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| author | Piotr Padlewski <prazek@google.com> | 2015-10-01 03:50:41 +0000 |
|---|---|---|
| committer | Piotr Padlewski <prazek@google.com> | 2015-10-01 03:50:41 +0000 |
| commit | 551c814e48d162634efaa31c7849059c62b53ecd (patch) | |
| tree | 9661e345b8a965f39babde0210fb7a6dc42a62f7 /clang/lib/CodeGen | |
| parent | 17433bd10259761a673390a01c63d3fa7766ae4a (diff) | |
| download | bcm5719-llvm-551c814e48d162634efaa31c7849059c62b53ecd.tar.gz bcm5719-llvm-551c814e48d162634efaa31c7849059c62b53ecd.zip | |
Decorating virtual functions load with invariant.load
http://reviews.llvm.org/D13279
llvm-svn: 248982
Diffstat (limited to 'clang/lib/CodeGen')
| -rw-r--r-- | clang/lib/CodeGen/ItaniumCXXABI.cpp | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/clang/lib/CodeGen/ItaniumCXXABI.cpp b/clang/lib/CodeGen/ItaniumCXXABI.cpp index 8392f6a7ba2..37b49dc6086 100644 --- a/clang/lib/CodeGen/ItaniumCXXABI.cpp +++ b/clang/lib/CodeGen/ItaniumCXXABI.cpp @@ -1609,7 +1609,16 @@ llvm::Value *ItaniumCXXABI::getVirtualFunctionPointer(CodeGenFunction &CGF, 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( |
