[TorchToLinalg] Fix integer type handling for aten.mm (#2615)

Despite aten.mm requiring the input and output types match, we still opt
to maintain signedness semantics in case later passes try to do any sort
of integer type narrowing.

lib/Conversion/TorchToLinalg/Linear.cpp

@@ -51,12 +51,24 @@ public:
     // The compiler cannot crash even if the user wrote an erroneous program!
     if (failed(verifyLinalgCompatibleTypes(op, rewriter)))
       return failure();
-    if (lhs.getType().cast<RankedTensorType>().getRank() != 2 ||
-        rhs.getType().cast<RankedTensorType>().getRank() != 2) {
+
+    RankedTensorType lhsType = lhs.getType().cast<RankedTensorType>();
+    RankedTensorType rhsType = rhs.getType().cast<RankedTensorType>();
+
+    if (lhsType.getRank() != 2 || rhsType.getRank() != 2) {
       return rewriter.notifyMatchFailure(
           op, "expected both operands to aten.mm to be rank 2");
     }
 
+    ValueTensorType lhsTorchType =
+        op.getSelf().getType().cast<ValueTensorType>();
+    ValueTensorType rhsTorchType =
+        op.getMat2().getType().cast<ValueTensorType>();
+    if (lhsTorchType.getDtype() != rhsTorchType.getDtype()) {
+      return rewriter.notifyMatchFailure(
+          op, "unsupported: aten.mm with different input element types");
+    }
+
     Value lhsDim0 = rewriter.create<tensor::DimOp>(loc, lhs, 0);
     Value rhsDim1 = rewriter.create<tensor::DimOp>(loc, rhs, 1);
 
@@ -73,16 +85,22 @@ public:
 
     Type newResultType = getTypeConverter()->convertType(op.getType());
     Type elementType = newResultType.cast<TensorType>().getElementType();
-    Value initTensor = rewriter.create<tensor::EmptyOp>(
-        loc, ArrayRef<OpFoldResult>{lhsDim0, rhsDim1}, elementType);
-    Value c0 = rewriter.create<arith::ConstantOp>(
-        loc, FloatAttr::get(elementType, 0.0));
-    Value zeroFill =
-        rewriter.create<linalg::FillOp>(loc, c0, initTensor).getResult(0);
-    Value matmul = rewriter
+    Value zeroFill = createZeroInitTensor(
+        rewriter, loc, ValueRange{lhsDim0, rhsDim1}, elementType);
+
+    Value matmul;
+    auto intType = dyn_cast<mlir::IntegerType>(lhsTorchType.getDtype());
+    if (intType && intType.isUnsigned()) {
+      matmul = rewriter
+                   .create<linalg::MatmulUnsignedOp>(
+                       loc, zeroFill.getType(), ValueRange{lhs, rhs}, zeroFill)
+                   .getResult(0);
+    } else {
+      matmul = rewriter
                    .create<linalg::MatmulOp>(loc, zeroFill.getType(),
                                              ValueRange{lhs, rhs}, zeroFill)
                    .getResult(0);
+    }
     // When constructed with just dynamic sizes, EmptyOp will have a result
     // type which has all `?`'s for dimensions, which might not be the result
     // type of `op`. The constraints on later linalg ops means that the result

projects/pt1/python/torch_mlir_e2e_test/test_suite/matmul.py

@@ -226,3 +226,39 @@ class Mv(torch.nn.Module):
 @register_test_case(module_factory=lambda: Mv())
 def Mv_basic(module, tu: TestUtils):
     module.forward(tu.rand(2, 2), tu.rand(2))
+
+# ==============================================================================
+
+class AtenMmFloatTypes(torch.nn.Module):
+
+    @export
+    @annotate_args([
+        None,
+        ([-1, -1], torch.float32, True),
+        ([-1, -1], torch.float32, True),
+    ])
+    def forward(self, a, b):
+        return torch.ops.aten.mm(a, b)
+
+
+@register_test_case(module_factory=lambda: AtenMmFloatTypes())
+def AtenMmFloatTypes_basic(module, tu: TestUtils):
+    module.forward(tu.rand(8, 8), tu.rand(8, 8))
+
+# ==============================================================================
+
+class AtenMmIntTypes(torch.nn.Module):
+
+    @export
+    @annotate_args([
+        None,
+        ([-1, -1], torch.int64, True),
+        ([-1, -1], torch.int64, True),
+    ])
+    def forward(self, a, b):
+        return torch.ops.aten.mm(a, b)
+
+
+@register_test_case(module_factory=lambda: AtenMmIntTypes())
+def AtenMmIntTypes_basic(module, tu: TestUtils):
+    module.forward(tu.randint(16, 4, high=100), tu.randint(4, 16, high=100))

test/Conversion/TorchToLinalg/basic.mlir

@@ -40,6 +40,17 @@ func.func @torch.aten.mm$basic_strict(%arg0: !torch.vtensor<[?,?],f32>, %arg1: !
 
 // -----
 
+// CHECK-LABEL: func.func @torch.aten.mm$basic_unsigned(
+// CHECK: linalg.matmul_unsigned
+func.func @torch.aten.mm$basic_unsigned(%arg0: !torch.vtensor<[?,?],ui32>, %arg1: !torch.vtensor<[?,?],ui32>) -> !torch.vtensor<[?,2],ui32> 
+  attributes {torch.assume_strict_symbolic_shapes}
+{
+  %0 = torch.aten.mm %arg0, %arg1 : !torch.vtensor<[?,?],ui32>, !torch.vtensor<[?,?],ui32> -> !torch.vtensor<[?,2],ui32>
+  return %0 : !torch.vtensor<[?,2],ui32>
+}
+
+// -----
+
 // If the operands are missing dtype, we cannot lower it.
 func.func @torch.aten.mm$no_convert$missing_dtype(%arg0: !torch.vtensor, %arg1: !torch.vtensor) -> !torch.vtensor {
   // expected-error@+1 {{failed to legalize}}