diff options
| -rw-r--r-- | lib/Target/X86/X86ISelLowering.cpp | 30 |
1 files changed, 19 insertions, 11 deletions
diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp index 8726c587ca..53bb81dd30 100644 --- a/lib/Target/X86/X86ISelLowering.cpp +++ b/lib/Target/X86/X86ISelLowering.cpp @@ -707,10 +707,11 @@ SDOperand X86TargetLowering::LowerRET(SDOperand Op, SelectionDAG &DAG) { Operands.push_back(StackAdjustment); // Copy registers used by the call. Last operand is a flag so it is not // copied. - for(unsigned i=3; i < TailCall.getNumOperands()-1;i++) { + for (unsigned i=3; i < TailCall.getNumOperands()-1; i++) { Operands.push_back(Chain.getOperand(i)); } - return DAG.getNode(X86ISD::TC_RETURN, MVT::Other, &Operands[0], Operands.size()); + return DAG.getNode(X86ISD::TC_RETURN, MVT::Other, &Operands[0], + Operands.size()); } // Regular return. @@ -1520,23 +1521,25 @@ SDOperand X86TargetLowering::LowerX86_TailCallTo(SDOperand Op, if (FPDiff < (MF.getInfo<X86MachineFunctionInfo>()->getTCReturnAddrDelta())) MF.getInfo<X86MachineFunctionInfo>()->setTCReturnAddrDelta(FPDiff); - // Adjust the ret address stack slot. + Chain = DAG. + getCALLSEQ_START(Chain, DAG.getConstant(NumBytesToBePushed, getPointerTy())); + + // Adjust the Return address stack slot. + SDOperand RetAddrFrIdx, NewRetAddrFrIdx; if (FPDiff) { MVT::ValueType VT = is64Bit ? MVT::i64 : MVT::i32; - SDOperand RetAddrFrIdx = getReturnAddressFrameIndex(DAG); + RetAddrFrIdx = getReturnAddressFrameIndex(DAG); + // Load the "old" Return address. RetAddrFrIdx = - DAG.getLoad(VT, DAG.getEntryNode(),RetAddrFrIdx, NULL, 0); - // Emit a store of the saved ret value to the new location. + DAG.getLoad(VT, Chain,RetAddrFrIdx, NULL, 0); + // Calculate the new stack slot for the return address. int SlotSize = is64Bit ? 8 : 4; int NewReturnAddrFI = MF.getFrameInfo()->CreateFixedObject(SlotSize, FPDiff-SlotSize); - SDOperand NewRetAddrFrIdx = DAG.getFrameIndex(NewReturnAddrFI, VT); - Chain = DAG.getStore(Chain,RetAddrFrIdx, NewRetAddrFrIdx, NULL, 0); + NewRetAddrFrIdx = DAG.getFrameIndex(NewReturnAddrFI, VT); + Chain = SDOperand(RetAddrFrIdx.Val, 1); } - Chain = DAG. - getCALLSEQ_START(Chain, DAG.getConstant(NumBytesToBePushed, getPointerTy())); - SmallVector<std::pair<unsigned, SDOperand>, 8> RegsToPass; SmallVector<SDOperand, 8> MemOpChains; SmallVector<SDOperand, 8> MemOpChains2; @@ -1592,6 +1595,7 @@ SDOperand X86TargetLowering::LowerX86_TailCallTo(SDOperand Op, InFlag = Chain.getValue(1); } InFlag = SDOperand(); + // Copy from stack slots to stack slot of a tail called function. This needs // to be done because if we would lower the arguments directly to their real // stack slot we might end up overwriting each other. @@ -1637,6 +1641,10 @@ SDOperand X86TargetLowering::LowerX86_TailCallTo(SDOperand Op, Chain = DAG.getNode(ISD::TokenFactor, MVT::Other, &MemOpChains2[0], MemOpChains.size()); + // Store the return address to the appropriate stack slot. + if (FPDiff) + Chain = DAG.getStore(Chain,RetAddrFrIdx, NewRetAddrFrIdx, NULL, 0); + // ELF / PIC requires GOT in the EBX register before function calls via PLT // GOT pointer. // Does not work with tail call since ebx is not restored correctly by |