// SPDX-License-Identifier: ISC /* * Copyright (c) 2010 Broadcom Corporation */ #include "phy_qmath.h" /* * Description: This function make 16 bit unsigned multiplication. * To fit the output into 16 bits the 32 bit multiplication result is right * shifted by 16 bits. */ u16 qm_mulu16(u16 op1, u16 op2) { … } /* * Description: This function make 16 bit multiplication and return the result * in 16 bits. To fit the multiplication result into 16 bits the multiplication * result is right shifted by 15 bits. Right shifting 15 bits instead of 16 bits * is done to remove the extra sign bit formed due to the multiplication. * When both the 16bit inputs are 0x8000 then the output is saturated to * 0x7fffffff. */ s16 qm_muls16(s16 op1, s16 op2) { … } /* * Description: This function add two 32 bit numbers and return the 32bit * result. If the result overflow 32 bits, the output will be saturated to * 32bits. */ s32 qm_add32(s32 op1, s32 op2) { … } /* * Description: This function add two 16 bit numbers and return the 16bit * result. If the result overflow 16 bits, the output will be saturated to * 16bits. */ s16 qm_add16(s16 op1, s16 op2) { … } /* * Description: This function make 16 bit subtraction and return the 16bit * result. If the result overflow 16 bits, the output will be saturated to * 16bits. */ s16 qm_sub16(s16 op1, s16 op2) { … } /* * Description: This function make a 32 bit saturated left shift when the * specified shift is +ve. This function will make a 32 bit right shift when * the specified shift is -ve. This function return the result after shifting * operation. */ s32 qm_shl32(s32 op, int shift) { … } /* * Description: This function make a 16 bit saturated left shift when the * specified shift is +ve. This function will make a 16 bit right shift when * the specified shift is -ve. This function return the result after shifting * operation. */ s16 qm_shl16(s16 op, int shift) { … } /* * Description: This function make a 16 bit right shift when shift is +ve. * This function make a 16 bit saturated left shift when shift is -ve. This * function return the result of the shift operation. */ s16 qm_shr16(s16 op, int shift) { … } /* * Description: This function return the number of redundant sign bits in a * 32 bit number. Example: qm_norm32(0x00000080) = 23 */ s16 qm_norm32(s32 op) { … } /* This table is log2(1+(i/32)) where i=[0:1:32], in q.15 format */ static const s16 log_table[] = …; #define LOG_TABLE_SIZE … #define LOG2_LOG_TABLE_SIZE … #define Q_LOG_TABLE … #define LOG10_2 … /* * Description: * This routine takes the input number N and its q format qN and compute * the log10(N). This routine first normalizes the input no N. Then N is in * mag*(2^x) format. mag is any number in the range 2^30-(2^31 - 1). * Then log2(mag * 2^x) = log2(mag) + x is computed. From that * log10(mag * 2^x) = log2(mag * 2^x) * log10(2) is computed. * This routine looks the log2 value in the table considering * LOG2_LOG_TABLE_SIZE+1 MSBs. As the MSB is always 1, only next * LOG2_OF_LOG_TABLE_SIZE MSBs are used for table lookup. Next 16 MSBs are used * for interpolation. * Inputs: * N - number to which log10 has to be found. * qN - q format of N * log10N - address where log10(N) will be written. * qLog10N - address where log10N qformat will be written. * Note/Problem: * For accurate results input should be in normalized or near normalized form. */ void qm_log10(s32 N, s16 qN, s16 *log10N, s16 *qLog10N) { … }
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