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

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Submitter Teresa Johnson
Date Sept. 27, 2013, 6:50 p.m.
Message ID <CAAe5K+X6nQrqasCKpDG4o5-o65vvP2jtBpkMqiaPSZH6hRGzmA@mail.gmail.com>
Download mbox | patch
Permalink /patch/278667/
State New
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Comments

Teresa Johnson - Sept. 27, 2013, 6:50 p.m.
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.
Xinliang David Li - Sept. 27, 2013, 7:01 p.m.
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?

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 - Sept. 27, 2013, 8:03 p.m.
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
Xinliang David Li - Sept. 27, 2013, 8:10 p.m.
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
Rong Xu - Sept. 27, 2013, 8:18 p.m.
I don't quite understand here. We use the profile-generate memory
consumption to estimate the profile use memory consumption.
we still have -g/-gmlt in profile-use compilation. Will this change
effectively under estimate the memory use in the use phrase?

-Rong

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.");
> -}
> +    }
>    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 - Sept. 27, 2013, 8:22 p.m.
The issue is that building the instrumented binary with and without,
say, -gmlt, may result in different module grouping.

Teresa

On Fri, Sep 27, 2013 at 1:18 PM, Rong Xu <xur@google.com> wrote:
> I don't quite understand here. We use the profile-generate memory
> consumption to estimate the profile use memory consumption.
> we still have -g/-gmlt in profile-use compilation. Will this change
> effectively under estimate the memory use in the use phrase?
>
> -Rong
>
> 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.");
>> -}
>> +    }
>>    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
Xinliang David Li - Sept. 27, 2013, 8:22 p.m.
The key is that grouping results should not dependent on the presence
of -g flags.  The downside of the patch is that it may slightly
underestimate the memory pressure at profile-use time, but that should
not be a big problem.

David

On Fri, Sep 27, 2013 at 1:18 PM, Rong Xu <xur@google.com> wrote:
> I don't quite understand here. We use the profile-generate memory
> consumption to estimate the profile use memory consumption.
> we still have -g/-gmlt in profile-use compilation. Will this change
> effectively under estimate the memory use in the use phrase?
>
> -Rong
>
> 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.");
>> -}
>> +    }
>>    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

Patch

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.");
-}
+    }
   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