From 2544a1de666ad7197c755b4dab6419f42df01f65 Mon Sep 17 00:00:00 2001 From: Dan Gohman Date: Mon, 1 Feb 2010 16:37:38 +0000 Subject: [PATCH] Add a generalized form of ConstantExpr::getOffsetOf which works for array types as well as struct types, and which accepts arbitrary Constant indicies. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94981 91177308-0d34-0410-b5e6-96231b3b80d8 --- include/llvm/Constants.h | 11 ++++++++--- lib/VMCore/Constants.cpp | 13 +++++++++---- 2 files changed, 17 insertions(+), 7 deletions(-) diff --git a/include/llvm/Constants.h b/include/llvm/Constants.h index 58077f0eb23..4111f36c5f0 100644 --- a/include/llvm/Constants.h +++ b/include/llvm/Constants.h @@ -652,10 +652,15 @@ public: /// 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* 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 StructType* Ty, unsigned FieldNo); + static Constant *getOffsetOf(const Type* Ty, Constant *FieldNo); static Constant *getNeg(Constant *C); static Constant *getFNeg(Constant *C); diff --git a/lib/VMCore/Constants.cpp b/lib/VMCore/Constants.cpp index 1415944885b..b1c942c214f 100644 --- a/lib/VMCore/Constants.cpp +++ b/lib/VMCore/Constants.cpp @@ -1493,16 +1493,21 @@ Constant* ConstantExpr::getAlignOf(const Type* Ty) { } 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, -- 2.34.1