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* [PATCH] Fix PR66870 ppc64le, ppc64 split stack
@ 2015-07-30 21:10 Lynn A. Boger
  2015-07-31  8:11 ` Alan Modra
  0 siblings, 1 reply; 4+ messages in thread
From: Lynn A. Boger @ 2015-07-30 21:10 UTC (permalink / raw)
  To: gcc-patches

[-- Attachment #1: Type: text/plain, Size: 732 bytes --]

The attached patch fixes a problem identified in PR66870 with
split stack on ppc64 and ppc64le.  If flag_split_stack is true, but
the function being processed has the no_split_stack attribute, then
the split stack prologue should not be generated.

Bootstrapped on ppc64le-linux and ppc64-linux, passed the
go and libgo testsuites (where split stack is enabled by default).


gcc/ChangeLog

2015-07-30    Lynn Boger <laboger@linux.vnet.ibm.com>

                 PR66870
                 * gcc/config/rs6000/rs6000.c:  Add check for no_split_stack
                 function attribute along with flag_split_stack check to
                 determine when to generate split stack prologue for
                 ppc64 and ppc64le.







[-- Attachment #2: gccgo-no-split-stack-fix.diff --]
[-- Type: text/x-patch, Size: 2200 bytes --]

Index: gcc/config/rs6000/rs6000.c
===================================================================
--- gcc/config/rs6000/rs6000.c	(revision 226401)
+++ gcc/config/rs6000/rs6000.c	(working copy)
@@ -23736,6 +23736,10 @@ rs6000_emit_prologue (void)
   int using_static_chain_p = (cfun->static_chain_decl != NULL_TREE
 			      && df_regs_ever_live_p (STATIC_CHAIN_REGNUM)
 			      && call_used_regs[STATIC_CHAIN_REGNUM]);
+  int using_split_stack = flag_split_stack &&
+   (lookup_attribute ("no_split_stack", DECL_ATTRIBUTES (cfun->decl))
+         == NULL);
+ 
   /* Offset to top of frame for frame_reg and sp respectively.  */
   HOST_WIDE_INT frame_off = 0;
   HOST_WIDE_INT sp_off = 0;
@@ -24006,7 +24010,7 @@ rs6000_emit_prologue (void)
       && info->cr_save_p
       && REGNO (frame_reg_rtx) != cr_save_regno
       && !(using_static_chain_p && cr_save_regno == 11)
-      && !(flag_split_stack && cr_save_regno == 12 && sp_adjust))
+      && !(using_split_stack && cr_save_regno == 12 && sp_adjust))
     {
       cr_save_rtx = gen_rtx_REG (SImode, cr_save_regno);
       START_USE (cr_save_regno);
@@ -24584,7 +24588,7 @@ rs6000_emit_prologue (void)
       if ((DEFAULT_ABI == ABI_AIX || DEFAULT_ABI == ABI_ELFv2)
 	  && !using_static_chain_p)
 	save_regno = 11;
-      else if (flag_split_stack || REGNO (frame_reg_rtx) == 12)
+      else if (using_split_stack || REGNO (frame_reg_rtx) == 12)
 	{
 	  save_regno = 11;
 	  if (using_static_chain_p)
@@ -24687,7 +24691,7 @@ rs6000_emit_prologue (void)
       emit_insn (gen_frame_store (reg, sp_reg_rtx, RS6000_TOC_SAVE_SLOT));
     }
 
-  if (flag_split_stack && split_stack_arg_pointer_used_p ())
+  if (using_split_stack && split_stack_arg_pointer_used_p ())
     {
       /* Set up the arg pointer (r12) for -fsplit-stack code.  If
 	 __morestack was called, it left the arg pointer to the old
@@ -26274,7 +26278,10 @@ rs6000_expand_split_stack_prologue (void)
 static rtx
 rs6000_internal_arg_pointer (void)
 {
-  if (flag_split_stack)
+  if (flag_split_stack
+     && (lookup_attribute ("no_split_stack", DECL_ATTRIBUTES (cfun->decl))
+         == NULL))
+
     {
       if (cfun->machine->split_stack_arg_pointer == NULL_RTX)
 	{

