[GISel][CallLowering] Make isIncomingArgumentHandler a pure virtual method

The default implementation of isIncomingArgumentHandler could lead
to generating incorrect code.
Make it a pure virtual method, so that targets know they have to
override it to produce correct code.

NFC

Differential Revision: https://reviews.llvm.org/D69187

llvm-svn: 375277

include/llvm/CodeGen/GlobalISel/CallLowering.h

@@ -118,7 +118,7 @@ public:
 
     /// Returns true if the handler is dealing with incoming arguments,
     /// i.e. those that move values from some physical location to vregs.
-    virtual bool isIncomingArgumentHandler() const { return false; }
+    virtual bool isIncomingArgumentHandler() const = 0;
 
     /// Materialize a VReg containing the address of the specified
     /// stack-based object. This is either based on a FrameIndex or

lib/Target/AArch64/AArch64CallLowering.cpp

@@ -136,6 +136,8 @@ struct OutgoingArgHandler : public CallLowering::ValueHandler {
         AssignFnVarArg(AssignFnVarArg), IsTailCall(IsTailCall), FPDiff(FPDiff),
         StackSize(0) {}
 
+  bool isIncomingArgumentHandler() const override { return false; }
+
   Register getStackAddress(uint64_t Size, int64_t Offset,
                            MachinePointerInfo &MPO) override {
     MachineFunction &MF = MIRBuilder.getMF();

lib/Target/AMDGPU/AMDGPUCallLowering.cpp

@@ -37,6 +37,8 @@ struct OutgoingValueHandler : public CallLowering::ValueHandler {
 
   MachineInstrBuilder MIB;
 
+  bool isIncomingArgumentHandler() const override { return false; }
+
   Register getStackAddress(uint64_t Size, int64_t Offset,
                            MachinePointerInfo &MPO) override {
     llvm_unreachable("not implemented");

lib/Target/ARM/ARMCallLowering.cpp

@@ -90,6 +90,8 @@ struct OutgoingValueHandler : public CallLowering::ValueHandler {
                        MachineInstrBuilder &MIB, CCAssignFn *AssignFn)
       : ValueHandler(MIRBuilder, MRI, AssignFn), MIB(MIB) {}
 
+  bool isIncomingArgumentHandler() const override { return false; }
+
   Register getStackAddress(uint64_t Size, int64_t Offset,
                            MachinePointerInfo &MPO) override {
     assert((Size == 1 || Size == 2 || Size == 4 || Size == 8) &&

lib/Target/X86/X86CallLowering.cpp

@@ -102,6 +102,8 @@ struct OutgoingValueHandler : public CallLowering::ValueHandler {
         DL(MIRBuilder.getMF().getDataLayout()),
         STI(MIRBuilder.getMF().getSubtarget<X86Subtarget>()) {}
 
+  bool isIncomingArgumentHandler() const override { return false; }
+
   Register getStackAddress(uint64_t Size, int64_t Offset,
                            MachinePointerInfo &MPO) override {
     LLT p0 = LLT::pointer(0, DL.getPointerSizeInBits(0));