On 06/23/2015 12:41 PM, Richard Sandiford wrote:
[A fair bit later than promised, sorry...]
Mikhail posted a patch to make genflags generate the default HAVE_foo
and gen_foo definitions that have recently been added to defaults.h:
https://gcc.gnu.org/ml/gcc-patches/2015-06/msg00723.html
I agree it'd be a good idea to generate this kind of thing automatically,
but I think we should take the opportunity to move the interface to the
target structure. I.e.:
HAVE_foo -> targetm.have_foo ()
gen_foo -> targetm.gen_foo ()
This should move us closer to the pipedream goal of supporting multiple
targets at once. It should also mean that only the target code depends
on insn-flags.h.
The patch just moves return and simple_return as an example. I have more
locally (in order to test other code paths), but they're just an obvious
extension of this one.
The patch relies on the hashing changes in:
https://gcc.gnu.org/ml/gcc-patches/2015-06/msg01066.html
https://gcc.gnu.org/ml/gcc-patches/2015-06/msg01564.html
and on this trivial patch:
https://gcc.gnu.org/ml/gcc-patches/2015-06/msg01604.html
It seems a bit heavyweight when you just look at these two instructions,
but I think it'll be a saving in the end.
Bootstrapped & regression-tested on x86_64-linux-gnu. Also tested
via config-list.mk. OK to install?
Thanks,
Richard
gcc/
* Makefile.in (TARGET_DEF): Add target-insns.def.
(.PRECIOUS, simple_rtl_generated_h): Add insn-target-def.h.
(build/gentarget-def.o): New rule.
(genprogrtl): Add target-def.
* target-insns.def, gentarget-def.c: New files.
* target.def: Add targetm.have_* and targetm.gen_* hooks,
based on the contents of target-insns.def.
* defaults.h (HAVE_simple_return, gen_simple_return): Delete.
(HAVE_return, gen_return): Delete.
* target-def.h: Include insn-target-def.h.
* cfgrtl.c (force_nonfallthru_and_redirect): Use targetm interface
instead of direct calls. Rely on them to do the appropriate assertions.
* function.c (gen_return_pattern): Likewise. Return an rtx_insn *.
(convert_jumps_to_returns): Use targetm interface instead of
direct calls.
(thread_prologue_and_epilogue_insns): Likewise.
* reorg.c (find_end_label, dbr_schedule): Likewise.
* shrink-wrap.h (SHRINK_WRAPPING_ENABLED): Likewise.
* shrink-wrap.c (convert_to_simple_return): Likewise.
(try_shrink_wrapping): Use SHRINK_WRAPPING_ENABLED.
As you're the gen* maintainer, I'm going to assume you got those bits
right and if there's a problem you'll address them :-)
This is fine once the prereqs are installed. Follow-ups to move more
insns to this style are pre-approved assuming their of a similar
mechanical nature.
jeff