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH] Fix PR66870 ppc64le, ppc64 split stack
  2015-07-30 21:10 [PATCH] Fix PR66870 ppc64le, ppc64 split stack Lynn A. Boger
@ 2015-07-31  8:11 ` Alan Modra
  2015-07-31  9:31   ` David Edelsohn
  0 siblings, 1 reply; 4+ messages in thread
From: Alan Modra @ 2015-07-31  8:11 UTC (permalink / raw)
  To: Lynn A. Boger, David Edelsohn; +Cc: gcc-patches

On Thu, Jul 30, 2015 at 03:30:12PM -0500, Lynn A. Boger wrote:
>                 PR66870
>                 * gcc/config/rs6000/rs6000.c:  Add check for no_split_stack
>                 function attribute along with flag_split_stack check to
>                 determine when to generate split stack prologue for
>                 ppc64 and ppc64le.

Looks good to me, except that the changelog entry should mention the
modified functions, for example:

	PR target/66870
	* gcc/config/rs6000/rs6000.c (rs6000_emit_prologue): Check for
	no_split_stack function attribute along with flag_split_stack.
	(rs6000_expand_split_stack_prologue): Likewise.

Also, formatting rules for gcc say to not split a line after an
operator.

> +  int using_split_stack = flag_split_stack &&
> +   (lookup_attribute ("no_split_stack", DECL_ATTRIBUTES (cfun->decl))
> +         == NULL);

The "&&" belongs on the next line, with parentheses added so that emacs
and indent will line up the continuation nicely.

  int using_split_stack = (flag_split_stack
			   && (lookup_attribute ("no_split_stack",
						 DECL_ATTRIBUTES (cfun->decl))
			       == NULL));


David, the following is another piece of the PR66870 fixes.  This
stops shrink-wrap from moving insns around in the first few blocks of
a function, in a way that is incorrect given that r12 is live.
Bootstrapped and regression tested powerpc64le-linux (and
powerpc64-linux by Lynn).

	PR target/66870
	* config/rs6000/rs6000.c (machine_function): Add split_stack_argp_used.
	(rs6000_emit_prologue): Set it.
	(rs6000_set_up_by_prologue): Specify r12 when split_stack_argp_used.

diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c
index 5d9ff88..dc2e20c 100644
--- a/gcc/config/rs6000/rs6000.c
+++ b/gcc/config/rs6000/rs6000.c
@@ -166,6 +166,7 @@ typedef struct GTY(()) machine_function
   rtx sdmode_stack_slot;
   /* Alternative internal arg pointer for -fsplit-stack.  */
   rtx split_stack_arg_pointer;
+  bool split_stack_argp_used;
   /* Flag if r2 setup is needed with ELFv2 ABI.  */
   bool r2_setup_needed;
 } machine_function;
@@ -24458,6 +24459,7 @@ rs6000_emit_prologue (void)
 	 __morestack was called, it left the arg pointer to the old
 	 stack in r29.  Otherwise, the arg pointer is the top of the
 	 current frame.  */
+      cfun->machine->split_stack_argp_used = true;
       if (sp_adjust)
 	{
 	  rtx r12 = gen_rtx_REG (Pmode, 12);
@@ -33711,6 +33713,8 @@ rs6000_set_up_by_prologue (struct hard_reg_set_container *set)
       && TARGET_MINIMAL_TOC
       && get_pool_size () != 0)
     add_to_hard_reg_set (&set->set, Pmode, RS6000_PIC_OFFSET_TABLE_REGNUM);
+  if (cfun->machine->split_stack_argp_used)
+    add_to_hard_reg_set (&set->set, Pmode, 12);
 }
 
 \f


-- 
Alan Modra
Australia Development Lab, IBM

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH] Fix PR66870 ppc64le, ppc64 split stack
  2015-07-31  8:11 ` Alan Modra
@ 2015-07-31  9:31   ` David Edelsohn
  2015-08-05  1:22     ` Lynn Boger
  0 siblings, 1 reply; 4+ messages in thread
From: David Edelsohn @ 2015-07-31  9:31 UTC (permalink / raw)
  To: Alan Modra; +Cc: Lynn A. Boger, gcc-patches

