diff options
| -rw-r--r-- | lib/CodeGen/CGExprConstant.cpp | 17 | ||||
| -rw-r--r-- | test/CodeGenCXX/cxx11-trivial-initializer-struct.cpp | 18 |
2 files changed, 35 insertions, 0 deletions
diff --git a/lib/CodeGen/CGExprConstant.cpp b/lib/CodeGen/CGExprConstant.cpp index 7a604013b7..c5f94726e6 100644 --- a/lib/CodeGen/CGExprConstant.cpp +++ b/lib/CodeGen/CGExprConstant.cpp @@ -1006,6 +1006,23 @@ public: llvm::Constant *CodeGenModule::EmitConstantInit(const VarDecl &D, CodeGenFunction *CGF) { + // Make a quick check if variable can be default NULL initialized + // and avoid going through rest of code which may do, for c++11, + // initialization of memory to all NULLs. + if (!D.hasLocalStorage()) { + QualType Ty = D.getType(); + if (Ty->isArrayType()) + Ty = Context.getBaseElementType(Ty); + if (Ty->isRecordType()) + if (const CXXConstructExpr *E = + dyn_cast_or_null<CXXConstructExpr>(D.getInit())) { + const CXXConstructorDecl *CD = E->getConstructor(); + if (CD->isTrivial() && CD->isDefaultConstructor() && + Ty->getAsCXXRecordDecl()->hasTrivialDestructor()) + return EmitNullConstant(D.getType()); + } + } + if (const APValue *Value = D.evaluateValue()) return EmitConstantValueForMemory(*Value, D.getType(), CGF); diff --git a/test/CodeGenCXX/cxx11-trivial-initializer-struct.cpp b/test/CodeGenCXX/cxx11-trivial-initializer-struct.cpp new file mode 100644 index 0000000000..f38d01a467 --- /dev/null +++ b/test/CodeGenCXX/cxx11-trivial-initializer-struct.cpp @@ -0,0 +1,18 @@ +// RUN: %clang_cc1 -S -emit-llvm -o %t.ll %s -triple x86_64-apple-darwin10 +// RUN: %clang_cc1 -std=c++11 -S -emit-llvm -o %t-c++11.ll %s -triple x86_64-apple-darwin10 +// RUN: diff %t.ll %t-c++11.ll + +// rdar://12897704 + +struct sAFSearchPos { + unsigned char *pos; + unsigned char count; +}; + +static volatile struct sAFSearchPos testPositions; + +static volatile struct sAFSearchPos arrayPositions[100][10][5]; + +int main() { + return testPositions.count + arrayPositions[10][4][3].count; +} |