DAG: Legalize truncstores to illegal int types

[arsenm]

Summary

Truncate to a legal int type, and produce a new
truncstore from a narrower type.

[arsenm]

ping

[bogner]

Looks good once the bug/redundancy is fixed.

lib/CodeGen/SelectionDAG/LegalizeDAG.cpp

634

We ReplaceNode twice in this path now?

[arsenm]

r319185

lib/CodeGen/SelectionDAG/LegalizeDAG.cpp

case TargetLowering::Custom: {
       if (Res && Res != SDValue(Node, 0))
         ReplaceNode(SDValue(Node, 0), Res);
       return;
     }
     case TargetLowering::Expand:
       assert(!StVT.isVector() &&
              "Vector Stores are handled in LegalizeVectorOps");
 
+      SDValue Result;
+
       // TRUNCSTORE:i16 i32 -> STORE i16
-      assert(TLI.isTypeLegal(StVT) &&
-             "Do not know how to expand this store!");
+      if (TLI.isTypeLegal(StVT)) {
         Value = DAG.getNode(ISD::TRUNCATE, dl, StVT, Value);
-      SDValue Result =
-          DAG.getStore(Chain, dl, Value, Ptr, ST->getPointerInfo(),
+        Result = DAG.getStore(Chain, dl, Value, Ptr, ST->getPointerInfo(),
                               Alignment, MMOFlags, AAInfo);
         ReplaceNode(SDValue(Node, 0), Result);
+      } else {
+        // The in-memory type isn't legal. Truncate to the type it would promote
+        // to, and then do a truncstore.
+        Value = DAG.getNode(ISD::TRUNCATE, dl,
+                            TLI.getTypeToTransformTo(*DAG.getContext(), StVT),
+                            Value);
+        Result = DAG.getTruncStore(Chain, dl, Value, Ptr, ST->getPointerInfo(),
+                                   StVT, Alignment, MMOFlags, AAInfo);
+      }
+
+      ReplaceNode(SDValue(Node, 0), Result);
       break;
     }
   }
 }
 
 void SelectionDAGLegalize::LegalizeLoadOps(SDNode *Node) {
   LoadSDNode *LD = cast<LoadSDNode>(Node);
   SDValue Chain = LD->getChain();  // The chain.

test/CodeGen/AMDGPU/store-weird-sizes.ll

+; RUN: llc -mtriple=amdgcn-amd-amdhsa -mcpu=hawaii -verify-machineinstrs < %s | FileCheck -enable-var-scope -check-prefixes=GCN,CIVI %s
+; RUN: llc -mtriple=amdgcn-amd-amdhsa -mcpu=fiji -verify-machineinstrs < %s | FileCheck -enable-var-scope -check-prefixes=GCN,CIVI %s
+; RUN: llc -mtriple=amdgcn-amd-amdhsa -mcpu=gfx900 -verify-machineinstrs < %s | FileCheck -enable-var-scope -check-prefixes=GCN,GFX9 %s
+
+; GCN-LABEL: {{^}}local_store_i56:
+; GCN-DAG: ds_write_b8 v0, v{{[0-9]+}} offset:6
+; GCN-DAG: ds_write_b16 v0, v{{[0-9]+}} offset:4
+; GCN-DAG: ds_write_b32 v0, v{{[0-9]+$}}
+define void @local_store_i56(i56 addrspace(3)* %ptr, i56 %arg) #0 {
+  store i56 %arg, i56 addrspace(3)* %ptr, align 8
+  ret void
+}
+
+; GCN-LABEL: {{^}}local_store_i55:
+; GCN-DAG: ds_write_b8 v0, v{{[0-9]+}} offset:6
+; GCN-DAG: ds_write_b16 v0, v{{[0-9]+}} offset:4
+; GCN-DAG: ds_write_b32 v0, v{{[0-9]+$}}
+define amdgpu_kernel void @local_store_i55(i55 addrspace(3)* %ptr, i55 %arg) #0 {
+  store i55 %arg, i55 addrspace(3)* %ptr, align 8
+  ret void
+}
+
+; GCN-LABEL: {{^}}local_store_i48:
+; GCN-DAG: ds_write_b16 v0, v{{[0-9]+}} offset:4
+; GCN-DAG: ds_write_b32 v0, v{{[0-9]+$}}
+define amdgpu_kernel void @local_store_i48(i48 addrspace(3)* %ptr, i48 %arg) #0 {
+  store i48 %arg, i48 addrspace(3)* %ptr, align 8
+  ret void
+}
+
+; GCN-LABEL: {{^}}local_store_i65:
+; GCN-DAG: ds_write_b8 v{{[0-9]+}}, v0 offset:8
+; GCN-DAG: ds_write_b64
+define amdgpu_kernel void @local_store_i65(i65 addrspace(3)* %ptr, i65 %arg) #0 {
+  store i65 %arg, i65 addrspace(3)* %ptr, align 8
+  ret void
+}
+
+; GCN-LABEL: {{^}}local_store_i13:
+; GCN: v_and_b32_e32 [[TRUNC:v[0-9]+]], 0x1fff, v1
+; GCN: ds_write_b16 v0, [[TRUNC]]
+define void @local_store_i13(i13 addrspace(3)* %ptr, i13 %arg) #0 {
+  store i13 %arg, i13 addrspace(3)* %ptr, align 8
+  ret void
+}
+
+; GCN-LABEL: {{^}}local_store_i17:
+; GCN: ds_write_b16 v0
+; CIVI: ds_write_b8 v0, v{{[0-9]+}} offset:2
+; GFX9: ds_write_b8_d16_hi v0, v{{[0-9]+}} offset:2
+define void @local_store_i17(i17 addrspace(3)* %ptr, i17 %arg) #0 {
+  store i17 %arg, i17 addrspace(3)* %ptr, align 8
+  ret void
+}
+
+attributes #0 = { nounwind }