ARM: lower fpowi appropriately for Windows ARM
This handles the last case of the builtin function calls that we would
generate code which differed from Microsoft's ABI. Rather than
generating a call to `__pow{d,s}i2` we now promote the parameter to a
float or double and invoke `powf` or `pow` instead.
Addresses PR30825!
llvm-svn: 286082
diff --git a/llvm/lib/Target/ARM/ARMISelLowering.cpp b/llvm/lib/Target/ARM/ARMISelLowering.cpp
index 7671c87..143c6d9 100644
--- a/llvm/lib/Target/ARM/ARMISelLowering.cpp
+++ b/llvm/lib/Target/ARM/ARMISelLowering.cpp
@@ -1017,6 +1017,10 @@
setOperationAction(ISD::UDIVREM, MVT::i32, Expand);
}
+ if (Subtarget->isTargetWindows() && Subtarget->getTargetTriple().isOSMSVCRT())
+ for (auto &VT : {MVT::f32, MVT::f64})
+ setOperationAction(ISD::FPOWI, VT, Custom);
+
setOperationAction(ISD::GlobalAddress, MVT::i32, Custom);
setOperationAction(ISD::ConstantPool, MVT::i32, Custom);
setOperationAction(ISD::GlobalTLSAddress, MVT::i32, Custom);
@@ -7525,6 +7529,58 @@
Results.push_back(SDValue(CmpSwap, 2));
}
+static SDValue LowerFPOWI(SDValue Op, const ARMSubtarget &Subtarget,
+ SelectionDAG &DAG) {
+ const auto &TLI = DAG.getTargetLoweringInfo();
+
+ assert(Subtarget.getTargetTriple().isOSMSVCRT() &&
+ "Custom lowering is MSVCRT specific!");
+
+ SDLoc dl(Op);
+ SDValue Val = Op.getOperand(0);
+ MVT Ty = Val->getSimpleValueType(0);
+ SDValue Exponent = DAG.getNode(ISD::SINT_TO_FP, dl, Ty, Op.getOperand(1));
+ SDValue Callee = DAG.getExternalSymbol(Ty == MVT::f32 ? "powf" : "pow",
+ TLI.getPointerTy(DAG.getDataLayout()));
+
+ TargetLowering::ArgListTy Args;
+ TargetLowering::ArgListEntry Entry;
+
+ Entry.Node = Val;
+ Entry.Ty = Val.getValueType().getTypeForEVT(*DAG.getContext());
+ Entry.isZExt = true;
+ Args.push_back(Entry);
+
+ Entry.Node = Exponent;
+ Entry.Ty = Exponent.getValueType().getTypeForEVT(*DAG.getContext());
+ Entry.isZExt = true;
+ Args.push_back(Entry);
+
+ Type *LCRTy = Val.getValueType().getTypeForEVT(*DAG.getContext());
+
+ // In the in-chain to the call is the entry node If we are emitting a
+ // tailcall, the chain will be mutated if the node has a non-entry input
+ // chain.
+ SDValue InChain = DAG.getEntryNode();
+ SDValue TCChain = InChain;
+
+ const auto *F = DAG.getMachineFunction().getFunction();
+ bool IsTC = TLI.isInTailCallPosition(DAG, Op.getNode(), TCChain) &&
+ F->getReturnType() == LCRTy;
+ if (IsTC)
+ InChain = TCChain;
+
+ TargetLowering::CallLoweringInfo CLI(DAG);
+ CLI.setDebugLoc(dl)
+ .setChain(InChain)
+ .setCallee(CallingConv::ARM_AAPCS_VFP, LCRTy, Callee, std::move(Args))
+ .setTailCall(IsTC);
+ std::pair<SDValue, SDValue> CI = TLI.LowerCallTo(CLI);
+
+ // Return the chain (the DAG root) if it is a tail call
+ return !CI.second.getNode() ? DAG.getRoot() : CI.first;
+}
+
SDValue ARMTargetLowering::LowerOperation(SDValue Op, SelectionDAG &DAG) const {
switch (Op.getOpcode()) {
default: llvm_unreachable("Don't know how to custom lower this!");
@@ -7611,6 +7667,7 @@
llvm_unreachable("Don't know how to custom lower this!");
case ISD::FP_ROUND: return LowerFP_ROUND(Op, DAG);
case ISD::FP_EXTEND: return LowerFP_EXTEND(Op, DAG);
+ case ISD::FPOWI: return LowerFPOWI(Op, *Subtarget, DAG);
case ARMISD::WIN__DBZCHK: return SDValue();
}
}