[MLIR][XeVM] blockload and blockstore ops should use scalar types (#161708)

instead of single element vectors.
XeVM type system does not support single element vectors.

Author: silee2

mlir/include/mlir/Dialect/LLVMIR/XeVMOps.td

@@ -190,8 +190,9 @@ def XeVM_StoreCacheControlAttr
 
 def XeVM_BlockLoadOp
     : XeVM_Op<"blockload">,
-      Results<(
-          outs FixedVectorOfRankAndType<[1], [XeVM_1DBlockElemType]>:$res)>,
+      Results<(outs AnyTypeOf<
+          [XeVM_1DBlockElemType,
+           FixedVectorOfRankAndType<[1], [XeVM_1DBlockElemType]>]>:$res)>,
       Arguments<(ins Arg<LLVM_AnyPointer, "", [MemRead]>:$ptr,
           OptionalAttr<XeVM_LoadCacheControlAttr>:$cache_control)> {
   let summary = "subgroup block load";
@@ -228,7 +229,9 @@ def XeVM_BlockLoadOp
 def XeVM_BlockStoreOp
     : XeVM_Op<"blockstore">,
       Arguments<(ins Arg<LLVM_AnyPointer, "", [MemWrite]>:$ptr,
-          FixedVectorOfRankAndType<[1], [XeVM_1DBlockElemType]>:$val,
+          AnyTypeOf<[XeVM_1DBlockElemType,
+                     FixedVectorOfRankAndType<[1],
+                                              [XeVM_1DBlockElemType]>]>:$val,
           OptionalAttr<XeVM_StoreCacheControlAttr>:$cache_control)> {
   let summary = "subgroup block store";
   let description = [{

mlir/lib/Dialect/LLVMIR/IR/XeVMDialect.cpp

@@ -310,26 +310,30 @@ LogicalResult BlockPrefetch2dOp::verify() {
 template <typename OpType, typename = std::enable_if_t<llvm::is_one_of<
                                OpType, BlockLoadOp, BlockStoreOp>::value>>
 LogicalResult verify1DBlockArg(OpType op) {
-  VectorType vTy;
+  Type srcOrDstTy;
   if constexpr (std::is_same_v<OpType, BlockLoadOp>)
-    vTy = op.getResult().getType();
+    srcOrDstTy = op.getResult().getType();
   else
-    vTy = op.getVal().getType();
+    srcOrDstTy = op.getVal().getType();
+  VectorType vTy = dyn_cast<VectorType>(srcOrDstTy);
+  // scalar case is always valid
+  if (!vTy)
+    return success();
   int elemTySize = vTy.getElementType().getIntOrFloatBitWidth() / 8;
   if (elemTySize == 1) {
-    llvm::SmallSet<int, 5> validSizes{1, 2, 4, 8, 16};
+    llvm::SmallSet<int, 4> validSizes{2, 4, 8, 16};
     if (validSizes.contains(vTy.getNumElements()))
       return success();
     else
       return op.emitOpError(
-          "vector size must be 1, 2, 4, 8 or 16 for 8-bit element type");
+          "vector size must be 2, 4, 8 or 16 for 8-bit element type");
   } else {
-    llvm::SmallSet<int, 4> validSizes{1, 2, 4, 8};
+    llvm::SmallSet<int, 3> validSizes{2, 4, 8};
     if (validSizes.contains(vTy.getNumElements()))
       return success();
     else
       return op.emitOpError(
-          "vector size must be 1, 2, 4 or 8 for element type > 8 bits");
+          "vector size must be 2, 4 or 8 for element type > 8 bits");
   }
 }
 

mlir/test/Dialect/LLVMIR/invalid.mlir

@@ -1973,14 +1973,14 @@ llvm.func @invalid_xevm_prefetch(%arg0: !llvm.ptr) {
 
 // -----
 llvm.func @invalid_xevm_blockload(%arg0: !llvm.ptr<1>) {
-  // expected-error@+1 {{op vector size must be 1, 2, 4 or 8 for element type > 8 bits}}
+  // expected-error@+1 {{op vector size must be 2, 4 or 8 for element type > 8 bits}}
   %0 = xevm.blockload %arg0 : (!llvm.ptr<1>) -> vector<3xi16>
   llvm.return
 }
 
 // -----
 llvm.func @invalid_xevm_blockstore(%arg0: !llvm.ptr<1>, %arg1: vector<5xi8>) {
-  // expected-error@+1 {{op vector size must be 1, 2, 4, 8 or 16 for 8-bit element type}}
+  // expected-error@+1 {{op vector size must be 2, 4, 8 or 16 for 8-bit element type}}
   xevm.blockstore %arg0, %arg1 : (!llvm.ptr<1>, vector<5xi8>)
   llvm.return
 }