From 989eeb78f9cd56dfd8679e1749b0444da889e8ed Mon Sep 17 00:00:00 2001
From: Andrew Waterman <andrew@sifive.com>
Date: Mon, 6 Nov 2017 11:04:06 -0800
Subject: [PATCH] Prevent some unnecessary pipeline replays

---
 src/main/scala/rocket/IBuf.scala | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/main/scala/rocket/IBuf.scala b/src/main/scala/rocket/IBuf.scala
index b24002de..d43e0590 100644
--- a/src/main/scala/rocket/IBuf.scala
+++ b/src/main/scala/rocket/IBuf.scala
@@ -60,9 +60,9 @@ class IBuf(implicit p: Parameters) extends CoreModule {
         buf := io.imem.bits
         buf.data := shiftInsnRight(io.imem.bits.data, shamt)(n*coreInstBits-1,0)
         buf.pc := io.imem.bits.pc & ~pcWordMask | (io.imem.bits.pc + (nICReady << log2Ceil(coreInstBytes))) & pcWordMask
-        ibufBTBHit := io.imem.bits.btb.valid
+        ibufBTBHit := io.imem.bits.btb.valid && io.imem.bits.btb.bits.bridx >= shamt
         ibufBTBResp := io.imem.bits.btb.bits
-        ibufBTBResp.bridx := io.imem.bits.btb.bits.bridx + nICReady
+        ibufBTBResp.bridx := io.imem.bits.btb.bits.bridx - shamt
       }
     }
     when (io.kill) {