From: Evan Cheng <evan.cheng@apple.com>
Date: Tue, 5 May 2009 18:18:57 +0000 (+0000)
Subject: Revert part of 70929 that has to do with determining whether a SIB byte is needed... 
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=ef1840173c6e7eadaac3e1bcb443088e49501816;p=oota-llvm.git

Revert part of 70929 that has to do with determining whether a SIB byte is needed. It causes a lot of x86_64 JIT failures.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@70986 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Target/X86/X86CodeEmitter.cpp b/lib/Target/X86/X86CodeEmitter.cpp
index e0396cfc2fd..c54a996cb23 100644
--- a/lib/Target/X86/X86CodeEmitter.cpp
+++ b/lib/Target/X86/X86CodeEmitter.cpp
@@ -338,8 +338,8 @@ void Emitter::emitMemModRMByte(const MachineInstr &MI,
   unsigned BaseReg = Base.getReg();
 
   // Is a SIB byte needed?
-  if (IndexReg.getReg() == 0 && (!Is64BitMode || BaseReg != 0) && 
-      (BaseReg == 0 || getX86RegNum(BaseReg) != N86::ESP)) {      
+  if ((!Is64BitMode || DispForReloc) && IndexReg.getReg() == 0 &&
+      (BaseReg == 0 || getX86RegNum(BaseReg) != N86::ESP)) {
     if (BaseReg == 0) {  // Just a displacement?
       // Emit special case [disp32] encoding
       MCE.emitByte(ModRMByte(0, RegOpcodeField, 5));
diff --git a/lib/Target/X86/X86InstrInfo.cpp b/lib/Target/X86/X86InstrInfo.cpp
index 0a3103af09a..50115c29ca3 100644
--- a/lib/Target/X86/X86InstrInfo.cpp
+++ b/lib/Target/X86/X86InstrInfo.cpp
@@ -2811,7 +2811,7 @@ static unsigned getMemModRMByteSize(const MachineInstr &MI, unsigned Op,
   unsigned BaseReg = Base.getReg();
 
   // Is a SIB byte needed?
-  if (IndexReg.getReg() == 0 && (!Is64BitMode || BaseReg != 0) && 
+  if ((!Is64BitMode || DispForReloc) && IndexReg.getReg() == 0 &&
       (BaseReg == 0 || X86RegisterInfo::getX86RegNum(BaseReg) != N86::ESP)) {      
     if (BaseReg == 0) {  // Just a displacement?
       // Emit special case [disp32] encoding