| Copyright (c) 2002, 2018, Oracle and/or its affiliates. All rights reserved. |
| DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| |
| This code is free software; you can redistribute it and/or modify it |
| under the terms of the GNU General Public License version 2 only, as |
| published by the Free Software Foundation. |
| |
| This code is distributed in the hope that it will be useful, but WITHOUT |
| ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| version 2 for more details (a copy is included in the LICENSE file that |
| accompanied this code). |
| |
| You should have received a copy of the GNU General Public License version |
| 2 along with this work; if not, write to the Free Software Foundation, |
| Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| |
| Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| or visit www.oracle.com if you need additional information or have any |
| questions. |
| |
| Strength Reduction |
| ------------------ |
| |
| Strength reduction replaces an expansive operation by a cheaper one, such as |
| multiplication by addition or subtraction, multiplication instead of |
| exponentiation; use compound assignment operators such as += wherever possible, |
| changing code of the form a[i] = a[i] + x to a[i] += x, since they result in |
| fewer bytecode instructions; use shifts instead of multiplication by powers of |
| two, etc. |
| |
| For example: |
| |
| x ** 2 = x * x |
| 2.0 * x = x + x |
| x / 2 = x * 0.5 |
| |
| |
| Induction Variable |
| ------------------ |
| |
| A variable is called an induction variables of a loop if every time the variable |
| changes values it is incremented or decrmented by some constant. |
| Basic induction variables i whose only assignments within the loop is of the |
| form i += c, where c is a constant. |
