From dd4066a4196e1e2b92b1d255d413264382df3bf1 Mon Sep 17 00:00:00 2001 From: Luke Kenneth Casson Leighton Date: Sun, 18 Aug 2019 17:12:04 +0100 Subject: [PATCH] use switch instead of mux, more obvious what is happening --- src/ieee754/part_mul_add/multiply.py | 22 ++++++++++++++++------ 1 file changed, 16 insertions(+), 6 deletions(-) diff --git a/src/ieee754/part_mul_add/multiply.py b/src/ieee754/part_mul_add/multiply.py index 2997dc0d..8b7500ba 100644 --- a/src/ieee754/part_mul_add/multiply.py +++ b/src/ieee754/part_mul_add/multiply.py @@ -601,6 +601,7 @@ class FinalOut(Elaboratable): self.d8 = [Signal(name=f"d8_{i}", reset_less=True) for i in range(8)] self.d16 = [Signal(name=f"d16_{i}", reset_less=True) for i in range(4)] self.d32 = [Signal(name=f"d32_{i}", reset_less=True) for i in range(2)] + self.d64 = [Signal(name=f"d64_{i}", reset_less=True) for i in range(1)] self.i8 = Signal(out_wid, reset_less=True) self.i16 = Signal(out_wid, reset_less=True) @@ -615,12 +616,19 @@ class FinalOut(Elaboratable): ol = [] for i in range(8): op = Signal(8, reset_less=True, name="op_%d" % i) - m.d.comb += op.eq( - Mux(self.d8[i] | self.d16[i // 2], - Mux(self.d8[i], self.i8.bit_select(i * 8, 8), - self.i16.bit_select(i * 8, 8)), - Mux(self.d32[i // 4], self.i32.bit_select(i * 8, 8), - self.i64.bit_select(i * 8, 8)))) + choice = Signal(4, reset_less=True) + m.d.comb += choice.eq(Cat(self.d8[i], self.d16[i//2], + self.d32[i//4], self.d64[i//8])) + # select one of the outputs. + with m.Switch(choice): + with m.Case(0b0001): # d8 + m.d.comb += op.eq(self.i8.bit_select(i * 8, 8)) + with m.Case(0b0010): # d16 + m.d.comb += op.eq(self.i16.bit_select(i * 8, 8)) + with m.Case(0b0100): # d32 + m.d.comb += op.eq(self.i32.bit_select(i * 8, 8)) + with m.Case(0b1000): # d64 + m.d.comb += op.eq(self.i64.bit_select(i * 8, 8)) ol.append(op) m.d.comb += self.out.eq(Cat(*ol)) return m @@ -835,6 +843,8 @@ class Mul8_16_32_64(Elaboratable): m.d.comb += fo.d16[i].eq(part_16.dplast[i]) for i in range(len(part_32.delayed_parts[-1])): m.d.comb += fo.d32[i].eq(part_32.dplast[i]) + for i in range(len(part_64.delayed_parts[-1])): + m.d.comb += fo.d64[i].eq(part_64.dplast[i]) m.d.comb += fo.i8.eq(io8.output) m.d.comb += fo.i16.eq(io16.output) m.d.comb += fo.i32.eq(io32.output) -- 2.30.2