/js/lib/Socket.IO-node/support/expresso/deps/jscoverage/js/jslong.cpp
http://github.com/onedayitwillmake/RealtimeMultiplayerNodeJs · C++ · 264 lines · 149 code · 33 blank · 82 comment · 45 complexity · 30322b36e9f7d921d1dabb88fc0b4567 MD5 · raw file
- /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
- /* ***** BEGIN LICENSE BLOCK *****
- * Version: MPL 1.1/GPL 2.0/LGPL 2.1
- *
- * The contents of this file are subject to the Mozilla Public License Version
- * 1.1 (the "License"); you may not use this file except in compliance with
- * the License. You may obtain a copy of the License at
- * http://www.mozilla.org/MPL/
- *
- * Software distributed under the License is distributed on an "AS IS" basis,
- * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
- * for the specific language governing rights and limitations under the
- * License.
- *
- * The Original Code is Mozilla Communicator client code, released
- * March 31, 1998.
- *
- * The Initial Developer of the Original Code is
- * Netscape Communications Corporation.
- * Portions created by the Initial Developer are Copyright (C) 1998
- * the Initial Developer. All Rights Reserved.
- *
- * Contributor(s):
- *
- * Alternatively, the contents of this file may be used under the terms of
- * either of the GNU General Public License Version 2 or later (the "GPL"),
- * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
- * in which case the provisions of the GPL or the LGPL are applicable instead
- * of those above. If you wish to allow use of your version of this file only
- * under the terms of either the GPL or the LGPL, and not to allow others to
- * use your version of this file under the terms of the MPL, indicate your
- * decision by deleting the provisions above and replace them with the notice
- * and other provisions required by the GPL or the LGPL. If you do not delete
- * the provisions above, a recipient may use your version of this file under
- * the terms of any one of the MPL, the GPL or the LGPL.
- *
- * ***** END LICENSE BLOCK ***** */
- #include "jsstddef.h"
- #include "jstypes.h"
- #include "jslong.h"
- #ifndef JS_HAVE_LONG_LONG
- /*
- ** Divide 64-bit a by 32-bit b, which must be normalized so its high bit is 1.
- */
- static void norm_udivmod32(JSUint32 *qp, JSUint32 *rp, JSUint64 a, JSUint32 b)
- {
- JSUint32 d1, d0, q1, q0;
- JSUint32 r1, r0, m;
- d1 = jshi16(b);
- d0 = jslo16(b);
- r1 = a.hi % d1;
- q1 = a.hi / d1;
- m = q1 * d0;
- r1 = (r1 << 16) | jshi16(a.lo);
- if (r1 < m) {
- q1--, r1 += b;
- if (r1 >= b /* i.e., we didn't get a carry when adding to r1 */
- && r1 < m) {
- q1--, r1 += b;
- }
- }
- r1 -= m;
- r0 = r1 % d1;
- q0 = r1 / d1;
- m = q0 * d0;
- r0 = (r0 << 16) | jslo16(a.lo);
- if (r0 < m) {
- q0--, r0 += b;
- if (r0 >= b
- && r0 < m) {
- q0--, r0 += b;
- }
- }
- *qp = (q1 << 16) | q0;
- *rp = r0 - m;
- }
- static JSUint32 CountLeadingZeros(JSUint32 a)
- {
- JSUint32 t;
- JSUint32 r = 32;
- if ((t = a >> 16) != 0)
- r -= 16, a = t;
- if ((t = a >> 8) != 0)
- r -= 8, a = t;
- if ((t = a >> 4) != 0)
- r -= 4, a = t;
- if ((t = a >> 2) != 0)
- r -= 2, a = t;
- if ((t = a >> 1) != 0)
- r -= 1, a = t;
- if (a & 1)
- r--;
- return r;
- }
- JS_PUBLIC_API(void) jsll_udivmod(JSUint64 *qp, JSUint64 *rp, JSUint64 a, JSUint64 b)
- {
- JSUint32 n0, n1, n2;
- JSUint32 q0, q1;
- JSUint32 rsh, lsh;
- n0 = a.lo;
- n1 = a.hi;
- if (b.hi == 0) {
- if (b.lo > n1) {
- /* (0 q0) = (n1 n0) / (0 D0) */
- lsh = CountLeadingZeros(b.lo);
- if (lsh) {
- /*
- * Normalize, i.e. make the most significant bit of the
- * denominator be set.
