replace copy of FPState with import of FPState

[ieee754fpu.git] / src / add / fmul.py

diff --git a/src/add/fmul.py b/src/add/fmul.py
index 728074e9a38f7187bb4e19543685e1146be4c332..46ad8099874b28899484477e321a9b3171c56db1 100644 (file)
--- a/src/add/fmul.py
+++ b/src/add/fmul.py
@@ -1,8 +1,8 @@
-from nmigen import Module, Signal
+from nmigen import Module, Signal, Cat, Mux, Array, Const

 from nmigen.cli import main, verilog
 
 from fpbase import FPNum, FPOp, Overflow, FPBase
 from nmigen.cli import main, verilog
 
 from fpbase import FPNum, FPOp, Overflow, FPBase

-
+from nmigen_add_experiment import FPState

 
 class FPMUL(FPBase):
 
 
 class FPMUL(FPBase):
 


@@ -20,79 +20,65 @@ class FPMUL(FPBase):
         m = Module()
 
         # Latches
         m = Module()
 
         # Latches

-        a = FPNum(self.width)
-        b = FPNum(self.width)
+        a = FPNum(self.width, False)
+        b = FPNum(self.width, False)

         z = FPNum(self.width, False)
 
         z = FPNum(self.width, False)
 

-        tot = Signal(28)     # sticky/round/guard bits, 23 result, 1 overflow
+        mw = (z.m_width)*2 - 1 + 3 # sticky/round/guard bits + (2*mant) - 1
+        product = Signal(mw)

 
         of = Overflow()
 
         with m.FSM() as fsm:
 
 
         of = Overflow()
 
         with m.FSM() as fsm:
 

-               with m.State("get_a"):
-                       m.next += "get_b"
-                       m.d.sync += s.in_a.ack.eq(1)
-                       with m.If(s.in_a.ack & in_a.stb):
-                               m.d.sync += [
-                               a.eq(in_a),
-                               s.in_a.ack(0)
-                       ]
-
-               with m.State("get_b"):
-                       m.next += "unpack"
-                       m.d.sync += s.in_b.ack.eq(1)
-                       with m.If(s.in_b.ack & in_b.stb):
-                               m.d.sync += [
-                               b.eq(in_b),
-                               s.in_b.ack(0)
-                       ]
-
-               with m.State("unpack"):
-                       m.next += "special_cases"
-                       m.d.sync += [
-                       a.m.eq(a[0:22]),
-                       b.m.eq(b[0:22]),
-                       a.e.eq(a[23:31] - 127),
-                       b.e.eq(b[23:31] - 127),
-                       a.s.eq(a[31]),
-                       b.s.eq(b[31])
-                       ]
-               
-               with m.State("special_cases"):
-                       m.next = "normalise_a"
-                       #if a or b is NaN return NaN
-                       with m.If(a.is_nan() | b.is_nan()):
-                               m.next += "put_z"
-                               m.d.sync += z.nan(1)
-                       #if a is inf return inf
-                       with m.Elif(a.is_inf()):
-                               m.next += "put_z"
-                               m.d.sync += z.inf(0)
-                       #if b is zero return NaN
-                       with m.If(b.is_zero()):
-                               m.d.sync += z.nan(1)
-                       #if b is inf return inf
-                       with m.Elif(b.is_inf()):
-                               m.next += "put_z"
-                               m.d.sync += z.inf(0)
-                       #if a is zero return NaN
-                       with m.If(a.is_zero()):
-                               m.next += "put_z"
-                               m.d.sync += z.nan(1)
-                       #if a is zero return zero
-                       with m.Elif(a.is_zero()):
-                               m.next += "put_z"
-                               m.d.sync += z.zero(0)
-                       #if b is zero return zero
-                       with m.Elif(b.is_zero()):
-                               m.next += "put_z"
-                               m.d.sync += z.zero(0)
+            # ******
+            # gets operand a
+
+            with m.State("get_a"):
+                self.get_op(m, self.in_a, a, "get_b")
+
+            # ******
+            # gets operand b
+
+            with m.State("get_b"):
+                self.get_op(m, self.in_b, b, "special_cases")
+
+            # ******
+            # special cases
+
+            with m.State("special_cases"):
+                #if a or b is NaN return NaN
+                with m.If(a.is_nan() | b.is_nan()):
+                    m.next = "put_z"
+                    m.d.sync += z.nan(1)
+                #if a is inf return inf
+                with m.Elif(a.is_inf()):
+                    m.next = "put_z"
+                    m.d.sync += z.inf(a.s ^ b.s)
+                    #if b is zero return NaN
+                    with m.If(b.is_zero()):
+                        m.d.sync += z.nan(1)
+                #if b is inf return inf
+                with m.Elif(b.is_inf()):
+                    m.next = "put_z"
+                    m.d.sync += z.inf(a.s ^ b.s)
+                    #if a is zero return NaN
+                    with m.If(a.is_zero()):
+                        m.next = "put_z"
+                        m.d.sync += z.nan(1)
+                #if a is zero return zero
+                with m.Elif(a.is_zero()):
+                    m.next = "put_z"
+                    m.d.sync += z.zero(a.s ^ b.s)
+                #if b is zero return zero
+                with m.Elif(b.is_zero()):
+                    m.next = "put_z"
+                    m.d.sync += z.zero(a.s ^ b.s)

