selftests/powerpc: Add memcmp testcase

Add a testcase for the new ppc64 memcmp.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

tools/testing/selftests/powerpc/stringloops/memcmp.c

@@ -0,0 +1,103 @@
+#include <malloc.h>
+#include <stdlib.h>
+#include <string.h>
+#include "../utils.h"
+
+#define SIZE 256
+#define ITERATIONS 10000
+
+int test_memcmp(const void *s1, const void *s2, size_t n);
+
+/* test all offsets and lengths */
+static void test_one(char *s1, char *s2)
+{
+	unsigned long offset, size;
+
+	for (offset = 0; offset < SIZE; offset++) {
+		for (size = 0; size < (SIZE-offset); size++) {
+			int x, y;
+			unsigned long i;
+
+			y = memcmp(s1+offset, s2+offset, size);
+			x = test_memcmp(s1+offset, s2+offset, size);
+
+			if (((x ^ y) < 0) &&	/* Trick to compare sign */
+				((x | y) != 0)) { /* check for zero */
+				printf("memcmp returned %d, should have returned %d (offset %ld size %ld)\n", x, y, offset, size);
+
+				for (i = offset; i < offset+size; i++)
+					printf("%02x ", s1[i]);
+				printf("\n");
+
+				for (i = offset; i < offset+size; i++)
+					printf("%02x ", s2[i]);
+				printf("\n");
+				abort();
+			}
+		}
+	}
+}
+
+static int testcase(void)
+{
+	char *s1;
+	char *s2;
+	unsigned long i;
+
+	s1 = memalign(128, SIZE);
+	if (!s1) {
+		perror("memalign");
+		exit(1);
+	}
+
+	s2 = memalign(128, SIZE);
+	if (!s2) {
+		perror("memalign");
+		exit(1);
+	}
+
+	srandom(1);
+
+	for (i = 0; i < ITERATIONS; i++) {
+		unsigned long j;
+		unsigned long change;
+
+		for (j = 0; j < SIZE; j++)
+			s1[j] = random();
+
+		memcpy(s2, s1, SIZE);
+
+		/* change one byte */
+		change = random() % SIZE;
+		s2[change] = random() & 0xff;
+
+		test_one(s1, s2);
+	}
+
+	srandom(1);
+
+	for (i = 0; i < ITERATIONS; i++) {
+		unsigned long j;
+		unsigned long change;
+
+		for (j = 0; j < SIZE; j++)
+			s1[j] = random();
+
+		memcpy(s2, s1, SIZE);
+
+		/* change multiple bytes, 1/8 of total */
+		for (j = 0; j < SIZE / 8; j++) {
+			change = random() % SIZE;
+			s2[change] = random() & 0xff;
+		}
+
+		test_one(s1, s2);
+	}
+
+	return 0;
+}
+
+int main(void)
+{
+	return test_harness(testcase, "memcmp");
+}