[cfe-commits] r86120 - in /cfe/trunk: lib/CodeGen/CGCXX.cpp test/CodeGenCXX/virt.cpp

[Mike Stump]

Author: mrs
Date: Thu Nov  5 00:12:26 2009
New Revision: 86120

URL: http://llvm.org/viewvc/llvm-project?rev=86120&view=rev
Log:
Refine covariant return value adjustments for thunks when null
pointers are returned.

Modified:
    cfe/trunk/lib/CodeGen/CGCXX.cpp
    cfe/trunk/test/CodeGenCXX/virt.cpp

Modified: cfe/trunk/lib/CodeGen/CGCXX.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGCXX.cpp?rev=86120&r1=86119&r2=86120&view=diff

==============================================================================
--- cfe/trunk/lib/CodeGen/CGCXX.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGCXX.cpp Thu Nov  5 00:12:26 2009
@@ -811,7 +811,25 @@
                        Callee, CallArgs, MD);
   if (nv_r || v_r) {
     // Do the return result adjustment.
-    RV = RValue::get(DynamicTypeAdjust(RV.getScalarVal(), nv_r, v_r));
+    llvm::BasicBlock *NonZeroBlock = createBasicBlock();
+    llvm::BasicBlock *ZeroBlock = createBasicBlock();
+    llvm::BasicBlock *ContBlock = createBasicBlock();
+
+    const llvm::Type *Ty = RV.getScalarVal()->getType();
+    llvm::Value *Zero = llvm::Constant::getNullValue(Ty);
+    Builder.CreateCondBr(Builder.CreateICmpNE(RV.getScalarVal(), Zero),
+                         NonZeroBlock, ZeroBlock);
+    EmitBlock(NonZeroBlock);
+    llvm::Value *NZ = DynamicTypeAdjust(RV.getScalarVal(), nv_r, v_r);
+    EmitBranch(ContBlock);
+    EmitBlock(ZeroBlock);
+    llvm::Value *Z = RV.getScalarVal();
+    EmitBlock(ContBlock);
+    llvm::PHINode *RVOrZero = Builder.CreatePHI(Ty);
+    RVOrZero->reserveOperandSpace(2);
+    RVOrZero->addIncoming(NZ, NonZeroBlock);
+    RVOrZero->addIncoming(Z, ZeroBlock);
+    RV = RValue::get(RVOrZero);
   }
 
   if (!ResultType->isVoidType())

Modified: cfe/trunk/test/CodeGenCXX/virt.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/virt.cpp?rev=86120&r1=86119&r2=86120&view=diff

==============================================================================
--- cfe/trunk/test/CodeGenCXX/virt.cpp (original)
+++ cfe/trunk/test/CodeGenCXX/virt.cpp Thu Nov  5 00:12:26 2009
@@ -1076,12 +1076,16 @@
 // CHECK-LPOPT64-NEXT:    subq    $8, %rsp
 // CHECK-LPOPT64-NEXT:Llabel
 // CHECK-LPOPT64-NEXT:    call    __ZN8test16_D4foo1Ev
-// FIXME: We need a == 0 check here
+// CHECK-LPOPT64-NEXT:    testq   %rax, %rax
+// CHECK-LPOPT64-NEXT:    je      LBB102_2
 // CHECK-LPOPT64-NEXT:    movq    16(%rax), %rcx
 // CHECK-LPOPT64-NEXT:    movq    -32(%rcx), %rcx
 // CHECK-LPOPT64-NEXT:    leaq    16(%rcx,%rax), %rax
 // CHECK-LPOPT64-NEXT:    addq    $8, %rsp
 // CHECK-LPOPT64-NEXT:    ret
+// CHECK-LPOPT64-NEXT:LBB102_2:
+// CHECK-LPOPT64-NEXT:    addq    $8, %rsp
+// CHECK-LPOPT64-NEXT:    ret
 
 
 class test17_B1 {