On 03/08/13 19:01, Venkataramanan Kumar wrote:
2013-08-02 Venkataramanan Kumar <venkataramanan.ku...@linaro.org>
* config/aarch64/aarch64.h (MCOUNT_NAME): Define.
(NO_PROFILE_COUNTERS): Likewise.
(PROFILE_HOOK): Likewise.
(FUNCTION_PROFILER): Likewise.
* config/aarch64/aarch64.c (aarch64_function_profiler): Remove.
.
regards,
Venkat.
Hi Venkat,
Looking at the various other ports it looks that the majority choose to
use FUNCTION_PROFILER_HOOK rather than PROFILE_HOOK.
Using PROFILE_HOOK to inject a regular call to to _mcount() means that
all arguments passed in registers in every function will be spilled and
reloaded because the _mcount call will kill the caller save registers.
Using the FUNCTION_PROFILER_HOOK and taking care not to kill the caller
save registers would be less invasive. The LR argument to _mcount would
need to be passed in a temporary register, say x9 and _mcount would also
need to ensure caller save registers are saved and restored.
The latter seems to be a better option to me, is there compelling reason
to choose PROFILE_HOOK over FUNCTION_PROFILER_HOOK ??
Cheers
/Marcus
