std_example.rs

#![feature(core_intrinsics, generators, generator_trait, is_sorted, repr_simd)]

#[cfg(target_arch = "x86_64")]
use std::arch::x86_64::*;
use std::hint::black_box;
use std::io::Write;
use std::ops::Generator;

fn main() {
    println!("{:?}", std::env::args().collect::<Vec<_>>());

    let mutex = std::sync::Mutex::new(());
    let _guard = mutex.lock().unwrap();

    let _ = ::std::iter::repeat('a' as u8).take(10).collect::<Vec<_>>();
    let stderr = ::std::io::stderr();
    let mut stderr = stderr.lock();

    std::thread::spawn(move || {
        println!("Hello from another thread!");
    });

    writeln!(stderr, "some {} text", "<unknown>").unwrap();

    let _ = std::process::Command::new("true").env("c", "d").spawn();

    println!("cargo:rustc-link-lib=z");

    static ONCE: std::sync::Once = std::sync::Once::new();
    ONCE.call_once(|| {});

    let _eq = LoopState::Continue(()) == LoopState::Break(());

    // Make sure ByValPair values with differently sized components are correctly passed
    map(None::<(u8, Box<Instruction>)>);

    println!("{}", 2.3f32.exp());
    println!("{}", 2.3f32.exp2());
    println!("{}", 2.3f32.abs());
    println!("{}", 2.3f32.sqrt());
    println!("{}", 2.3f32.floor());
    println!("{}", 2.3f32.ceil());
    println!("{}", 2.3f32.min(1.0));
    println!("{}", 2.3f32.max(1.0));
    println!("{}", 2.3f32.powi(2));
    println!("{}", 2.3f32.log2());
    assert_eq!(2.3f32.copysign(-1.0), -2.3f32);
    println!("{}", 2.3f32.powf(2.0));

    assert_eq!(i64::MAX.checked_mul(2), None);

    assert_eq!(-128i8, (-128i8).saturating_sub(1));
    assert_eq!(127i8, 127i8.saturating_sub(-128));
    assert_eq!(-128i8, (-128i8).saturating_add(-128));
    assert_eq!(127i8, 127i8.saturating_add(1));

    assert_eq!(0b0000000000000000000000000010000010000000000000000000000000000000_0000000000100000000000000000000000001000000000000100000000000000u128.leading_zeros(), 26);
    assert_eq!(0b0000000000000000000000000010000000000000000000000000000000000000_0000000000000000000000000000000000001000000000000000000010000000u128.trailing_zeros(), 7);
    assert_eq!(
        core::intrinsics::saturating_sub(0, -170141183460469231731687303715884105728i128),
        170141183460469231731687303715884105727i128
    );

    std::hint::black_box(std::hint::black_box(7571400400375753350092698930310845914i128) * 10);
    assert!(0i128.checked_div(2i128).is_some());
    assert!(0u128.checked_div(2u128).is_some());
    assert_eq!(1u128 + 2, 3);

    assert_eq!(0b100010000000000000000000000000000u128 >> 10, 0b10001000000000000000000u128);
    assert_eq!(0xFEDCBA987654321123456789ABCDEFu128 >> 64, 0xFEDCBA98765432u128);
    assert_eq!(0xFEDCBA987654321123456789ABCDEFu128 as i128 >> 64, 0xFEDCBA98765432i128);

    let tmp = 353985398u128;
    assert_eq!(tmp * 932490u128, 330087843781020u128);

    let tmp = -0x1234_5678_9ABC_DEF0i64;
    assert_eq!(tmp as i128, -0x1234_5678_9ABC_DEF0i128);

    // Check that all u/i128 <-> float casts work correctly.
    let houndred_u128 = 100u128;
    let houndred_i128 = 100i128;
    let houndred_f32 = 100.0f32;
    let houndred_f64 = 100.0f64;
    assert_eq!(houndred_u128 as f32, 100.0);
    assert_eq!(houndred_u128 as f64, 100.0);
    assert_eq!(houndred_f32 as u128, 100);
    assert_eq!(houndred_f64 as u128, 100);
    assert_eq!(houndred_i128 as f32, 100.0);
    assert_eq!(houndred_i128 as f64, 100.0);
    assert_eq!(houndred_f32 as i128, 100);
    assert_eq!(houndred_f64 as i128, 100);
    assert_eq!(1u128.rotate_left(2), 4);

    assert_eq!(black_box(f32::NAN) as i128, 0);
    assert_eq!(black_box(f32::NAN) as u128, 0);

    // Test signed 128bit comparing
    let max = usize::MAX as i128;
    if 100i128 < 0i128 || 100i128 > max {
        panic!();
    }

    test_checked_mul();

    let _a = 1u32 << 2u8;

    let empty: [i32; 0] = [];
    assert!(empty.is_sorted());

    println!("{:?}", std::intrinsics::caller_location());

