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re PR tree-optimization/30562 (remove unused variable is removing a referenced variable (in STORED_SYMS or LOADED_SYMS))

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PR 30562
	* tree-flow.h (struct var_ann_d): Remove field 'is_used'.
	Update all users.
	* tree-ssa-alias.c (compute_is_aliased): Remove.  Update all
	users.
	(init_alias_info):
	* tree-ssa-live.c (remove_unused_locals): Do not remove
	TREE_ADDRESSABLE variables.
	* tree-ssa-structalias.c (compute_points_to_sets): Tidy.
	* tree-ssa-operands.c (add_virtual_operand): Remove argument
	FOR_CLOBBER.  Update all users.
	If VAR has an associated alias set, add a virtual operand for
	it if no alias is found to conflict with the memory reference.

From-SVN: r121715
This commit is contained in:
Diego Novillo 2007-02-08 16:55:43 +00:00 • committed by Diego Novillo
parent e35a0e6476
commit d37d06fef8
8 changed files with 44 additions and 103 deletions
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16
gcc/ChangeLog
View file

@ -1,3 +1,19 @@
2007-02-08 Diego Novillo <dnovillo@redhat.com>
PR 30562
* tree-flow.h (struct var_ann_d): Remove field 'is_used'.
Update all users.
* tree-ssa-alias.c (compute_is_aliased): Remove. Update all
users.
(init_alias_info):
* tree-ssa-live.c (remove_unused_locals): Do not remove
TREE_ADDRESSABLE variables.
* tree-ssa-structalias.c (compute_points_to_sets): Tidy.
* tree-ssa-operands.c (add_virtual_operand): Remove argument
FOR_CLOBBER. Update all users.
If VAR has an associated alias set, add a virtual operand for
it if no alias is found to conflict with the memory reference.
2007-02-07 Jan Hubicka <jh@suse.cz>
Robert Kidd <rkidd@crhc.uiuc.edu>

3
gcc/tree-dfa.c
View file

@ -337,9 +337,6 @@ dump_variable (FILE *file, tree var)
print_generic_expr (file, ann->symbol_mem_tag, dump_flags);
}
if (ann && ann->is_aliased)
fprintf (file, ", is aliased");
if (TREE_ADDRESSABLE (var))
fprintf (file, ", is addressable");

3
gcc/tree-flow.h
View file

@ -228,9 +228,6 @@ struct var_ann_d GTY(())
/* Used when building base variable structures in a var_map. */
unsigned base_var_processed : 1;
/* Nonzero if this variable is in the alias set of another variable. */
unsigned is_aliased : 1;
/* Nonzero if this variable was used after SSA optimizations were
applied. We set this when translating out of SSA form. */
unsigned used : 1;

44
gcc/tree-ssa-alias.c
View file

@ -776,43 +776,6 @@ done:
timevar_pop (TV_MEMORY_PARTITIONING);
}
/* This function computes the value of the is_aliased bit for
variables. is_aliased is true for any variable that is in an
alias bitmap. */
static void
compute_is_aliased (void)
{
referenced_var_iterator rvi;
tree tag;
bitmap aliased_vars = BITMAP_ALLOC (NULL);
bitmap_iterator bi;
unsigned int i;
/* Add is_aliased for all vars pointed to by the symbol tags. */
FOR_EACH_REFERENCED_VAR (tag, rvi)
{
bitmap aliases;
if (TREE_CODE (tag) != SYMBOL_MEMORY_TAG
&& TREE_CODE (tag) != NAME_MEMORY_TAG)
continue;
aliases = MTAG_ALIASES (tag);
if (!aliases)
continue;
bitmap_ior_into (aliased_vars, aliases);
}
EXECUTE_IF_SET_IN_BITMAP (aliased_vars, 0, i, bi)
{
tree var = referenced_var (i);
var_ann (var)->is_aliased = true;
}
BITMAP_FREE (aliased_vars);
}
/* Compute may-alias information for every variable referenced in function
FNDECL.
@ -980,9 +943,6 @@ compute_may_aliases (void)
dump_points_to_info (dump_file);
dump_alias_info (dump_file);
}
/* Set up is_aliased flags. */
compute_is_aliased ();
/* Deallocate memory used by aliasing data structures. */
delete_alias_info (ai);
@ -1170,10 +1130,6 @@ init_alias_info (void)
/* Clear flow-insensitive alias information from each symbol. */
FOR_EACH_REFERENCED_VAR (var, rvi)
{
var_ann_t ann = var_ann (var);
ann->is_aliased = 0;
if (MTAG_P (var))
MTAG_ALIASES (var) = NULL;

14
gcc/tree-ssa-live.c
View file

@ -502,18 +502,20 @@ remove_unused_locals (void)
cell = &TREE_CHAIN (*cell);
}
/* Remove unused variables from REFERENCED_VARs. As an special exception
keep the variables that are believed to be aliased. Those can't be
easily removed from the alias sets and and operand caches.
They will be removed shortly after next may_alias pass is performed. */
/* Remove unused variables from REFERENCED_VARs. As a special
exception keep the variables that are believed to be aliased.
Those can't be easily removed from the alias sets and operand
caches. They will be removed shortly after the next may_alias
pass is performed. */
FOR_EACH_REFERENCED_VAR (t, rvi)
if (!is_global_var (t)
&& !MTAG_P (t)
&& TREE_CODE (t) != PARM_DECL
&& TREE_CODE (t) != RESULT_DECL
&& !(ann = var_ann (t))->used
&& !ann->is_aliased && !is_call_clobbered (t) && !ann->symbol_mem_tag)
remove_referenced_var (t);
&& !ann->symbol_mem_tag
&& !TREE_ADDRESSABLE (t))
remove_referenced_var (t);
}

