHECK-LABEL: swap_simd:
#[no_mangle]
pub fn swap_simd(x: &mut __m128, y: &mut __m128) {
    // CHECK: movaps (%[[ARG1:r..?]]), %[[T1:xmm.]]
    // CHECK-NEXT: movaps (%[[ARG2:r..?]]), %[[T2:xmm.]]
    // CHECK-DAG: movaps %[[T2]], (%[[ARG1]])
    // CHECK-DAG: movaps %[[T1]], (%[[ARG2]])
    // CHECK-NEXT: retq
    swap(x, y)
}

// CHECK-LABEL: swap_string:
#[no_mangle]
pub fn swap_string(x: &mut String, y: &mut String) {
    // CHECK-NOT: mov
    // CHECK-COUNT-4: movups
    // CHECK-NOT: mov
    // CHECK-COUNT-4: movq
    // CHECK-NOT: mov
    swap(x, y)
}

// CHECK-LABEL: swap_44_bytes:
#[no_mangle]
pub fn swap_44_bytes(x: &mut [u8; 44], y: &mut [u8; 44]) {
    // Ensure we do better than a long run of byte copies,
    // see <https://github.com/rust-lang/rust/issues/134946>

    // CHECK-NOT: movb
    // CHECK-COUNT-8: movups{{.+}}xmm
    // CHECK-NOT: movb
    // CHECK-COUNT-4: movq
    // CHECK-NOT: movb
    // CHECK-COUNT-4: movl
    // CHECK-NOT: movb
    // CHECK: retq
    swap(x, y)
}