Author: prazek Date: Wed Sep 30 22:50:41 2015 New Revision: 248982 URL: http://llvm.org/viewvc/llvm-project?rev=248982&view=rev Log: Decorating virtual functions load with invariant.load
http://reviews.llvm.org/D13279 Modified: cfe/trunk/lib/CodeGen/ItaniumCXXABI.cpp cfe/trunk/test/CodeGenCXX/virtual-function-calls.cpp Modified: cfe/trunk/lib/CodeGen/ItaniumCXXABI.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/ItaniumCXXABI.cpp?rev=248982&r1=248981&r2=248982&view=diff ============================================================================== --- cfe/trunk/lib/CodeGen/ItaniumCXXABI.cpp (original) +++ cfe/trunk/lib/CodeGen/ItaniumCXXABI.cpp Wed Sep 30 22:50:41 2015 @@ -1609,7 +1609,16 @@ llvm::Value *ItaniumCXXABI::getVirtualFu uint64_t VTableIndex = CGM.getItaniumVTableContext().getMethodVTableIndex(GD); llvm::Value *VFuncPtr = CGF.Builder.CreateConstInBoundsGEP1_64(VTable, VTableIndex, "vfn"); - return CGF.Builder.CreateAlignedLoad(VFuncPtr, CGF.getPointerAlign()); + auto *Inst = CGF.Builder.CreateAlignedLoad(VFuncPtr, CGF.getPointerAlign()); + + // It's safe to add "invariant.load" without -fstrict-vtable-pointers, but it + // would not help in devirtualization. + if (CGM.getCodeGenOpts().OptimizationLevel > 0 && + CGM.getCodeGenOpts().StrictVTablePointers) + Inst->setMetadata(llvm::LLVMContext::MD_invariant_load, + llvm::MDNode::get(CGM.getLLVMContext(), + llvm::ArrayRef<llvm::Metadata *>())); + return Inst; } llvm::Value *ItaniumCXXABI::EmitVirtualDestructorCall( Modified: cfe/trunk/test/CodeGenCXX/virtual-function-calls.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/virtual-function-calls.cpp?rev=248982&r1=248981&r2=248982&view=diff ============================================================================== --- cfe/trunk/test/CodeGenCXX/virtual-function-calls.cpp (original) +++ cfe/trunk/test/CodeGenCXX/virtual-function-calls.cpp Wed Sep 30 22:50:41 2015 @@ -1,4 +1,5 @@ // RUN: %clang_cc1 %s -triple %itanium_abi_triple -std=c++11 -emit-llvm -o - | FileCheck %s +// RUN: %clang_cc1 %s -triple %itanium_abi_triple -std=c++11 -emit-llvm -o - -fstrict-vtable-pointers -O1 | FileCheck --check-prefix=CHECK-INVARIANT %s // PR5021 namespace PR5021 { @@ -42,10 +43,14 @@ namespace VirtualNoreturn { [[noreturn]] virtual void f(); }; - // CHECK: @_ZN15VirtualNoreturn1f + // CHECK-LABEL: @_ZN15VirtualNoreturn1f + // CHECK-INVARIANT-LABEL: define void @_ZN15VirtualNoreturn1f void f(A *p) { p->f(); // CHECK: call {{.*}}void %{{[^#]*$}} // CHECK-NOT: unreachable + // CHECK-INVARIANT: load {{.*}} align 8, !invariant.load ![[EMPTY_NODE:[0-9]]] } } + +// CHECK-INVARIANT: ![[EMPTY_NODE]] = !{} _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
