The following code

extern double f(double, double);
void g (double x)
{
  double z, y;

  z = 0.0;
  y = 1.0 - x;

again:
  z = y - z;
  f(z, 1.0);
  if (z == 0.0)
    goto again;
}

has a fld1 instruction when compiled with "-mfpmath=sse -msse2 -msseregparm
-mtune=pentiumpro -O2".

This instruction is caused by a reload into a FLOAT_REGS register, and moving
the value to a SSE register needs secondary memory.