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| author | Dan Gohman <gohman@apple.com> | 2009-07-27 21:59:50 +0000 |
|---|---|---|
| committer | Dan Gohman <gohman@apple.com> | 2009-07-27 21:59:50 +0000 |
| commit | 79c87141f1800ba06140b5228f4752e84242b2d8 (patch) | |
| tree | 161a14a199031030e3bdd2f569e70aeea84f8471 | |
| parent | 3e5bc0c33e0565b84c429caf2bbff0da70e549c2 (diff) | |
| download | external_llvm-79c87141f1800ba06140b5228f4752e84242b2d8.zip external_llvm-79c87141f1800ba06140b5228f4752e84242b2d8.tar.gz external_llvm-79c87141f1800ba06140b5228f4752e84242b2d8.tar.bz2 | |
Add a comment about the "getelementptr null" trick.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77262 91177308-0d34-0410-b5e6-96231b3b80d8
| -rw-r--r-- | lib/VMCore/LLVMContext.cpp | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/lib/VMCore/LLVMContext.cpp b/lib/VMCore/LLVMContext.cpp index d7f4594..722e29e 100644 --- a/lib/VMCore/LLVMContext.cpp +++ b/lib/VMCore/LLVMContext.cpp @@ -419,6 +419,7 @@ Constant* LLVMContext::getConstantExprInsertValue(Constant* Agg, Constant* Val, Constant* LLVMContext::getConstantExprSizeOf(const Type* Ty) { // sizeof is implemented as: (i64) gep (Ty*)null, 1 + // Note that a non-inbounds gep is used, as null isn't within any object. Constant *GEPIdx = ConstantInt::get(Type::Int32Ty, 1); Constant *GEP = getConstantExprGetElementPtr( getNullValue(getPointerTypeUnqual(Ty)), &GEPIdx, 1); |