This finally switches us to not record global vars in referenced-vars.
For this to work I had to re-engineer how we handle global var removal
from local-decls in remove_unused_locals. Incidentially that code
already had some sort of a bitmap (for some weird reason even), thus
I borrowed that and simplified the handling. You may notice that
it would be easy to handle all vars that way ...
So eventually 5/n will make referenced-vars go away completely
(the only serious user seems to be the SSA renamer for its
SYMS_TO_RENAME bitmap).
Bootstrapped on x86_64-unknown-linux-gnu, testing in progress.
Richard.
2012-05-23 Richard Guenther <rguent...@suse.de>
* tree-dfa.c (add_referenced_var_1): Do not add global vars.
* tree-ssa-live.c (mark_all_vars_used_1): Handle global vars
via the global_unused_vars bitmap.
(remove_unused_locals): Handle global vars in local-decls via
a global_unused_vars bitmap instead of the used flag in the
var annotation. Simplify global variable handling and removal.
* gcc.dg/torture/pr39074-2.c: Adjust.
* gcc.dg/torture/pr39074.c: Likewise.
* gcc.dg/torture/pta-structcopy-1.c: Likewise.
* gcc.dg/tree-ssa/alias-19.c: Likewise.
Index: gcc/tree-dfa.c
===================================================================
*** gcc/tree-dfa.c.orig 2012-05-22 14:50:50.000000000 +0200
--- gcc/tree-dfa.c 2012-05-22 15:26:37.868506459 +0200
*************** add_referenced_var_1 (tree var, struct f
*** 581,586 ****
--- 581,591 ----
|| TREE_CODE (var) == PARM_DECL
|| TREE_CODE (var) == RESULT_DECL);
+ if (!(TREE_CODE (var) == VAR_DECL
+ && VAR_DECL_IS_VIRTUAL_OPERAND (var))
+ && is_global_var (var))
+ return false;
+
if (!*DECL_VAR_ANN_PTR (var))
create_var_ann (var);
Index: gcc/testsuite/gcc.dg/torture/pr39074-2.c
===================================================================
*** gcc/testsuite/gcc.dg/torture/pr39074-2.c.orig 2011-12-06
10:39:54.000000000 +0100
--- gcc/testsuite/gcc.dg/torture/pr39074-2.c 2012-05-22 15:42:43.068473038
+0200
*************** int main()
*** 30,34 ****
return 0;
}
! /* { dg-final { scan-tree-dump "y.._., points-to vars: { i }" "alias" } } */
/* { dg-final { cleanup-tree-dump "alias" } } */
--- 30,35 ----
return 0;
}
! /* { dg-final { scan-tree-dump "y.._. = { i }" "alias" } } */
! /* { dg-final { scan-tree-dump "y.._., points-to vars: { D..... }" "alias" }
} */
/* { dg-final { cleanup-tree-dump "alias" } } */
Index: gcc/testsuite/gcc.dg/torture/pr39074.c
===================================================================
*** gcc/testsuite/gcc.dg/torture/pr39074.c.orig 2012-04-12 11:32:07.000000000
+0200
--- gcc/testsuite/gcc.dg/torture/pr39074.c 2012-05-22 15:43:07.770472209
+0200
*************** int main()
*** 29,33 ****
return 0;
}
! /* { dg-final { scan-tree-dump "y.._., points-to vars: { i }" "alias" } } */
/* { dg-final { cleanup-tree-dump "alias" } } */
--- 29,34 ----
return 0;
}
! /* { dg-final { scan-tree-dump "y.._. = { i }" "alias" } } */
! /* { dg-final { scan-tree-dump "y.._., points-to vars: { D..... }" "alias" }
} */
/* { dg-final { cleanup-tree-dump "alias" } } */
Index: gcc/testsuite/gcc.dg/torture/pta-structcopy-1.c
===================================================================
*** gcc/testsuite/gcc.dg/torture/pta-structcopy-1.c.orig 2011-06-21
13:06:08.000000000 +0200
--- gcc/testsuite/gcc.dg/torture/pta-structcopy-1.c 2012-05-22
15:42:19.922473852 +0200
*************** int main()
*** 31,35 ****
return 0;
}
! /* { dg-final { scan-tree-dump "points-to vars: { i }" "ealias" } } */
/* { dg-final { cleanup-tree-dump "ealias" } } */
--- 31,36 ----
return 0;
}
! /* { dg-final { scan-tree-dump "y.* = { i }" "ealias" } } */
