From 5c138fe263d3d0908b242df7727e3543c82367e8 Mon Sep 17 00:00:00 2001
From: Peter Rugg <pdr32@cam.ac.uk>
Date: Wed, 1 Apr 2020 12:46:55 +0100
Subject: [PATCH] Fix overly strict derivability check

---
 CHERICC_Fat.bsv | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/CHERICC_Fat.bsv b/CHERICC_Fat.bsv
index b38edad..cbcdab5 100644
--- a/CHERICC_Fat.bsv
+++ b/CHERICC_Fat.bsv
@@ -1079,7 +1079,7 @@ instance CHERICap #(CapReg, OTypeW, FlagsW, CapAddressW, CapW, TSub#(MW, 3));
   function Bool isDerivable (CapReg cap);
     return cap.bounds.exp <= resetExp
         && !(cap.bounds.exp == resetExp && ((truncateLSB(cap.bounds.topBits) != 1'b0) || (truncateLSB(cap.bounds.baseBits) != 2'b0)))
-        && !(cap.bounds.exp == resetExp-1 && (truncateLSB(cap.bounds.baseBits) != 2'b0))
+        && !(cap.bounds.exp == resetExp-1 && (truncateLSB(cap.bounds.baseBits) != 1'b0))
         && (cap.reserved == 0);
   endfunction