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// If the lowest bit of each byte is 1, set that byte to 255, else 0.
// Should emit constant-load+and+orc.b
export fn orc_b_opportunity1(x: u64) u64 {
    return (x & 0x0101010101010101) *% 0xFF;
}

// If the lowest bit of each byte is 1, set that byte to 255, else 0.
// Should emit constant-load+and+orc.b
export fn orc_b_opportunity1_fixed(x: u64) u64 {
    return orc_b(x & 0x0101010101010101);
}

// If the highest bit of each byte is 1, set that byte to 255, else 0.
// Should emit constant-load+and+orc.b
export fn orc_b_opportunity2(x: u64) u64 {
    return ((x & 0x8080808080808080) >> 7) *% 0xFF;
}

// If the highest bit of each byte is 1, set that byte to 255, else 0.
// Should emit constant-load+and+orc.b
export fn orc_b_opportunity3(x: u64) u64 {
    const y = x & 0x8080808080808080;
    return (y << 1) -% (y >> 7);
}

// If the highest bit of each byte is 1, set that byte to 255, else 0.
// Should emit constant-load+and+orc.b
export fn orc_b_opportunity4(x: u64) u64 {
    return ((x >> 7) & 0x0101010101010101) *% 0xFF;
}

// If the highest bit of each byte is 1, set that byte to 255, else 0.
export fn orc_b_opportunity2_and_3_and_4_fixed(x: u64) u64 {
    return orc_b(x & 0x8080808080808080);
}

// If any byte is non-zero, set that byte to 255 (all ones), else 0.
// This should just emit the `orc.b` instruction.
export fn orc_b_opportunity5(x: u64) u64 {
    const c1: u64 = @bitCast([_]u8{0x7F} ** 8);
    return orc_b_opportunity2(((x & c1) +% c1) | x);
}

// If any byte is non-zero, set that byte to 255 (all ones), else 0.
// This should just emit the `orc.b` instruction.
export fn orc_b_opportunity6(x: u64) u64 {
    const c1: u64 = @bitCast([_]u8{0x7F} ** 8);
    return orc_b_opportunity3(((x & c1) +% c1) | x);
}

// If any byte is non-zero, set that byte to 255 (all ones), else 0.
// This should just emit the `orc.b` instruction.
export fn orc_b_opportunity7(x: u64) u64 {
    const c1: u64 = @bitCast([_]u8{0x7F} ** 8);
    return orc_b_opportunity4(((x & c1) +% c1) | x);
}

export fn orc_b_opportunity5_and_6_and_7_fixed(x: u64) u64 {
    return orc_b(x);
}

fn orc_b(x: u64) u64 {
    return struct {
        extern fn @"llvm.riscv.orc.b.i64"(u64) u64;
    }.@"llvm.riscv.orc.b.i64"(x);
}