https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121148
Jonathan Wakely <redi at gcc dot gnu.org> changed:
What |Removed |Added
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CC| |danglin at gcc dot gnu.org
--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> ---
If I understand correctly, the hppa code in
libstdc++-v3/config/cpu/hppa/atomicity.h is only using assembly for a spinlock,
then the actual arithmetic happens in plain C++ code:
_Atomic_word result;
int tmp;
volatile int& lock = _Atomicity_lock<0>::_S_atomicity_lock;
__asm__ __volatile__ (_PA_LDCW_INSN " 0(%1),%0\n\t"
"cmpib,<>,n 0,%0,.+20\n\t"
"ldw,ma 0(%1),%0\n\t"
"cmpib,<> 0,%0,.-12\n\t"
"nop\n\t"
"b,n .-12"
: "=&r" (tmp)
: "r" (&lock)
: "memory");
result = *__mem;
*__mem = result + __val;
__asm__ __volatile__ ("stw,ma %1,0(%0)"
: : "r" (&lock), "r" (tmp) : "memory");
return result;
So this will need to use an unsigned type, as shown in comment 0.
