[PATCH v7 3/3] test: add tests for reciprocal based division

[Pavan Nikhilesh <pbhagavatula@caviumnetworks.com>]

This commit provides a set of tests for verifying the correctness and
performance of both unsigned 32 and 64bit reciprocal based division.

Signed-off-by: Pavan Nikhilesh <pbhagavatula@caviumnetworks.com>
---
 test/test/Makefile                        |   2 +
 test/test/test_reciprocal_division.c      | 190 +++++++++++++++++++++++++
 test/test/test_reciprocal_division_perf.c | 229 ++++++++++++++++++++++++++++++
 3 files changed, 421 insertions(+)
 create mode 100644 test/test/test_reciprocal_division.c
 create mode 100644 test/test/test_reciprocal_division_perf.c

diff --git a/test/test/Makefile b/test/test/Makefile
index bb54c9808..7f4aa67b9 100644
--- a/test/test/Makefile
+++ b/test/test/Makefile
@@ -95,6 +95,8 @@ SRCS-y += test_spinlock.c
 SRCS-y += test_memory.c
 SRCS-y += test_memzone.c
 SRCS-y += test_bitmap.c
+SRCS-y += test_reciprocal_division.c
+SRCS-y += test_reciprocal_division_perf.c
 
 SRCS-y += test_ring.c
 SRCS-y += test_ring_perf.c
diff --git a/test/test/test_reciprocal_division.c b/test/test/test_reciprocal_division.c
new file mode 100644
index 000000000..75313c486
--- /dev/null
+++ b/test/test/test_reciprocal_division.c
@@ -0,0 +1,190 @@
+/*
+ *   BSD LICENSE
+ *
+ *   Copyright (C) Cavium, Inc. 2017.
+ *
+ *   Redistribution and use in source and binary forms, with or without
+ *   modification, are permitted provided that the following conditions
+ *   are met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in
+ *       the documentation and/or other materials provided with the
+ *       distribution.
+ *     * Neither the name of Cavium, Inc nor the names of its
+ *       contributors may be used to endorse or promote products derived
+ *       from this software without specific prior written permission.
+ *
+ *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "test.h"
+
+#include <stdio.h>
+#include <unistd.h>
+#include <inttypes.h>
+
+#include <rte_common.h>
+#include <rte_cycles.h>
+#include <rte_random.h>
+#include <rte_reciprocal.h>
+
+#define MAX_ITERATIONS	(1ULL << 32)
+#define DIVIDE_ITER	(100)
+
+static int
+test_reciprocal(void)
+{
+	int result = 0;
+	uint32_t divisor_u32 = 0;
+	uint32_t dividend_u32;
+	uint32_t nresult_u32;
+	uint32_t rresult_u32;
+	uint64_t i;
+	uint64_t divisor_u64 = 0;
+	uint64_t dividend_u64;
+	uint64_t nresult_u64;
+	uint64_t rresult_u64;
+	struct rte_reciprocal reci_u32 = {0};
+	struct rte_reciprocal_u64 reci_u64 = {0};
+
+	rte_srand(rte_rdtsc());
+	printf("Validating unsigned 32bit division.\n");
+	for (i = 0; i < MAX_ITERATIONS; i++) {
+		/* Change divisor every DIVIDE_ITER iterations. */
+		if (i % DIVIDE_ITER == 0) {
+			divisor_u32 = rte_rand();
+			reci_u32 = rte_reciprocal_value(divisor_u32);
+		}
+
+		dividend_u32 = rte_rand();
+		nresult_u32 = dividend_u32 / divisor_u32;
+		rresult_u32 = rte_reciprocal_divide(dividend_u32,
+				reci_u32);
+		if (nresult_u32 != rresult_u32) {
+			printf("Division failed, %"PRIu32"/%"PRIu32" = "
+					"expected %"PRIu32" result %"PRIu32"\n",
+					dividend_u32, divisor_u32,
+					nresult_u32, rresult_u32);
+			result = 1;
+			break;
+		}
+	}
