1 files changed, 65 insertions, 0 deletions
diff --git a/node_modules/bn.js/util/genCombMulTo.js b/node_modules/bn.js/util/genCombMulTo.js
new file mode 100644
index 000000000..8b456c7c6
--- /dev/null
+++ b/node_modules/bn.js/util/genCombMulTo.js
@@ -0,0 +1,65 @@
+'use strict';
+
+// NOTE: This could be potentionally used to generate loop-less multiplications
+function genCombMulTo (alen, blen) {
+  var len = alen + blen - 1;
+  var src = [
+    'var a = self.words;',
+    'var b = num.words;',
+    'var o = out.words;',
+    'var c = 0;',
+    'var lo;',
+    'var mid;',
+    'var hi;'
+  ];
+  for (var i = 0; i < alen; i++) {
+    src.push('var a' + i + ' = a[' + i + '] | 0;');
+    src.push('var al' + i + ' = a' + i + ' & 0x1fff;');
+    src.push('var ah' + i + ' = a' + i + ' >>> 13;');
+  }
+  for (i = 0; i < blen; i++) {
+    src.push('var b' + i + ' = b[' + i + '] | 0;');
+    src.push('var bl' + i + ' = b' + i + ' & 0x1fff;');
+    src.push('var bh' + i + ' = b' + i + ' >>> 13;');
+  }
+  src.push('');
+  src.push('out.negative = self.negative ^ num.negative;');
+  src.push('out.length = ' + len + ';');
+
+  for (var k = 0; k < len; k++) {
+    var minJ = Math.max(0, k - alen + 1);
+    var maxJ = Math.min(k, blen - 1);
+
+    src.push('\/* k = ' + k + ' *\/');
+    src.push('var w' + k + ' = c;');
+    src.push('c = 0;');
+    for (var j = minJ; j <= maxJ; j++) {
+      i = k - j;
+
+      src.push('lo = Math.imul(al' + i + ', bl' + j + ');');
+      src.push('mid = Math.imul(al' + i + ', bh' + j + ');');
+      src.push('mid = (mid + Math.imul(ah' + i + ', bl' + j + ')) | 0;');
+      src.push('hi = Math.imul(ah' + i + ', bh' + j + ');');
+
+      src.push('w' + k + ' = (w' + k + ' + lo) | 0;');
+      src.push('w' + k + ' = (w' + k + ' + ((mid & 0x1fff) << 13)) | 0;');
+      src.push('c = (c + hi) | 0;');
+      src.push('c = (c + (mid >>> 13)) | 0;');
+      src.push('c = (c + (w' + k + ' >>> 26)) | 0;');
+      src.push('w' + k + ' &= 0x3ffffff;');
+    }
+  }
+  // Store in separate step for better memory access
+  for (k = 0; k < len; k++) {
+    src.push('o[' + k + '] = w' + k + ';');
+  }
+  src.push('if (c !== 0) {',
+           '  o[' + k + '] = c;',
+           '  out.length++;',
+           '}',
+           'return out;');
+
+  return src.join('\n');
+}
+
+console.log(genCombMulTo(10, 10));