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Re: [google/4_8] Disable -g/-gmlt during LIPO instrumentation


ok.

David

On Fri, Sep 27, 2013 at 1:03 PM, Teresa Johnson <tejohnson@google.com> wrote:
> On Fri, Sep 27, 2013 at 12:01 PM, Xinliang David Li <davidxl@google.com> wrote:
>> On Fri, Sep 27, 2013 at 11:50 AM, Teresa Johnson <tejohnson@google.com> wrote:
>>> David and Rong,
>>>
>>> The following patch will disable -g/-gmlt when instrumenting for LIPO
>>> since they will affect the recorded ggc_memory used in the module
>>> grouping decision. Added -fripa-allow-debug to override this behavior.
>>>
>>> Passes regression tests and simple tests on the new functionality.
>>>
>>> Ok for google/4_8?
>>>
>>> Teresa
>>>
>>> 2013-09-27  Teresa Johnson  <tejohnson@google.com>
>>>
>>>         * opts.c (finish_options): Suppress -g/-gmlt when we are
>>>         building for LIPO instrumention.
>>>         * common.opt (fripa-allow-debug): New option.
>>>
>>> Index: opts.c
>>> ===================================================================
>>> --- opts.c      (revision 202976)
>>> +++ opts.c      (working copy)
>>> @@ -799,7 +799,7 @@ finish_options (struct gcc_options *opts, struct g
>>>  #endif
>>>        if (!opts->x_flag_fat_lto_objects && !HAVE_LTO_PLUGIN)
>>>          error_at (loc, "-fno-fat-lto-objects are supported only with
>>> linker plugin.");
>>> -}
>>> +    }
>>
>>
>> Unrelated format change?
>
> Well, related in the sense that it messed up my editor's
> auto-indention logic when making the change below. Ok to include the
> formatting fix if I mention it in the commit log?
>
> Teresa
>
>>
>> Otherwise looks ok.
>>
>> thanks,
>>
>> David
>>
>>
>>>    if ((opts->x_flag_lto_partition_balanced != 0) +
>>> (opts->x_flag_lto_partition_1to1 != 0)
>>>         + (opts->x_flag_lto_partition_none != 0) >= 1)
>>>      {
>>> @@ -852,6 +852,26 @@ finish_options (struct gcc_options *opts, struct g
>>>    /* Turn on -ffunction-sections when -freorder-functions=* is used.  */
>>>    if (opts->x_flag_reorder_functions > 1)
>>>      opts->x_flag_function_sections = 1;
>>> +
>>> +  /* LIPO module grouping depends on the memory consumed by the profile-gen
>>> +     parsing phase, recorded in a per-module ggc_memory field of the module
>>> +     info struct. This will be higher when debug generation is on via
>>> +     -g/-gmlt, which causes the FE to generate debug structures that will
>>> +     increase the ggc_total_memory. This could in theory cause the module
>>> +     groups to be slightly more conservative. Disable -g/-gmlt under
>>> +     -fripa -fprofile-generate, but provide an option to override this
>>> +     in case we actually need to debug an instrumented binary.  */
>>> +  if (opts->x_profile_arc_flag
>>> +      && opts->x_flag_dyn_ipa
>>> +      && opts->x_debug_info_level != DINFO_LEVEL_NONE
>>> +      && !opts->x_flag_dyn_ipa_allow_debug)
>>> +    {
>>> +      inform (loc,
>>> +             "Debug generation via -g option disabled under -fripa "
>>> +              "-fprofile-generate (use -fripa-allow-debug to override)");
>>> +      set_debug_level (NO_DEBUG, DEFAULT_GDB_EXTENSIONS, "0", opts, opts_set,
>>> +                       loc);
>>> +    }
>>>  }
>>>
>>>  #define LEFT_COLUMN    27
>>> Index: common.opt
>>> ===================================================================
>>> --- common.opt  (revision 202976)
>>> +++ common.opt  (working copy)
>>> @@ -1155,6 +1155,10 @@ fripa
>>>  Common Report Var(flag_dyn_ipa)
>>>  Perform Dynamic Inter-Procedural Analysis.
>>>
>>> +fripa-allow-debug
>>> +Common Report Var(flag_dyn_ipa_allow_debug) Init(0)
>>> +Allow -g enablement for -fripa -fprofile-generate compiles.
>>> +
>>>  fripa-disallow-asm-modules
>>>  Common Report Var(flag_ripa_disallow_asm_modules)
>>>  Don't import an auxiliary module if it contains asm statements
>>>
>>> --
>>> Teresa Johnson | Software Engineer | tejohnson@google.com | 408-460-2413
>
>
>
> --
> Teresa Johnson | Software Engineer | tejohnson@google.com | 408-460-2413


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