+
+	printf("Validating unsigned 64bit division.\n");
+	for (i = 0; i < MAX_ITERATIONS; i++) {
+		/* Change divisor every DIVIDE_ITER iterations. */
+		if (i % DIVIDE_ITER == 0) {
+			divisor_u64 = rte_rand();
+			reci_u64 = rte_reciprocal_value_u64(divisor_u64);
+		}
+
+		dividend_u64 = rte_rand();
+		nresult_u64 = dividend_u64 / divisor_u64;
+		rresult_u64 = rte_reciprocal_divide_u64(dividend_u64,
+				&reci_u64);
+		if (nresult_u64 != rresult_u64) {
+			printf("Division failed,  %"PRIu64"/%"PRIu64" = "
+					"expected %"PRIu64" result %"PRIu64"\n",
+					dividend_u64, divisor_u64,
+					nresult_u64, rresult_u64);
+			result = 1;
+			break;
+		}
+	}
+
+	printf("Validating unsigned 64bit division with 32bit divisor.\n");
+	for (i = 0; i < MAX_ITERATIONS; i++) {
+		/* Change divisor every DIVIDE_ITER iterations. */
+		if (i % DIVIDE_ITER == 0) {
+			divisor_u64 = rte_rand() >> 32;
+			reci_u64 = rte_reciprocal_value_u64(divisor_u64);
+		}
+
+		dividend_u64 = rte_rand();
+
+		nresult_u64 = dividend_u64 / divisor_u64;
+		rresult_u64 = rte_reciprocal_divide_u64(dividend_u64,
+				&reci_u64);
+
+		if (nresult_u64 != rresult_u64) {
+			printf("Division failed, %"PRIu64"/%"PRIu64" = "
+					"expected %"PRIu64" result %"PRIu64"\n",
+					dividend_u64, divisor_u64,
+					nresult_u64, rresult_u64);
+			result = 1;
+			break;
+		}
+	}
+
+	printf("Validating division by power of 2.\n");
+	for (i = 0; i < 32; i++) {
+		divisor_u64 = 1ull << i;
+		reci_u64 = rte_reciprocal_value_u64(divisor_u64);
+		reci_u32 = rte_reciprocal_value((uint32_t)divisor_u64);
+
+		dividend_u64 = rte_rand();
+
+		nresult_u64 = dividend_u64 / divisor_u64;
+		rresult_u64 = rte_reciprocal_divide_u64(dividend_u64,
+				&reci_u64);
+
+		if (nresult_u64 != rresult_u64) {
+			printf("Division 64 failed, %"PRIu64"/%"PRIu64" = "
+					"expected %"PRIu64" result %"PRIu64"\n",
+					dividend_u64, divisor_u64,
+					nresult_u64, rresult_u64);
+			result = 1;
+		}
+
+		nresult_u32 = (dividend_u64 >> 32) / divisor_u64;
+		rresult_u32 = rte_reciprocal_divide((dividend_u64 >> 32),
+				reci_u32);
+
+		if (nresult_u32 != rresult_u32) {
+			printf("Division 32 failed, %"PRIu64"/%"PRIu64" = "
+					"expected %"PRIu64" result %"PRIu64"\n",
+					dividend_u64 >> 32, divisor_u64,
+					nresult_u64, rresult_u64);
+			result = 1;
+			break;
+		}
+	}
+
+	for (; i < 64; i++) {
+		divisor_u64 = 1ull << i;
+		reci_u64 = rte_reciprocal_value_u64(divisor_u64);
+
+		dividend_u64 = rte_rand();
+
+		nresult_u64 = dividend_u64 / divisor_u64;
+		rresult_u64 = rte_reciprocal_divide_u64(dividend_u64,
+				&reci_u64);
+
+		if (nresult_u64 != rresult_u64) {
+			printf("Division failed, %"PRIu64"/%"PRIu64" = "
+					"expected %"PRIu64" result %"PRIu64"\n",
+					dividend_u64, divisor_u64,
+					nresult_u64, rresult_u64);
+			result = 1;
+			break;
+		}
+
+	}
+
+	return result;
+}
+
+REGISTER_TEST_COMMAND(reciprocal_division, test_reciprocal);
diff --git a/test/test/test_reciprocal_division_perf.c b/test/test/test_reciprocal_division_perf.c
new file mode 100644
index 000000000..e759331de
--- /dev/null
+++ b/test/test/test_reciprocal_division_perf.c
@@ -0,0 +1,229 @@
+/*
+ *   BSD LICENSE
+ *
+ *   Copyright (C) Cavium, Inc. 2017.
