2 files changed, 53 insertions, 1 deletions
diff --git a/test/math/Makefile.in b/test/math/Makefile.in
index e801112c6..9ceb6c6d5 100644
--- a/test/math/Makefile.in
+++ b/test/math/Makefile.in
@@ -1,7 +1,8 @@
 # uClibc math tests
 # Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball.
 
-TESTS := basic-test rint signgam tst-definitions test-fpucw test-float test-ifloat test-double test-idouble
+TESTS := basic-test tst-definitions test-fpucw test-float test-ifloat test-double test-idouble \
+    rint signgam ilogb
 ifeq ($(UCLIBC_HAS_LONG_DOUBLE_MATH),y)
 TESTS += test-ldouble test-ildoubl compile_test
 else
diff --git a/test/math/ilogb.c b/test/math/ilogb.c
new file mode 100644
index 000000000..e439f8c37
--- /dev/null
+++ b/test/math/ilogb.c
@@ -0,0 +1,51 @@
+#include <math.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <limits.h>
+#include <stdio.h>
+
+#define check_d1(func, param, expected) \
+do { \
+	int err; hex_union ur; hex_union up; \
+	double result = func(param); up.f = param; ur.f = result; \
+	errors += (err = (result != (expected))); \
+	err \
+	? printf("FAIL: %s(%g/"HEXFMT")=%g/"HEXFMT" (expected %g)\n", \
+		#func, (double)(param), (long long)up.hex, result, (long long)ur.hex, (double)(expected)) \
+	: printf("PASS: %s(%g)=%g\n", #func, (double)(param), result); \
+} while (0)
+
+#define check_i1(func, param, expected) \
+do { \
+	int err; hex_union up; \
+	long long result = func(param); up.f = param; \
+	errors += (err = (result != (expected))); \
+	err \
+	? printf("FAIL: %s(%g/"HEXFMT")=%lld/%llu (expected %llu)\n", \
+		#func, (double)(param), (long long)up.hex, result, result, (long long)(expected)) \
+	: printf("PASS: %s(%g)=%lld/%llu\n", #func, (double)(param), result, result); \
+} while (0)
+
+#define HEXFMT "%08llx"
+typedef union {
+	double f;
+	uint64_t hex;
+} hex_union;
+
+double nan_value = 0.0;
+int errors = 0;
+
+int main(void)
+{
+	nan_value /= nan_value;
+
+	check_i1(ilogb, 0.0, FP_ILOGB0);
+	check_i1(ilogb, HUGE_VAL, INT_MAX);
+	check_i1(ilogb, nan_value, FP_ILOGBNAN);
+	check_i1(ilogbf, 0.0, FP_ILOGB0);
+	check_i1(ilogbf, HUGE_VALF, INT_MAX);
+	check_i1(ilogbf, nan_value, FP_ILOGBNAN);
+
+	printf("Errors: %d\n", errors);
+	return errors;
+}