------- Additional Comments From pinskia at gcc dot gnu dot org 2005-01-30
23:00 -------
(In reply to comment #7)
> Triggered by this change:
I think that only added the pure attribute on __builtin_cos.
You might want to try this testcase which shows the problem without a builtin:
float f(float) __attribute__((__pure__));
void FFT(int NumSamples, float *RealOut, float ar1)
{
int i, j, n;
int BlockSize, BlockEnd;
if (NumSamples <= 1)
return;
i = 0;
L1:
RealOut[i] = (RealOut == 0) ? 0.0 : RealOut[i];
i++;
if (NumSamples <= i) goto L1;
BlockEnd = 1;
for (BlockSize = 2; BlockSize <= NumSamples; BlockSize *=2)
{
float cm1 = f(-1.0);
for (i = 0; i < NumSamples; i += BlockSize)
for (j = i, n = 0; n < BlockEnd; j++, n++)
RealOut[j] = cm1 * ar1;
BlockEnd = BlockSize;
}
}
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19698
