Re: [PATCH, vec-tails 01/10] New compiler options

[Ilya Enkovich <enkovich.gnu@gmail.com>]

2016-05-20 14:17 GMT+03:00 Richard Biener <richard.guenther@gmail.com>:
> On Fri, May 20, 2016 at 11:50 AM, Ilya Enkovich <enkovich.gnu@gmail.com> wrote:
>> 2016-05-20 12:26 GMT+03:00 Richard Biener <richard.guenther@gmail.com>:
>>> On Thu, May 19, 2016 at 9:36 PM, Ilya Enkovich <enkovich.gnu@gmail.com> wrote:
>>>> Hi,
>>>>
>>>> This patch introduces new options used for loop epilogues vectorization.
>>>
>>> Why's that?  This is a bit too much for the casual user and if it is
>>> really necessary
>>> to control this via options then it is not fine-grained enough.
>>>
>>> Why doesn't the vectorizer/backend have enough info to decide this itself?
>>
>> I don't expect casual user to decide which modes to choose.  These controls are
>> added for debugging and performance measurement purposes.  I see now I miss
>> -ftree-vectorize-epilogues aliased to -ftree-vectorize-epilogues=all.  Surely
>> I expect epilogues and short loops vectorization be enabled by default on -O3
>> or by -ftree-vectorize-loops.
>
> Can you make all these --params then?  I think to be useful to users we'd want
> them to be loop pragmas rather than options.

OK, I'll change it to params.  I didn't think about control via
pragmas but will do now.