! /* { dg-final { scan-tree-dump "y.*, points-to vars: { D..... }" "ealias" } }
*/
/* { dg-final { cleanup-tree-dump "ealias" } } */
Index: gcc/testsuite/gcc.dg/tree-ssa/alias-19.c
===================================================================
*** gcc/testsuite/gcc.dg/tree-ssa/alias-19.c.orig 2009-04-03
12:56:17.000000000 +0200
--- gcc/testsuite/gcc.dg/tree-ssa/alias-19.c 2012-05-22 15:39:53.318478953
+0200
*************** int main()
*** 26,30 ****
}
/* { dg-final { scan-tree-dump "q_. = { a b }" "alias" } } */
! /* { dg-final { scan-tree-dump "q_., points-to vars: { a b }" "alias" } } */
/* { dg-final { cleanup-tree-dump "alias" } } */
--- 26,30 ----
}
/* { dg-final { scan-tree-dump "q_. = { a b }" "alias" } } */
! /* { dg-final { scan-tree-dump "q_., points-to vars: { D..... b }" "alias" }
} */
/* { dg-final { cleanup-tree-dump "alias" } } */
Index: gcc/tree-ssa-live.c
===================================================================
*** gcc/tree-ssa-live.c (revision 187771)
--- gcc/tree-ssa-live.c (working copy)
*************** static inline void mark_all_vars_used (t
*** 348,353 ****
--- 348,354 ----
static tree
mark_all_vars_used_1 (tree *tp, int *walk_subtrees, void *data)
{
+ bitmap global_unused_vars = (bitmap)data;
tree t = *tp;
enum tree_code_class c = TREE_CODE_CLASS (TREE_CODE (t));
tree b;
*************** mark_all_vars_used_1 (tree *tp, int *wal
*** 374,388 ****
eliminated as unused. */
if (TREE_CODE (t) == VAR_DECL)
{
! if (data != NULL && bitmap_clear_bit ((bitmap) data, DECL_UID (t))
! && DECL_CONTEXT (t) == current_function_decl)
! mark_all_vars_used (&DECL_INITIAL (t), data);
! if (var_ann (t) != NULL)
set_is_used (t);
}
/* remove_unused_scope_block_p requires information about labels
which are not DECL_IGNORED_P to tell if they might be used in the IL. */
! if (TREE_CODE (t) == LABEL_DECL)
/* Although the TREE_USED values that the frontend uses would be
acceptable (albeit slightly over-conservative) for our purposes,
init_vars_expansion clears TREE_USED for LABEL_DECLs too, so we
--- 375,394 ----
eliminated as unused. */
if (TREE_CODE (t) == VAR_DECL)
{
! /* Global vars do not have a var-annotation so their use is tracked
! with the global_unused_vars bitmap. Also walk their initializer
! when they are first recognized as used. */
! if (is_global_var (t))
! {
! if (bitmap_clear_bit (global_unused_vars, DECL_UID (t)))
! mark_all_vars_used (&DECL_INITIAL (t), data);
! }
! else
set_is_used (t);
}
/* remove_unused_scope_block_p requires information about labels
which are not DECL_IGNORED_P to tell if they might be used in the IL. */
! else if (TREE_CODE (t) == LABEL_DECL)
/* Although the TREE_USED values that the frontend uses would be
acceptable (albeit slightly over-conservative) for our purposes,
init_vars_expansion clears TREE_USED for LABEL_DECLs too, so we
*************** remove_unused_locals (void)
*** 689,695 ****
tree var, t;
referenced_var_iterator rvi;
bitmap global_unused_vars = NULL;
! unsigned srcidx, dstidx, num;
bool have_local_clobbers = false;
/* Removing declarations from lexical blocks when not optimizing is
--- 695,701 ----
tree var, t;
referenced_var_iterator rvi;
bitmap global_unused_vars = NULL;
! unsigned srcidx, dstidx, num, ix;
bool have_local_clobbers = false;
/* Removing declarations from lexical blocks when not optimizing is
*************** remove_unused_locals (void)
*** 706,711 ****
--- 712,724 ----
FOR_EACH_REFERENCED_VAR (cfun, t, rvi)
clear_is_used (t);
+ /* Assume all globals in local decls are unused. */
+ global_unused_vars = BITMAP_ALLOC (NULL);
+ FOR_EACH_LOCAL_DECL (cfun, ix, var)
+ if (TREE_CODE (var) == VAR_DECL
+ && is_global_var (var))
