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Diffstat (limited to 'drivers/staging/brcm80211/util/qmath.c')
| -rw-r--r-- | drivers/staging/brcm80211/util/qmath.c | 681 |
1 files changed, 0 insertions, 681 deletions
diff --git a/drivers/staging/brcm80211/util/qmath.c b/drivers/staging/brcm80211/util/qmath.c deleted file mode 100644 index 40c9929de2bb..000000000000 --- a/drivers/staging/brcm80211/util/qmath.c +++ /dev/null @@ -1,681 +0,0 @@ -/* - * Copyright (c) 2010 Broadcom Corporation - * - * Permission to use, copy, modify, and/or distribute this software for any - * purpose with or without fee is hereby granted, provided that the above - * copyright notice and this permission notice appear in all copies. - * - * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES - * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF - * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY - * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES - * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION - * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN - * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. - */ - -#include <linux/types.h> -#include "qmath.h" - -/* -Description: This function saturate input 32 bit number into a 16 bit number. -If input number is greater than 0x7fff then output is saturated to 0x7fff. -else if input number is less than 0xffff8000 then output is saturated to 0xffff8000 -else output is same as input. -*/ -s16 qm_sat32(s32 op) -{ - s16 result; - if (op > (s32) 0x7fff) { - result = 0x7fff; - } else if (op < (s32) 0xffff8000) { - result = (s16) (0x8000); - } else { - result = (s16) op; - } - return result; -} - -/* -Description: This function multiply two input 16 bit numbers and return the 32 bit result. -This multiplication is similar to compiler multiplication. This operation is defined if -16 bit multiplication on the processor platform is cheaper than 32 bit multiplication (as -the most of qmath functions can be replaced with processor intrinsic instructions). -*/ -s32 qm_mul321616(s16 op1, s16 op2) -{ - return (s32) (op1) * (s32) (op2); -} - -/* -Description: This function make 16 bit multiplication and return the result in 16 bits. -To fit the result into 16 bits the 32 bit multiplication result is right -shifted by 16 bits. -*/ -s16 qm_mul16(s16 op1, s16 op2) -{ - s32 result; - result = ((s32) (op1) * (s32) (op2)); - return (s16) (result >> 16); -} - -/* -Description: This function multiply two 16 bit numbers and return the result in 32 bits. -This function remove the extra sign bit created by the multiplication by leftshifting the -32 bit multiplication result by 1 bit before returning the result. So the output is -twice that of compiler multiplication. (i.e. qm_muls321616(2,3)=12). -When both input 16 bit numbers are 0x8000, then the result is saturated to 0x7fffffff. -*/ -s32 qm_muls321616(s16 op1, s16 op2) -{ - s32 result; - if (op1 == (s16) (0x8000) && op2 == (s16) (0x8000)) { - result = 0x7fffffff; - } else { - result = ((s32) (op1) * (s32) (op2)); - result = result << 1; - } - return result; -} - -/* -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) -{ - return (u16) (((u32) op1 * (u32) op2) >> 16); -} - -/* -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) -{ - s32 result; - if (op1 == (s16) 0x8000 && op2 == (s16) 0x8000) { - result = 0x7fffffff; - } else { - result = ((s32) (op1) * (s32) (op2)); - } - return (s16) (result >> 15); -} - -/* -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) -{ - s32 result; - result = op1 + op2; - if (op1 < 0 && op2 < 0 && result > 0) { - result = 0x80000000; - } else if (op1 > 0 && op2 > 0 && result < 0) { - result = 0x7fffffff; - } - return result; -} - -/* -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) -{ - s16 result; - s32 temp = (s32) op1 + (s32) op2; - if (temp > (s32) 0x7fff) { - result = (s16) 0x7fff; - } else if (temp < (s32) 0xffff8000) { - result = (s16) 0xffff8000; - } else { - result = (s16) temp; - } - return result; -} - -/* -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) -{ - s16 result; - s32 temp = (s32) op1 - (s32) op2; - if (temp > (s32) 0x7fff) { - result = (s16) 0x7fff; - } else if (temp < (s32) 0xffff8000) { - result = (s16) 0xffff8000; - } else { - result = (s16) temp; - } - return