--- src/computefourier-1.0-2.0.cc.orig 2013-06-13 08:12:25.000000000 -0400 +++ src/computefourier-1.0-2.0.cc 2013-08-09 00:26:54.000000000 -0400 @@ -248,8 +248,13 @@ __m128d ad_bc = _mm_mul_pd(ab, dc); __m128d ac_mbd = _mm_mul_pd(ac_bd, signs); +#ifdef __SSE3__ __m128d ab_times_cd = _mm_hadd_pd(ac_mbd, ad_bc); - +#else + __m128d ab_times_cd_lo = _mm_shuffle_pd(ac_mbd, ad_bc, 0); + __m128d ab_times_cd_hi = _mm_shuffle_pd(ac_mbd, ad_bc, 3); + __m128d ab_times_cd = _mm_add_pd(ab_times_cd_lo, ab_times_cd_hi); +#endif unsigned int i_mod_B_p_offset = (i & B2_m_1) + offset; __m128d xy = _mm_load_pd(d_x_sampt + i_mod_B_p_offset); __m128d st = _mm_add_pd(xy, ab_times_cd); @@ -283,7 +288,13 @@ __m128d ab_square = _mm_mul_pd(ab, ab); __m128d cd_square = _mm_mul_pd(cd, cd); +#ifdef __SSE3__ __m128d r = _mm_hadd_pd(ab_square, cd_square); +#else + __m128d r_lo = _mm_shuffle_pd(ab_square, cd_square, 0); + __m128d r_hi = _mm_shuffle_pd(ab_square, cd_square, 3); + __m128d r = _mm_add_pd(r_lo, r_hi); +#endif _mm_store_pd(samples + j, r); } @@ -390,11 +401,23 @@ __m128d ad_bc = _mm_mul_pd(ab, dc); __m128d mad_bc = _mm_mul_pd(ad_bc, signs); +#ifdef __SSE3__ __m128d acpbd_bcmad = _mm_hadd_pd(ac_bd, mad_bc); +#else + __m128d acpbd_bcmad_lo = _mm_shuffle_pd(ac_bd, mad_bc, 0); + __m128d acpbd_bcmad_hi = _mm_shuffle_pd(ac_bd, mad_bc, 3); + __m128d acpbd_bcmad = _mm_add_pd(acpbd_bcmad_lo, acpbd_bcmad_hi); +#endif __m128d cd_squares = _mm_mul_pd(cd, cd); + +#ifdef __SSE3__ __m128d cd_squares_sum = _mm_hadd_pd(cd_squares, cd_squares); +#else + __m128d cd_squares_flip = _mm_shuffle_pd(cd_squares, cd_squares, 1); + __m128d cd_squares_sum = _mm_add_pd(cd_squares, cd_squares_flip); +#endif __m128d r = _mm_div_pd(acpbd_bcmad, cd_squares_sum);