On Feb 25, 2012, at 11:49 AM, Jean-Daniel Dupas wrote:
clang move very fast, and it is actually better than llvm-gcc IMHO.
clang has great diagnostics and is designed to be integrated exceptional well in IDEs.
From my experience however, and against what Apple folks try to make us believe, code quality regarding optimization and code size is still behind apple-gcc 4.2 - not to mention gcc 4.7. Especially in C++ sources with heavy templates and inherently more complex code due to micro sized functions, runtime is occasionally two to three times longer than code from gcc. Even typical C code runs 10% to 20% slower with clang compared to apple-gcc 4.2 (I've made bench tests with ICU sources, here). Code size is another matter: even the code runs often slower, it is much larger than when compiled with gcc.
I do believe however that this will be fixed in the future - but don't believe this is any time soon.
If it is possible, I would appreciate it, if a gcc compiler could be integrated with Xcode. In this case clang doesn't need to be disabled completely, it is still an invaluable tool during development within the IDE (syntax checking, indexing, navigation, analysis, etc.).
Andreas