From: Gabe Black <gblack@eecs.umich.edu>
Date: Wed, 5 Aug 2009 10:01:23 +0000 (-0700)
Subject: X86: Fix the overflow bit for rotate right with carry.
X-Git-Tag: Calvin_Submission~172
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=77dc6b33ee836e030a2e9c230b8ce67e0e39c322;p=gem5.git

X86: Fix the overflow bit for rotate right with carry.
---

diff --git a/src/arch/x86/isa/microops/regop.isa b/src/arch/x86/isa/microops/regop.isa
index e3ad164eb..0bf3420b8 100644
--- a/src/arch/x86/isa/microops/regop.isa
+++ b/src/arch/x86/isa/microops/regop.isa
@@ -777,13 +777,15 @@ let {{
         flag_code = '''
             // If the shift amount is zero, no flags should be modified.
             if (shiftAmt) {
+                int origCFBit = (ccFlagBits & CFBit) ? 1 : 0;
                 //Zero out any flags we might modify. This way we only have to
                 //worry about setting them.
                 ccFlagBits = ccFlagBits & ~(ext & (CFBit | ECFBit | OFBit));
                 //Figure out what the OF bit should be.
-                if ((ext & OFBit) && ((ccFlagBits & CFBit) ^
-                                      bits(SrcReg1, dataSize * 8 - 1)))
+                if ((ext & OFBit) && (origCFBit ^
+                                      bits(SrcReg1, dataSize * 8 - 1))) {
                     ccFlagBits = ccFlagBits | OFBit;
+                }
                 //If some combination of the CF bits need to be set, set them.
                 if ((ext & (CFBit | ECFBit)) && bits(SrcReg1, shiftAmt - 1))
                     ccFlagBits = ccFlagBits | (ext & (CFBit | ECFBit));