add tests for non-power-of-2 shifts for MultiShift* classes

[ieee754fpu.git] / README.md

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-# IEEE754 Floating-Point ALU, in nmigen
+# IEEE754 Floating-Point ALU, in nmigen(tm)
 
-This project implements a pipelined IEEE754 floating-point ALU that
-supports FP16, FP32 and FP64.  It is a general-purpose unit that
-may be used in any project (not limited to one specific processor).
+nmigen (and all aliases) are Trademarks of M-Labs.
+nmigen is a Registered Trademark of M-Labs
+https://uspto.report/TM/88980893
+
+This project implements a parameteriseable pipelined IEEE754 floating-point
+ALU that supports FP16, FP32 and FP64.  Other FP sizes (FP80, BF16, FP128)
+are a matter of adding new parameters for mantissa and exponent.
+The IEEE754 FP Library is a general-purpose unit that may be used in
+any project (not limited to one specific processor).  Limited Formal
+Correctness Proofs are provided (so far for fpadd, fpsub) as well as
+hundreds of thousands of unit tests.
+
+Developed under Grants from NLnet (http://nlnet.nl), from
+EU Grants 871528 and 957073.  more information may be found at
+http://libre-soc.org
+
+# Requirements
+
+* nmigen (https://gitlab.com/nmigen/nmigen)
+* libresoc-nmutil (https://git.libre-soc.org/?p=nmutil.git;a=summary)
+* yosys (latest git repository, required by nmigen)
+* sfpy (running unit tests).  provides python bindings to berkeley softfloat-3
+
+# Building sfpy
+
+The standard sfpy will not work without being modified to the type of
+IEEE754 FP emulation being tested.  This FPU is emulating RISC-V, and
+there is some weirdness in x86 IEEE754 implementations when it comes
+to FP16 non-canonical NaNs.
+
+The following modifications are required to the sfpy berkeley-softfloat-3
+submodule:
+
+    cd /path/to/sfpy/berkeley-softfloat-3
+    git apply /path/to/ieee754fpu/berkeley-softfloat.patch
+
+The following modifications are required to the sfpy SoftPosit Makefile:
+
+    cd /path/to/sfpy/SoftPosit
+    git apply /path/to/ieee754fpu/SoftPosit.patch
 
 # Useful resources
 
 * https://en.wikipedia.org/wiki/IEEE_754-1985
 * http://weitz.de/ieee/
 * https://steve.hollasch.net/cgindex/coding/ieeefloat.html
+