On Thu, Jun 25, 2015 at 1:09 PM, H.J. Lu <hjl.to...@gmail.com> wrote:
> On Tue, Jun 23, 2015 at 11:41 AM, Richard Sandiford
> <rdsandif...@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
>
There are
unsigned int opno = 0;
for (const char *p = prototype; *p; ++p)
if (*p == 'x' && ISDIGIT (p[1]))
{
/* This should be a parameter name of the form "x<OPNO>".
That doesn't contribute to the suffix, so skip ahead and
process the following character. */
char *endptr;
if (strtol (p + 1, &endptr, 10) != opno
|| (*endptr != ',' && *endptr != ')'))
strtol returns long int. Somehow, there is no warning on x86-64.
--
H.J.
