1 // SPDX-License-Identifier: BSD-3-Clause
20  * +------------------+-----------------+--------+--------+
22  * +----+-----+-------+----+----+-------+--------+--------+
24  * +----+-----+-------+----+----+-------+--------+--------+
26  * +------------------+-----------------+--------+--------+
63 	uint16_t v;  in sqrt_int16()  local
87 	 * byte of V, and shift them out to the left. Continue with the  in sqrt_int16()
88 	 * shifted V for as many bytes as it has.  in sqrt_int16()
90 	 * one-based index.  in sqrt_int16()
91 	 * Index into the number-of-leading-zeros lookup table.  This lookup  in sqrt_int16()
97 	/*  Left-shift out all the leading zeros in the high byte. */  in sqrt_int16()
98 	v = u << shift_factor;  in sqrt_int16()
99 	/*  Update the total number of left-shifts */  in sqrt_int16()
102 	 * byte of V, and shift them out to the left. Continue with the  in sqrt_int16()
103 	 * shifted V for as many bytes as it has.  in sqrt_int16()
105 	 * one-based index.  in sqrt_int16()
106 	 * Index into the number-of-leading-zeros lookup table.  This lookup  in sqrt_int16()
110 	shift_factor = iv[v >> 8];  in sqrt_int16()
111 	/*  Left-shift out all the leading zeros in the high byte.  in sqrt_int16()
112 	 *  Update the total number of left-shifts  in sqrt_int16()
115 	/*  The input has been left-shifted so the most-significant-bit is a 1.  in sqrt_int16()
118 	 *  Let Q = int(u).  Then u = Q*2^(-u_fraction_length),  in sqrt_int16()
119 	 *  and x = Q*2^num_left_shifts * 2^(1-word_length).  Therefore,  in sqrt_int16()
122 	xfi_tmp = (3 - num_left_shifts) & 1;  in sqrt_int16()
123 	v = (v << shift_factor) >> xfi_tmp;  in sqrt_int16()
126 	slice_temp = SQRT_WRAP_SCHAR_BITS & (v >> 8);  in sqrt_int16()
131 	a_i = iv1[((v >> 8) - 63) - 1];  in sqrt_int16()
133 	l1_i = iv1[SQRT_WRAP_SCHAR_BITS & ((slice_temp + 194) - 1)];  in sqrt_int16()
134 	l2_i = iv1[(slice_temp - 63) - 1];  in sqrt_int16()
135 	y = a_i + (v & SQRT_WRAP_SCHAR_BITS) * (l1_i - l2_i);  in sqrt_int16()
136 	xfi = (((xfi_tmp - num_left_shifts) + 3) >> 1);  in sqrt_int16()
137 	shift_factor = (((xfi_tmp - num_left_shifts) + 3) >> 1);  in sqrt_int16()
142 			y >>= -sign * xfi;  in sqrt_int16()