gcc/testsuite/gcc.dg/var-expand1.c

   1 /* { dg-do compile } */
   2 /* We don't (and don't want to) perform this optimisation on soft-float
   3    targets, where each addition is a library call.  */
   4 /* { dg-require-effective-target hard_float } */
   5 /* { dg-options "-O2 -funroll-loops --fast-math -fvariable-expansion-in-unroller -fdump-rtl-loop2_unroll" } */
   6
   7 extern void abort (void);
   8
   9 float array[30] = { 1,2,3,4,5,6,7,8,9,10 };
  10
  11 int foo (int n)
  12 {
  13   unsigned i;
  14   float accum = 1.0;
  15
  16   for (i = 0; i < n; i++)
  17     accum += array[i];
  18
  19   return accum;
  20 }
  21
  22 int main (void)
  23 {
  24   return foo (10);
  25 }
  26
  27 /* { dg-final { scan-rtl-dump "Expanding Accumulator" "loop2_unroll" } } */
  28 /* { dg-final { cleanup-rtl-dump "loop2_unroll" } } */