gcc/testsuite/gcc.dg/vect/pr97832-3.c

   1 /* { dg-do compile } */
   2 /* { dg-additional-options "-Ofast" } */
   3 /* { dg-require-effective-target vect_double } */
   4
   5 void foo(double* restrict y, const double* restrict x0, const double* restrict x1, int clen)
   6 {
   7   int xi = clen & 2;
   8   double f00_re = x0[0+xi+0];
   9   double f10_re = x1[0+xi+0];
  10   double f01_re = x0[0+xi+1];
  11   double f11_re = x1[0+xi+1];
  12   double f00_im = x0[4+xi+0];
  13   double f10_im = x1[4+xi+0];
  14   double f01_im = x0[4+xi+1];
  15   double f11_im = x1[4+xi+1];
  16   int clen2 = (clen+xi) * 2;
  17   double* y0 = &y[0];
  18   double* y1 = &y[clen2];
  19   #pragma GCC unroll 0
  20   for (int c = 0; c < clen2; c += 8) {
  21     // y0[c] = y0[c] - x0[c]*conj(f00) - x1[c]*conj(f10);
  22     // y1[c] = y1[c] - x0[c]*conj(f01) - x1[c]*conj(f11);
  23     #pragma GCC unroll 4
  24     for (int k = 0; k < 4; ++k) {
  25       double x0_re = x0[c+0+k];
  26       double x0_im = x0[c+4+k];
  27       double y0_re = y0[c+0+k];
  28       double y0_im = y0[c+4+k];
  29       double y1_re = y1[c+0+k];
  30       double y1_im = y1[c+4+k];
  31       y0_re = y0_re - x0_re * f00_re - x0_im * f00_im;
  32       y0_im = y0_im + x0_re * f00_im - x0_im * f00_re;
  33       y1_re = y1_re - x0_re * f01_re - x0_im * f01_im;
  34       y1_im = y1_im + x0_re * f01_im - x0_im * f01_re;
  35       double x1_re = x1[c+0+k];
  36       double x1_im = x1[c+4+k];
  37       y0_re = y0_re - x1_re * f10_re - x1_im * f10_im;
  38       y0_im = y0_im + x1_re * f10_im - x1_im * f10_re;
  39       y1_re = y1_re - x1_re * f11_re - x1_im * f11_im;
  40       y1_im = y1_im + x1_re * f11_im - x1_im * f11_re;
  41       y0[c+0+k] = y0_re;
  42       y0[c+4+k] = y0_im;
  43       y1[c+0+k] = y1_re;
  44       y1[c+4+k] = y1_im;
  45     }
  46   }
  47 }
  48
  49 /* { dg-final { scan-tree-dump "vectorizing stmts using SLP" "vect" { target { ! { vect_load_lanes && vect_strided8 } } } } } */
  50 /* { dg-final { scan-tree-dump "Loop contains only SLP stmts" "vect" { target { ! { vect_load_lanes && vect_strided8 } } } } } */