The object representation for floating-point values is implementation defined. However, an implementation that defines the __STDC_IEC_559__ macro shall conform to the IEC 60559 floating-point standard and uses what is frequently referred to as IEEE 754 floating-point arithmetic [ISO/IEC 9899:20112024]. The floating-point object representation used by IEC 60559 is one of the most common floating-point object representations in use today.
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Using the object representation of a floating-point value for comparisons can lead to incorrect equality results, which can lead to unexpected behavior.
Rule | Severity | Likelihood | Remediation Cost | Priority | Level |
|---|---|---|---|---|---|
FLP37-C | Low | Unlikely | Medium | P2 | L3 |
Automated Detection
Tool | Version | Checker | Description | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Astrée |
| memcmp-with-float | Partially checked | ||||||
| Axivion Bauhaus Suite |
| CertC-FLP37 | Fully implemented | ||||||
| Cppcheck Premium |
| premium-cert-flp37-c | Fully implemented | ||||||
| Helix QAC |
| C5026 C++3118 | |||||||
| Klocwork |
| MISRA.STDLIB.MEMCMP.PTR_ARG_TYPES | |||||||
| LDRA tool suite |
| 618 S | Enhanced Enforcement | ||||||
| Parasoft C/C++test |
| CERT_C-FLP37-c | Do not use object representations to compare floating-point values | ||||||
| PC-lint Plus |
| 2498, 2499 | Fully supported | ||||||
| CERT C: Rule FLP37-C | Checks for memory comparison of floating-point values (rule fully covered) | |||||||
| PVS-Studio |
| V1014 | |||||||
| RuleChecker |
| memcmp-with-float | Partially checked | ||||||
| TrustInSoft Analyzer |
| Exhaustively verified. |
Related Vulnerabilities
Search for vulnerabilities resulting from the violation of this rule on the CERT website.
Related Guidelines
Bibliography
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