Forum Discussion

SBioo's avatar
SBioo
Icon for Occasional Contributor rankOccasional Contributor
6 years ago
Solved

Doing low bit-width fixed precision FMA on DSP in OpenCL

Hi, I'm developing a specific design, where my variables are either 8 or 16 bit fix precision. For example, data are stored as `char` or `short`. Now each iteration, multiple FMAs are being done, bu...
  • HRZ's avatar
    HRZ
    6 years ago

    The appropriate IP Core is either directly used by the OpenCL compiler, or eventually employed by the mapper depending on the width of your variables. I remember there were some topics in the forum about this subject before and the compiler's behavior was kinda buggy, though. You can also take a look at the variable-width integer extension and the instructions for correctly inferring fixed-point arithmetic in the Best Practices Guide.

SBioo's avatar
SBioo
Icon for Occasional Contributor rankOccasional Contributor
6 years ago

Thanks much for the reply,

I've taken a look at the documentations you mentioned, and understood various IP cores that can be used for something like 18x18 FMA. Now my question is. how should I change my code so the compiler adopts these specific IP cores for me? Should I just extend my variables from 8 bit to 18 bits? Or are these FMA modes are provided as built-in functions, so I can just call them?

Thanks