[llvm-commits] [llvm] r94981 - in /llvm/trunk: include/llvm/Constants.h lib/VMCore/Constants.cpp

[Dan Gohman]

Author: djg
Date: Mon Feb  1 10:37:38 2010
New Revision: 94981

URL: http://llvm.org/viewvc/llvm-project?rev=94981&view=rev
Log:
Add a generalized form of ConstantExpr::getOffsetOf which works for
array types as well as struct types, and which accepts arbitrary
Constant indicies.  

Modified:
    llvm/trunk/include/llvm/Constants.h
    llvm/trunk/lib/VMCore/Constants.cpp

Modified: llvm/trunk/include/llvm/Constants.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Constants.h?rev=94981&r1=94980&r2=94981&view=diff

==============================================================================
--- llvm/trunk/include/llvm/Constants.h (original)
+++ llvm/trunk/include/llvm/Constants.h Mon Feb  1 10:37:38 2010
@@ -652,10 +652,15 @@
   ///
   static Constant *getSizeOf(const Type* Ty);
 
-  /// getOffsetOf constant expr - computes the offset of a field in a target
-  /// independent way (Note: the return type is an i64).
+  /// getOffsetOf constant expr - computes the offset of a struct field in a 
+  /// target independent way (Note: the return type is an i64).
   ///
-  static Constant *getOffsetOf(const StructType* Ty, unsigned FieldNo);
+  static Constant *getOffsetOf(const StructType* STy, unsigned FieldNo);
+
+  /// getOffsetOf constant expr - This is a generalized form of getOffsetOf,
+  /// which supports any aggregate type, and any Constant index.
+  ///
+  static Constant *getOffsetOf(const Type* Ty, Constant *FieldNo);
   
   static Constant *getNeg(Constant *C);
   static Constant *getFNeg(Constant *C);

Modified: llvm/trunk/lib/VMCore/Constants.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/VMCore/Constants.cpp?rev=94981&r1=94980&r2=94981&view=diff

==============================================================================
--- llvm/trunk/lib/VMCore/Constants.cpp (original)
+++ llvm/trunk/lib/VMCore/Constants.cpp Mon Feb  1 10:37:38 2010
@@ -1493,16 +1493,21 @@
 }
 
 Constant* ConstantExpr::getOffsetOf(const StructType* STy, unsigned FieldNo) {
+  return getOffsetOf(STy, ConstantInt::get(Type::getInt32Ty(STy->getContext()),
+                                           FieldNo));
+}
+
+Constant* ConstantExpr::getOffsetOf(const Type* Ty, Constant *FieldNo) {
   // offsetof is implemented as: (i64) gep (Ty*)null, 0, FieldNo
   // Note that a non-inbounds gep is used, as null isn't within any object.
   Constant *GEPIdx[] = {
-    ConstantInt::get(Type::getInt64Ty(STy->getContext()), 0),
-    ConstantInt::get(Type::getInt32Ty(STy->getContext()), FieldNo)
+    ConstantInt::get(Type::getInt64Ty(Ty->getContext()), 0),
+    FieldNo
   };
   Constant *GEP = getGetElementPtr(
-                Constant::getNullValue(PointerType::getUnqual(STy)), GEPIdx, 2);
+                Constant::getNullValue(PointerType::getUnqual(Ty)), GEPIdx, 2);
   return getCast(Instruction::PtrToInt, GEP,
-                 Type::getInt64Ty(STy->getContext()));
+                 Type::getInt64Ty(Ty->getContext()));
 }
 
 Constant *ConstantExpr::getCompare(unsigned short pred,