R600: Check if a sextload should be used for parameter loads.

[arsenm]

Summary

Through some oddity where truncate (sextload x) isn't folded into
an anyextload for vectors, the sextload remains if the
vector isn't immediately scalarized. This keeps the expected
zextload instructions in the kernel-args test when small type
vectors aren't scalarized.

R600 should do the same thing, but the handling of anything other than sextload on parameters
for vectors seems produce invalid code

[arsenm]

Ping

[arsenm]

r206070

lib/Target/R600/R600ISelLowering.cpp

 
     // The first 36 bytes of the input buffer contains information about
     // thread group and global sizes.
-    SDValue Arg = DAG.getExtLoad(ISD::SEXTLOAD, DL, VT, Chain,
+
+    // FIXME: This should really check the extload type, but the handling of
+    // extload vecto parameters seems to be broken.
+    //ISD::LoadExtType Ext = Ins[i].Flags.isSExt() ? ISD::SEXTLOAD : ISD::ZEXTLOAD;
+    ISD::LoadExtType Ext = ISD::SEXTLOAD;
+    SDValue Arg = DAG.getExtLoad(Ext, DL, VT, Chain,
                                  DAG.getConstant(36 + VA.getLocMemOffset(), MVT::i32),
                                  MachinePointerInfo(UndefValue::get(PtrTy)),
                                  MemVT, false, false, 4);

lib/Target/R600/SIISelLowering.h

 
 class SITargetLowering : public AMDGPUTargetLowering {
   SDValue LowerParameter(SelectionDAG &DAG, EVT VT, EVT MemVT, SDLoc DL,
-                         SDValue Chain, unsigned Offset) const;
+                         SDValue Chain, unsigned Offset, bool Signed) const;
   SDValue LowerSampleIntrinsic(unsigned Opcode, const SDValue &Op,
                                SelectionDAG &DAG) const;
   SDValue LowerLOAD(SDValue Op, SelectionDAG &DAG) const;

lib/Target/R600/SIISelLowering.cpp

 
 SDValue SITargetLowering::LowerParameter(SelectionDAG &DAG, EVT VT, EVT MemVT,
                                          SDLoc DL, SDValue Chain,
-                                         unsigned Offset) const {
+                                         unsigned Offset, bool Signed) const {
   MachineRegisterInfo &MRI = DAG.getMachineFunction().getRegInfo();
   PointerType *PtrTy = PointerType::get(VT.getTypeForEVT(*DAG.getContext()),
                                             AMDGPUAS::CONSTANT_ADDRESS);

                            MRI.getLiveInVirtReg(AMDGPU::SGPR0_SGPR1), MVT::i64);
   SDValue Ptr = DAG.getNode(ISD::ADD, DL, MVT::i64, BasePtr,
                                              DAG.getConstant(Offset, MVT::i64));
-  return DAG.getExtLoad(ISD::SEXTLOAD, DL, VT, Chain, Ptr,
+  return DAG.getExtLoad(Signed ? ISD::SEXTLOAD : ISD::ZEXTLOAD, DL, VT, Chain, Ptr,
                             MachinePointerInfo(UndefValue::get(PtrTy)), MemVT,
                             false, false, MemVT.getSizeInBits() >> 3);
 

       // The first 36 bytes of the input buffer contains information about
       // thread group and global sizes.
       SDValue Arg = LowerParameter(DAG, VT, MemVT,  DL, DAG.getRoot(),
-                                   36 + VA.getLocMemOffset());
+                                   36 + VA.getLocMemOffset(),
+                                   Ins[i].Flags.isSExt());
       InVals.push_back(Arg);
       continue;
     }

     switch (IntrinsicID) {
     default: return AMDGPUTargetLowering::LowerOperation(Op, DAG);
     case Intrinsic::r600_read_ngroups_x:
-      return LowerParameter(DAG, VT, VT, DL, DAG.getEntryNode(), 0);
+      return LowerParameter(DAG, VT, VT, DL, DAG.getEntryNode(), 0, false);
     case Intrinsic::r600_read_ngroups_y:
-      return LowerParameter(DAG, VT, VT, DL, DAG.getEntryNode(), 4);
+      return LowerParameter(DAG, VT, VT, DL, DAG.getEntryNode(), 4, false);
     case Intrinsic::r600_read_ngroups_z:
-      return LowerParameter(DAG, VT, VT, DL, DAG.getEntryNode(), 8);
+      return LowerParameter(DAG, VT, VT, DL, DAG.getEntryNode(), 8, false);
     case Intrinsic::r600_read_global_size_x:
-      return LowerParameter(DAG, VT, VT, DL, DAG.getEntryNode(), 12);
+      return LowerParameter(DAG, VT, VT, DL, DAG.getEntryNode(), 12, false);
     case Intrinsic::r600_read_global_size_y:
-      return LowerParameter(DAG, VT, VT, DL, DAG.getEntryNode(), 16);
+      return LowerParameter(DAG, VT, VT, DL, DAG.getEntryNode(), 16, false);
     case Intrinsic::r600_read_global_size_z:
-      return LowerParameter(DAG, VT, VT, DL, DAG.getEntryNode(), 20);
+      return LowerParameter(DAG, VT, VT, DL, DAG.getEntryNode(), 20, false);
     case Intrinsic::r600_read_local_size_x:
-      return LowerParameter(DAG, VT, VT, DL, DAG.getEntryNode(), 24);
+      return LowerParameter(DAG, VT, VT, DL, DAG.getEntryNode(), 24, false);
     case Intrinsic::r600_read_local_size_y:
-      return LowerParameter(DAG, VT, VT, DL, DAG.getEntryNode(), 28);
+      return LowerParameter(DAG, VT, VT, DL, DAG.getEntryNode(), 28, false);
     case Intrinsic::r600_read_local_size_z:
-      return LowerParameter(DAG, VT, VT, DL, DAG.getEntryNode(), 32);
+      return LowerParameter(DAG, VT, VT, DL, DAG.getEntryNode(), 32, false);
     case Intrinsic::r600_read_tgid_x:
       return CreateLiveInRegister(DAG, &AMDGPU::SReg_32RegClass,
                      AMDGPU::SReg_32RegClass.getRegister(NumUserSGPRs + 0), VT);