README.md

   1 # IEEE754 Floating-Point ALU, in nmigen
   2
   3 This project implements a pipelined IEEE754 floating-point ALU that
   4 supports FP16, FP32 and FP64.  It is a general-purpose unit that
   5 may be used in any project (not limited to one specific processor).
   6
   7 # Requirements
   8
   9 * nmigen
  10 * yosys (latest git repository, required by nmigen)
  11 * sfpy (running unit tests).  provides python bindings to berkeley softfloat-3
  12
  13 # Building sfpy
  14
  15 The standard sfpy will not work without being modified to the type of
  16 IEEE754 FP emulation being tested.  This FPU is emulating RISC-V, and
  17 there is some weirdness in x86 IEEE754 implementations when it comes
  18 to FP16 non-canonical NaNs.
  19
  20 The following modifications are required to the sfpy berkeley-softfloat-3
  21 submodule:
  22
  23     cd /path/to/sfpy/berkeley-softfloat-3
  24     git apply /path/to/ieee754fpu/berkeley-softfloat.patch
  25
  26
  27
  28 The following modifications are required to the sfpy SoftPosit Makefile:
  29
  30     cd /path/to/sfpy/SoftPosit
  31     git apply /path/to/ieee754fpu/SoftPosit.patch
  32
  33 # Useful resources
  34
  35 * https://en.wikipedia.org/wiki/IEEE_754-1985
  36 * http://weitz.de/ieee/
  37 * https://steve.hollasch.net/cgindex/coding/ieeefloat.html
  38