    #[cfg(target_arch = "x86_64")]
    unsafe {
        test_simd();
    }

    Box::pin(move |mut _task_context| {
        yield ();
    })
    .as_mut()
    .resume(0);

    #[derive(Copy, Clone)]
    enum Nums {
        NegOne = -1,
    }

    let kind = Nums::NegOne;
    assert_eq!(-1i128, kind as i128);

    let options = [1u128];
    match options[0] {
        1 => (),
        0 => loop {},
        v => panic(v),
    };

    if black_box(false) {
        // Based on https://github.com/rust-lang/rust/blob/2f320a224e827b400be25966755a621779f797cc/src/test/ui/debuginfo/debuginfo_with_uninhabitable_field_and_unsized.rs
        let _ = Foo::<dyn Send>::new();

        #[allow(dead_code)]
        struct Foo<T: ?Sized> {
            base: Never,
            value: T,
        }

        impl<T: ?Sized> Foo<T> {
            pub fn new() -> Box<Foo<T>> {
                todo!()
            }
        }

        enum Never {}
    }

    foo(I64X2(0, 0));
}

fn panic(_: u128) {
    panic!();
}

#[repr(simd)]
struct I64X2(i64, i64);

#[allow(improper_ctypes_definitions)]
extern "C" fn foo(_a: I64X2) {}

#[cfg(target_arch = "x86_64")]
#[target_feature(enable = "sse2")]
unsafe fn test_simd() {
    assert!(is_x86_feature_detected!("sse2"));

    let x = _mm_setzero_si128();
    let y = _mm_set1_epi16(7);
    let or = _mm_or_si128(x, y);
    let cmp_eq = _mm_cmpeq_epi8(y, y);
    let cmp_lt = _mm_cmplt_epi8(y, y);

    let (zero0, zero1) = std::mem::transmute::<_, (u64, u64)>(x);
    assert_eq!((zero0, zero1), (0, 0));
    assert_eq!(std::mem::transmute::<_, [u16; 8]>(or), [7, 7, 7, 7, 7, 7, 7, 7]);
    assert_eq!(
        std::mem::transmute::<_, [u16; 8]>(cmp_eq),
        [0xffff, 0xffff, 0xffff, 0xffff, 0xffff, 0xffff, 0xffff, 0xffff]
    );
    assert_eq!(std::mem::transmute::<_, [u16; 8]>(cmp_lt), [0, 0, 0, 0, 0, 0, 0, 0]);

    test_mm_slli_si128();
    test_mm_movemask_epi8();
    test_mm256_movemask_epi8();
    test_mm_add_epi8();
    test_mm_add_pd();
    test_mm_cvtepi8_epi16();
    test_mm_cvtsi128_si64();

    test_mm_extract_epi8();
    test_mm_insert_epi16();

    #[rustfmt::skip]
    let mask1 = _mm_movemask_epi8(dbg!(_mm_setr_epi8(255u8 as i8, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0)));
    assert_eq!(mask1, 1);
}

#[cfg(target_arch = "x86_64")]
#[target_feature(enable = "sse2")]
unsafe fn test_mm_slli_si128() {
    #[rustfmt::skip]
    let a = _mm_setr_epi8(
        1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16,
    );
    let r = _mm_slli_si128(a, 1);
    let e = _mm_setr_epi8(0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15);
    assert_eq_m128i(r, e);

    #[rustfmt::skip]
    let a = _mm_setr_epi8(
        1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16,
    );
    let r = _mm_slli_si128(a, 15);
    let e = _mm_setr_epi8(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1);
    assert_eq_m128i(r, e);

    #[rustfmt::skip]
    let a = _mm_setr_epi8(
        1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16,
    );
    let r = _mm_slli_si128(a, 16);
    assert_eq_m128i(r, _mm_set1_epi8(0));
}

#[cfg(target_arch = "x86_64")]
#[target_feature(enable = "sse2")]
unsafe fn test_mm_movemask_epi8() {
    #[rustfmt::skip]
    let a = _mm_setr_epi8(
        0b1000_0000u8 as i8, 0b0, 0b1000_0000u8 as i8, 0b01,
        0b0101, 0b1111_0000u8 as i8, 0, 0,
        0, 0, 0b1111_0000u8 as i8, 0b0101,
        0b01, 0b1000_0000u8 as i8, 0b0, 0b1000_0000u8 as i8,
    );
    let r = _mm_movemask_epi8(a);
    assert_eq!(r, 0b10100100_00100101);
}

#[cfg(target_arch = "x86_64")]
#[target_feature(enable = "avx2")]
unsafe fn test_mm256_movemask_epi8() {
    let a = _mm256_set1_epi8(-1);
    let r = _mm256_movemask_epi8(a);
    let e = -1;
    assert_eq!(r, e);
}

