On 29.10.2014 12:00, Tom Hughes wrote: > On 29/10/14 10:29, Julian Seward wrote: >> On 10/29/2014 09:24 AM, Florian Krohm wrote: >>> I've fixed this in revision 14673. >>> Curious, what GCC version have you been using? >> >> I think the deciding factor might be, not the gcc version, but the CPU >> variant being compiled for. In particular that some AMDs do or don't >> have >> special variants of these in hardware, or some such. > > That was my initial assumption, but I'm not sure it can be true because > a fairly generic build that just targets any old x86_64 or whatever does > work.
Right.. If GCC knows nothing about, say, __builtin_popcount then __builtin_popcount(value) appears to the compiler as call to an unknown (undeclared) function. That compiles OK (K&R allows that) but probably with a warning. Linking of cause will fail. Florian ------------------------------------------------------------------------------ _______________________________________________ Valgrind-users mailing list Valgrind-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/valgrind-users
