From 8fbc00b5bab870d3c756d40add9b0eb27827fb97 Mon Sep 17 00:00:00 2001
From: Sean Callanan <scallanan@apple.com>
Date: Wed, 23 Feb 2011 03:31:28 +0000
Subject: [PATCH] Fixed a bug in the enhanced disassembler that caused it to
 ignore valid uses of FS and GS as additional base registers in address
 computations.  Added a test case for this.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126302 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/MC/MCDisassembler/EDOperand.cpp   | 20 +++++++++++++++++---
 test/MC/Disassembler/X86/enhanced.txt |  2 ++
 2 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/lib/MC/MCDisassembler/EDOperand.cpp b/lib/MC/MCDisassembler/EDOperand.cpp
index cfeb56fa3df..2b0c73e8059 100644
--- a/lib/MC/MCDisassembler/EDOperand.cpp
+++ b/lib/MC/MCDisassembler/EDOperand.cpp
@@ -152,10 +152,23 @@ int EDOperand::evaluate(uint64_t &result,
       uint64_t scaleAmount = Inst.Inst->getOperand(MCOpIndex+1).getImm();
       unsigned indexReg = Inst.Inst->getOperand(MCOpIndex+2).getReg();
       int64_t displacement = Inst.Inst->getOperand(MCOpIndex+3).getImm();
-      //unsigned segmentReg = Inst.Inst->getOperand(MCOpIndex+4).getReg();
-      
+    
       uint64_t addr = 0;
         
+      unsigned segmentReg = Inst.Inst->getOperand(MCOpIndex+4).getReg();
+        
+      if (segmentReg != 0 && Disassembler.Key.Arch == Triple::x86_64) {
+        unsigned fsID = Disassembler.registerIDWithName("FS");
+        unsigned gsID = Disassembler.registerIDWithName("GS");
+        
+        if (segmentReg == fsID ||
+            segmentReg == gsID) {
+          uint64_t segmentBase;
+          if (!callback(&segmentBase, segmentReg, arg))
+            addr += segmentBase;        
+        }
+      }
+        
       if (baseReg) {
         uint64_t baseVal;
         if (callback(&baseVal, baseReg, arg))
@@ -175,7 +188,7 @@ int EDOperand::evaluate(uint64_t &result,
       result = addr;
       return 0;
     }
-    }
+    } // switch (operandType)
     break;
   case Triple::arm:
   case Triple::thumb:
@@ -203,6 +216,7 @@ int EDOperand::evaluate(uint64_t &result,
       return 0;
     }
     }
+    break;
   }
   
   return -1;
diff --git a/test/MC/Disassembler/X86/enhanced.txt b/test/MC/Disassembler/X86/enhanced.txt
index 691f87651c3..fc6949901b7 100644
--- a/test/MC/Disassembler/X86/enhanced.txt
+++ b/test/MC/Disassembler/X86/enhanced.txt
@@ -2,3 +2,5 @@
 
 # CHECK: [o:jne][w:	][0-p:-][0-l:10=10] <br> 0:[RIP/111](pc)=18446744073709551606
 0x0f 0x85 0xf6 0xff 0xff 0xff
+# CHECK: [o:movq][w:	][1-r:%gs=r63][1-p::][1-l:8=8][p:,][w: ][0-r:%rcx=r108] <mov> 0:[RCX/108]=0 1:[GS/63]=8
+0x65 0x48 0x8b 0x0c 0x25 0x08 0x00 0x00 0x00
-- 
2.34.1