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A less portable but potentially more secure solution is to use the capabilities provided by the underlying implementation. If this approach is taken, the caveats of that system must be well understood. The following table provides a starting point for some common operating systems:

Operating System	How to Handle Floating-Point Errors
Linux Solaris 10 AIX 5.3 HP-UX 11.31 Mac OS X 10.5	Use the C floating-point exception functions
Windows	Use either the C floating-point exception functions or structured exception handling through `_fpieee_flt` [MSDN]

Noncompliant Code Example

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Undetected floating-point errors may result in lower program efficiency, inaccurate results, or software vulnerabilities. Most processors stall for a significant duration (sometimes up to a second or even more on 32-bit desktop processors) when an operation incurs a NaN (not a number) value.

Recommendation	Severity	Likelihood	Remediation Cost	Priority	Level
FLP03-C	Low	Probable	High	P2	L3

Automated Detection

Tool

Version

Checker

Description

Astrée

Include Page

	Astrée_V
	Astrée_V

float-division-by-zero

Partially checked

Compass/ROSE

Could detect violations of this rule by ensuring that floating-point operations are surrounded by feclearexcept() and fetestexcept(). It would need to look for type conversions to float or double, divisions (by a number not known to be nonzero), and multiplication. It may be wisest to apply this to all floating-point operations in general

PRQA QA-C

LDRA tool suite

Include Page

PRQA

	LDRA_V

PRQA

	LDRA_V

4123
4124
4125
4126
4127
4128

43 D

Partially implemented

Parasoft C/C++test

Include Page

	Parasoft_V
	Parasoft_V

CERT_C-FLP03-a
CERT_C-FLP03-b
CERT_C-FLP03-c
CERT_C-FLP03-d

Avoid division by zero
Avoid implicit conversions from wider to narrower floating type
Avoid implicit conversions from narrower to wider floating type
Avoid implicit conversions of floating point numbers from wider to narrower floating type

Parasoft Insure++

Runtime analysis

PC-lint Plus

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