On Fri, Jul 31, 2015 at 12:00 AM, Alan Modra <amodra@gmail.com> wrote:
> On Thu, Jul 30, 2015 at 03:30:12PM -0500, Lynn A. Boger wrote:
>>                 PR66870
>>                 * gcc/config/rs6000/rs6000.c:  Add check for no_split_stack
>>                 function attribute along with flag_split_stack check to
>>                 determine when to generate split stack prologue for
>>                 ppc64 and ppc64le.
>
> Looks good to me, except that the changelog entry should mention the
> modified functions, for example:
>
>         PR target/66870
>         * gcc/config/rs6000/rs6000.c (rs6000_emit_prologue): Check for
>         no_split_stack function attribute along with flag_split_stack.
>         (rs6000_expand_split_stack_prologue): Likewise.
>
> Also, formatting rules for gcc say to not split a line after an
> operator.
>
>> +  int using_split_stack = flag_split_stack &&
>> +   (lookup_attribute ("no_split_stack", DECL_ATTRIBUTES (cfun->decl))
>> +         == NULL);
>
> The "&&" belongs on the next line, with parentheses added so that emacs
> and indent will line up the continuation nicely.
>
>   int using_split_stack = (flag_split_stack
>                            && (lookup_attribute ("no_split_stack",
>                                                  DECL_ATTRIBUTES (cfun->decl))
>                                == NULL));
>
>
> David, the following is another piece of the PR66870 fixes.  This
> stops shrink-wrap from moving insns around in the first few blocks of
> a function, in a way that is incorrect given that r12 is live.
> Bootstrapped and regression tested powerpc64le-linux (and
> powerpc64-linux by Lynn).
>
>         PR target/66870
>         * config/rs6000/rs6000.c (machine_function): Add split_stack_argp_used.
>         (rs6000_emit_prologue): Set it.
>         (rs6000_set_up_by_prologue): Specify r12 when split_stack_argp_used.

Both patches with your suggested changes are okay.

Thanks, David

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH] Fix PR66870 ppc64le, ppc64 split stack
  2015-07-31  9:31   ` David Edelsohn
@ 2015-08-05  1:22     ` Lynn Boger
  0 siblings, 0 replies; 4+ messages in thread
From: Lynn Boger @ 2015-08-05  1:22 UTC (permalink / raw)
  To: David Edelsohn, Alan Modra; +Cc: gcc-patches

[-- Attachment #1: Type: text/plain, Size: 2416 bytes --]

Updated changelog and attached patch based on Alan's comments.

gcc/ChangeLog

2015-07-30    Lynn Boger <laboger@linux.vnet.ibm.com>

		PR66870
         	* gcc/config/rs6000/rs6000.c (rs6000_emit_prologue): Check for
         	no_split_stack function attribute along with flag_split_stack.
         	(rs6000_expand_split_stack_prologue): Likewise.


On 7/31/2015 4:00 AM, David Edelsohn wrote:
> On Fri, Jul 31, 2015 at 12:00 AM, Alan Modra <amodra@gmail.com> wrote:
>> On Thu, Jul 30, 2015 at 03:30:12PM -0500, Lynn A. Boger wrote:
>>>                  PR66870
>>>                  * gcc/config/rs6000/rs6000.c:  Add check for no_split_stack
>>>                  function attribute along with flag_split_stack check to
>>>                  determine when to generate split stack prologue for
>>>                  ppc64 and ppc64le.
>> Looks good to me, except that the changelog entry should mention the
>> modified functions, for example:
>>
>>          PR target/66870
>>          * gcc/config/rs6000/rs6000.c (rs6000_emit_prologue): Check for
>>          no_split_stack function attribute along with flag_split_stack.
>>          (rs6000_expand_split_stack_prologue): Likewise.
>>
>> Also, formatting rules for gcc say to not split a line after an
>> operator.
>>
>>> +  int using_split_stack = flag_split_stack &&
>>> +   (lookup_attribute ("no_split_stack", DECL_ATTRIBUTES (cfun->decl))
>>> +         == NULL);
>> The "&&" belongs on the next line, with parentheses added so that emacs
>> and indent will line up the continuation nicely.
>>
>>    int using_split_stack = (flag_split_stack
>>                             && (lookup_attribute ("no_split_stack",
>>                                                   DECL_ATTRIBUTES (cfun->decl))
>>                                 == NULL));
>>
>>
>> David, the following is another piece of the PR66870 fixes.  This
>> stops shrink-wrap from moving insns around in the first few blocks of
>> a function, in a way that is incorrect given that r12 is live.
>> Bootstrapped and regression tested powerpc64le-linux (and
>> powerpc64-linux by Lynn).
>>
>>          PR target/66870
>>          * config/rs6000/rs6000.c (machine_function): Add split_stack_argp_used.
>>          (rs6000_emit_prologue): Set it.
>>          (rs6000_set_up_by_prologue): Specify r12 when split_stack_argp_used.
> Both patches with your suggested changes are okay.
>
> Thanks, David
>
>


