Sorry, but this is just wrong...
Posted May 30, 2011 18:47 UTC (Mon) by khim
In reply to: It's different viewpoints...
Parent article: What Every C Programmer Should Know About Undefined Behavior #3/3
It did not use to be risky until some compiler writers made it so; on the contrary, it worked as I expect it to on all targets suppored by gcc-2.x
Sorry, but this is just not true. Lots of platforms it was flaky because FPU was physically separate. Most of them were embedded but it was the problem for 80386CPU+80287FPU (yes, it's legal and yes, such plaforms were actually produced), for example.Sure, some platforms were perfectly happy with such code. But then if you want low-level non-portable language... asm is always there.
Maybe your programs are not affected in this way, unlike some of my programs, but then you don't need a low-level language and could just as well use a higher-level language.
Or, alternatively, you can actually read specifications and see what the language actually supports. Most (but not all) "crazy behaviors" of gcc and clang just faithfully emulate hardware portability problems, nothing more, nothing less. It's kind of funny, but real low-level stuff (like OS kernels or portable on-bare-metal programs) usually survive "evil compilers" just fine. It's code from "programmer cowboys" who know how the 8086 works and ignore everything else which is problematic.
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