From: Jacob Lifshay Date: Sat, 25 Jun 2022 01:04:09 +0000 (-0700) Subject: add initial f16 fadd formal proof X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=98bf485dc96efc74e259809ad2829ccad6324cd4;p=ieee754fpu.git add initial f16 fadd formal proof --- diff --git a/src/ieee754/fpadd/test/test_add_formal.py b/src/ieee754/fpadd/test/test_add_formal.py new file mode 100644 index 00000000..9540de97 --- /dev/null +++ b/src/ieee754/fpadd/test/test_add_formal.py @@ -0,0 +1,45 @@ +import unittest +from nmutil.formaltest import FHDLTestCase +from ieee754.fpadd.pipeline import FPADDBasePipe +from nmigen.hdl.dsl import Module +from nmigen.hdl.ast import AnySeq, Assert, AnyConst, Signal, Assume +from nmigen.hdl.smtlib2 import (SmtFloatingPoint, SmtSortFloat16, + ROUND_NEAREST_TIES_TO_EVEN) +from ieee754.pipeline import PipelineSpec + + +class TestFAdd16Formal(FHDLTestCase): + def test_fadd16_rne_formal(self): + dut = FPADDBasePipe(PipelineSpec(width=16, id_width=4)) + m = Module() + m.submodules.dut = dut + m.d.comb += dut.n.i_ready.eq(AnySeq(1)) + m.d.comb += dut.p.i_valid.eq(AnySeq(1)) + a = dut.p.i_data.a + b = dut.p.i_data.b + z = dut.n.o_data.z + f16 = SmtSortFloat16() + rm = ROUND_NEAREST_TIES_TO_EVEN + a_fp = SmtFloatingPoint.from_bits(a, sort=f16) + b_fp = SmtFloatingPoint.from_bits(b, sort=f16) + z_fp = SmtFloatingPoint.from_bits(z, sort=f16) + expected_fp = a_fp.add(b_fp, rm=rm) + expected = Signal(16) + m.d.comb += expected.eq(AnySeq(16)) + # Important Note: expected and z won't necessarily match bit-exactly + # if it's a NaN, all this checks for is z is also any NaN + m.d.comb += Assume((SmtFloatingPoint.from_bits(expected, sort=f16) + == expected_fp).as_value()) + # FIXME: check that it produces the correct NaNs + m.d.comb += a.eq(AnyConst(16)) + m.d.comb += b.eq(AnyConst(16)) + with m.If(dut.n.trigger): + m.d.sync += Assert((z_fp == expected_fp).as_value()) + self.assertFormal(m, depth=5, solver="z3") + + # FIXME: check other rounding modes + # FIXME: check exception flags + + +if __name__ == '__main__': + unittest.main()