https://github.com/bitcoin/bitcoin/blob/5f0c6a7b0e47e03f848dc992d37fe209dd9c6975/src/crypto/sha256.cpp#L183

This checks whether the CPU supports SSE4. It should also check if the OS supports SSE4. See this [StackOverflow answer](https://stackoverflow.com/a/22521619/6557621).
e += 0x510e527ful;
    f += 0x9b05688cul;
    g += 0x1f83d9abul;
    h += 0x5be0cd19ul;
    uint32_t t0 = a, t1 = b, t2 = c, t3 = d, t4 = e, t5 = f, t6 = g, t7 = h;
    
    Round(a, b, c, d, e, f, g, h, 0xc28a2f98ul);
    Round(h, a, b, c, d, e, f, g, 0x71374491ul);
    Round(g, h, a, b, c, d, e, f, 0xb5c0fbcful);
    Round(f, g, h, a, b, c, d, e, 0xe9b5dba5ul);
    Round(e, f, g, h, a, b, c, d, 0x3956c25bul);
    Round(d, e, f, g, h, a, b, c, 0x59f111f1ul);
    Round(c, d, e, f, g, h, a, b, 0x923f82a4ul);
    Round(b, c, d, e, f, g, h, a, 0xab1c5ed5ul);
    Round(a, b, c, d, e, f, g, h, 0xd807aa98ul);
    Round(h, a, b, c, d, e, f, g, 0x12835b01ul);
    Round(g, h, a, b, c, d, e, f, 0x243185beul);
    Round(f, g, h, a, b, c, d, e, 0x550c7dc3ul);
    Round(e, f, g, h, a, b, c, d, 0x72be5d74ul);
    Round(d, e, f, g, h, a, b, c, 0x80deb1feul);
    Round(c, d, e, f, g, h, a, b, 0x9bdc06a7ul);
    Round(b, c, d, e, f, g, h, a, 0xc19bf374ul);
    Round(a, b, c, d, e, f, g, h, 0x649b69c1ul);
    Round(h, a, b, c, d, e, f, g, 0xf0fe4786ul);
    Round(g, h, a, b, c, d, e, f, 0x0fe1edc6ul);
    Round(f, g, h, a, b, c, d, e, 0x240cf254ul);
    Round(e, f, g, h, a, b, c, d, 0x4fe9346ful);
    Round(d, e, f, g, h, a, b, c, 0x6cc984beul);
    Round(c, d, e, f, g, h, a, b, 0x61b9411eul);
    Round(b, c, d, e, f, g, h, a, 0x16f988faul);