+++ /dev/null
-/*
- * Copyright 1992 by Jutta Degener and Carsten Bormann, Technische
- * Universitaet Berlin. See the accompanying file "COPYRIGHT" for
- * details. THERE IS ABSOLUTELY NO WARRANTY FOR THIS SOFTWARE.
- */
-
-/*
- * See private.h for the more commonly used macro versions.
- */
-
-#include <stdio.h>
-#include <assert.h>
-
-#include "gsm610_priv.h"
-
-#define saturate(x) \
- ((x) < MIN_WORD ? MIN_WORD : (x) > MAX_WORD ? MAX_WORD: (x))
-
-word gsm_add ( word a, word b)
-{
- longword sum = (longword)a + (longword)b;
- return saturate(sum);
-}
-
-word gsm_sub ( word a, word b)
-{
- longword diff = (longword)a - (longword)b;
- return saturate(diff);
-}
-
-word gsm_mult ( word a, word b)
-{
- if (a == MIN_WORD && b == MIN_WORD)
- return MAX_WORD;
-
- return SASR_L( (longword)a * (longword)b, 15 );
-}
-
-word gsm_mult_r ( word a, word b)
-{
- if (b == MIN_WORD && a == MIN_WORD) return MAX_WORD;
- else {
- longword prod = (longword)a * (longword)b + 16384;
- prod >>= 15;
- return prod & 0xFFFF;
- }
-}
-
-word gsm_abs (word a)
-{
- return a < 0 ? (a == MIN_WORD ? MAX_WORD : -a) : a;
-}
-
-longword gsm_L_mult (word a, word b)
-{
- assert( a != MIN_WORD || b != MIN_WORD );
- return ((longword)a * (longword)b) << 1;
-}
-
-longword gsm_L_add ( longword a, longword b)
-{
- if (a < 0) {
- if (b >= 0) return a + b;
- else {
- ulongword A = (ulongword)-(a + 1) + (ulongword)-(b + 1);
- return A >= MAX_LONGWORD ? MIN_LONGWORD :-(longword)A-2;
- }
- }
- else if (b <= 0) return a + b;
- else {
- ulongword A = (ulongword)a + (ulongword)b;
- return A > MAX_LONGWORD ? MAX_LONGWORD : A;
- }
-}
-
-longword gsm_L_sub ( longword a, longword b)
-{
- if (a >= 0) {
- if (b >= 0) return a - b;
- else {
- /* a>=0, b<0 */
-
- ulongword A = (ulongword)a + -(b + 1);
- return A >= MAX_LONGWORD ? MAX_LONGWORD : (A + 1);
- }
- }
- else if (b <= 0) return a - b;
- else {
- /* a<0, b>0 */
-
- ulongword A = (ulongword)-(a + 1) + b;
- return A >= MAX_LONGWORD ? MIN_LONGWORD : -(longword)A - 1;
- }
-}
-
-static unsigned char const bitoff[ 256 ] = {
- 8, 7, 6, 6, 5, 5, 5, 5, 4, 4, 4, 4, 4, 4, 4, 4,
- 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
- 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
- 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
- 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
- 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
- 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
- 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
- 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
- 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
- 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
- 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
- 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
- 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
- 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
- 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
-};
-
-word gsm_norm (longword a )
-/*
- * the number of left shifts needed to normalize the 32 bit
- * variable L_var1 for positive values on the interval
- *
- * with minimum of
- * minimum of 1073741824 (01000000000000000000000000000000) and
- * maximum of 2147483647 (01111111111111111111111111111111)
- *
- *
- * and for negative values on the interval with
- * minimum of -2147483648 (-10000000000000000000000000000000) and
- * maximum of -1073741824 ( -1000000000000000000000000000000).
- *
- * in order to normalize the result, the following
- * operation must be done: L_norm_var1 = L_var1 << norm( L_var1 );
- *
- * (That's 'ffs', only from the left, not the right..)
- */
-{
- assert(a != 0);
-
- if (a < 0) {
- if (a <= -1073741824) return 0;
- a = ~a;
- }
-
- return a & 0xffff0000
- ? ( a & 0xff000000
- ? -1 + bitoff[ 0xFF & (a >> 24) ]
- : 7 + bitoff[ 0xFF & (a >> 16) ] )
- : ( a & 0xff00
- ? 15 + bitoff[ 0xFF & (a >> 8) ]
- : 23 + bitoff[ 0xFF & a ] );
-}
-
-longword gsm_L_asl (longword a, int n)
-{
- if (n >= 32) return 0;
- if (n <= -32) return -(a < 0);
- if (n < 0) return gsm_L_asr(a, -n);
- return a << n;
-}
-
-word gsm_asr (word a, int n)
-{
- if (n >= 16) return -(a < 0);
- if (n <= -16) return 0;
- if (n < 0) return a << -n;
-
- return SASR_W (a, (word) n);
-}
-
-word gsm_asl (word a, int n)
-{
- if (n >= 16) return 0;
- if (n <= -16) return -(a < 0);
- if (n < 0) return gsm_asr(a, -n);
- return a << n;
-}
-
-longword gsm_L_asr (longword a, int n)
-{
- if (n >= 32) return -(a < 0);
- if (n <= -32) return 0;
- if (n < 0) return a << -n;
-
- return SASR_L (a, (word) n);
-}
-
-/*
-** word gsm_asr (word a, int n)
-** {
-** if (n >= 16) return -(a < 0);
-** if (n <= -16) return 0;
-** if (n < 0) return a << -n;
-**
-** # ifdef SASR_W
-** return a >> n;
-** # else
-** if (a >= 0) return a >> n;
-** else return -(word)( -(uword)a >> n );
-** # endif
-** }
-**
-*/
-/*
- * (From p. 46, end of section 4.2.5)
- *
- * NOTE: The following lines gives [sic] one correct implementation
- * of the div(num, denum) arithmetic operation. Compute div
- * which is the integer division of num by denum: with denum
- * >= num > 0
- */
-
-word gsm_div (word num, word denum)
-{
- longword L_num = num;
- longword L_denum = denum;
- word div = 0;
- int k = 15;
-
- /* The parameter num sometimes becomes zero.
- * Although this is explicitly guarded against in 4.2.5,
- * we assume that the result should then be zero as well.
- */
-
- /* assert(num != 0); */
-
- assert(num >= 0 && denum >= num);
- if (num == 0)
- return 0;
-
- while (k--) {
- div <<= 1;
- L_num <<= 1;
-
- if (L_num >= L_denum) {
- L_num -= L_denum;
- div++;
- }
- }
-
- return div;
-}
-
projects / Faustine.git / blobdiff