11175 libm should use signbit() correctly
11188 c99 math macros should return strictly backward compatible values

@@ -64,17 +64,17 @@
  * C99 7.12.3 classification macros
  */
 #undef  isnan
 #undef  isinf
 #if __GNUC__ >= 4
-#define isnan(x)        __builtin_isnan(x)
-#define isinf(x)        __builtin_isinf(x)
 #define fpclassify(x)   __builtin_fpclassify(FP_NAN, FP_INFINITE, FP_NORMAL, \
     FP_SUBNORMAL, FP_ZERO, x)
-#define isfinite(x)     __builtin_isfinite(x)
-#define isnormal(x)     __builtin_isnormal(x)
-#define signbit(x)      (__builtin_signbit(x) > 0)
+#define isnan(x)        __builtin_isnan(x)
+#define isinf(x)        __builtin_isinf(x)
+#define isfinite(x)     (__builtin_isfinite(x) != 0)
+#define isnormal(x)     (__builtin_isnormal(x) != 0)
+#define signbit(x)      (__builtin_signbit(x) != 0)
 #else  /* __GNUC__ >= 4 */
 #define isnan(x)        __extension__( \
                         { __typeof(x) __x_n = (x); \
                         __builtin_isunordered(__x_n, __x_n); })
 #define isinf(x)        __extension__( \