From 60ab1402981a757c5ee785de540a5d0f85839c5d Mon Sep 17 00:00:00 2001
From: Alkis Evlogimenos <alkis@evlogimenos.com>
Date: Sun, 24 Oct 2004 01:41:10 +0000
Subject: [PATCH] Add ConstantExpr::getSizeOf(Type*).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@17196 91177308-0d34-0410-b5e6-96231b3b80d8
---
include/llvm/Constants.h | 4 ++++
lib/VMCore/Constants.cpp | 9 +++++++++
2 files changed, 13 insertions(+)
diff --git a/include/llvm/Constants.h b/include/llvm/Constants.h
index 6a59cfa732b..502974dc779 100644
--- a/include/llvm/Constants.h
+++ b/include/llvm/Constants.h
@@ -557,6 +557,10 @@ public:
return getSelectTy(V1->getType(), C, V1, V2);
}
+ /// getSizeOf constant expr - computes the size of a type in a
+ /// target independent way
+ ///
+ static Constant *getSizeOf(const Type *Ty);
/// ConstantExpr::get - Return a binary or shift operator constant expression,
/// folding if possible.
diff --git a/lib/VMCore/Constants.cpp b/lib/VMCore/Constants.cpp
index 77aa23135e5..3d2e658e634 100644
--- a/lib/VMCore/Constants.cpp
+++ b/lib/VMCore/Constants.cpp
@@ -1244,6 +1244,15 @@ Constant *ConstantExpr::getZeroExtend(Constant *C, const Type *Ty) {
return ConstantExpr::getCast(C, Ty);
}
+Constant *ConstantExpr::getSizeOf(const Type *Ty) {
+ // sizeof is implemented as: (unsigned) gep (Ty)null, 1
+ return getCast(
+ getGetElementPtr(
+ getNullValue(Ty),
+ std::vector<Constant*>(1, ConstantInt::get(Type::UByteTy, 1))),
+ Type::UIntTy);
+}
+
Constant *ConstantExpr::getTy(const Type *ReqTy, unsigned Opcode,
Constant *C1, Constant *C2) {
if (Opcode == Instruction::Shl || Opcode == Instruction::Shr)