Dave Korn <dave.korn.cyg...@googlemail.com> writes: > Is that really right? The type of the pointer (in6->__s6_addr) that we're > casting is unsigned char *, so shouldn't it already alias everything anyway > and dereferencing it be allowed, like it is for the casted (a)? I'll file a > PR if so. (I can't pretend I find the language in the spec easy to follow.)
IIUC both accesses are actually wrong, but in the case of a there is no information about the actual target type, so the compiler cannot optimize. In both cases an object is accessed as type uint32_t, but the effective type is different. Aliasing is not symmetric, the aliasing exception only applies to the case of accessing through a character type, the effective type of the object does not matter. Andreas. -- Andreas Schwab, sch...@linux-m68k.org GPG Key fingerprint = 58CA 54C7 6D53 942B 1756 01D3 44D5 214B 8276 4ED5 "And now for something completely different."
