From: Michael Nolan <mtnolan2640@gmail.com>
Date: Fri, 8 May 2020 17:49:27 +0000 (-0400)
Subject: Have input_stage set the b operand to imm_data if it is valid
X-Git-Tag: div_pipeline~1339
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=939c409c32e7a522edeb4879d14c30a4efb6b2f8;p=soc.git

Have input_stage set the b operand to imm_data if it is valid
---

diff --git a/src/soc/alu/formal/proof_input_stage.py b/src/soc/alu/formal/proof_input_stage.py
index ab679e01..b3fc7f28 100644
--- a/src/soc/alu/formal/proof_input_stage.py
+++ b/src/soc/alu/formal/proof_input_stage.py
@@ -56,7 +56,11 @@ class Driver(Elaboratable):
             comb += Assert(dut.o.a == ~a)
         with m.Else():
             comb += Assert(dut.o.a == a)
-        comb += Assert(dut.o.b == b)
+
+        with m.If(rec.imm_data.imm_ok):
+            comb += Assert(dut.o.b == rec.imm_data.imm)
+        with m.Else():
+            comb += Assert(dut.o.b == b)
 
 
 
diff --git a/src/soc/alu/input_stage.py b/src/soc/alu/input_stage.py
index f7c38673..6d5e1e46 100644
--- a/src/soc/alu/input_stage.py
+++ b/src/soc/alu/input_stage.py
@@ -28,7 +28,11 @@ class ALUInputStage(PipeModBase):
 
         comb += self.o.a.eq(a)
 
-        comb += self.o.b.eq(self.i.b)
+        # If there's an immediate, set the B operand to that
+        with m.If(self.i.ctx.op.imm_data.imm_ok):
+            comb += self.o.b.eq(self.i.ctx.op.imm_data.imm)
+        with m.Else():
+            comb += self.o.b.eq(self.i.b)
 
         comb += self.o.ctx.eq(self.i.ctx)