Absolute value and sign flip demo with bitmask and SSE instructions.

absflip.cc

#include <iostream>

static constexpr int kAbsMask = 0x7FFFFFFF;
static constexpr int kFlipMask = 0x80000000;

int main(int argc, char const *argv[])
{

    float y = -30.234;
    float z = 40.023;

    // abs value

    __asm {
        movss xmm9, kAbsMask
        movss xmm0, y
        andps xmm0, xmm9
        movss y, xmm0
    }

    // flip sign
    __asm {
        movss xmm9, kFlipMask
        movss xmm0, z
        xorps xmm0, xmm9
        movss z, xmm0
    }

    std::cout << "Abs Value: " << y << std::endl;
    std::cout << "Flipped: " << z << std::endl;

    return 0;
}