- */
- b.lo = b.lo << lsh;
- n1 = (n1 << lsh) | (n0 >> (32 - lsh));
- n0 = n0 << lsh;
- }
- a.lo = n0, a.hi = n1;
- norm_udivmod32(&q0, &n0, a, b.lo);
- q1 = 0;
- /* remainder is in n0 >> lsh */
- } else {
- /* (q1 q0) = (n1 n0) / (0 d0) */
- if (b.lo == 0) /* user wants to divide by zero! */
- b.lo = 1 / b.lo; /* so go ahead and crash */
- lsh = CountLeadingZeros(b.lo);
- if (lsh == 0) {
- /*
- * From (n1 >= b.lo)
- * && (the most significant bit of b.lo is set),
- * conclude that
- * (the most significant bit of n1 is set)
- * && (the leading quotient digit q1 = 1).
- *
- * This special case is necessary, not an optimization
- * (Shifts counts of 32 are undefined).
- */
- n1 -= b.lo;
- q1 = 1;
- } else {
- /*
- * Normalize.
- */
- rsh = 32 - lsh;
- b.lo = b.lo << lsh;
- n2 = n1 >> rsh;
- n1 = (n1 << lsh) | (n0 >> rsh);
- n0 = n0 << lsh;
- a.lo = n1, a.hi = n2;
- norm_udivmod32(&q1, &n1, a, b.lo);
- }
- /* n1 != b.lo... */
- a.lo = n0, a.hi = n1;
- norm_udivmod32(&q0, &n0, a, b.lo);
- /* remainder in n0 >> lsh */
- }
- if (rp) {
- rp->lo = n0 >> lsh;
- rp->hi = 0;
- }
- } else {
- if (b.hi > n1) {
- /* (0 0) = (n1 n0) / (D1 d0) */
- q0 = 0;
- q1 = 0;
- /* remainder in (n1 n0) */
- if (rp) {
- rp->lo = n0;
- rp->hi = n1;
- }
- } else {
- /* (0 q0) = (n1 n0) / (d1 d0) */
- lsh = CountLeadingZeros(b.hi);
- if (lsh == 0) {
- /*
- * From (n1 >= b.hi)
- * && (the most significant bit of b.hi is set),
- * conclude that
- * (the most significant bit of n1 is set)
- * && (the quotient digit q0 = 0 or 1).
- *
- * This special case is necessary, not an optimization.
- */
- /*
- * The condition on the next line takes advantage of that
- * n1 >= b.hi (true due to control flow).
- */
- if (n1 > b.hi || n0 >= b.lo) {
- q0 = 1;
- a.lo = n0, a.hi = n1;
- JSLL_SUB(a, a, b);
- } else {
- q0 = 0;
- }
- q1 = 0;
- if (rp) {
- rp->lo = n0;
- rp->hi = n1;
- }
- } else {
- JSInt64 m;
- /*
- * Normalize.
- */
- rsh = 32 - lsh;
- b.hi = (b.hi << lsh) | (b.lo >> rsh);
- b.lo = b.lo << lsh;
- n2 = n1 >> rsh;
- n1 = (n1 << lsh) | (n0 >> rsh);
- n0 = n0 << lsh;
- a.lo = n1, a.hi = n2;
- norm_udivmod32(&q0, &n1, a, b.hi);
- JSLL_MUL32(m, q0, b.lo);
- if ((m.hi > n1) || ((m.hi == n1) && (m.lo > n0))) {
- q0--;
- JSLL_SUB(m, m, b);
- }
- q1 = 0;
- /* Remainder is ((n1 n0) - (m1 m0)) >> lsh */
- if (rp) {
- a.lo = n0, a.hi = n1;
- JSLL_SUB(a, a, m);
- rp->lo = (a.hi << rsh) | (a.lo >> lsh);
- rp->hi = a.hi >> lsh;
- }
- }
- }
- }
- if (qp) {
- qp->lo = q0;
- qp->hi = q1;
- }
- }
- #endif /* !JS_HAVE_LONG_LONG */