Re: Add .def file for public target instructions

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

On Thu, Jun 25, 2015 at 4:37 PM, H.J. Lu <hjl.tools@gmail.com> wrote:
> On Thu, Jun 25, 2015 at 4:00 PM, Andrew Pinski <pinskia@gmail.com> wrote:
>> On Thu, Jun 25, 2015 at 3:57 PM, H.J. Lu <hjl.tools@gmail.com> wrote:
>>> On Thu, Jun 25, 2015 at 1:09 PM, H.J. Lu <hjl.tools@gmail.com> wrote:
>>>> 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
>>>>
>>>
>>> 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.
>>
>> Because on x86_64 (and all LP64 targets), the comparison gets promoted
>> to long (which is 64bit) so the conversion from unsigned int to long
>> does not lose precision.
>>
>
> I am testing this.
>
>
> --
> H.J.
> ---
> diff --git a/gcc/gentarget-def.c b/gcc/gentarget-def.c
> index d4839e8..3ca9cfd 100644
> --- a/gcc/gentarget-def.c
> +++ b/gcc/gentarget-def.c
> @@ -77,7 +77,7 @@ def_target_insn (const char *name, const char *prototype)
>       together to get a suffix.  */
>    char *suffix = XALLOCAVEC (char, strlen (prototype) + 1);
>    i = 0;
> -  unsigned int opno = 0;
> +  long opno = 0;
>    for (const char *p = prototype; *p; ++p)
>      if (*p == 'x' && ISDIGIT (p[1]))
>        {

It doesn't work.  I checked in this patch instead.


-- 
H.J.
---
Index: ChangeLog
===================================================================
--- ChangeLog (revision 224992)
+++ ChangeLog (working copy)
@@ -1,3 +1,8 @@
+2015-06-25  H.J. Lu  <hongjiu.lu@intel.com>
+
+ * gentarget-def.c (def_target_insn): Cast return of strtol to
+ unsigned int.
+
 2015-06-25  Andrew MacLeod  <amacleod@redhat.com>

  * gimple.h (gimple_call_set_fn): Move inline function.
Index: gentarget-def.c
===================================================================
--- gentarget-def.c (revision 224992)
+++ gentarget-def.c (working copy)
@@ -85,7 +85,7 @@ def_target_insn (const char *name, const
    That doesn't contribute to the suffix, so skip ahead and
    process the following character.  */
  char *endptr;
- if (strtol (p + 1, &endptr, 10) != opno
+ if ((unsigned int) strtol (p + 1, &endptr, 10) != opno
     || (*endptr != ',' && *endptr != ')'))
   {
     error ("invalid prototype for '%s'", name);