result; -} - -/* -Description: This function make 32 bit subtraction and return the 32bit result. -If the result overflow 32 bits, the output will be saturated to 32bits. -*/ -s32 qm_sub32(s32 op1, s32 op2) -{ - s32 result; - result = op1 - op2; - if (op1 >= 0 && op2 < 0 && result < 0) { - result = 0x7fffffff; - } else if (op1 < 0 && op2 > 0 && result > 0) { - result = 0x80000000; - } - return result; -} - -/* -Description: This function multiply input 16 bit numbers and accumulate the result -into the input 32 bit number and return the 32 bit accumulated result. -If the accumulation result in overflow, then the output will be saturated. -*/ -s32 qm_mac321616(s32 acc, s16 op1, s16 op2) -{ - s32 result; - result = qm_add32(acc, qm_mul321616(op1, op2)); - return result; -} - -/* -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) -{ - int i; - s32 result; - result = op; - if (shift > 31) - shift = 31; - else if (shift < -31) - shift = -31; - if (shift >= 0) { - for (i = 0; i < shift; i++) { - result = qm_add32(result, result); - } - } else { - result = result >> (-shift); - } - return result; -} - -/* -Description: This function make a 32 bit right shift when shift is +ve. -This function make a 32 bit saturated left shift when shift is -ve. This function -return the result of the shift operation. -*/ -s32 qm_shr32(s32 op, int shift) -{ - return qm_shl32(op, -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) -{ - int i; - s16 result; - result = op; - if (shift > 15) - shift = 15; - else if (shift < -15) - shift = -15; - if (shift > 0) { - for (i = 0; i < shift; i++) { - result = qm_add16(result, result); - } - } else { - result = result >> (-shift); - } - return result; -} - -/* -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) -{ - return qm_shl16(op, -shift); -} - -/* -Description: This function return the number of redundant sign bits in a 16 bit number. -Example: qm_norm16(0x0080) = 7. -*/ -s16 qm_norm16(s16 op) -{ - u16 u16extraSignBits; - if (op == 0) { - return 15; - } else { - u16extraSignBits = 0; - while ((op >> 15) == (op >> 14)) { - u16extraSignBits++; - op = op << 1; - } - } - return u16extraSignBits; -} - -/* -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) -{ - u16 u16extraSignBits; - if (op == 0) { - return 31; - } else { - u16extraSignBits = 0; - while ((op >> 31) == (op >> 30)) { - u16extraSignBits++; - op = op << 1; - } - } - return u16extraSignBits; -} - -/* -Description: This function divide two 16 bit unsigned numbers. -The numerator should be less than denominator. So the quotient is always less than 1. -This function return the quotient in q.15 format. -*/ -s16 qm_div_s(s16 num, s16 denom) -{ - s16 var_out; - s16 iteration; - s32 L_num; - s32 L_denom; - L_num = (num) << 15; - L_denom = (denom) << 15; - for (iteration = 0; iteration < 15; iteration++) { - L_num <<= 1; - if (L_num >= L_denom) { - L_num = qm_sub32(L_num, L_denom); - L_num = qm_add32(L_num, 1); - } - } - var_out = (s16) (L_num & 0x7fff); - return var_out; -} - -/* -Description: This function compute the absolute value of a 16 bit number. -*/ -s16 qm_abs16(s16 op) -{ - if (op < 0) { - if (op == (s16) 0xffff8000) { - return 0x7fff; - } else { - return -op; - } - } else { - return op; - } -} - -/* -Description: This function divide two 16 bit numbers. -The quotient is returned through return value. -The qformat of the quotient is returned through the pointer (qQuotient) passed -to this function. The qformat of quotient is adjusted appropriately such that -the quotient occupies all 16 bits. -*/ -s16 qm_div16(s16 num, s16 denom, s16 *qQuotient) -{ - s16 sign; - s16 nNum, nDenom; - sign = num ^ denom; - num = qm_abs16(num); - denom = qm_abs16(denom); - nNum = qm_norm16(num); - nDenom = qm_norm16(denom); - num = qm_shl16(num, nNum - 1); - denom = qm_shl16(denom, nDenom); - *qQuotient = nNum - 1 - nDenom + 15; - if (sign >= 0) { - return qm_div_s(num, denom); - } else { - return -qm_div_s(num, denom); - } -} - -/* -Description: This function compute absolute value of a 32 bit number. -*/ -s32 qm_abs32(s32 op) -{ - if (op < 0) { - if (op == (s32) 0x80000000) { - return 0x7fffffff; - } else { - return -op; - } - } else { - return op; - } -} - -/* -Description: This function divide two 32 bit numbers. The division is performed -by