diff --git a/c-programming/math/opt_int_div.c b/c-programming/math/opt_int_div.c
new file mode 100644
index 0000000..78d2a5d
--- /dev/null
+++ b/c-programming/math/opt_int_div.c
@@ -0,0 +1,44 @@
+/*
+ * opt_int_div.c
+ *
+ * Author: Intel A80486DX2-66
+ * License: Creative Commons Zero 1.0 Universal
+ */
+
+#include "opt_int_div.h"
+
+#ifdef TEST
+# include <inttypes.h>
+# include <stdio.h>
+
+int main(void) {
+	printf("Loop: a > 0, b > 0\n");
+	for (uint8_t a = 3; a <= 24; a++)
+		for (uint8_t b = 1; b <= 8; b++) {
+			if (b >= a)
+				break;
+			printf("%" PRIu8 " / %" PRIu8 " = %" PRIu8 "\n", a, b,
+			       OPT_INT_DIV(a, b));
+		}
+
+	printf("Loop: a < 0, b > 0\n");
+	for (int8_t a = -3; a >= -24; a--)
+		for (int8_t b = 1; b <= 8; b++) {
+			if (b >= abs(a))
+				break;
+			printf("%" PRId8 " / %" PRId8 " = %" PRId8 "\n", a, b,
+			       OPT_INT_DIV(a, b));
+		}
+
+	printf("Loop: a < 0, b < 0\n");
+	for (int8_t a = -3; a >= -24; a--)
+		for (int8_t b = -1; b >= -8; b--) {
+			if (b <= a)
+				break;
+			printf("%" PRId8 " / %" PRId8 " = %" PRId8 "\n", a, b,
+			       OPT_INT_DIV(a, b));
+		}
+
+	return 0;
+}
+#endif
diff --git a/c-programming/math/opt_int_div.h b/c-programming/math/opt_int_div.h
new file mode 100644
index 0000000..10a83fc
--- /dev/null
+++ b/c-programming/math/opt_int_div.h
@@ -0,0 +1,47 @@
+/*
+ * opt_int_div.h
+ *
+ * Author: Intel A80486DX2-66
+ * License: Creative Commons Zero 1.0 Universal
+ */
+
+#include <math.h>
+#include <stdint.h>
+
+// parameters
+#define OPT_INT_DIV_TEST_PRECISION 8
+
+// constants
+#define OPT_INT_DIV_ROUNDING                                                  \
+    /* 10^OPT_INT_DIV_TEST_PRECISION */                                       \
+    powl(10.l, (long double) OPT_INT_DIV_TEST_PRECISION)                      \
+
+// helper functions
+#define INT_BIN_DIV(a, b) ((a) >> (uintmax_t) log2l((b)))
+#define INT_DIV_NEG_RESULT_SIGN(a, b) (((a) < 0) ^ ((b) < 0))
+#define INT_ABS(x) ((x) < 0 ? -(x) : (x))
+
+// the main macro
+#define OPT_INT_DIV(a, b)                                                     \
+    ( /* beginning */                                                         \
+        /* check for equality of a and b */                                   \
+        INT_ABS((a)) == INT_ABS((b)) ?                                        \
+            /* if only one of the numbers is negative, the result is -1, */   \
+            /* otherwise it is 1. */                                          \
+            (INT_DIV_NEG_RESULT_SIGN(a, b) ? -1 : 1) : (                      \
+                                                                              \
+        /* check if b is a power of 2 */                                      \
+        /* */                                                                 \
+        /* formula: round(log_2(b) % 1, OPT_INT_DIV_TEST_PRECISION digits */  \
+        /* after point) == 0                                              */  \
+        (roundl(fmodl(log2l((b)), 1.l) * OPT_INT_DIV_ROUNDING) /              \
+         OPT_INT_DIV_ROUNDING == 0.l) ? (                                     \
+            /* if only one of the numbers is negative, the result is */       \
+            /* negative */                                                    \
+            INT_DIV_NEG_RESULT_SIGN(a, b) ?                                   \
+                -INT_BIN_DIV(INT_ABS(a), INT_ABS(b))                          \
+            :                                                                 \
+                INT_BIN_DIV(INT_ABS(a), INT_ABS(b)))                          \
+        :                                                                     \
+            ((a) / (b)) )                                                     \
+    ) /* end */