[llvm-commits] [llvm] r85762 - in /llvm/trunk: include/llvm/CodeGen/PseudoSourceValue.h lib/CodeGen/PseudoSourceValue.cpp

[Evan Cheng]

Author: evancheng
Date: Sun Nov  1 17:50:04 2009
New Revision: 85762

URL: http://llvm.org/viewvc/llvm-project?rev=85762&view=rev
Log:
Add PseudoSourceValue::mayAlias. It returns true if the object can ever alias any LLVM IR value.

Modified:
    llvm/trunk/include/llvm/CodeGen/PseudoSourceValue.h
    llvm/trunk/lib/CodeGen/PseudoSourceValue.cpp

Modified: llvm/trunk/include/llvm/CodeGen/PseudoSourceValue.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/CodeGen/PseudoSourceValue.h?rev=85762&r1=85761&r2=85762&view=diff

==============================================================================
--- llvm/trunk/include/llvm/CodeGen/PseudoSourceValue.h (original)
+++ llvm/trunk/include/llvm/CodeGen/PseudoSourceValue.h Sun Nov  1 17:50:04 2009
@@ -43,6 +43,10 @@
     /// PseudoSourceValue may also be pointed to by an LLVM IR Value.
     virtual bool isAliased(const MachineFrameInfo *) const;
 
+    /// mayAlias - Return true if the memory pointed to by this
+    /// PseudoSourceValue can ever alias a LLVM IR Value.
+    virtual bool mayAlias(const MachineFrameInfo *) const;
+
     /// classof - Methods for support type inquiry through isa, cast, and
     /// dyn_cast:
     ///

Modified: llvm/trunk/lib/CodeGen/PseudoSourceValue.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/PseudoSourceValue.cpp?rev=85762&r1=85761&r2=85762&view=diff

==============================================================================
--- llvm/trunk/lib/CodeGen/PseudoSourceValue.cpp (original)
+++ llvm/trunk/lib/CodeGen/PseudoSourceValue.cpp Sun Nov  1 17:50:04 2009
@@ -64,6 +64,8 @@
 
     virtual bool isAliased(const MachineFrameInfo *MFI) const;
 
+    virtual bool mayAlias(const MachineFrameInfo *) const;
+
     virtual void printCustom(raw_ostream &OS) const {
       OS << "FixedStack" << FI;
     }
@@ -100,6 +102,14 @@
   return true;
 }
 
+bool PseudoSourceValue::mayAlias(const MachineFrameInfo *MFI) const {
+  if (this == getGOT() ||
+      this == getConstantPool() ||
+      this == getJumpTable())
+    return false;
+  return true;
+}
+
 bool FixedStackPseudoSourceValue::isConstant(const MachineFrameInfo *MFI) const{
   return MFI && MFI->isImmutableObjectIndex(FI);
 }
@@ -113,3 +123,10 @@
   // Spill slots should not alias others.
   return !MFI->isFixedObjectIndex(FI) && !MFI->isSpillSlotObjectIndex(FI);
 }
+
+bool FixedStackPseudoSourceValue::mayAlias(const MachineFrameInfo *MFI) const {
+  if (!MFI)
+    return true;
+  // Spill slots will not alias any LLVM IR value.
+  return !MFI->isSpillSlotObjectIndex(FI);
+}