AMDGPU: Avoid explicitly listing all the memory nodes

Author: arsenm

llvm/lib/Target/AMDGPU/SIISelLowering.cpp

@@ -8564,6 +8564,8 @@ SDValue SITargetLowering::performSHLPtrCombine(SDNode *N,
 
 SDValue SITargetLowering::performMemSDNodeCombine(MemSDNode *N,
                                                   DAGCombinerInfo &DCI) const {
+  // FIXME: getBasePtr does not work correctly for intrinsic nodes and will find
+  // the intrinsic ID, not the pointer.
   SDValue Ptr = N->getBasePtr();
   SelectionDAG &DAG = DCI.DAG;
   SDLoc SL(N);
@@ -10477,8 +10479,6 @@ SDValue SITargetLowering::PerformDAGCombine(SDNode *N,
   if (getTargetMachine().getOptLevel() == CodeGenOpt::None)
     return SDValue();
   switch (N->getOpcode()) {
-  default:
-    return AMDGPUTargetLowering::PerformDAGCombine(N, DCI);
   case ISD::ADD:
     return performAddCombine(N, DCI);
   case ISD::SUB:
@@ -10505,35 +10505,6 @@ SDValue SITargetLowering::PerformDAGCombine(SDNode *N,
     return performMinMaxCombine(N, DCI);
   case ISD::FMA:
     return performFMACombine(N, DCI);
-  case ISD::LOAD: {
-    if (SDValue Widended = widenLoad(cast<LoadSDNode>(N), DCI))
-      return Widended;
-    LLVM_FALLTHROUGH;
-  }
-  case ISD::STORE:
-  case ISD::ATOMIC_LOAD:
-  case ISD::ATOMIC_STORE:
-  case ISD::ATOMIC_CMP_SWAP:
-  case ISD::ATOMIC_CMP_SWAP_WITH_SUCCESS:
-  case ISD::ATOMIC_SWAP:
-  case ISD::ATOMIC_LOAD_ADD:
-  case ISD::ATOMIC_LOAD_SUB:
-  case ISD::ATOMIC_LOAD_AND:
-  case ISD::ATOMIC_LOAD_OR:
-  case ISD::ATOMIC_LOAD_XOR:
-  case ISD::ATOMIC_LOAD_NAND:
-  case ISD::ATOMIC_LOAD_MIN:
-  case ISD::ATOMIC_LOAD_MAX:
-  case ISD::ATOMIC_LOAD_UMIN:
-  case ISD::ATOMIC_LOAD_UMAX:
-  case ISD::ATOMIC_LOAD_FADD:
-  case AMDGPUISD::ATOMIC_INC:
-  case AMDGPUISD::ATOMIC_DEC:
-  case AMDGPUISD::ATOMIC_LOAD_FMIN:
-  case AMDGPUISD::ATOMIC_LOAD_FMAX: // TODO: Target mem intrinsics.
-    if (DCI.isBeforeLegalize())
-      break;
-    return performMemSDNodeCombine(cast<MemSDNode>(N), DCI);
   case ISD::AND:
     return performAndCombine(N, DCI);
   case ISD::OR:
@@ -10598,7 +10569,21 @@ SDValue SITargetLowering::PerformDAGCombine(SDNode *N,
     return performExtractVectorEltCombine(N, DCI);
   case ISD::INSERT_VECTOR_ELT:
     return performInsertVectorEltCombine(N, DCI);
+  case ISD::LOAD: {
+    if (SDValue Widended = widenLoad(cast<LoadSDNode>(N), DCI))
+      return Widended;
+    LLVM_FALLTHROUGH;
   }
+  default: {
+    if (!DCI.isBeforeLegalize()) {
+      if (MemSDNode *MemNode = dyn_cast<MemSDNode>(N))
+        return performMemSDNodeCombine(MemNode, DCI);
+    }
+
+    break;
+  }
+  }
+
   return AMDGPUTargetLowering::PerformDAGCombine(N, DCI);
 }