gcc/testsuite/gcc.target/powerpc/ppc-fma-7.c

   1 /* { dg-do compile { target { powerpc*-*-* } } } */
   2 /* { dg-skip-if "" { powerpc*-*-darwin* } } */
   3 /* { dg-options "-O3 -ftree-vectorize -mdejagnu-cpu=power6 -ffast-math" } */
   4 /* { dg-require-effective-target powerpc_altivec } */
   5 /* { dg-require-effective-target powerpc_fprs } */
   6 /* { dg-final { scan-assembler-times "fmadd" 1 } } */
   7 /* { dg-final { scan-assembler-times "fmsub " 1 } } */
   8 /* { dg-final { scan-assembler-not "fmul" } } */
   9 /* { dg-final { scan-assembler-not "fadd " } } */
  10
  11 /* Check whether the common FFT idiom (a*b)+c and (a*b)-c generates two fma
  12    instructions, instead of a multiply, add, and subtract.  */
  13
  14 void
  15 fft (double *result, double a, double b, double c)
  16 {
  17   result[0] = (a*b) + c;
  18   result[1] = (a*b) - c;
  19 }