# initialise out from in (overridden below)
m.d.comb += self.o.z.eq(insel_z)
m.d.comb += Overflow.eq(of, i.of)
- with m.If(~self.i.out_do_z):
-
- # normalisation increase/decrease conditions
- decrease = Signal(reset_less=True)
- increase = Signal(reset_less=True)
- m.d.comb += decrease.eq(insel_z.m_msbzero & insel_z.exp_gt_n126)
- m.d.comb += increase.eq(insel_z.exp_lt_n126)
-
- # concatenate s/r/g with mantissa. (it was easier to do this
- # than to have the mantissa contain the three extra bits)
- temp_m = Signal(mwid+2, reset_less=True)
- m.d.comb += temp_m.eq(Cat(i.of.sticky, i.of.round_bit, i.of.guard,
- insel_z.m)),
-
- # decrease exponent
- with m.If(decrease):
- # make sure that the amount to decrease by does NOT
- # go below the minimum non-INF/NaN exponent
- m.d.comb += msb.limclz.eq(insel_z.exp_sub_n126)
- m.d.comb += [
- # inputs: mantissa and exponent
- msb.m_in.eq(temp_m),
- msb.e_in.eq(insel_z.e),
-
- # outputs: mantissa first (s/r/g/m[3:])
- self.o.z.m.eq(msb.m_out[3:]), # exclude bits 0&1
- of.m0.eq(msb.m_out[3]), # copy of mantissa[0]
- # overflow in bits 0..1: got shifted too (leave sticky)
- of.guard.eq(msb.m_out[2]), # guard
- of.round_bit.eq(msb.m_out[1]), # round
- # now exponent out
- self.o.z.e.eq(msb.e_out),
- ]
- # increase exponent
- with m.Elif(increase):
- ediff_n126 = Signal(espec, reset_less=True)
- m.d.comb += [
- # concatenate
- ediff_n126.eq(insel_z.fp.N126 - insel_z.e),
- # connect multi-shifter to inp/out m/e (and ediff)
- msr.m_in.eq(temp_m),
- msr.e_in.eq(insel_z.e),
- msr.ediff.eq(ediff_n126),
-
- # outputs: mantissa first (s/r/g/m[3:])
- self.o.z.m.eq(msr.m_out[3:]),
- of.m0.eq(msr.m_out[3]), # copy of mantissa[0]
- # overflow in bits 0..2: got shifted too (leave sticky)
- of.guard.eq(msr.m_out[2]), # guard
- of.round_bit.eq(msr.m_out[1]), # round
- of.sticky.eq(msr.m_out[0]), # sticky
- # now exponent
- self.o.z.e.eq(msr.e_out),
- ]
+
+ # normalisation increase/decrease conditions
+ decrease = Signal(reset_less=True)
+ increase = Signal(reset_less=True)
+ m.d.comb += decrease.eq(insel_z.m_msbzero & insel_z.exp_gt_n126)
+ m.d.comb += increase.eq(insel_z.exp_lt_n126)
+
+ # concatenate s/r/g with mantissa. (it was easier to do this
+ # than to have the mantissa contain the three extra bits)
+ temp_m = Signal(mwid+2, reset_less=True)
+ m.d.comb += temp_m.eq(Cat(i.of.sticky, i.of.round_bit, i.of.guard,
+ insel_z.m)),
+
+ # decrease exponent
+ with m.If(decrease):
+ # make sure that the amount to decrease by does NOT
+ # go below the minimum non-INF/NaN exponent
+ m.d.comb += msb.limclz.eq(insel_z.exp_sub_n126)
+ m.d.comb += [
+ # inputs: mantissa and exponent
+ msb.m_in.eq(temp_m),
+ msb.e_in.eq(insel_z.e),
+
+ # outputs: mantissa first (s/r/g/m[3:])
+ self.o.z.m.eq(msb.m_out[3:]), # exclude bits 0&1
+ of.m0.eq(msb.m_out[3]), # copy of mantissa[0]
+ # overflow in bits 0..1: got shifted too (leave sticky)
+ of.guard.eq(msb.m_out[2]), # guard
+ of.round_bit.eq(msb.m_out[1]), # round
+ # now exponent out
+ self.o.z.e.eq(msb.e_out),
+ ]
+ # increase exponent
+ with m.Elif(increase):
+ ediff_n126 = Signal(espec, reset_less=True)
+ m.d.comb += [
+ # concatenate
+ ediff_n126.eq(insel_z.fp.N126 - insel_z.e),
+ # connect multi-shifter to inp/out m/e (and ediff)
+ msr.m_in.eq(temp_m),
+ msr.e_in.eq(insel_z.e),
+ msr.ediff.eq(ediff_n126),
+
+ # outputs: mantissa first (s/r/g/m[3:])
+ self.o.z.m.eq(msr.m_out[3:]),
+ of.m0.eq(msr.m_out[3]), # copy of mantissa[0]
+ # overflow in bits 0..2: got shifted too (leave sticky)
+ of.guard.eq(msr.m_out[2]), # guard
+ of.round_bit.eq(msr.m_out[1]), # round
+ of.sticky.eq(msr.m_out[0]), # sticky
+ # now exponent
+ self.o.z.e.eq(msr.e_out),
+ ]
m.d.comb += self.o.roundz.eq(of.roundz_out)
m.d.comb += self.o.ctx.eq(self.i.ctx)