From dfed413ef6bfb05754ee5a9f3a3c7f98c764a374 Mon Sep 17 00:00:00 2001
From: Chris Lattner <sabre@nondot.org>
Date: Fri, 10 Jul 2009 07:38:24 +0000
Subject: [PATCH] eliminate GVRequiresRegister, replacing it with predicates we
 need for other purposes.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75243 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Target/X86/X86ISelLowering.cpp | 14 +++++++++-----
 lib/Target/X86/X86Subtarget.cpp    | 14 --------------
 lib/Target/X86/X86Subtarget.h      |  5 -----
 3 files changed, 9 insertions(+), 24 deletions(-)

diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index cd87553fef1..11a75966955 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -7036,12 +7036,16 @@ bool X86TargetLowering::isLegalAddressingMode(const AddrMode &AM,
     return false;
 
   if (AM.BaseGV) {
-    // We can only fold this if we don't need an extra load.
-    if (Subtarget->GVRequiresExtraLoad(AM.BaseGV, getTargetMachine()))
+    unsigned GVFlags =
+      Subtarget->ClassifyGlobalReference(AM.BaseGV, getTargetMachine());
+    
+    // If a reference to this global requires an extra load, we can't fold it.
+    if (isGlobalStubReference(GVFlags))
       return false;
-    // If BaseGV requires a register, we cannot also have a BaseReg.
-    if (Subtarget->GVRequiresRegister(AM.BaseGV, getTargetMachine()) &&
-        AM.HasBaseReg)
+    
+    // If BaseGV requires a register for the PIC base, we cannot also have a
+    // BaseReg specified.
+    if (AM.HasBaseReg && isGlobalRelativeToPICBase(GVFlags))
       return false;
 
     // X86-64 only supports addr of globals in small code model.
diff --git a/lib/Target/X86/X86Subtarget.cpp b/lib/Target/X86/X86Subtarget.cpp
index d9c915a696b..82eee216bdb 100644
--- a/lib/Target/X86/X86Subtarget.cpp
+++ b/lib/Target/X86/X86Subtarget.cpp
@@ -120,20 +120,6 @@ bool X86Subtarget::GVRequiresExtraLoad(const GlobalValue *GV,
   return isGlobalStubReference(ClassifyGlobalReference(GV, TM));
 }
 
-/// True if accessing the GV requires a register.  This is a superset of the
-/// cases where GVRequiresExtraLoad is true.  Some variations of PIC require
-/// a register, but not an extra load.
-bool X86Subtarget::GVRequiresRegister(const GlobalValue *GV,
-                                      const TargetMachine &TM) const {
-  if (GVRequiresExtraLoad(GV, TM))
-    return true;
-  
-  // Code below here need only consider cases where GVRequiresExtraLoad
-  // returns false.
-  if (TM.getRelocationModel() == Reloc::PIC_)
-    return GV->hasLocalLinkage() || GV->hasExternalLinkage();
-  return false;
-}
 
 /// getBZeroEntry - This function returns the name of a function which has an
 /// interface like the non-standard bzero function, if such a function exists on
diff --git a/lib/Target/X86/X86Subtarget.h b/lib/Target/X86/X86Subtarget.h
index 2990df52342..f67ba0b4d76 100644
--- a/lib/Target/X86/X86Subtarget.h
+++ b/lib/Target/X86/X86Subtarget.h
@@ -206,11 +206,6 @@ public:
   /// or index register of the address, not the GV offset field.
   bool GVRequiresExtraLoad(const GlobalValue *GV, const TargetMachine &TM)const;
 
-  /// True if accessing the GV requires a register.  This is a superset of the
-  /// cases where GVRequiresExtraLoad is true.  Some variations of PIC require
-  /// a register, but not an extra load.
-  bool GVRequiresRegister(const GlobalValue *GV, const TargetMachine &TM) const;
-
   /// IsLegalToCallImmediateAddr - Return true if the subtarget allows calls
   /// to immediate address.
   bool IsLegalToCallImmediateAddr(const TargetMachine &TM) const;