optimize signbit macro

diff --git a/include/math.h b/include/math.h
index 8791bba807588fd93bf3279aded7bbdcebffedb3..ff62cb7cf35b70b6da677a76777d51c568dd744b 100644 (file)
--- a/include/math.h
+++ b/include/math.h
@@ -77,8 +77,8 @@ int __signbitf(float);
 int __signbitl(long double);
 
 #define signbit(x) ( \
-       sizeof(x) == sizeof(float) ? !!(__FLOAT_BITS(x) & 0x80000000) : \
-       sizeof(x) == sizeof(double) ? !!(__DOUBLE_BITS(x) & (__uint64_t)1<<63) : \
+       sizeof(x) == sizeof(float) ? (int)(__FLOAT_BITS(x)>>31) : \
+       sizeof(x) == sizeof(double) ? (int)(__DOUBLE_BITS(x)>>63) : \
        __signbitl(x) )
 
 #define isunordered(x,y) (isnan((x)) ? ((void)(y),1) : isnan((y)))