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authorDenys Vlasenko <vda.linux@googlemail.com>2010-10-30 22:45:06 (GMT)
committerDenys Vlasenko <vda.linux@googlemail.com>2010-10-30 22:45:06 (GMT)
commite9807e243b454b06f279d7593abaeb74c73aef1e (patch)
treef78686c8bdd4e92e69232d10e5dd5452e9486c30
parent4435b3ae24b6f76892b7c06c300687c23fab2729 (diff)
libm: fix remaining failures in test-float
These two failures are fixed: Failure: Test: ilogb (0.0) == FP_ILOGB0 plus exceptions allowed Failure: Test: ilogb (NaN) == FP_ILOGBNAN plus exceptions allowed Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
-rw-r--r--libm/s_ilogb.c47
-rw-r--r--test/math/Makefile.in3
-rw-r--r--test/math/ilogb.c51
3 files changed, 84 insertions, 17 deletions
diff --git a/libm/s_ilogb.c b/libm/s_ilogb.c
index ce30296..259ae7b 100644
--- a/libm/s_ilogb.c
+++ b/libm/s_ilogb.c
@@ -10,9 +10,10 @@
*/
/* ilogb(double x)
- * return the binary exponent of non-zero x
- * ilogb(0) = 0x80000001
- * ilogb(inf/NaN) = 0x7fffffff (no signal is raised)
+ * return the binary exponent of x
+ * ilogb(+-0) = FP_ILOGB0
+ * ilogb(+-inf) = INT_MAX
+ * ilogb(NaN) = FP_ILOGBNAN (no signal is raised)
*/
#include "math.h"
@@ -22,21 +23,35 @@ int ilogb(double x)
{
int32_t hx,lx,ix;
- GET_HIGH_WORD(hx,x);
+ GET_HIGH_WORD(hx, x);
hx &= 0x7fffffff;
- if(hx<0x00100000) {
- GET_LOW_WORD(lx,x);
- if((hx|lx)==0)
- return 0x80000001; /* ilogb(0) = 0x80000001 */
- else /* subnormal x */
- if(hx==0) {
- for (ix = -1043; lx>0; lx<<=1) ix -=1;
- } else {
- for (ix = -1022,hx<<=11; hx>0; hx<<=1) ix -=1;
+
+ if (hx < 0x00100000) {
+ GET_LOW_WORD(lx, x);
+ if ((hx|lx)==0) /* +-0, ilogb(0) = FP_ILOGB0 */
+ return FP_ILOGB0;
+ /* subnormal x */
+ ix = -1043;
+ if (hx != 0) {
+ ix = -1022;
+ lx = (hx << 11);
}
- return ix;
+ /* each leading zero mantissa bit makes exponent smaller */
+ for (; lx > 0; lx <<= 1)
+ ix--;
+ return ix;
}
- else if (hx<0x7ff00000) return (hx>>20)-1023;
- else return 0x7fffffff;
+
+ if (hx < 0x7ff00000) /* normal x */
+ return (hx>>20) - 1023;
+
+ if (FP_ILOGBNAN != (~0U >> 1)) {
+ GET_LOW_WORD(lx, x);
+ if (hx == 0x7ff00000 && lx == 0) /* +-inf */
+ return ~0U >> 1; /* = INT_MAX */
+ }
+
+ /* NAN. ilogb(NAN) = FP_ILOGBNAN */
+ return FP_ILOGBNAN;
}
libm_hidden_def(ilogb)
diff --git a/test/math/Makefile.in b/test/math/Makefile.in
index e801112..9ceb6c6 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 0000000..e439f8c
--- /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;
+}