Patchwork Fix PR tree-optimization/47005

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Submitter Eric Botcazou
Date Jan. 4, 2011, 5:30 p.m.
Message ID <201101041830.19491.ebotcazou@adacore.com>
Download mbox | patch
Permalink /patch/77504/
State New
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Comments

Eric Botcazou - Jan. 4, 2011, 5:30 p.m.
Hi,

this is the recent failure of ACATS c62002a at -O2 on platforms that use SJLJ 
exceptions, for example the ARM.  It's an aliasing issue created by IPA-SRA 
whose fix is the equivalent of:

2010-07-28  Eric Botcazou  <ebotcazou@adacore.com>

	PR tree-optimization/44885
	* tree-sra.c (find_param_candidates): Skip pointer types to arrays
	with non-aliased component.

but for the other special aliasing flag, namely DECL_NONADDRESSABLE_P.

Tested on i586-suse-linux, OK for the mainline?


2011-01-04  Eric Botcazou  <ebotcazou@adacore.com>

	PR tree-optimization/47005
	* tree-sra.c (struct access): Add 'non_addressable' bit.
	(create_access): Set it for a DECL_NONADDRESSABLE_P field.
	(decide_one_param_reduction): Return 0 if the parameter is passed by
	reference and one of the accesses in the group is non_addressable.


2011-01-04  Eric Botcazou  <ebotcazou@adacore.com>

	* gnat.dg/opt14.adb: New test.
Richard Guenther - Jan. 5, 2011, 10:54 a.m.
On Tue, Jan 4, 2011 at 6:30 PM, Eric Botcazou <ebotcazou@adacore.com> wrote:
> Hi,
>
> this is the recent failure of ACATS c62002a at -O2 on platforms that use SJLJ
> exceptions, for example the ARM.  It's an aliasing issue created by IPA-SRA
> whose fix is the equivalent of:
>
> 2010-07-28  Eric Botcazou  <ebotcazou@adacore.com>
>
>        PR tree-optimization/44885
>        * tree-sra.c (find_param_candidates): Skip pointer types to arrays
>        with non-aliased component.
>
> but for the other special aliasing flag, namely DECL_NONADDRESSABLE_P.
>
> Tested on i586-suse-linux, OK for the mainline?

Ok.

Thanks,
Richard.

>
> 2011-01-04  Eric Botcazou  <ebotcazou@adacore.com>
>
>        PR tree-optimization/47005
>        * tree-sra.c (struct access): Add 'non_addressable' bit.
>        (create_access): Set it for a DECL_NONADDRESSABLE_P field.
>        (decide_one_param_reduction): Return 0 if the parameter is passed by
>        reference and one of the accesses in the group is non_addressable.
>
>
> 2011-01-04  Eric Botcazou  <ebotcazou@adacore.com>
>
>        * gnat.dg/opt14.adb: New test.
>
>
> --
> Eric Botcazou
>

Patch

Index: tree-sra.c
===================================================================
--- tree-sra.c	(revision 168391)
+++ tree-sra.c	(working copy)
@@ -173,6 +173,9 @@  struct access
      entirely? */
   unsigned total_scalarization : 1;
 
+  /* Is this access an access to a non-addressable field? */
+  unsigned non_addressable : 1;
+
   /* Is this access currently in the work queue?  */
   unsigned grp_queued : 1;
 
@@ -815,6 +818,10 @@  create_access (tree expr, gimple stmt, b
   access->grp_unscalarizable_region = unscalarizable_region;
   access->stmt = stmt;
 
+  if (TREE_CODE (expr) == COMPONENT_REF
+      && DECL_NONADDRESSABLE_P (TREE_OPERAND (expr, 1)))
+    access->non_addressable = 1;
+
   return access;
 }
 
@@ -3665,13 +3672,18 @@  decide_one_param_reduction (struct acces
   for (; repr; repr = repr->next_grp)
     {
       gcc_assert (parm == repr->base);
-      new_param_count++;
+
+      /* Taking the address of a non-addressable field is verboten.  */
+      if (by_ref && repr->non_addressable)
+	return 0;
 
       if (!by_ref || (!repr->grp_maybe_modified
 		      && !repr->grp_not_necessarilly_dereferenced))
 	total_size += repr->size;
       else
 	total_size += cur_parm_size;
+
+      new_param_count++;
     }
 
   gcc_assert (new_param_count > 0);