[-- Attachment #2: gccgo-no-split-stack-review.diff --]
[-- Type: text/plain, Size: 2283 bytes --]

Index: gcc/config/rs6000/rs6000.c
===================================================================
--- gcc/config/rs6000/rs6000.c  (revision 226606)
+++ gcc/config/rs6000/rs6000.c  (working copy)
@@ -23748,6 +23748,11 @@
   int using_static_chain_p = (cfun->static_chain_decl != NULL_TREE
                              && df_regs_ever_live_p (STATIC_CHAIN_REGNUM)
                              && call_used_regs[STATIC_CHAIN_REGNUM]);
+  int using_split_stack = (flag_split_stack
+                           && (lookup_attribute ("no_split_stack",
+                                                 DECL_ATTRIBUTES (cfun->decl))
+                               == NULL));
+ 
   /* Offset to top of frame for frame_reg and sp respectively.  */
   HOST_WIDE_INT frame_off = 0;
   HOST_WIDE_INT sp_off = 0;
@@ -24018,7 +24023,7 @@
       && info->cr_save_p
       && REGNO (frame_reg_rtx) != cr_save_regno
       && !(using_static_chain_p && cr_save_regno == 11)
-      && !(flag_split_stack && cr_save_regno == 12 && sp_adjust))
+      && !(using_split_stack && cr_save_regno == 12 && sp_adjust))
     {
       cr_save_rtx = gen_rtx_REG (SImode, cr_save_regno);
       START_USE (cr_save_regno);
@@ -24596,7 +24601,7 @@
       if ((DEFAULT_ABI == ABI_AIX || DEFAULT_ABI == ABI_ELFv2)
          && !using_static_chain_p)
        save_regno = 11;
-      else if (flag_split_stack || REGNO (frame_reg_rtx) == 12)
+      else if (using_split_stack || REGNO (frame_reg_rtx) == 12)
        {
          save_regno = 11;
          if (using_static_chain_p)
@@ -24699,7 +24704,7 @@
       emit_insn (gen_frame_store (reg, sp_reg_rtx, RS6000_TOC_SAVE_SLOT));
     }
 
-  if (flag_split_stack && split_stack_arg_pointer_used_p ())
+  if (using_split_stack && split_stack_arg_pointer_used_p ())
     {
       /* Set up the arg pointer (r12) for -fsplit-stack code.  If
         __morestack was called, it left the arg pointer to the old
@@ -26287,7 +26292,10 @@
 static rtx
 rs6000_internal_arg_pointer (void)
 {
-  if (flag_split_stack)
+  if (flag_split_stack
+     && (lookup_attribute ("no_split_stack", DECL_ATTRIBUTES (cfun->decl))
+         == NULL))
+
     {
       if (cfun->machine->split_stack_arg_pointer == NULL_RTX)
        {

^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2015-08-05  1:22 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2015-07-30 21:10 [PATCH] Fix PR66870 ppc64le, ppc64 split stack Lynn A. Boger
2015-07-31  8:11 ` Alan Modra
2015-07-31  9:31   ` David Edelsohn
2015-08-05  1:22     ` Lynn Boger

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