                 # Denormalised Number checks
                 # Denormalised Number checks

-                               with m.Else():
-                                       m.next += "normalise_a"
-                                       self.denormalise(m, a)
-                                       self.denormalise(m, b)
+                with m.Else():
+                    m.next = "normalise_a"
+                    self.denormalise(m, a)
+                    self.denormalise(m, b)

 
             # ******
             # normalise_a
 
             # ******
             # normalise_a


@@ -108,24 +94,25 @@ class FPMUL(FPBase):
 
             #multiply_0
             with m.State("multiply_0"):
 
             #multiply_0
             with m.State("multiply_0"):

-               m.next += "multiply_1"
-                       m.d.sync += [
-                       z.s.eq(a.s ^ b.s),
-                       z.e.eq(a.e + b.e + 1),
-                       product.eq(a.m * b.m * 4)
-               ]
-
-                       #multiply_1
-               with m.State("multiply_1"):
-                       m.next += "normalise_1"
-                       m.d.sync += [
-                       z.m.eq(product[26:50]),
-                       guard.eq(product[25]),
-                       round_bit.eq(product[24]),
-                       sticky.eq(product[0:23] != 0)
-               ]
-
-               # ******
+                m.next = "multiply_1"
+                m.d.sync += [
+                   z.s.eq(a.s ^ b.s),
+                   z.e.eq(a.e + b.e + 1),
+                   product.eq(a.m * b.m * 4)
+                ]
+
+            #multiply_1
+            with m.State("multiply_1"):
+                mw = z.m_width
+                m.next = "normalise_1"
+                m.d.sync += [
+                z.m.eq(product[mw+2:]),
+                of.guard.eq(product[mw+1]),
+                of.round_bit.eq(product[mw]),
+                of.sticky.eq(product[0:mw] != 0)
+            ]
+
+            # ******

             # First stage of normalisation.
             with m.State("normalise_1"):
                 self.normalise_1(m, z, of, "normalise_2")
             # First stage of normalisation.
             with m.State("normalise_1"):
                 self.normalise_1(m, z, of, "normalise_2")


@@ -142,7 +129,13 @@ class FPMUL(FPBase):
             with m.State("round"):
                 self.roundz(m, z, of, "corrections")
 
             with m.State("round"):
                 self.roundz(m, z, of, "corrections")
 

-                       # ******
+            # ******
+            # correction stage
+
+            with m.State("corrections"):
+                self.corrections(m, z, "pack")
+
+            # ******

             # pack stage
             with m.State("pack"):
                 self.pack(m, z, "put_z")
             # pack stage
             with m.State("pack"):
                 self.pack(m, z, "put_z")


@@ -155,175 +148,6 @@ class FPMUL(FPBase):
 
         return m
 
 
         return m
 

-"""
-special_cases:
-      begin
-        //if a is NaN or b is NaN return NaN 
-        if ((a_e == 128 && a_m != 0) || (b_e == 128 && b_m != 0)) begin
-          z[31] <= 1;
-          z[30:23] <= 255;
-          z[22] <= 1;
-          z[21:0] <= 0;
-          state <= put_z;
-        //if a is inf return inf
-        end else if (a_e == 128) begin
-          z[31] <= a_s ^ b_s;
-          z[30:23] <= 255;
-          z[22:0] <= 0;
-          //if b is zero return NaN
-          if (($signed(b_e) == -127) && (b_m == 0)) begin
-            z[31] <= 1;
-            z[30:23] <= 255;
-            z[22] <= 1;
-            z[21:0] <= 0;
-          end
-          state <= put_z;
-        //if b is inf return inf
-        end else if (b_e == 128) begin
-          z[31] <= a_s ^ b_s;
-          z[30:23] <= 255;
-          z[22:0] <= 0;
-          //if a is zero return NaN
-          if (($signed(a_e) == -127) && (a_m == 0)) begin
-            z[31] <= 1;
-            z[30:23] <= 255;
-            z[22] <= 1;
-            z[21:0] <= 0;
-          end
-          state <= put_z;
-        //if a is zero return zero
-        end else if (($signed(a_e) == -127) && (a_m == 0)) begin
-          z[31] <= a_s ^ b_s;
-          z[30:23] <= 0;
-          z[22:0] <= 0;
-          state <= put_z;
-        //if b is zero return zero
-        end else if (($signed(b_e) == -127) && (b_m == 0)) begin
-          z[31] <= a_s ^ b_s;
-          z[30:23] <= 0;
-          z[22:0] <= 0;
-          state <= put_z;
-          //^ done up to here
-        end else begin
-          //Denormalised Number
-          if ($signed(a_e) == -127) begin
-            a_e <= -126;
-          end else begin
-            a_m[23] <= 1;
-          end
-          //Denormalised Number
-          if ($signed(b_e) == -127) begin
-            b_e <= -126;
-          end else begin
-            b_m[23] <= 1;
-          end
-          state <= normalise_a;
-        end
-      end
-
-      normalise_a:
-      begin
-        if (a_m[23]) begin
-          state <= normalise_b;
-        end else begin
-          a_m <= a_m << 1;
-          a_e <= a_e - 1;
-        end
-      end
-
-      normalise_b:
-      begin
-        if (b_m[23]) begin
-          state <= multiply_0;
-        end else begin
-          b_m <= b_m << 1;
-          b_e <= b_e - 1;
-        end
-      end
-
-      multiply_0:
-      begin
-        z_s <= a_s ^ b_s;
-        z_e <= a_e + b_e + 1;
-        product <= a_m * b_m * 4;
-        state <= multiply_1;
-      end
-
-      multiply_1:
-      begin
-        z_m <= product[49:26];
-        guard <= product[25];
-        round_bit <= product[24];
-        sticky <= (product[23:0] != 0);
-        state <= normalise_1;
-      end
-
-      normalise_1:
-      begin
-        if (z_m[23] == 0) begin
-          z_e <= z_e - 1;
-          z_m <= z_m << 1;
-          z_m[0] <= guard;
-          guard <= round_bit;
-          round_bit <= 0;
-        end else begin
-          state <= normalise_2;
-        end
-      end
-
-      normalise_2:
-      begin
-        if ($signed(z_e) < -126) begin
-          z_e <= z_e + 1;
-          z_m <= z_m >> 1;
-          guard <= z_m[0];
-          round_bit <= guard;
-          sticky <= sticky | round_bit;
-        end else begin
-          state <= round;
-        end
-      end
-
-      round:
-      begin
-        if (guard && (round_bit | sticky | z_m[0])) begin
-          z_m <= z_m + 1;
-          if (z_m == 24'hffffff) begin
-            z_e <=z_e + 1;
-          end
-        end
-        state <= pack;
-      end
-
-      pack:
-      begin
-        z[22 : 0] <= z_m[22:0];
-        z[30 : 23] <= z_e[7:0] + 127;
-        z[31] <= z_s;
-        if ($signed(z_e) == -126 && z_m[23] == 0) begin
-          z[30 : 23] <= 0;
-        end
-        //if overflow occur
-        s, return inf
-        if ($signed(z_e) > 127) begin
-          z[22 : 0] <= 0;
-          z[30 : 23] <= 255;
-          z[31] <= z_s;
-        end
-        state <= put_z;
-      end
-
-      put_z:
-      begin
-        s_output_z_stb <= 1;
-        s_output_z <= z;
-        if (s_output_z_stb && output_z_ack) begin
-          s_output_z_stb <= 0;
-          state <= get_a;
-        end
-end
-
-"""

 
 if __name__ == "__main__":
     alu = FPMUL(width=32)
 
 if __name__ == "__main__":
     alu = FPMUL(width=32)