re PR middle-end/61456 (Bogus "may be used uninitialized" warning)

2014-06-10  Richard Biener  <rguenther@suse.de>

	PR middle-end/61456
	* tree-ssa-alias.c (nonoverlapping_component_refs_of_decl_p):
	Do not use the main variant for the type comparison.
	(ncr_compar): Likewise.
	(nonoverlapping_component_refs_p): Likewise.

	* g++.dg/opt/pr61456.C: New testcase.

From-SVN: r211411
This commit is contained in:
Richard Biener 2014-06-10 14:10:57 +00:00 committed by Richard Biener
parent f1ab971761
commit cdf0ab72f4
4 changed files with 49 additions and 12 deletions

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@ -1,3 +1,11 @@
2014-06-10 Richard Biener <rguenther@suse.de>
PR middle-end/61456
* tree-ssa-alias.c (nonoverlapping_component_refs_of_decl_p):
Do not use the main variant for the type comparison.
(ncr_compar): Likewise.
(nonoverlapping_component_refs_p): Likewise.
2014-06-10 Marcus Shawcroft <marcus.shawcroft@arm.com>
* config/aarch64/aarch64.c (aarch64_save_or_restore_fprs): Fix

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@ -1,3 +1,8 @@
2014-06-10 Richard Biener <rguenther@suse.de>
PR middle-end/61456
* g++.dg/opt/pr61456.C: New testcase.
2014-06-10 Dominique d'Humieres <dominiq@lps.ens.fr>
Mikael Morin <mikael@gcc.gnu.org>

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@ -0,0 +1,26 @@
// { dg-do compile }
// { dg-options "-O2 -std=c++11 -Werror=uninitialized" }
int rand ();
class Funcs
{
public:
int *f1 ();
int *f2 ();
};
typedef decltype (&Funcs::f1) pfunc;
static int Set (Funcs * f, const pfunc & fp)
{
(f->*fp) ();
}
void
Foo ()
{
pfunc fp = &Funcs::f1;
if (rand ())
fp = &Funcs::f2;
Set (0, fp);
}

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@ -835,8 +835,8 @@ nonoverlapping_component_refs_of_decl_p (tree ref1, tree ref2)
/* ??? We cannot simply use the type of operand #0 of the refs here
as the Fortran compiler smuggles type punning into COMPONENT_REFs
for common blocks instead of using unions like everyone else. */
tree type1 = TYPE_MAIN_VARIANT (DECL_CONTEXT (field1));
tree type2 = TYPE_MAIN_VARIANT (DECL_CONTEXT (field2));
tree type1 = DECL_CONTEXT (field1);
tree type2 = DECL_CONTEXT (field2);
/* We cannot disambiguate fields in a union or qualified union. */
if (type1 != type2 || TREE_CODE (type1) != RECORD_TYPE)
@ -866,10 +866,8 @@ ncr_compar (const void *field1_, const void *field2_)
{
const_tree field1 = *(const_tree *) const_cast <void *>(field1_);
const_tree field2 = *(const_tree *) const_cast <void *>(field2_);
unsigned int uid1
= TYPE_UID (TYPE_MAIN_VARIANT (DECL_FIELD_CONTEXT (field1)));
unsigned int uid2
= TYPE_UID (TYPE_MAIN_VARIANT (DECL_FIELD_CONTEXT (field2)));
unsigned int uid1 = TYPE_UID (DECL_FIELD_CONTEXT (field1));
unsigned int uid2 = TYPE_UID (DECL_FIELD_CONTEXT (field2));
if (uid1 < uid2)
return -1;
else if (uid1 > uid2)
@ -893,7 +891,7 @@ nonoverlapping_component_refs_p (const_tree x, const_tree y)
while (TREE_CODE (x) == COMPONENT_REF)
{
tree field = TREE_OPERAND (x, 1);
tree type = TYPE_MAIN_VARIANT (DECL_FIELD_CONTEXT (field));
tree type = DECL_FIELD_CONTEXT (field);
if (TREE_CODE (type) == RECORD_TYPE)
fieldsx.safe_push (field);
x = TREE_OPERAND (x, 0);
@ -904,7 +902,7 @@ nonoverlapping_component_refs_p (const_tree x, const_tree y)
while (TREE_CODE (y) == COMPONENT_REF)
{
tree field = TREE_OPERAND (y, 1);
tree type = TYPE_MAIN_VARIANT (DECL_FIELD_CONTEXT (field));
tree type = DECL_FIELD_CONTEXT (field);
if (TREE_CODE (type) == RECORD_TYPE)
fieldsy.safe_push (TREE_OPERAND (y, 1));
y = TREE_OPERAND (y, 0);
@ -915,8 +913,8 @@ nonoverlapping_component_refs_p (const_tree x, const_tree y)
/* Most common case first. */
if (fieldsx.length () == 1
&& fieldsy.length () == 1)
return ((TYPE_MAIN_VARIANT (DECL_FIELD_CONTEXT (fieldsx[0]))
== TYPE_MAIN_VARIANT (DECL_FIELD_CONTEXT (fieldsy[0])))
return ((DECL_FIELD_CONTEXT (fieldsx[0])
== DECL_FIELD_CONTEXT (fieldsy[0]))
&& fieldsx[0] != fieldsy[0]
&& !(DECL_BIT_FIELD (fieldsx[0]) && DECL_BIT_FIELD (fieldsy[0])));
@ -949,8 +947,8 @@ nonoverlapping_component_refs_p (const_tree x, const_tree y)
{
const_tree fieldx = fieldsx[i];
const_tree fieldy = fieldsy[j];
tree typex = TYPE_MAIN_VARIANT (DECL_FIELD_CONTEXT (fieldx));
tree typey = TYPE_MAIN_VARIANT (DECL_FIELD_CONTEXT (fieldy));
tree typex = DECL_FIELD_CONTEXT (fieldx);
tree typey = DECL_FIELD_CONTEXT (fieldy);
if (typex == typey)
{
/* We're left with accessing different fields of a structure,