considering only important 16 bits in 32 bit numbers. -The quotient is returned through return value. -The qformat of the quotient is returned through the pointer (qquotient) passed -to this function. The qformat of quotient is adjusted appropriately such that -the quotient occupies all 16 bits. -*/ -s16 qm_div163232(s32 num, s32 denom, s16 *qquotient) -{ - s32 sign; - s16 nNum, nDenom; - sign = num ^ denom; - num = qm_abs32(num); - denom = qm_abs32(denom); - nNum = qm_norm32(num); - nDenom = qm_norm32(denom); - num = qm_shl32(num, nNum - 1); - denom = qm_shl32(denom, nDenom); - *qquotient = nNum - 1 - nDenom + 15; - if (sign >= 0) { - return qm_div_s((s16) (num >> 16), (s16) (denom >> 16)); - } else { - return -qm_div_s((s16) (num >> 16), (s16) (denom >> 16)); - } -} - -/* -Description: This function multiply a 32 bit number with a 16 bit number. -The multiplicaton result is right shifted by 16 bits to fit the result -into 32 bit output. -*/ -s32 qm_mul323216(s32 op1, s16 op2) -{ - s16 hi; - u16 lo; - s32 result; - hi = op1 >> 16; - lo = (s16) (op1 & 0xffff); - result = qm_mul321616(hi, op2); - result = result + (qm_mulsu321616(op2, lo) >> 16); - return result; -} - -/* -Description: This function multiply signed 16 bit number with unsigned 16 bit number and return -the result in 32 bits. -*/ -s32 qm_mulsu321616(s16 op1, u16 op2) -{ - return (s32) (op1) * op2; -} - -/* -Description: This function multiply 32 bit number with 16 bit number. The multiplication result is -right shifted by 15 bits to fit the result into 32 bits. Right shifting by only 15 bits instead of -16 bits is done to remove the extra sign bit formed by multiplication from the return value. -When the input numbers are 0x80000000, 0x8000 the return value is saturated to 0x7fffffff. -*/ -s32 qm_muls323216(s32 op1, s16 op2) -{ - s16 hi; - u16 lo; - s32 result; - hi = op1 >> 16; - lo = (s16) (op1 & 0xffff); - result = qm_muls321616(hi, op2); - result = qm_add32(result, (qm_mulsu321616(op2, lo) >> 15)); - return result; -} - -/* -Description: This function multiply two 32 bit numbers. The multiplication result is right -shifted by 32 bits to fit the multiplication result into 32 bits. The right shifted -multiplication result is returned as output. -*/ -s32 qm_mul32(s32 a, s32 b) -{ - s16 hi1, hi2; - u16 lo1, lo2; - s32 result; - hi1 = a >> 16; - hi2 = b >> 16; - lo1 = (u16) (a & 0xffff); - lo2 = (u16) (b & 0xffff); - result = qm_mul321616(hi1, hi2); - result = result + (qm_mulsu321616(hi1, lo2) >> 16); - result = result + (qm_mulsu321616(hi2, lo1) >> 16); - return result; -} - -/* -Description: This function multiply two 32 bit numbers. The multiplication result is -right shifted by 31 bits to fit the multiplication result into 32 bits. The right -shifted multiplication result is returned as output. Right shifting by only 31 bits -instead of 32 bits is done to remove the extra sign bit formed by multiplication. -When the input numbers are 0x80000000, 0x80000000 the return value is saturated to -0x7fffffff. -*/ -s32 qm_muls32(s32 a, s32 b) -{ - s16 hi1, hi2; - u16 lo1, lo2; - s32 result; - hi1 = a >> 16; - hi2 = b >> 16; - lo1 = (u16) (a & 0xffff); - lo2 = (u16) (b & 0xffff); - result = qm_muls321616(hi1, hi2); - result = qm_add32(result, (qm_mulsu321616(hi1, lo2) >> 15)); - result = qm_add32(result, (qm_mulsu321616(hi2, lo1) >> 15)); - result = qm_add32(result, (qm_mulu16(lo1, lo2) >> 15)); - return result; -} - -/* This table is log2(1+(i/32)) where i=[0:1:31], in q.15 format */ -static const s16 log_table[] = { - 0, - 1455, - 2866, - 4236, - 5568, - 6863, - 8124, - 9352, - 10549, - 11716, - 12855, - 13968, - 15055, - 16117, - 17156, - 18173, - 19168, - 20143, - 21098, - 22034, - 22952, - 23852, - 24736, - 25604, - 26455, - 27292, - 28114, - 28922, - 29717, - 30498, - 31267, - 32024 -}; - -#define LOG_TABLE_SIZE 32 /* log_table size */ -#define LOG2_LOG_TABLE_SIZE 5 /* log2(log_table size) */ -#define Q_LOG_TABLE 15 /* qformat of log_table */ -#define LOG10_2 19728 /* log10(2) in q.16 */ - -/* -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) -{ - s16 s16norm, s16tableIndex, s16errorApproximation; - u16 u16offset; - s32 s32log; - - /* Logerithm of negative values is undefined. - * assert N is greater than 0. - */ - /* ASSERT(N > 0); */ - - /* normalize the N. */ - s16norm = qm_norm32(N); - N = N << s16norm; - - /* The qformat of N after normalization. - * -30 is added to treat the no as between 1.0 to 2.0 - * i.e. after adding the -30 to the qformat the decimal point will be - * just rigtht of the MSB. (i.e. after sign bit and 1st MSB). i.e. - * at the right side of 30th bit. - */ - qN = qN + s16norm - 30; - - /* take the table index as the LOG2_OF_LOG_TABLE_SIZE bits right of the MSB */ - s16tableIndex = (s16) (N >> (32 - (2 + LOG2_LOG_TABLE_SIZE))); - - /* remove the MSB. the MSB is always 1 after normalization. */ - s16tableIndex = - s16tableIndex & (s16) ((1 << LOG2_LOG_TABLE_SIZE) - 1); - - /* remove the (1+LOG2_OF_LOG_TABLE_SIZE) MSBs in the N. */ - N = N & ((1 << (32 - (2 + LOG2_LOG_TABLE_SIZE))) - 1); - - /* take the offset as the 16 MSBS after table index. - */ - u16offset = (u16) (N >> (32 - (2 + LOG2_LOG_TABLE_SIZE + 16))); - - /* look the log value in the table. */ - s32log = log_table[s16tableIndex]; /* q.15 format */ - - /* interpolate using the offset. */ - s16errorApproximation = (s16) qm_mulu16(u16offset, (u16) (log_table[s16tableIndex + 1] - log_table[s16tableIndex])); /* q.15 */ - - s32log = qm_add16((s16) s32log, s16errorApproximation); /* q.15 format */ - - /* adjust for the qformat of the N as - * log2(mag * 2^x) = log2(mag) + x - */ - s32log = qm_add32(s32log, ((s32) -qN) << 15); /* q.15 format */ - - /* normalize the result. */ - s16norm = qm_norm32(s32log); - - /* bring all the important bits into lower 16 bits */ - s32log = qm_shl32(s32log, s16norm - 16); /* q.15+s16norm-16 format */ - - /* compute the log10(N) by multiplying log2(N) with log10(2). - * as log10(mag * 2^x) = log2(mag * 2^x) * log10(2) - * log10N in q.15+s16norm-16+1 (LOG10_2 is in q.16) - */ - *log10N = qm_muls16((s16) s32log, (s16) LOG10_2); - - /* write the q format of the result. */ - *qLog10N = 15 + s16norm - 16 + 1; - - return; -} - -/* -Description: -This routine compute 1/N. -This routine reformates the given no N as N * 2^qN where N is in between 0.5 and 1.0 -in q.15 format in 16 bits. So the problem now boils down to finding the inverse of a -q.15 no in 16 bits which is in the range of 0.5 to 1.0. The output is always between -2.0 to 1. So the output is 2.0 to 1.0 in q.30 format. Once the final output format is found -by taking the qN into account. Inverse is found with newton rapson method. Initially -inverse (x) is guessed as 1/0.75 (with appropriate sign). The new guess is calculated -using the formula x' = 2*x - N*x*x. After 4 or 5 iterations the inverse is very close to -inverse of N. -Inputs: -N - number to which 1/N has to be found. -qn - q format of N. -sqrtN - address where 1/N has to be written. -qsqrtN - address where q format of 1/N has to be written. -*/ -#define qx 29 -void qm_1byN(s32 N, s16 qN, s32 *result, s16 *qResult) -{ - s16 normN; - s32 s32firstTerm, s32secondTerm, x; - int i; - - normN = qm_norm32(N); - - /* limit N to least significant 16 bits. 15th bit is the sign bit. */ - N = qm_shl32(N, normN - 16); - qN = qN + normN - 16 - 15; - /* -15 is added to treat N as 16 bit q.15 number in the range from 0.5 to 1 */ - - /* Take the initial guess as 1/0.75 in qx format with appropriate sign. */ - if (N >= 0) { - x = (s32) ((1 / 0.75) * (1 << qx)); - /* input no is in the range 0.5 to 1. So 1/0.75 is taken as initial guess. */ - } else { - x = (s32) ((1 / -0.75) * (1 << qx)); - /* input no is in the range -0.5 to -1. So 1/-0.75 is taken as initial guess. */ - } - - /* iterate the equation x = 2*x - N*x*x for 4 times. */ - for (i = 0; i < 4; i++) { - s32firstTerm = qm_shl32(x, 1); /* s32firstTerm = 2*x in q.29 */ - s32secondTerm = - qm_muls321616((s16) (s32firstTerm >> 16), - (s16) (s32firstTerm >> 16)); - /* s32secondTerm = x*x in q.(29+1-16)*2+1 */ - s32secondTerm = - qm_muls321616((s16) (s32secondTerm >> 16), (s16) N); - /* s32secondTerm = N*x*x in q.((29+1-16)*2+1)-16+15+1 i.e. in q.29 */ - x = qm_sub32(s32firstTerm, s32secondTerm); - /* can be added directly as both are in q.29 */ - } - - /* Bring the x to q.30 format. */ - *result = qm_shl32(x, 1); - /* giving the output in q.30 format for q.15 input in 16 bits. */ - - /* compute the final q format of the result. */ - *qResult = -qN + 30; /* adjusting the q format of actual output */ - - return; -} - -#undef qx |