case PPCISD::Hi: return "PPCISD::Hi";
case PPCISD::Lo: return "PPCISD::Lo";
case PPCISD::TOC_ENTRY: return "PPCISD::TOC_ENTRY";
+ case PPCISD::TOC_RESTORE: return "PPCISD::TOC_RESTORE";
+ case PPCISD::LOAD: return "PPCISD::LOAD";
+ case PPCISD::LOAD_TOC: return "PPCISD::LOAD_TOC";
case PPCISD::DYNALLOC: return "PPCISD::DYNALLOC";
case PPCISD::GlobalBaseReg: return "PPCISD::GlobalBaseReg";
case PPCISD::SRL: return "PPCISD::SRL";
SDValue &Chain, DebugLoc dl, int SPDiff, bool isTailCall,
SmallVector<std::pair<unsigned, SDValue>, 8> &RegsToPass,
SmallVector<SDValue, 8> &Ops, std::vector<EVT> &NodeTys,
- bool isSVR4ABI) {
+ bool isPPC64, bool isSVR4ABI) {
EVT PtrVT = DAG.getTargetLoweringInfo().getPointerTy();
NodeTys.push_back(MVT::Other); // Returns a chain
NodeTys.push_back(MVT::Flag); // Returns a flag for retval copy to use.
// Otherwise, this is an indirect call. We have to use a MTCTR/BCTRL pair
// to do the call, we can't use PPCISD::CALL.
SDValue MTCTROps[] = {Chain, Callee, InFlag};
+
+ if (isSVR4ABI && isPPC64) {
+ // Function pointers in the 64-bit SVR4 ABI do not point to the function
+ // entry point, but to the function descriptor (the function entry point
+ // address is part of the function descriptor though).
+ // The function descriptor is a three doubleword structure with the
+ // following fields: function entry point, TOC base address and
+ // environment pointer.
+ // Thus for a call through a function pointer, the following actions need
+ // to be performed:
+ // 1. Save the TOC of the caller in the TOC save area of its stack
+ // frame (this is done in LowerCall_Darwin()).
+ // 2. Load the address of the function entry point from the function
+ // descriptor.
+ // 3. Load the TOC of the callee from the function descriptor into r2.
+ // 4. Load the environment pointer from the function descriptor into
+ // r11.
+ // 5. Branch to the function entry point address.
+ // 6. On return of the callee, the TOC of the caller needs to be
+ // restored (this is done in FinishCall()).
+ //
+ // All those operations are flagged together to ensure that no other
+ // operations can be scheduled in between. E.g. without flagging the
+ // operations together, a TOC access in the caller could be scheduled
+ // between the load of the callee TOC and the branch to the callee, which
+ // results in the TOC access going through the TOC of the callee instead
+ // of going through the TOC of the caller, which leads to incorrect code.
+
+ // Load the address of the function entry point from the function
+ // descriptor.
+ SDVTList VTs = DAG.getVTList(MVT::i64, MVT::Other, MVT::Flag);
+ SDValue LoadFuncPtr = DAG.getNode(PPCISD::LOAD, dl, VTs, MTCTROps,
+ InFlag.getNode() ? 3 : 2);
+ Chain = LoadFuncPtr.getValue(1);
+ InFlag = LoadFuncPtr.getValue(2);
+
+ // Load environment pointer into r11.
+ // Offset of the environment pointer within the function descriptor.
+ SDValue PtrOff = DAG.getIntPtrConstant(16);
+
+ SDValue AddPtr = DAG.getNode(ISD::ADD, dl, MVT::i64, Callee, PtrOff);
+ SDValue LoadEnvPtr = DAG.getNode(PPCISD::LOAD, dl, VTs, Chain, AddPtr,
+ InFlag);
+ Chain = LoadEnvPtr.getValue(1);
+ InFlag = LoadEnvPtr.getValue(2);
+
+ SDValue EnvVal = DAG.getCopyToReg(Chain, dl, PPC::X11, LoadEnvPtr,
+ InFlag);
+ Chain = EnvVal.getValue(0);
+ InFlag = EnvVal.getValue(1);
+
+ // Load TOC of the callee into r2. We are using a target-specific load
+ // with r2 hard coded, because the result of a target-independent load
+ // would never go directly into r2, since r2 is a reserved register (which
+ // prevents the register allocator from allocating it), resulting in an
+ // additional register being allocated and an unnecessary move instruction
+ // being generated.
