From 3a1737030e3c8d209987325c61dacb8e4a65123b Mon Sep 17 00:00:00 2001
From: Eli Friedman <eli.friedman@gmail.com>
Date: Fri, 11 Dec 2009 09:26:29 +0000
Subject: [PATCH] Move the code for converting a member pointer to a bool so
 that it is usable for logical not.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@91112 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/CGExpr.cpp                       | 15 ++++++++++
 lib/CodeGen/CGExprScalar.cpp                 | 30 ++------------------
 test/CodeGenCXX/member-function-pointers.cpp | 15 ++++++++++
 3 files changed, 32 insertions(+), 28 deletions(-)

diff --git a/lib/CodeGen/CGExpr.cpp b/lib/CodeGen/CGExpr.cpp
index 0f351be01c..70fa004de8 100644
--- a/lib/CodeGen/CGExpr.cpp
+++ b/lib/CodeGen/CGExpr.cpp
@@ -38,6 +38,21 @@ llvm::AllocaInst *CodeGenFunction::CreateTempAlloca(const llvm::Type *Ty,
 /// expression and compare the result against zero, returning an Int1Ty value.
 llvm::Value *CodeGenFunction::EvaluateExprAsBool(const Expr *E) {
   QualType BoolTy = getContext().BoolTy;
+  if (E->getType()->isMemberFunctionPointerType()) {
+    llvm::Value *Ptr = CreateTempAlloca(ConvertType(E->getType()));
+    EmitAggExpr(E, Ptr, /*VolatileDest=*/false);
+
+    // Get the pointer.
+    llvm::Value *FuncPtr = Builder.CreateStructGEP(Ptr, 0, "src.ptr");
+    FuncPtr = Builder.CreateLoad(FuncPtr);
+
+    llvm::Value *IsNotNull = 
+      Builder.CreateICmpNE(FuncPtr,
+                            llvm::Constant::getNullValue(FuncPtr->getType()),
+                            "tobool");
+
+    return IsNotNull;
+  }
   if (!E->getType()->isAnyComplexType())
     return EmitScalarConversion(EmitScalarExpr(E), E->getType(), BoolTy);
 
diff --git a/lib/CodeGen/CGExprScalar.cpp b/lib/CodeGen/CGExprScalar.cpp
index 20da198a28..6f65638236 100644
--- a/lib/CodeGen/CGExprScalar.cpp
+++ b/lib/CodeGen/CGExprScalar.cpp
@@ -954,34 +954,8 @@ Value *ScalarExprEmitter::EmitCastExpr(CastExpr *CE) {
   case CastExpr::CK_FloatingCast:
     return EmitScalarConversion(Visit(E), E->getType(), DestTy);
 
-  case CastExpr::CK_MemberPointerToBoolean: {
-    const MemberPointerType* T = E->getType()->getAs<MemberPointerType>();
-    
-    if (T->getPointeeType()->isFunctionType()) {
-      // We have a member function pointer.
-      llvm::Value *Ptr = CGF.CreateTempAlloca(ConvertType(E->getType()));
-      
-      CGF.EmitAggExpr(E, Ptr, /*VolatileDest=*/false);
-      
-      // Get the pointer.
-      llvm::Value *FuncPtr = Builder.CreateStructGEP(Ptr, 0, "src.ptr");
-      FuncPtr = Builder.CreateLoad(FuncPtr);
-      
-      llvm::Value *IsNotNull = 
-        Builder.CreateICmpNE(FuncPtr,
-                             llvm::Constant::getNullValue(FuncPtr->getType()),
-                             "tobool");
-      
-      return IsNotNull;
-    }
-   
-    // We have a regular member pointer.
-    Value *Ptr = Visit(const_cast<Expr*>(E));
-    llvm::Value *IsNotNull = 
-      Builder.CreateICmpNE(Ptr, CGF.CGM.EmitNullConstant(E->getType()),
-                           "tobool");
-    return IsNotNull;
-  }
+  case CastExpr::CK_MemberPointerToBoolean:
+    return CGF.EvaluateExprAsBool(E);
   }
 
   // Handle cases where the source is an non-complex type.
diff --git a/test/CodeGenCXX/member-function-pointers.cpp b/test/CodeGenCXX/member-function-pointers.cpp
index 341c074e99..491ca5345a 100644
--- a/test/CodeGenCXX/member-function-pointers.cpp
+++ b/test/CodeGenCXX/member-function-pointers.cpp
@@ -113,3 +113,18 @@ namespace PR5718 {
     return f == g;
   }
 }
+
+namespace BoolMemberPointer {
+  struct A { };
+  
+  bool f(void (A::*f)()) {
+    return !f;
+  }
+
+  bool g(void (A::*f)()) {
+    if (!!f)
+      return true;
+    return false;
+  }
+}
+