Segher Boessenkool wrote: >>>> The comment is wrong. The code checks for signed overflow, but the >>>> following assignment still overflwos when ux is larger than INT_MAX. >>> No, it doesn't. This conversion is implementation-defined (6.3.1.3/3), >>> and GCC does the obvious two's complement thing. This code is fine. >> It's fine with GCC 4.4, and likely with GCC 4.5 as well. But what >> about GCC 4.6? And how will a user compiling third-party software >> notice the discrepancy (if it ever arises)? > > Implementation-defined means the implementation defines > the behaviour, and GCC defines it like this: We know, we already discussed this upthread. The question is not whether it works, but how to do it portably, not just for gcc. Depending on 2's complement is fine, but depending on a particular compiler is less so. Andrew.
