[T106][ZXW-22]7520V3SCV2.01.01.02P42U09_VEC_V0.8_AP_VEC origin source commit
Change-Id: Ic6e05d89ecd62fc34f82b23dcf306c93764aec4b
diff --git a/ap/build/uClibc/libm/s_logb.c b/ap/build/uClibc/libm/s_logb.c
new file mode 100644
index 0000000..9016b97
--- /dev/null
+++ b/ap/build/uClibc/libm/s_logb.c
@@ -0,0 +1,33 @@
+/*
+ * ====================================================
+ * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
+ *
+ * Developed at SunPro, a Sun Microsystems, Inc. business.
+ * Permission to use, copy, modify, and distribute this
+ * software is freely granted, provided that this notice
+ * is preserved.
+ * ====================================================
+ */
+
+/*
+ * double logb(x)
+ * IEEE 754 logb. Included to pass IEEE test suite. Not recommend.
+ * Use ilogb instead.
+ */
+
+#include "math.h"
+#include "math_private.h"
+
+double logb(double x)
+{
+ int32_t lx,ix;
+ EXTRACT_WORDS(ix,lx,x);
+ ix &= 0x7fffffff; /* high |x| */
+ if((ix|lx)==0) return -1.0/fabs(x);
+ if(ix>=0x7ff00000) return x*x;
+ if((ix>>=20)==0) /* IEEE 754 logb */
+ return -1022.0;
+ else
+ return (double) (ix-1023);
+}
+libm_hidden_def(logb)