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/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
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/* ***** BEGIN LICENSE BLOCK *****
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* Version: MPL 1.1/GPL 2.0/LGPL 2.1
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* The contents of this file are subject to the Mozilla Public License Version
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* 1.1 (the "License"); you may not use this file except in compliance with
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* the License. You may obtain a copy of the License at
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* http://www.mozilla.org/MPL/
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* Software distributed under the License is distributed on an "AS IS" basis,
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* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
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* for the specific language governing rights and limitations under the
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* The Original Code is Mozilla Communicator client code, released
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* The Initial Developer of the Original Code is
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* Netscape Communications Corporation.
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* Portions created by the Initial Developer are Copyright (C) 1998
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* the Initial Developer. All Rights Reserved.
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* Alternatively, the contents of this file may be used under the terms of
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* either of the GNU General Public License Version 2 or later (the "GPL"),
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* or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
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* in which case the provisions of the GPL or the LGPL are applicable instead
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* of those above. If you wish to allow use of your version of this file only
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* under the terms of either the GPL or the LGPL, and not to allow others to
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* use your version of this file under the terms of the MPL, indicate your
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* decision by deleting the provisions above and replace them with the notice
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* and other provisions required by the GPL or the LGPL. If you do not delete
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* the provisions above, a recipient may use your version of this file under
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* the terms of any one of the MPL, the GPL or the LGPL.
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* ***** END LICENSE BLOCK ***** */
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static JSInt64 ll_zero = JSLL_INIT( 0x00000000,0x00000000 );
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static JSInt64 ll_maxint = JSLL_INIT( 0x7fffffff, 0xffffffff );
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static JSInt64 ll_minint = JSLL_INIT( 0x80000000, 0x00000000 );
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#ifdef HAVE_WATCOM_BUG_2
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JSInt64 __pascal __loadds __export
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JSLL_Zero(void) { return ll_zero; }
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JSInt64 __pascal __loadds __export
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JSLL_MaxInt(void) { return ll_maxint; }
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JSInt64 __pascal __loadds __export
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JSLL_MinInt(void) { return ll_minint; }
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JS_PUBLIC_API(JSInt64) JSLL_Zero(void) { return ll_zero; }
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JS_PUBLIC_API(JSInt64) JSLL_MaxInt(void) { return ll_maxint; }
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JS_PUBLIC_API(JSInt64) JSLL_MinInt(void) { return ll_minint; }
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#ifndef JS_HAVE_LONG_LONG
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** Divide 64-bit a by 32-bit b, which must be normalized so its high bit is 1.
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static void norm_udivmod32(JSUint32 *qp, JSUint32 *rp, JSUint64 a, JSUint32 b)
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JSUint32 d1, d0, q1, q0;
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r1 = (r1 << 16) | jshi16(a.lo);
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if (r1 >= b /* i.e., we didn't get a carry when adding to r1 */
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r0 = (r0 << 16) | jslo16(a.lo);
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*qp = (q1 << 16) | q0;
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static JSUint32 CountLeadingZeros(JSUint32 a)
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if ((t = a >> 16) != 0)
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if ((t = a >> 8) != 0)
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if ((t = a >> 4) != 0)
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if ((t = a >> 2) != 0)
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if ((t = a >> 1) != 0)
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JS_PUBLIC_API(void) jsll_udivmod(JSUint64 *qp, JSUint64 *rp, JSUint64 a, JSUint64 b)
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/* (0 q0) = (n1 n0) / (0 D0) */
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lsh = CountLeadingZeros(b.lo);
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* Normalize, i.e. make the most significant bit of the
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* denominator be set.
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n1 = (n1 << lsh) | (n0 >> (32 - lsh));
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a.lo = n0, a.hi = n1;
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norm_udivmod32(&q0, &n0, a, b.lo);
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/* remainder is in n0 >> lsh */
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/* (q1 q0) = (n1 n0) / (0 d0) */
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if (b.lo == 0) /* user wants to divide by zero! */
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b.lo = 1 / b.lo; /* so go ahead and crash */
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lsh = CountLeadingZeros(b.lo);
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* && (the most significant bit of b.lo is set),
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* (the most significant bit of n1 is set)
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* && (the leading quotient digit q1 = 1).
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* This special case is necessary, not an optimization
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* (Shifts counts of 32 are undefined).
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n1 = (n1 << lsh) | (n0 >> rsh);
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a.lo = n1, a.hi = n2;
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norm_udivmod32(&q1, &n1, a, b.lo);
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a.lo = n0, a.hi = n1;
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norm_udivmod32(&q0, &n0, a, b.lo);
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/* remainder in n0 >> lsh */
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/* (0 0) = (n1 n0) / (D1 d0) */
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/* remainder in (n1 n0) */
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/* (0 q0) = (n1 n0) / (d1 d0) */
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lsh = CountLeadingZeros(b.hi);
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* && (the most significant bit of b.hi is set),
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* (the most significant bit of n1 is set)
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* && (the quotient digit q0 = 0 or 1).
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* This special case is necessary, not an optimization.
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* The condition on the next line takes advantage of that
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* n1 >= b.hi (true due to control flow).
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if (n1 > b.hi || n0 >= b.lo) {
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a.lo = n0, a.hi = n1;
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b.hi = (b.hi << lsh) | (b.lo >> rsh);
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n1 = (n1 << lsh) | (n0 >> rsh);
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a.lo = n1, a.hi = n2;
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norm_udivmod32(&q0, &n1, a, b.hi);
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JSLL_MUL32(m, q0, b.lo);
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if ((m.hi > n1) || ((m.hi == n1) && (m.lo > n0))) {
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/* Remainder is ((n1 n0) - (m1 m0)) >> lsh */
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a.lo = n0, a.hi = n1;
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rp->lo = (a.hi << rsh) | (a.lo >> lsh);
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rp->hi = a.hi >> lsh;
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#endif /* !JS_HAVE_LONG_LONG */
added
removed
src/js/jslong.c
