aureooms-js-integer
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integer code bricks for JavaScript
90 lines (68 loc) • 1.72 kB
JavaScript
/**
* /!\ BLOCK MULTIPLICATION RESULT MUST HOLD IN THE JAVASCRIPT NUMBER TYPE (DOUBLE i.e. 53 bits)
*
* big endian 1 block multiplication
*
*/
export function bmul53_t (r){
/**
* Multiply two blocks, result is put in a 1 or 2 blocks big endian array.
* aj - ai <= 1, bj - bi <= 1, cj - ci <= 2
*
*
* @param {array} a first operand
* @param {int} ai a left
* @param {int} aj a right
* @param {array} b second operand
* @param {int} bi b left
* @param {int} bj b right
* @param {array} c result, must be 0 initialized
* @param {int} ci c left
* @param {int} cj c right
*/
var mul = function(a, ai, aj, b, bi, bj, c, ci, cj){
var v;
// EMPTY CASE
if (aj <= ai || bj <= bi || cj <= ci) return;
v = a[ai] * b[bi];
c[cj-1] = v % r;
if (cj > ci + 1) {
c[cj-2] = (v - c[cj-1]) / r;
}
};
return mul;
}
/**
* /!\ BLOCK MULTIPLICATION RESULT MUST HOLD IN THE JAVASCRIPT NUMBER TYPE (DOUBLE i.e. 53 bits)
*
* little endian 1 block multiplication
*
*/
export function lmul53_t (r){
/**
* Multiply two blocks, result is put in a 1 or 2 blocks little endian array.
* aj - ai <= 1, bj - bi <= 1, cj - ci <= 2
*
*
* @param {array} a first operand
* @param {int} ai a left
* @param {int} aj a right
* @param {array} b second operand
* @param {int} bi b left
* @param {int} bj b right
* @param {array} c result, must be 0 initialized
* @param {int} ci c left
* @param {int} cj c right
*/
var mul = function(a, ai, aj, b, bi, bj, c, ci, cj){
var v;
// EMPTY CASE
if (aj <= ai || bj <= bi || cj <= ci) return;
v = a[ai] * b[bi];
c[ci] = v % r;
if (cj > ci + 1) {
c[ci+1] = (v - c[ci]) / r;
}
};
return mul;
}