Improving accuracy in goutbins calc in DFT32.c

[bbkiwi]

No description provided.

[bbkiwi]

In the orginal code isps and ispc loose 16 bits accuracy to prevent overflow at line 197 when they are squared. With the APPROXNORM == 1 option this was not neccessary. However isps and ispc are also used to compute goutbins in the non-CCEMBEDDED case. With floating point calculations the higher accuracy values should be used. I think it would be better to always compute isps and ispc as in lines 172 and 173 irregardless of APPROXNORM.
Calculate 185 by
float mux = ( ((float)isps) * ((float)isps)) + (((float)ispc) * ((float)ispc));
goutbins[i] = sqrtf( (float)mux )/65536.0;
Calculate 197 by
uint32_t rmux = ( (isps>>16) * (isps>>16)) + ((ispc>>16) * (ispc>>16));

[bbkiwi]

See #93