avoid duplication of some logic

Author: zloirock

packages/core-js/internals/math-float-round.js

@@ -1,14 +1,10 @@
 'use strict';
 var sign = require('../internals/math-sign');
+var roundTiesToEven = require('../internals/math-round-ties-to-even');
 
 var abs = Math.abs;
 
 var EPSILON = 2.220446049250313e-16; // Number.EPSILON
-var INVERSE_EPSILON = 1 / EPSILON;
-
-var roundTiesToEven = function (n) {
-  return n + INVERSE_EPSILON - INVERSE_EPSILON;
-};
 
 module.exports = function (x, FLOAT_EPSILON, FLOAT_MAX_VALUE, FLOAT_MIN_VALUE) {
   var n = +x;

packages/core-js/internals/math-log2.js

@@ -0,0 +1,10 @@
+'use strict';
+var log = Math.log;
+var LN2 = Math.LN2;
+
+// `Math.log2` method
+// https://tc39.es/ecma262/#sec-math.log2
+// eslint-disable-next-line es/no-math-log2 -- safe
+module.exports = Math.log2 || function log2(x) {
+  return log(x) / LN2;
+};

packages/core-js/internals/math-round-ties-to-even.js

@@ -0,0 +1,7 @@
+'use strict';
+var EPSILON = 2.220446049250313e-16; // Number.EPSILON
+var INVERSE_EPSILON = 1 / EPSILON;
+
+module.exports = function (n) {
+  return n + INVERSE_EPSILON - INVERSE_EPSILON;
+};

packages/core-js/modules/es.math.log2.js

@@ -1,13 +1,9 @@
 'use strict';
 var $ = require('../internals/export');
-
-var log = Math.log;
-var LN2 = Math.LN2;
+var log2 = require('../internals/math-log2');
 
 // `Math.log2` method
 // https://tc39.es/ecma262/#sec-math.log2
 $({ target: 'Math', stat: true }, {
-  log2: function log2(x) {
-    return log(x) / LN2;
-  }
+  log2: log2
 });

packages/core-js/modules/esnext.data-view.set-float16.js

@@ -3,17 +3,11 @@ var $ = require('../internals/export');
 var uncurryThis = require('../internals/function-uncurry-this');
 var aDataView = require('../internals/a-data-view');
 var toIndex = require('../internals/to-index');
+// TODO: Replace with module dependency in `core-js@4`
+var log2 = require('../internals/math-log2');
+var roundTiesToEven = require('../internals/math-round-ties-to-even');
 
 var pow = Math.pow;
-var log = Math.log;
-var LN2 = Math.LN2;
-
-var EPSILON = 2.220446049250313e-16; // Number.EPSILON
-var INVERSE_EPSILON = 1 / EPSILON;
-
-var roundTiesToEven = function (n) {
-  return n + INVERSE_EPSILON - INVERSE_EPSILON;
-};
 
 var MIN_INFINITY16 = 65520; // (2 - 2 ** -11) * 2 ** 15
 var MIN_NORMAL16 = 0.000061005353927612305; // (1 - 2 ** -11) * 2 ** -14
@@ -31,7 +25,7 @@ var packFloat16 = function (value) {
   if (value < MIN_NORMAL16) return neg << 15 | roundTiesToEven(value * REC_MIN_SUBNORMAL16); // subnormal
 
   // normal
-  var exponent = log(value) / LN2 | 0;
+  var exponent = log2(value) | 0;
   if (exponent === -15) {
     // we round from a value between 2 ** -15 * (1 + 1022/1024) (the largest subnormal) and 2 ** -14 * (1 + 0/1024) (the smallest normal)
     // to the latter (former impossible because of the subnormal check above)