From: Gabe Black <gblack@eecs.umich.edu>
Date: Wed, 12 May 2010 07:49:12 +0000 (-0700)
Subject: X86: Actual change that fixes div. How did that happen?
X-Git-Tag: stable_2012_02_02~1411
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=cc76842f830f15b12c0f4a64e90fe3ca9e35a45a;p=gem5.git

X86: Actual change that fixes div. How did that happen?
---

diff --git a/src/arch/x86/isa/microops/regop.isa b/src/arch/x86/isa/microops/regop.isa
index f3fc1fc59..4d31a5545 100644
--- a/src/arch/x86/isa/microops/regop.isa
+++ b/src/arch/x86/isa/microops/regop.isa
@@ -620,14 +620,18 @@ let {{
                         remaining--;
                     }
                     if (dividend & (ULL(1) << 63)) {
+                        bool highBit = false;
                         if (dividend < divisor && remaining) {
+                            highBit = true;
                             dividend = (dividend << 1) |
                                 bits(SrcReg1, remaining - 1);
                             quotient <<= 1;
                             remaining--;
                         }
-                        quotient++;
-                        dividend -= divisor;
+                        if (highBit || divisor <= dividend) {
+                            quotient++;
+                            dividend -= divisor;
+                        }
                     }
                     remainder = dividend;
                 } else {