On 10/27/2015 09:42 AM, Ramana Radhakrishnan wrote:
On 27/10/15 14:50, H.J. Lu wrote:
On Tue, Oct 27, 2015 at 7:34 AM, Ramana Radhakrishnan
<ramana.radhakrish...@foss.arm.com> wrote:
OK, then it's fairly x86-64 specific optimization, because we can't do "call
*mem" in
aarch64 and some other targets.
It is a fairly x86_64 specific optimization and doesn't apply to AArch64.
The question really is what impact does removing the generic code handling have
on aarch64 - is it a no-op or not for the existing -fno-plt implementation in
the AArch64 backend ? The only case that is of interest is the bit below in
calls.c and it looks like that may well be redundant with the logic in the
backend already, but I have not done the full analysis to convince myself that
the code in the backend is sufficient.
- && (!flag_plt
- || lookup_attribute ("noplt", DECL_ATTRIBUTES (fndecl_or_type)))
- && !targetm.binds_local_p (fndecl_or_type))
-fno-plt is a backend specific optimization and should be handled
in backend.
HJ, Thanks for committing the change even when we were discussing the change -
As I suspected the handling in the backend isn't sufficient, the call expanders
need to handle this case in the AArch64 backend. Minimally tested -
Ok if no regressions on aarch64-none-elf?
regards
Ramana
* config/aarch64/aarch64.md (call, call_value): Handle noplt.
FWIW -ENOPATCH.
jeff
