[Bug target/19653] x87 reg allocated for constants for -mfpmath=sse

[bonzini at gcc dot gnu dot org]

------- Additional Comments From bonzini at gcc dot gnu dot org  2005-07-13 
11:51 -------
Smaller testcase from PR22453:


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.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19653