Re: [LAU] building a debian system for audio

On Wed, May 23, 2007 at 06:46:45PM -0500, Jack O'Quin wrote: Yes, that works, even if inlined. Meanwhile I've found out what happened. The problem was not with the float to int conversion, but with the FP calculation itself. In one case, an intermediate value was stored to memory and re-used from the stored value. In the second the register value was used. A FP register has higher precision than a 32-bit FP in memory, so storing it to memory requires rounding. And rounding can change even the integer part in some rare cases. Having both a register and a memory copy of the same variable can produce very strange results, e.g. float v; v = // some calculation printf ("v = %12.9lf %08x\n", v, *((int *)(&v))); can print either v = 29.990000000 41efeb85 or v = 29.989999771 41efeb85 depending on the context. In the second line printf() uses the register value for the first field, in the first the one stored in the variable v. It just depends on what the optimiser prefers. The hex format always uses the value stored in v. -- FA Follie! Follie! Delirio vano è questo !