[PD-dev] freeverb's type-punned pointers

[Martin Peach]

Hans-Christoph Steiner wrote:
> Hey,
>
> I want to fix the type-punned pointer problem in freeverb~ so it can  
> be compiled with full optimization.  Here's the code snippets in  
> question, with the warnings being issued for the FIX_DENORM_NAN_FLOAT 
> () lines:
>
> #define IS_DENORM_FLOAT(v)  ((((*(unsigned long*)&(v))&0x7f800000)==0) 
> &&((v)!=0.f))
> #define FIX_DENORM_NAN_FLOAT(v)    ((v)=IS_DENORM_NAN_FLOAT(v)?0.f:(v))
>
>
> static inline t_float comb_processR(t_freeverb *x, int filteridx,  
> t_float input)
> {
> 	t_float output;
> 	int bufidx = x->x_combidxR[filteridx];
>
> 	output = x->x_bufcombR[filteridx][bufidx];
> 	FIX_DENORM_NAN_FLOAT(output);
>
> 	x->x_filterstoreR[filteridx] = (output*x->x_combdamp2) + (x- 
>  >x_filterstoreR[filteridx]*x->x_combdamp1);
> 	FIX_DENORM_NAN_FLOAT(x->x_filterstoreR[filteridx]);
>
> [snip]
>
>
> Could I just cast things to (unsigned long)?  Or is there a better way?
>
>   
I think the proper way is to use a union, so you can refer to the same 
thing as two different types.

Martin