tests/codegen-llvm/autovec/dont-shuffle-bswaps-opt2.rs


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//@ compile-flags: -Copt-level=2

#![crate_type = "lib"]
#![no_std]

// This test is paired with the arch-specific -opt3.rs test.

// The code is from https://github.com/rust-lang/rust/issues/122805.
// Ensure we do not generate the shufflevector instruction
// to avoid complicating the code.

// CHECK-LABEL: define{{.*}}void @convert(
// CHECK-NOT: shufflevector
#[no_mangle]
pub fn convert(value: [u16; 8]) -> [u8; 16] {
    #[cfg(target_endian = "little")]
    let bswap = u16::to_be;
    #[cfg(target_endian = "big")]
    let bswap = u16::to_le;
    let addr16 = [
        bswap(value[0]),
        bswap(value[1]),
        bswap(value[2]),
        bswap(value[3]),
        bswap(value[4]),
        bswap(value[5]),
        bswap(value[6]),
        bswap(value[7]),
    ];
    unsafe { core::mem::transmute::<_, [u8; 16]>(addr16) }
}