extern void abort (void); typedef float v4flt __attribute__ ((vector_size (16))); void __attribute__ ((noinline)) foo (float *dst, float **src, int a, int n) { int i, j; int z = sizeof (v4flt) / sizeof (float); unsigned m = sizeof (v4flt) - 1; for (j = 0; j < n && (((unsigned long) dst + j) & m); ++j) { float t = src[0][j]; for (i = 1; i < a; ++i) t += src[i][j]; dst[j] = t; } for (; j < (n - (4 * z - 1)); j += 4 * z) { v4flt t0 = *(v4flt *) (src[0] + j + 0 * z); v4flt t1 = *(v4flt *) (src[0] + j + 1 * z); v4flt t2 = *(v4flt *) (src[0] + j + 2 * z); v4flt t3 = *(v4flt *) (src[0] + j + 3 * z); for (i = 1; i < a; ++i) { t0 += *(v4flt *) (src[i] + j + 0 * z); t1 += *(v4flt *) (src[i] + j + 1 * z); t2 += *(v4flt *) (src[i] + j + 2 * z); t3 += *(v4flt *) (src[i] + j + 3 * z); } *(v4flt *) (dst + j + 0 * z) = t0; *(v4flt *) (dst + j + 1 * z) = t1; *(v4flt *) (dst + j + 2 * z) = t2; *(v4flt *) (dst + j + 3 * z) = t3; } for (; j < n; ++j) { float t = src[0][j]; for (i = 1; i < a; ++i) t += src[i][j]; dst[j] = t; } } float buffer[64]; int main (void) { int i; float *dst, *src[2]; char *cptr; cptr = (char *)buffer; cptr += (-(long int) buffer & (16 * sizeof (float) - 1)); dst = (float *)cptr; src[0] = dst + 16; src[1] = dst + 32; for (i = 0; i < 16; ++i) { src[0][i] = (float) i + 11 * (float) i; src[1][i] = (float) i + 12 * (float) i; } foo (dst, src, 2, 16); for (i = 0; i < 16; ++i) { float e = (float) i + 11 * (float) i + (float) i + 12 * (float) i; if (dst[i] != e) abort (); } return 0; }