ROUNDZ evaluation stubs

PiperOrigin-RevId: 311256662
diff --git a/src/math/roundz-sse41.c b/src/math/roundz-sse41.c
new file mode 100644
index 0000000..78cbefe
--- /dev/null
+++ b/src/math/roundz-sse41.c
@@ -0,0 +1,30 @@
+// Copyright 2020 Google LLC
+//
+// This source code is licensed under the BSD-style license found in the
+// LICENSE file in the root directory of this source tree.
+
+#include <assert.h>
+#include <stddef.h>
+
+#include <smmintrin.h>
+
+#include <xnnpack/math-stubs.h>
+
+
+void xnn_math_f32_roundz__sse41(
+    size_t n,
+    const float* input,
+    float* output)
+{
+  assert(n % (4 * sizeof(float)) == 0);
+
+  for (; n != 0; n -= 4 * sizeof(float)) {
+    const __m128 vx = _mm_load_ps(input);
+    input += 4;
+
+    const __m128 vy = _mm_round_ps(vx, _MM_FROUND_TO_ZERO | _MM_FROUND_NO_EXC);
+
+    _mm_store_ps(output, vy);
+    output += 4;
+  }
+}