+ *
+ *   Redistribution and use in source and binary forms, with or without
+ *   modification, are permitted provided that the following conditions
+ *   are met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in
+ *       the documentation and/or other materials provided with the
+ *       distribution.
+ *     * Neither the name of Cavium, Inc nor the names of its
+ *       contributors may be used to endorse or promote products derived
+ *       from this software without specific prior written permission.
+ *
+ *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "test.h"
+
+#include <stdio.h>
+#include <unistd.h>
+#include <inttypes.h>
+
+#include <rte_common.h>
+#include <rte_cycles.h>
+#include <rte_random.h>
+#include <rte_reciprocal.h>
+
+#define MAX_ITERATIONS	(1ULL << 32)
+#define DIVIDE_ITER	(1ULL << 28)
+
+static int
+test_reciprocal_division_perf(void)
+{
+	int result = 0;
+	uint32_t divisor_u32 = 0;
+	uint32_t dividend_u32;
+	uint64_t divisor_u64 = 0;
+	uint64_t dividend_u64;
+	volatile uint32_t nresult_u32;
+	volatile uint32_t rresult_u32;
+	volatile uint64_t nresult_u64;
+	volatile uint64_t rresult_u64;
+	uint64_t start_cyc;
+	uint64_t split_cyc;
+	uint64_t end_cyc;
+	uint64_t tot_cyc_n = 0;
+	uint64_t tot_cyc_r = 0;
+	uint64_t i;
+	struct rte_reciprocal reci_u32 = {0};
+	struct rte_reciprocal_u64 reci_u64 = {0};
+
+	rte_srand(rte_rdtsc());
+
+	printf("Validating unsigned 32bit division.\n");
+	for (i = 0; i < MAX_ITERATIONS; i++) {
+		/* Change divisor every DIVIDE_ITER iterations. */
+		if (i % DIVIDE_ITER == 0) {
+			divisor_u32 = rte_rand();
+			reci_u32 = rte_reciprocal_value(divisor_u32);
+		}
+
+		dividend_u32 = rte_rand();
+
+		start_cyc = rte_rdtsc();
+		nresult_u32 = dividend_u32 / divisor_u32;
+		split_cyc = rte_rdtsc();
+		rresult_u32 = rte_reciprocal_divide(dividend_u32,
+				reci_u32);
+		end_cyc = rte_rdtsc();
+
+		tot_cyc_n += split_cyc - start_cyc;
+		tot_cyc_r += end_cyc - split_cyc;
+		if (nresult_u32 != rresult_u32) {
+			printf("Division failed, expected %"PRIu32" "
+					"result %"PRIu32"",
+					nresult_u32, rresult_u32);
+			result = 1;
+			break;
+		}
+	}
+	printf("32bit Division results:\n");
+	printf("Total number of cycles normal division     : %"PRIu64"\n",
+			tot_cyc_n);
+	printf("Total number of cycles reciprocal division : %"PRIu64"\n",
+			tot_cyc_r);
+	printf("Cycles per division(normal) : %3.2f\n",
+			((double)tot_cyc_n)/i);
+	printf("Cycles per division(reciprocal) : %3.2f\n\n",
+			((double)tot_cyc_r)/i);
+
+	tot_cyc_n = 0;
+	tot_cyc_r = 0;
+
+	printf("Validating unsigned 64bit division.\n");
+	for (i = 0; i < MAX_ITERATIONS; i++) {
+		/* Change divisor every DIVIDE_ITER iterations. */
+		if (i % DIVIDE_ITER == 0) {
+			divisor_u64 = rte_rand();
+			reci_u64 = rte_reciprocal_value_u64(divisor_u64);
+		}
+
+		dividend_u64 = rte_rand();
+
+		start_cyc = rte_rdtsc();
+		nresult_u64 = dividend_u64 / divisor_u64;
+		split_cyc = rte_rdtsc();
+		rresult_u64 = rte_reciprocal_divide_u64(dividend_u64,
+				&reci_u64);
+		end_cyc = rte_rdtsc();
+
