From: Gabe Black <gblack@eecs.umich.edu>
Date: Mon, 27 Aug 2007 03:37:41 +0000 (-0700)
Subject: X86: Fix the sign extension microop so it extends zeros correctly.
X-Git-Tag: m5_2.0_beta4~168
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=9c99f5f825a3440ce8efef2e31f801527c5939d6;p=gem5.git

X86: Fix the sign extension microop so it extends zeros correctly.

--HG--
extra : convert_revision : 9d7ca286ba7709175fa75226320601acce4ced98
---

diff --git a/src/arch/x86/isa/microops/regop.isa b/src/arch/x86/isa/microops/regop.isa
index 608b86a70..b91c77c21 100644
--- a/src/arch/x86/isa/microops/regop.isa
+++ b/src/arch/x86/isa/microops/regop.isa
@@ -661,8 +661,10 @@ let {{
     defineMicroRegOpImm('Sext', '''
             IntReg val = psrc1;
             int sign_bit = bits(val, imm8-1, imm8-1);
-            val = sign_bit ? (val | ~mask(imm8)) : val;
-            DestReg = merge(DestReg, val, dataSize);''')
+            uint64_t maskVal = mask(imm8);
+            val = sign_bit ? (val | ~maskVal) : (val & maskVal);
+            DestReg = merge(DestReg, val, dataSize);
+            ''')
 
     defineMicroRegOpImm('Zext', 'DestReg = bits(psrc1, imm8-1, 0);')
 }};