From 927287da34a0e3c3be2fc2000da9055829f73b0c Mon Sep 17 00:00:00 2001
From: Andrew Waterman <waterman@eecs.berkeley.edu>
Date: Mon, 7 Apr 2014 23:47:53 -0700
Subject: [PATCH] Bypass RAS push/pop

---
 rocket/src/main/scala/btb.scala | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/rocket/src/main/scala/btb.scala b/rocket/src/main/scala/btb.scala
index d4beed04..a6a99a8b 100644
--- a/rocket/src/main/scala/btb.scala
+++ b/rocket/src/main/scala/btb.scala
@@ -204,12 +204,16 @@ class BTB(implicit conf: BTBConfig) extends Module {
 
   if (conf.nras > 0) {
     val ras = new RAS
-    when (!ras.isEmpty && Mux1H(hits, useRAS)) {
+    val doPeek = Mux1H(hits, useRAS)
+    when (!ras.isEmpty && doPeek) {
       io.resp.bits.target := ras.peek
     }
     when (io.update.valid) {
       when (io.update.bits.isCall) {
         ras.push(io.update.bits.returnAddr)
+        when (doPeek) {
+          io.resp.bits.target := io.update.bits.returnAddr
+        }
       }.elsewhen (io.update.bits.isReturn && io.update.bits.prediction.valid) {
         ras.pop
       }