On 20/04/16 16:14, Alex Bennée wrote: > Sergey Fedorov <serge.f...@gmail.com> writes: > >> On 20/04/16 12:42, Alex Bennée wrote: >>> Sergey Fedorov <sergey.fedo...@linaro.org> writes: >>>> diff --git a/tcg/tci/tcg-target.inc.c b/tcg/tci/tcg-target.inc.c >>>> index 4afe4d7a8d59..7e6180e62898 100644 >>>> --- a/tcg/tci/tcg-target.inc.c >>>> +++ b/tcg/tci/tcg-target.inc.c >>>> @@ -556,6 +556,8 @@ static void tcg_out_op(TCGContext *s, TCGOpcode opc, >>>> const TCGArg *args, >>>> if (s->tb_jmp_offset) { >>>> /* Direct jump method. */ >>>> assert(args[0] < ARRAY_SIZE(s->tb_jmp_offset)); >>>> + /* Align for atomic patching and thread safety */ >>>> + s->code_ptr = (uint8_t *)(((uintptr_t)s->code_ptr + 3) & >>>> ~3); >>> Seeing this pattern is being used over and over again I wonder if we >>> should have some utility helper functions for this? Perhaps we should >>> steal the kernels ALIGN macros? >> Good point, really. I see such a macro in hw/display/qxl.c and >> kvm-all.c. It'd be better a common definition. Any idea of where to >> put it? > Somewhere inside include/qemu. osdep.h has ROUND_UP/DOWN functions maybe > there makes the most sense?
Hmm, ROUND_UP() seems to be exactly what we need here. Though I think compiler could be smart enough to give the same code with QEMU_ALIGN_UP() as well. But we'd benefit from something like: /* n-byte align pointer down */ #define QEMU_ALIGN_PTR_DOWN(p, n) \ ((typeof(p))QEMU_ALIGN_DOWN((uintptr_t)(p), (n))) /* n-byte align pointer up */ #define QEMU_ALIGN_PTR_UP(p, n) \ ((typeof(p))QEMU_ALIGN_UP((uintptr_t)(p), (n))) Kind regards, Sergey