Re: Add .def file for public target instructions

["H.J. Lu" <hjl.tools@gmail.com>]

On Tue, Jun 23, 2015 at 11:41 AM, Richard Sandiford
<rdsandiford@googlemail.com> 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.
>

This breaks bootstrap on Linux/ia32:

https://gcc.gnu.org/ml/gcc-regression/2015-06/msg00649.html

../../src-trunk/gcc/gentarget-def.c: In function âvoid
def_target_insn(const char*, const char*)â:
../../src-trunk/gcc/gentarget-def.c:88:34: error: comparison between
signed and unsigned integer expressions [-Werror=sign-compare]
  if (strtol (p + 1, &endptr, 10) != opno

-- 
H.J.