1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License, Version 1.0 only 6 * (the "License"). You may not use this file except in compliance 7 * with the License. 8 * 9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10 * or http://www.opensolaris.org/os/licensing. 11 * See the License for the specific language governing permissions 12 * and limitations under the License. 13 * 14 * When distributing Covered Code, include this CDDL HEADER in each 15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16 * If applicable, add the following below this CDDL HEADER, with the 17 * fields enclosed by brackets "[]" replaced with your own identifying 18 * information: Portions Copyright [yyyy] [name of copyright owner] 19 * 20 * CDDL HEADER END 21 */ 22 /* 23 * Copyright 1988 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 #pragma ident "%Z%%M% %I% %E% SMI" 28 29 #include "base_conversion.h" 30 31 /* Fundamental utilities for base conversion that should be recoded as assembly language subprograms or as inline expansion templates. */ 32 33 /* Converts t < 10000 into four ascii digits at *pc. */ 34 void 35 _fourdigitsquick(short unsigned t, char *d) 36 { 37 short i; 38 39 i = 3; 40 do { 41 d[i] = '0' + t % 10; 42 t = t / 10; 43 } 44 while (--i != -1); 45 } 46 47 void 48 _multiply_base_two_vector(short unsigned n, _BIG_FLOAT_DIGIT *px, 49 short unsigned *py, _BIG_FLOAT_DIGIT product[3]) 50 { 51 /* 52 * Given xi and yi, base 2**16 vectors of length n, computes dot 53 * product 54 * 55 * sum (i=0,n-1) of x[i]*y[n-1-i] 56 * 57 * Product may fill as many as three short-unsigned buckets. Product[0] 58 * is least significant, product[2] most. 59 */ 60 61 unsigned long acc, p; 62 short unsigned carry; 63 int i; 64 65 acc = 0; 66 carry = 0; 67 for (i = 0; i < n; i++) { 68 p=_umac(px[i],py[n - 1 - i],acc); 69 if (p < acc) 70 carry++; 71 acc = p; 72 } 73 product[0] = (_BIG_FLOAT_DIGIT) (acc & 0xffff); 74 product[1] = (_BIG_FLOAT_DIGIT) (acc >> 16); 75 product[2] = (_BIG_FLOAT_DIGIT) (carry); 76 } 77 78 void 79 _multiply_base_ten_vector(short unsigned n, _BIG_FLOAT_DIGIT *px, 80 short unsigned *py, _BIG_FLOAT_DIGIT product[3]) 81 { 82 /* 83 * Given xi and yi, base 10**4 vectors of length n, computes dot 84 * product 85 * 86 * sum (i=0,n-1) of x[i]*y[n-1-i] 87 * 88 * Product may fill as many as three short-unsigned buckets. Product[0] 89 * is least significant, product[2] most. 90 */ 91 92 #define ABASE 3000000000U /* Base of accumulator. */ 93 94 unsigned long acc; 95 short unsigned carry; 96 int i; 97 98 acc = 0; 99 carry = 0; 100 for (i = 0; i < n; i++) { 101 acc=_umac(px[i],py[n - 1 - i],acc); 102 if (acc >= (unsigned long) ABASE) { 103 carry++; 104 acc -= ABASE; 105 } 106 } 107 /* 108 NOTE: because 109 acc * <= ABASE-1, 110 acc/10000 <= 299999 111 which would overflow a short unsigned 112 */ 113 product[0] = (_BIG_FLOAT_DIGIT) (acc % 10000); 114 acc /= 10000; 115 product[1] = (_BIG_FLOAT_DIGIT) (acc % 10000); 116 acc /= 10000; 117 product[2] = (_BIG_FLOAT_DIGIT) (acc + (ABASE / 100000000) * carry); 118 } 119