diff options
Diffstat (limited to 'lib')
-rw-r--r-- | lib/Target/X86/X86ISelLowering.cpp | 22 |
1 files changed, 8 insertions, 14 deletions
diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp index 9df0232..0deb181 100644 --- a/lib/Target/X86/X86ISelLowering.cpp +++ b/lib/Target/X86/X86ISelLowering.cpp @@ -2665,21 +2665,15 @@ X86TargetLowering::LowerCall(TargetLowering::CallLoweringInfo &CLI, RegsToPass.push_back(std::make_pair(unsigned(X86::EBX), DAG.getNode(X86ISD::GlobalBaseReg, SDLoc(), getPointerTy()))); } else { - // If we are tail calling and generating PIC/GOT style code load the - // address of the callee into ECX. The value in ecx is used as target of - // the tail jump. This is done to circumvent the ebx/callee-saved problem - // for tail calls on PIC/GOT architectures. Normally we would just put the - // address of GOT into ebx and then call target@PLT. But for tail calls - // ebx would be restored (since ebx is callee saved) before jumping to the - // target@PLT. - - // Note: The actual moving to ECX is done further down. + // If we are tail calling a global or external symbol in GOT pic mode, we + // cannot use a direct jump, since that would make lazy dynamic linking + // impossible (see PR15086). So pretend this is not a tail call, to + // prevent the optimization to a jump. GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee); - if (G && !G->getGlobal()->hasHiddenVisibility() && - !G->getGlobal()->hasProtectedVisibility()) - Callee = LowerGlobalAddress(Callee, DAG); - else if (isa<ExternalSymbolSDNode>(Callee)) - Callee = LowerExternalSymbol(Callee, DAG); + if ((G && !G->getGlobal()->hasHiddenVisibility() && + !G->getGlobal()->hasProtectedVisibility()) || + isa<ExternalSymbolSDNode>(Callee)) + isTailCall = false; } } |