+		tot_cyc_n += split_cyc - start_cyc;
+		tot_cyc_r += end_cyc - split_cyc;
+		if (nresult_u64 != rresult_u64) {
+			printf("Division failed, expected %"PRIu64" "
+					"result %"PRIu64"",
+					nresult_u64, rresult_u64);
+			result = 1;
+			break;
+		}
+	}
+	printf("64bit Division results:\n");
+	printf("Total number of cycles normal division     : %"PRIu64"\n",
+			tot_cyc_n);
+	printf("Total number of cycles reciprocal division : %"PRIu64"\n",
+			tot_cyc_r);
+	printf("Cycles per division(normal) : %3.2f\n",
+			((double)tot_cyc_n)/i);
+	printf("Cycles per division(reciprocal) : %3.2f\n\n",
+			((double)tot_cyc_r)/i);
+
+	tot_cyc_n = 0;
+	tot_cyc_r = 0;
+
+	printf("Validating unsigned 64bit division with 32bit divisor.\n");
+	for (i = 0; i < MAX_ITERATIONS; i++) {
+		/* Change divisor every DIVIDE_ITER iterations. */
+		if (i % DIVIDE_ITER == 0) {
+			divisor_u64 = rte_rand() >> 32;
+			reci_u64 = rte_reciprocal_value_u64(divisor_u64);
+		}
+
+		dividend_u64 = rte_rand();
+
+		start_cyc = rte_rdtsc();
+		nresult_u64 = dividend_u64 / divisor_u64;
+		split_cyc = rte_rdtsc();
+		rresult_u64 = rte_reciprocal_divide_u64(dividend_u64,
+				&reci_u64);
+		end_cyc = rte_rdtsc();
+
+		tot_cyc_n += split_cyc - start_cyc;
+		tot_cyc_r += end_cyc - split_cyc;
+		if (nresult_u64 != rresult_u64) {
+			printf("Division failed, expected %"PRIu64" "
+					"result %"PRIu64"",
+					nresult_u64, rresult_u64);
+			result = 1;
+			break;
+		}
+	}
+
+	printf("64bit Division results:\n");
+	printf("Total number of cycles normal division     : %"PRIu64"\n",
+			tot_cyc_n);
+	printf("Total number of cycles reciprocal division : %"PRIu64"\n",
+			tot_cyc_r);
+	printf("Cycles per division(normal) : %3.2f\n",
+			((double)tot_cyc_n)/i);
+	printf("Cycles per division(reciprocal) : %3.2f\n\n",
+			((double)tot_cyc_r)/i);
+
+	tot_cyc_n = 0;
+	tot_cyc_r = 0;
+
+	printf("Validating division by power of 2.\n");
+	for (i = 0; i < 64; i++) {
+		divisor_u64 = 1ull << i;
+		reci_u64 = rte_reciprocal_value_u64(divisor_u64);
+
+		dividend_u64 = rte_rand();
+
+		start_cyc = rte_rdtsc();
+		nresult_u64 = dividend_u64 / divisor_u64;
+		split_cyc = rte_rdtsc();
+		rresult_u64 = rte_reciprocal_divide_u64(dividend_u64,
+				&reci_u64);
+		end_cyc = rte_rdtsc();
+
+		tot_cyc_n += split_cyc - start_cyc;
+		tot_cyc_r += end_cyc - split_cyc;
+		if (nresult_u64 != rresult_u64) {
+			printf("Division 64 failed, %"PRIu64"/%"PRIu64" = "
+					"expected %"PRIu64" result %"PRIu64"\n",
+					dividend_u64, divisor_u64,
+					nresult_u64, rresult_u64);
+			result = 1;
+			break;
+		}
+	}
+	printf("64bit Division results:\n");
+	printf("Total number of cycles normal division     : %"PRIu64"\n",
+			tot_cyc_n);
+	printf("Total number of cycles reciprocal division : %"PRIu64"\n",
+			tot_cyc_r);
+	printf("Cycles per division(normal) : %3.2f\n",
+			((double)tot_cyc_n)/i);
+	printf("Cycles per division(reciprocal) : %3.2f\n",
+			((double)tot_cyc_r)/i);
+
+	return result;
+}
+
+REGISTER_TEST_COMMAND(reciprocal_division_perf, test_reciprocal_division_perf);
-- 
2.14.1