[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_ilogb.c b/ap/build/uClibc/libm/s_ilogb.c
new file mode 100644
index 0000000..259ae7b
--- /dev/null
+++ b/ap/build/uClibc/libm/s_ilogb.c
@@ -0,0 +1,57 @@
+/*
+ * ====================================================
+ * 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.
+ * ====================================================
+ */
+
+/* ilogb(double x)
+ * 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"
+#include "math_private.h"
+
+int ilogb(double x)
+{
+ int32_t hx,lx,ix;
+
+ GET_HIGH_WORD(hx, x);
+ hx &= 0x7fffffff;
+
+ 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);
+ }
+ /* each leading zero mantissa bit makes exponent smaller */
+ for (; lx > 0; lx <<= 1)
+ ix--;
+ return ix;
+ }
+
+ 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)