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class Strictfp { public static void main(String[] args) { double d = Double.MAX_VALUE; System.out.println(""This value \"""" + ((d * 1.1) / 1.1) + "\""\" cannot be represented as double.""); } } |
Compliant Solution
To be compliant, use the strictfp
modifier within an expression (class, method or interface) to guarantee that intermediate results do not vary because of implementation defined compiler optimizations or by design. This code snippet is guaranteed to return positive INFINITY
because of the intermediate overflow condition.
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strictfp class Strictfp { public static void main(String[] args) { double d = Double.MAX_VALUE; System.out.println(""This value \"""" + ((d * 1.1) / 1.1) + "\""\" cannot be represented as double.""); } } |
Risk Assessment
Not using the strictfp
modifier can result in platform defined behavior with respect to the accuracy of floating point operations.
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Search for vulnerabilities resulting from the violation of this rule on the CERT website.
References
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\[[JLS 05|AA. Java References#JLS 05]\] 15.4 FP-strict Expressions \[[JPL 05|AA. Java References#JPL 05]\] 9.1.3. Strict and Non-Strict Floating-Point Arithmetic \[[McCluskey 01|AA. Java References#McCluskey 01]\] Making Deep Copies of Objects, Using strictfp, and Optimizing String Performance \[[Darwin 04|AA. Java References#Darwin 04]\] Ensuring the Accuracy of Floating-Point Numbers |
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FLP02-J. Do not attempt comparisons with NaN 07. Floating Point (FLP) FLP04-J. Check floating point inputs for exceptional values