abi-sysv64-register-usage.rs

//@ run-pass
// Checks if the correct registers are being used to pass arguments
// when the sysv64 ABI is specified.

//@ ignore-android
//@ ignore-arm
//@ ignore-aarch64
//@ needs-asm-support

#[cfg(target_arch = "x86_64")]
pub extern "sysv64" fn all_the_registers(
    rdi: i64,
    rsi: i64,
    rdx: i64,
    rcx: i64,
    r8: i64,
    r9: i64,
    xmm0: f32,
    xmm1: f32,
    xmm2: f32,
    xmm3: f32,
    xmm4: f32,
    xmm5: f32,
    xmm6: f32,
    xmm7: f32,
) -> i64 {
    assert_eq!(rdi, 1);
    assert_eq!(rsi, 2);
    assert_eq!(rdx, 3);
    assert_eq!(rcx, 4);
    assert_eq!(r8, 5);
    assert_eq!(r9, 6);
    assert_eq!(xmm0, 1.0f32);
    assert_eq!(xmm1, 2.0f32);
    assert_eq!(xmm2, 4.0f32);
    assert_eq!(xmm3, 8.0f32);
    assert_eq!(xmm4, 16.0f32);
    assert_eq!(xmm5, 32.0f32);
    assert_eq!(xmm6, 64.0f32);
    assert_eq!(xmm7, 128.0f32);
    42
}

// this struct contains 8 i64's, while only 6 can be passed in registers.
#[cfg(target_arch = "x86_64")]
#[derive(PartialEq, Eq, Debug)]
pub struct LargeStruct(i64, i64, i64, i64, i64, i64, i64, i64);

#[cfg(target_arch = "x86_64")]
#[inline(never)]
#[allow(improper_ctypes_definitions)]
pub extern "sysv64" fn large_struct_by_val(mut foo: LargeStruct) -> LargeStruct {
    foo.0 *= 1;
    foo.1 *= 2;
    foo.2 *= 3;
    foo.3 *= 4;
    foo.4 *= 5;
    foo.5 *= 6;
    foo.6 *= 7;
    foo.7 *= 8;
    foo
}

#[cfg(target_arch = "x86_64")]
pub fn main() {
    use std::arch::asm;

    let result: i64;
    unsafe {
        asm!("mov rdi, 1",
             "mov rsi, 2",
             "mov rdx, 3",
             "mov rcx, 4",
             "mov r8,  5",
             "mov r9,  6",
             "mov eax, 0x3F800000",
             "movd xmm0, eax",
             "mov eax, 0x40000000",
             "movd xmm1, eax",
             "mov eax, 0x40800000",
             "movd xmm2, eax",
             "mov eax, 0x41000000",
             "movd xmm3, eax",
             "mov eax, 0x41800000",
             "movd xmm4, eax",
             "mov eax, 0x42000000",
             "movd xmm5, eax",
             "mov eax, 0x42800000",
             "movd xmm6, eax",
             "mov eax, 0x43000000",
             "movd xmm7, eax",
             "call {0}",
             sym all_the_registers,
             out("rax") result,
             clobber_abi("sysv64"),
        );
    }
    assert_eq!(result, 42);

    assert_eq!(
        large_struct_by_val(LargeStruct(1, 2, 3, 4, 5, 6, 7, 8)),
        LargeStruct(1, 4, 9, 16, 25, 36, 49, 64)
    );
}

#[cfg(not(target_arch = "x86_64"))]
pub fn main() {}