Thanks,
Ilya

>
> Richard.
>
>> Thanks,
>> Ilya
>>
>>>
>>> Richard.
>>>
>>>> Thanks,
>>>> Ilya
>>>> --
>>>> gcc/
>>>>
>>>> 2016-05-19  Ilya Enkovich  <ilya.enkovich@intel.com>
>>>>
>>>>         * common.opt (flag_tree_vectorize_epilogues): New.
>>>>         (ftree-vectorize-short-loops): New.
>>>>         (ftree-vectorize-epilogues=): New.
>>>>         (fno-tree-vectorize-epilogues): New.
>>>>         (fvect-epilogue-cost-model=): New.
>>>>         * flag-types.h (enum vect_epilogue_mode): New.
>>>>         * opts.c (parse_vectorizer_options): New.
>>>>         (common_handle_option): Support -ftree-vectorize-epilogues=
>>>>         and -fno-tree-vectorize-epilogues options.
>>>>
>>>>
>>>> diff --git a/gcc/common.opt b/gcc/common.opt
>>>> index 682cb41..6b83b79 100644
>>>> --- a/gcc/common.opt
>>>> +++ b/gcc/common.opt
>>>> @@ -243,6 +243,10 @@ bool dump_base_name_prefixed = false
>>>>  Variable
>>>>  bool flag_disable_hsa = false
>>>>
>>>> +; Flag holding modes for loop epilogue vectorization
>>>> +Variable
>>>> +unsigned int flag_tree_vectorize_epilogues
>>>> +
>>>>  ###
>>>>  Driver
>>>>
>>>> @@ -2557,6 +2561,19 @@ ftree-vectorize
>>>>  Common Report Var(flag_tree_vectorize) Optimization
>>>>  Enable vectorization on trees.
>>>>
>>>> +ftree-vectorize-short-loops
>>>> +Common Report Var(flag_tree_vectorize_short_loops) Optimization
>>>> +Enable vectorization of loops with low trip count using masking.
>>>> +
>>>> +ftree-vectorize-epilogues=
>>>> +Common Report Joined Optimization
>>>> +Comma separated list of loop epilogue vectorization modes.
>>>> +Available modes: combine, mask, nomask.
>>>> +
>>>> +fno-tree-vectorize-epilogues
>>>> +Common RejectNegative Optimization
>>>> +Disable epilogues vectorization.
>>>> +
>>>>  ftree-vectorizer-verbose=
>>>>  Common Joined RejectNegative Ignore
>>>>  Does nothing.  Preserved for backward compatibility.
>>>> @@ -2577,6 +2594,10 @@ fsimd-cost-model=
>>>>  Common Joined RejectNegative Enum(vect_cost_model) Var(flag_simd_cost_model) Init(VECT_COST_MODEL_UNLIMITED) Optimization
>>>>  Specifies the vectorization cost model for code marked with a simd directive.
>>>>
>>>> +fvect-epilogue-cost-model=
>>>> +Common Joined RejectNegative Enum(vect_cost_model) Var(flag_vect_epilogue_cost_model) Init(VECT_COST_MODEL_DEFAULT) Optimization
>>>> +Specifies the cost model for epilogue vectorization.
>>>> +
>>>>  Enum
>>>>  Name(vect_cost_model) Type(enum vect_cost_model) UnknownError(unknown vectorizer cost model %qs)
>>>>
>>>> diff --git a/gcc/flag-types.h b/gcc/flag-types.h
>>>> index dd57e16..24081b1 100644
>>>> --- a/gcc/flag-types.h
>>>> +++ b/gcc/flag-types.h
>>>> @@ -200,6 +200,15 @@ enum vect_cost_model {
>>>>    VECT_COST_MODEL_DEFAULT = 3
>>>>  };
>>>>
>>>> +/* Epilogue vectorization modes.  */
>>>> +enum vect_epilogue_mode {
>>>> +  VECT_EPILOGUE_COMBINE = 1 << 0,
>>>> +  VECT_EPILOGUE_MASK = 1 << 1,
>>>> +  VECT_EPILOGUE_NOMASK = 1 << 2,
>>>> +  VECT_EPILOGUE_ALL = VECT_EPILOGUE_COMBINE | VECT_EPILOGUE_MASK
>>>> +                     | VECT_EPILOGUE_NOMASK
>>>> +};
>>>> +
>>>>  /* Different instrumentation modes.  */
>>>>  enum sanitize_code {
>>>>    /* AddressSanitizer.  */
>>>> diff --git a/gcc/opts.c b/gcc/opts.c
>>>> index 0f9431a..a0c0987 100644
>>>> --- a/gcc/opts.c
>>>> +++ b/gcc/opts.c
>>>> @@ -1531,6 +1531,63 @@ parse_sanitizer_options (const char *p, location_t loc, int scode,
>>>>    return flags;
>>>>  }
>>>>
>>>> +/* Parse comma separated vectorizer suboptions from P for option SCODE,
>>>> +   adjust previous FLAGS and return new ones.  If COMPLAIN is false,
>>>> +   don't issue diagnostics.  */
>>>> +
>>>> +unsigned int
>>>> +parse_vectorizer_options (const char *p, location_t loc, int scode,
>>>> +                         unsigned int flags, int value, bool complain)
>>>> +{
>>>> +  if (scode != OPT_ftree_vectorize_epilogues_)
>>>> +    return flags;
>>>> +
>>>> +  if (!p)
>>>> +    return value;
>>>> +
>>>> +  while (*p != 0)
>>>> +    {
>>>> +      size_t len;
>>>> +      const char *comma = strchr (p, ',');
>>>> +      unsigned int flag = 0;
>>>> +
>>>> +      if (comma == NULL)
>>>> +       len = strlen (p);
>>>> +      else
>>>> +       len = comma - p;
>>>> +      if (len == 0)
>>>> +       {
>>>> +         p = comma + 1;
>>>> +         continue;
>>>> +       }
>>>> +
>>>> +      /* Check to see if the string matches an option class name.  */
>>>> +      if (len == strlen ("combine")
>>>> +         && memcmp (p, "combine", len) == 0)
>>>> +       flag = VECT_EPILOGUE_COMBINE;
>>>> +      else if (len == strlen ("mask")
>>>> +         && memcmp (p, "mask", len) == 0)
>>>> +       flag = VECT_EPILOGUE_MASK;
>>>> +      else if (len == strlen ("nomask")
>>>> +         && memcmp (p, "nomask", len) == 0)
>>>> +       flag = VECT_EPILOGUE_NOMASK;
>>>> +      else if (complain)
>>>> +       error_at (loc, "unrecognized argument to -ftree-vectorize-epilogues= "
>>>> +                 "option: %q.*s", (int) len, p);
>>>> +
>>>> +      if (value)
>>>> +       flags |= flag;
>>>> +      else
>>>> +       flags &= ~flag;
>>>> +
>>>> +      if (comma == NULL)
>>>> +       break;
>>>> +      p = comma + 1;
>>>> +    }
>>>> +
>>>> +  return flags;
>>>> +}
>>>> +
>>>>  /* Handle target- and language-independent options.  Return zero to
>>>>     generate an "unknown option" message.  Only options that need
>>>>     extra handling need to be listed here; if you simply want
>>>> @@ -2018,6 +2075,18 @@ common_handle_option (struct gcc_options *opts,
>>>>        if (!opts_set->x_flag_tree_slp_vectorize)
>>>>          opts->x_flag_tree_slp_vectorize = value;
>>>>        break;
>>>> +
>>>> +    case OPT_ftree_vectorize_epilogues_:
>>>> +      opts->x_flag_tree_vectorize_epilogues
>>>> +       = parse_vectorizer_options (arg, loc, code,
>>>> +                                   opts->x_flag_tree_vectorize_epilogues,
>>>> +                                   value, true);
>>>> +      break;
>>>> +
>>>> +    case OPT_fno_tree_vectorize_epilogues:
>>>> +      opts->x_flag_tree_vectorize_epilogues = 0;
>>>> +      break;
>>>> +
>>>>      case OPT_fshow_column:
>>>>        dc->show_column = value;
>>>>        break;