- # exponent of a greater than b: increment b exp, shift b mant
- with m.If(a.e > b.e):
- m.d.sync += b.shift_down()
- # exponent of b greater than a: increment a exp, shift a mant
- with m.Elif(a.e < b.e):
- m.d.sync += a.shift_down()
- # exponents equal: move to next stage.
- with m.Else():
+ if not self.single_cycle:
+ # NOTE: this does *not* do single-cycle multi-shifting,
+ # it *STAYS* in the align state until exponents match
+
+ # exponent of a greater than b: shift b down
+ with m.If(a.e > b.e):
+ m.d.sync += b.shift_down()
+ # exponent of b greater than a: shift a down
+ with m.Elif(a.e < b.e):
+ m.d.sync += a.shift_down()
+ # exponents equal: move to next stage.
+ with m.Else():
+ m.next = "add_0"
+ else:
+ # This one however (single-cycle) will do the shift
+ # in one go.
+
+ ediff = Signal((len(a.e), True))
+ ediffr = Signal((len(a.e), True))
+ m.d.comb += ediff.eq(a.e - b.e)
+ m.d.comb += ediffr.eq(b.e - a.e)
+ with m.If(ediff > 0):
+ m.d.sync += b.shift_down_multi(ediff)
+ # exponent of b greater than a: shift a down
+ with m.Elif(ediff < 0):
+ m.d.sync += a.shift_down_multi(ediffr)
+