EmbeddingGemma 2: an open, lightweight multimodal embedding model
deepmind.google·6d ago
AI Engineering
Lobsters·6h ago·5 min read
your c is not standard c
TL;DR
C compilers like gcc and clang exhibit numerous incompatibilities with the C standard, affecting features like the asm keyword, FLT_ROUNDS macro, and standard pragmas. These discrepancies can lead to unexpected behavior in code that adheres to the standard.
✦ Why It Matters
Review your code for compatibility with the C standard to avoid unexpected behavior in gcc and clang.
Key Takeaways
- Check asm keyword usage to ensure compatibility with gcc and clang.
- Verify FLT_ROUNDS behavior in your floating-point code.
- Utilize standard pragmas where supported, especially in clang.
- Be aware of glibc's initstate behavior when handling errors.
Full Summary
C compilers, particularly gcc and clang, often deviate from the C standard, leading to compatibility issues for developers. For instance, the asm keyword is treated as an extension rather than a reserved word, which can cause standard-compliant code to fail to compile.
Additionally, the FLT_ROUNDS macro is incorrectly defined in gcc, always returning 1 instead of adapting to the runtime environment as required by the standard. Standard pragmas for floating-point arithmetic, introduced in C99 and C23, are largely unsupported in gcc, limiting their utility.
Furthermore, glibc's implementation of initstate does not return NULL on error as specified by POSIX, creating further inconsistencies. These issues highlight the challenges developers face when writing portable C code across different environments.