47
gcc/tree-ssa-operands.c
View file

@ -1433,13 +1433,12 @@ access_can_touch_variable (tree ref, tree alias, HOST_WIDE_INT offset,
get_expr_operands. FULL_REF is a tree that contains the entire
pointer dereference expression, if available, or NULL otherwise.
OFFSET and SIZE come from the memory access expression that
generated this virtual operand. FOR_CLOBBER is true is this is
adding a virtual operand for a call clobber. */
generated this virtual operand. */
static void
add_virtual_operand (tree var, stmt_ann_t s_ann, int flags,
tree full_ref, HOST_WIDE_INT offset,
HOST_WIDE_INT size, bool for_clobber)
HOST_WIDE_INT size)
{
bitmap aliases = NULL;
tree sym;
@ -1514,24 +1513,13 @@ add_virtual_operand (tree var, stmt_ann_t s_ann, int flags,
append_vdef (al);
}
/* If the variable is also an alias tag, add a virtual
operand for it, otherwise we will miss representing
references to the members of the variable's alias set.
This fixes the bug in gcc.c-torture/execute/20020503-1.c.
It is also necessary to add bare defs on clobbers for
SMT's, so that bare SMT uses caused by pruning all the
aliases will link up properly with calls. In order to
keep the number of these bare defs we add down to the
minimum necessary, we keep track of which SMT's were used
alone in statement vdefs or VUSEs. */
if (v_ann->is_aliased
|| none_added
|| (TREE_CODE (var) == SYMBOL_MEMORY_TAG
&& for_clobber))
{
append_vdef (var);
}
/* Even if no aliases have been added, we still need to
establish def-use and use-def chains, lest
transformations think that this is not a memory
reference. For an example of this scenario, see
testsuite/g++.dg/opt/cleanup1.C. */
if (none_added)
append_vdef (var);
}
else
{
@ -1545,9 +1533,12 @@ add_virtual_operand (tree var, stmt_ann_t s_ann, int flags,
append_vuse (al);
}
/* Similarly, append a virtual uses for VAR itself, when
it is an alias tag. */
if (v_ann->is_aliased || none_added)
/* Even if no aliases have been added, we still need to
establish def-use and use-def chains, lest
transformations think that this is not a memory
reference. For an example of this scenario, see
testsuite/g++.dg/opt/cleanup1.C. */
if (none_added)
append_vuse (var);
}
}
@ -1584,7 +1575,7 @@ add_stmt_operand (tree *var_p, stmt_ann_t s_ann, int flags)
append_use (var_p);
}
else
add_virtual_operand (var, s_ann, flags, NULL_TREE, 0, -1, false);
add_virtual_operand (var, s_ann, flags, NULL_TREE, 0, -1);
}
@ -1631,7 +1622,7 @@ get_indirect_ref_operands (tree stmt, tree expr, int flags,
{
/* PTR has its own memory tag. Use it. */
add_virtual_operand (pi->name_mem_tag, s_ann, flags,
full_ref, offset, size, false);
full_ref, offset, size);
}
else
{
@ -1660,7 +1651,7 @@ get_indirect_ref_operands (tree stmt, tree expr, int flags,
if (v_ann->symbol_mem_tag)
add_virtual_operand (v_ann->symbol_mem_tag, s_ann, flags,
full_ref, offset, size, false);
full_ref, offset, size);
/* Aliasing information is missing; mark statement as volatile so we
won't optimize it out too actively. */
else if (s_ann && !gimple_aliases_computed_p (cfun)
@ -1818,7 +1809,7 @@ add_call_clobber_ops (tree stmt, tree callee)
clobber_stats.static_read_clobbers_avoided++;
}
else
add_virtual_operand (var, s_ann, opf_def, NULL, 0, -1, true);
add_virtual_operand (var, s_ann, opf_def, NULL, 0, -1);
}
}

1
gcc/tree-ssa-structalias.c
View file

@ -4663,6 +4663,7 @@ compute_points_to_sets (struct alias_info *ai)
if (is_gimple_reg (PHI_RESULT (phi)))
{
find_func_aliases (phi);
/* Update various related attributes like escaped
addresses, pointer dereferences for loads and stores.
This is used when creating name tags and alias

19
gcc/tree-ssa.c
View file

@ -375,7 +375,6 @@ static void
verify_flow_insensitive_alias_info (void)
{
tree var;
bitmap visited = BITMAP_ALLOC (NULL);
referenced_var_iterator rvi;
FOR_EACH_REFERENCED_VAR (var, rvi)
@ -393,7 +392,6 @@ verify_flow_insensitive_alias_info (void)
EXECUTE_IF_SET_IN_BITMAP (aliases, 0, j, bi)
{
alias = referenced_var (j);
bitmap_set_bit (visited, j);
if (TREE_CODE (alias) != MEMORY_PARTITION_TAG
&& !may_be_aliased (alias))
@ -405,23 +403,6 @@ verify_flow_insensitive_alias_info (void)
}
}
FOR_EACH_REFERENCED_VAR (var, rvi)
{
var_ann_t ann;
ann = var_ann (var);
if (!MTAG_P (var)
&& ann->is_aliased
&& memory_partition (var) == NULL_TREE
&& !bitmap_bit_p (visited, DECL_UID (var)))
{
error ("addressable variable that is aliased but is not in any "
"alias set");
goto err;
}
}
BITMAP_FREE (visited);
return;
err: