Major shifter-ALU redesign

The shifter unit now works in parallel with the ALU and is no longer
part of it. Instructions that use the shifter as input to the ALU will
now take an additional cycle, unless the control unit can detect a
"trivial shift" situation where the shifter's output will be the same as
its input. This change improves Fmax substantially.

1 files changed, 7 insertions, 8 deletions

diff --git a/rtl/core/uarch.sv b/rtl/core/uarch.sv
index c382cba..0c5bc84 100644
--- a/rtl/core/uarch.sv
+++ b/rtl/core/uarch.sv
@@ -72,16 +72,15 @@ typedef struct packed
 	           sign_extend;
 	logic[7:0] imm;
 	logic[5:0] shift_imm;
-} alu_decode;
+} data_decode;
 
 typedef struct packed
 {
-	alu_op op;
-	logic  shl,
-	       shr,
-	       ror,
-	       put_carry,
-	       sign_extend;
-} alu_control;
+	logic shl,
+	      shr,
+	      ror,
+	      put_carry,
+	      sign_extend;
+} shifter_control;
 
 `endif