+ VTs = DAG.getVTList(MVT::Other, MVT::Flag);
+ SDValue LoadTOCPtr = DAG.getNode(PPCISD::LOAD_TOC, dl, VTs, Chain,
+ Callee, InFlag);
+ Chain = LoadTOCPtr.getValue(0);
+ InFlag = LoadTOCPtr.getValue(1);
+
+ MTCTROps[0] = Chain;
+ MTCTROps[1] = LoadFuncPtr;
+ MTCTROps[2] = InFlag;
+ }
+
Chain = DAG.getNode(PPCISD::MTCTR, dl, NodeTys, MTCTROps,
2 + (InFlag.getNode() != 0));
InFlag = Chain.getValue(1);
SmallVector<SDValue, 8> Ops;
unsigned CallOpc = PrepareCall(DAG, Callee, InFlag, Chain, dl, SPDiff,
isTailCall, RegsToPass, Ops, NodeTys,
+ PPCSubTarget.isPPC64(),
PPCSubTarget.isSVR4ABI());
// When performing tail call optimization the callee pops its arguments off
// stack frame. If caller and callee belong to the same module (and have the
// same TOC), the NOP will remain unchanged.
if (!isTailCall && PPCSubTarget.isSVR4ABI()&& PPCSubTarget.isPPC64()) {
- // Insert NOP.
- InFlag = DAG.getNode(PPCISD::NOP, dl, MVT::Flag, InFlag);
+ SDVTList VTs = DAG.getVTList(MVT::Other, MVT::Flag);
+ if (CallOpc == PPCISD::BCTRL_SVR4) {
+ // This is a call through a function pointer.
+ // Restore the caller TOC from the save area into R2.
+ // See PrepareCall() for more information about calls through function
+ // pointers in the 64-bit SVR4 ABI.
+ // We are using a target-specific load with r2 hard coded, because the
+ // result of a target-independent load would never go directly into r2,
+ // since r2 is a reserved register (which prevents the register allocator
+ // from allocating it), resulting in an additional register being
+ // allocated and an unnecessary move instruction being generated.
+ Chain = DAG.getNode(PPCISD::TOC_RESTORE, dl, VTs, Chain, InFlag);
+ InFlag = Chain.getValue(1);
+ } else {
+ // Otherwise insert NOP.
+ InFlag = DAG.getNode(PPCISD::NOP, dl, MVT::Flag, InFlag);
+ }
}
Chain = DAG.getCALLSEQ_END(Chain, DAG.getIntPtrConstant(NumBytes, true),
Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other,
&MemOpChains[0], MemOpChains.size());
+ // Check if this is an indirect call (MTCTR/BCTRL).
+ // See PrepareCall() for more information about calls through function
+ // pointers in the 64-bit SVR4 ABI.
+ if (!isTailCall && isPPC64 && PPCSubTarget.isSVR4ABI() &&
+ !dyn_cast<GlobalAddressSDNode>(Callee) &&
+ !dyn_cast<ExternalSymbolSDNode>(Callee) &&
+ !isBLACompatibleAddress(Callee, DAG)) {
+ // Load r2 into a virtual register and store it to the TOC save area.
+ SDValue Val = DAG.getCopyFromReg(Chain, dl, PPC::X2, MVT::i64);
+ // TOC save area offset.
+ SDValue PtrOff = DAG.getIntPtrConstant(40);
+ SDValue AddPtr = DAG.getNode(ISD::ADD, dl, PtrVT, StackPtr, PtrOff);
+ Chain = DAG.getStore(Val.getValue(1), dl, Val, AddPtr, NULL, 0);
+ }
+
// Build a sequence of copy-to-reg nodes chained together with token chain
// and flag operands which copy the outgoing args into the appropriate regs.
SDValue InFlag;
projects / oota-llvm.git / blobdiff