[mlir][tosa] Relax constraint on matmul verifier requiring equal operand types (llvm#155799)

Removes the verifier constraint allowing support for matmul with
different operand types such as fp8e5m2xfp8e4m3. Support for specific
operand types strictly adhering to the TOSA specification will still be
caught in the validation pass.

Author: lhutton1

mlir/lib/Dialect/Tosa/IR/TosaOps.cpp

@@ -1843,12 +1843,6 @@ LogicalResult MatMulOp::verify() {
       return emitOpError("expect quantized operands to have same widths, got ")
              << aQuantWidth << " and " << bQuantWidth;
     }
-  } else {
-    // non-quantized element types
-    if (aElementType != bElementType) {
-      return emitOpError("expect same element type for inputs a and b, got ")
-             << aElementType << " and " << bElementType;
-    }
   }
 
   // check a_zp and b_zp

mlir/test/Dialect/Tosa/ops.mlir

@@ -976,6 +976,15 @@ func.func @test_matmul_f8E5M2(%arg0: tensor<1x14x19xf8E5M2>, %arg1: tensor<1x19x
   return %0 : tensor<1x14x28xf16>
 }
 
+// -----
+// CHECK-LABEL: test_matmul_f8E5M2_f8E4M3
+func.func @test_matmul_f8E5M2_f8E4M3(%arg0: tensor<1x14x19xf8E5M2>, %arg1: tensor<1x19x28xf8E4M3FN>) -> tensor<1x14x28xf16> {
+  %azp0 = "tosa.const"() <{values = dense<0.0> : tensor<1xf8E5M2>}> : () -> tensor<1xf8E5M2>
+  %bzp0 = "tosa.const"() <{values = dense<0.0> : tensor<1xf8E4M3FN>}> : () -> tensor<1xf8E4M3FN>
+  %0 = tosa.matmul %arg0, %arg1, %azp0, %bzp0 : (tensor<1x14x19xf8E5M2>, tensor<1x19x28xf8E4M3FN>, tensor<1xf8E5M2>, tensor<1xf8E4M3FN>) -> tensor<1x14x28xf16>
+  return %0 : tensor<1x14x28xf16>
+}
+
 // -----
 // CHECK-LABEL: max_pool2d_f8E5M2
 func.func @test_max_pool2d_f8E5M2(%arg0: tensor<1x32x32x8xf8E5M2>) -> tensor<1x32x32x8xf8E5M2> {