sse2 version of vec4 dot product

* use this for normalizing vector

test/src/test_vec4.c

@@ -0,0 +1,30 @@
+/*
+ * Copyright (c), Recep Aslantas.
+ *
+ * MIT License (MIT), http://opensource.org/licenses/MIT
+ * Full license can be found in the LICENSE file
+ */
+
+#include "test_common.h"
+
+CGLM_INLINE
+float
+test_vec4_dot(vec4 a, vec4 b) {
+  return a[0] * b[0] + a[1] * b[1] + a[2] * b[2] + a[3] * b[3];
+}
+
+void
+test_vec4(void **state) {
+  vec4  v;
+  int   i;
+  float d1, d2;
+
+  /* test SSE/SIMD dot product */
+  for (i = 0; i < 100; i++) {
+    test_rand_vec4(v);
+    d1 = glm_vec4_dot(v, v);
+    d2 = test_vec4_dot(v, v);
+
+    assert_true(fabsf(d1 - d2) <= 0.000009);
+  }
+}