From 65e9747752eeeaa6c709b37eb6aa5c28185ccc99 Mon Sep 17 00:00:00 2001
From: Shreya Sanghai <ssanghai@hmc.edu>
Date: Wed, 31 Mar 2021 21:56:14 -0400
Subject: [PATCH] fixed bugs in global history to read latest GHRE

---
 wally-pipelined/config/rv64BP/wally-config.vh     | 2 +-
 wally-pipelined/src/ifu/globalHistoryPredictor.sv | 9 +++++----
 2 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/wally-pipelined/config/rv64BP/wally-config.vh b/wally-pipelined/config/rv64BP/wally-config.vh
index bd053750c..f39c6cee3 100644
--- a/wally-pipelined/config/rv64BP/wally-config.vh
+++ b/wally-pipelined/config/rv64BP/wally-config.vh
@@ -97,5 +97,5 @@
 
 `define TWO_BIT_PRELOAD "../config/rv64icfd/twoBitPredictor.txt"
 `define BTB_PRELOAD "../config/rv64icfd/BTBPredictor.txt"
-`define BPTYPE "BPGSHARE" // BPGLOBAL or BPTWOBIT or BPGSHARE
+`define BPTYPE "BPGLOBAL" // BPGLOBAL or BPTWOBIT or BPGSHARE
 `define TESTSBP 1
diff --git a/wally-pipelined/src/ifu/globalHistoryPredictor.sv b/wally-pipelined/src/ifu/globalHistoryPredictor.sv
index b9addb381..babafb525 100644
--- a/wally-pipelined/src/ifu/globalHistoryPredictor.sv
+++ b/wally-pipelined/src/ifu/globalHistoryPredictor.sv
@@ -41,12 +41,13 @@ module globalHistoryPredictor
    input logic [1:0] 	   UpdatePrediction
    
    );
-   logic [k-1:0] GHRF, GHRD, GHRE;
+   logic [k-1:0] GHRF, GHRD, GHRE, GHRENext;
+   assign GHRENext = {PCSrcE, GHRE[k-1:1]}; 
 
     flopenr #(k) GlobalHistoryRegister(.clk(clk),
             .reset(reset),
             .en(UpdateEN),
-            .d({PCSrcE, GHRF[k-1:1] }),
+            .d(GHRENext),
             .q(GHRF));
 
 
@@ -66,8 +67,8 @@ module globalHistoryPredictor
 				.reset(reset),
 				.RA1(GHRF),
 				.RD1(PredictionMemory),
-				.REN1(1'b1),
-				.WA1(GHRE),
+				.REN1(~StallF),
+				.WA1(GHRENext),
 				.WD1(UpdatePrediction),
 				.WEN1(UpdateEN),
 				.BitWEN1(2'b11));