#[cfg(target_arch = "x86_64")]
#[target_feature(enable = "sse2")]
unsafe fn test_mm_add_epi8() {
    let a = _mm_setr_epi8(0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15);
    #[rustfmt::skip]
    let b = _mm_setr_epi8(
        16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31,
    );
    let r = _mm_add_epi8(a, b);
    #[rustfmt::skip]
    let e = _mm_setr_epi8(
        16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46,
    );
    assert_eq_m128i(r, e);
}

#[cfg(target_arch = "x86_64")]
#[target_feature(enable = "sse2")]
unsafe fn test_mm_add_pd() {
    let a = _mm_setr_pd(1.0, 2.0);
    let b = _mm_setr_pd(5.0, 10.0);
    let r = _mm_add_pd(a, b);
    assert_eq_m128d(r, _mm_setr_pd(6.0, 12.0));
}

#[cfg(target_arch = "x86_64")]
fn assert_eq_m128i(x: std::arch::x86_64::__m128i, y: std::arch::x86_64::__m128i) {
    unsafe {
        assert_eq!(std::mem::transmute::<_, [u8; 16]>(x), std::mem::transmute::<_, [u8; 16]>(y));
    }
}

#[cfg(target_arch = "x86_64")]
#[target_feature(enable = "sse2")]
pub unsafe fn assert_eq_m128d(a: __m128d, b: __m128d) {
    if _mm_movemask_pd(_mm_cmpeq_pd(a, b)) != 0b11 {
        panic!("{:?} != {:?}", a, b);
    }
}

#[cfg(target_arch = "x86_64")]
#[target_feature(enable = "sse2")]
unsafe fn test_mm_cvtsi128_si64() {
    let r = _mm_cvtsi128_si64(std::mem::transmute::<[i64; 2], _>([5, 0]));
    assert_eq!(r, 5);
}

#[cfg(target_arch = "x86_64")]
#[target_feature(enable = "sse4.1")]
unsafe fn test_mm_cvtepi8_epi16() {
    let a = _mm_set1_epi8(10);
    let r = _mm_cvtepi8_epi16(a);
    let e = _mm_set1_epi16(10);
    assert_eq_m128i(r, e);
    let a = _mm_set1_epi8(-10);
    let r = _mm_cvtepi8_epi16(a);
    let e = _mm_set1_epi16(-10);
    assert_eq_m128i(r, e);
}

#[cfg(target_arch = "x86_64")]
#[target_feature(enable = "sse4.1")]
unsafe fn test_mm_extract_epi8() {
    #[rustfmt::skip]
    let a = _mm_setr_epi8(
        -1, 1, 2, 3, 4, 5, 6, 7,
        8, 9, 10, 11, 12, 13, 14, 15
    );
    let r1 = _mm_extract_epi8(a, 0);
    let r2 = _mm_extract_epi8(a, 3);
    assert_eq!(r1, 0xFF);
    assert_eq!(r2, 3);
}

#[cfg(target_arch = "x86_64")]
#[target_feature(enable = "sse2")]
unsafe fn test_mm_insert_epi16() {
    let a = _mm_setr_epi16(0, 1, 2, 3, 4, 5, 6, 7);
    let r = _mm_insert_epi16(a, 9, 0);
    let e = _mm_setr_epi16(9, 1, 2, 3, 4, 5, 6, 7);
    assert_eq_m128i(r, e);
}

fn test_checked_mul() {
    let u: Option<u8> = u8::from_str_radix("1000", 10).ok();
    assert_eq!(u, None);

    assert_eq!(1u8.checked_mul(255u8), Some(255u8));
    assert_eq!(255u8.checked_mul(255u8), None);
    assert_eq!(1i8.checked_mul(127i8), Some(127i8));
    assert_eq!(127i8.checked_mul(127i8), None);
    assert_eq!((-1i8).checked_mul(-127i8), Some(127i8));
    assert_eq!(1i8.checked_mul(-128i8), Some(-128i8));
    assert_eq!((-128i8).checked_mul(-128i8), None);

    assert_eq!(1u64.checked_mul(u64::MAX), Some(u64::MAX));
    assert_eq!(u64::MAX.checked_mul(u64::MAX), None);
    assert_eq!(1i64.checked_mul(i64::MAX), Some(i64::MAX));
    assert_eq!(i64::MAX.checked_mul(i64::MAX), None);
    assert_eq!((-1i64).checked_mul(i64::MIN + 1), Some(i64::MAX));
    assert_eq!(1i64.checked_mul(i64::MIN), Some(i64::MIN));
    assert_eq!(i64::MIN.checked_mul(i64::MIN), None);
}

#[derive(PartialEq)]
enum LoopState {
    Continue(()),
    Break(()),
}

pub enum Instruction {
    Increment,
    Loop,
}

fn map(a: Option<(u8, Box<Instruction>)>) -> Option<Box<Instruction>> {
    match a {
        None => None,
        Some((_, instr)) => Some(instr),
    }
}