+ bitmap_set_bit (global_unused_vars, DECL_UID (var));
+
/* Walk the CFG marking all referenced symbols. */
FOR_EACH_BB (bb)
{
*************** remove_unused_locals (void)
*** 733,739 ****
TREE_USED (b) = true;
for (i = 0; i < gimple_num_ops (stmt); i++)
! mark_all_vars_used (gimple_op_ptr (gsi_stmt (gsi), i), NULL);
}
for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
--- 746,753 ----
TREE_USED (b) = true;
for (i = 0; i < gimple_num_ops (stmt); i++)
! mark_all_vars_used (gimple_op_ptr (gsi_stmt (gsi), i),
! global_unused_vars);
}
for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
*************** remove_unused_locals (void)
*** 743,759 ****
tree def;
gimple phi = gsi_stmt (gsi);
! /* No point processing globals. */
! if (is_global_var (SSA_NAME_VAR (gimple_phi_result (phi))))
continue;
def = gimple_phi_result (phi);
! mark_all_vars_used (&def, NULL);
FOR_EACH_PHI_ARG (arg_p, phi, i, SSA_OP_ALL_USES)
{
tree arg = USE_FROM_PTR (arg_p);
! mark_all_vars_used (&arg, NULL);
}
}
--- 757,772 ----
tree def;
gimple phi = gsi_stmt (gsi);
! if (!is_gimple_reg (gimple_phi_result (phi)))
continue;
def = gimple_phi_result (phi);
! mark_all_vars_used (&def, global_unused_vars);
FOR_EACH_PHI_ARG (arg_p, phi, i, SSA_OP_ALL_USES)
{
tree arg = USE_FROM_PTR (arg_p);
! mark_all_vars_used (&arg, global_unused_vars);
}
}
*************** remove_unused_locals (void)
*** 783,789 ****
lhs = get_base_address (lhs);
if (TREE_CODE (lhs) == SSA_NAME)
lhs = SSA_NAME_VAR (lhs);
! if (DECL_P (lhs) && (!var_ann (lhs) || !is_used_p (lhs)))
{
unlink_stmt_vdef (stmt);
gsi_remove (&gsi, true);
--- 796,805 ----
lhs = get_base_address (lhs);
if (TREE_CODE (lhs) == SSA_NAME)
lhs = SSA_NAME_VAR (lhs);
! if (TREE_CODE (lhs) == VAR_DECL
! && ((is_global_var (lhs)
! && bitmap_bit_p (global_unused_vars, DECL_UID (lhs)))
! || (!is_global_var (lhs) && !is_used_p (lhs))))
{
unlink_stmt_vdef (stmt);
gsi_remove (&gsi, true);
*************** remove_unused_locals (void)
*** 799,825 ****
cfun->has_local_explicit_reg_vars = false;
! /* Remove unmarked local vars from local_decls. */
num = VEC_length (tree, cfun->local_decls);
for (srcidx = 0, dstidx = 0; srcidx < num; srcidx++)
{
var = VEC_index (tree, cfun->local_decls, srcidx);
! if (TREE_CODE (var) != FUNCTION_DECL
! && (!var_ann (var)
! || !is_used_p (var)))
{
if (is_global_var (var))
{
! if (global_unused_vars == NULL)
! global_unused_vars = BITMAP_ALLOC (NULL);
! bitmap_set_bit (global_unused_vars, DECL_UID (var));
}
- else
- continue;
}
! else if (TREE_CODE (var) == VAR_DECL
! && DECL_HARD_REGISTER (var)
! && !is_global_var (var))
cfun->has_local_explicit_reg_vars = true;
if (srcidx != dstidx)
--- 815,844 ----
cfun->has_local_explicit_reg_vars = false;
! /* Remove unmarked local and global vars from local_decls
! and referenced vars. */
num = VEC_length (tree, cfun->local_decls);
for (srcidx = 0, dstidx = 0; srcidx < num; srcidx++)
{
var = VEC_index (tree, cfun->local_decls, srcidx);
! if (TREE_CODE (var) == VAR_DECL)
{
if (is_global_var (var))
{
! if (bitmap_bit_p (global_unused_vars, DECL_UID (var)))
! continue;
! }
! else if (var_ann (var) == NULL
! || !is_used_p (var))
! {
! if (var_ann (var))
! remove_referenced_var (var);
! continue;
}
}
! if (TREE_CODE (var) == VAR_DECL
! && DECL_HARD_REGISTER (var)
! && !is_global_var (var))
cfun->has_local_explicit_reg_vars = true;
if (srcidx != dstidx)
*************** remove_unused_locals (void)
*** 828,872 ****
}
if (dstidx != num)
VEC_truncate (tree, cfun->local_decls, dstidx);
- /* Remove unmarked global vars from local_decls. */
- if (global_unused_vars != NULL)
- {
- tree var;
- unsigned ix;
- FOR_EACH_LOCAL_DECL (cfun, ix, var)
- if (TREE_CODE (var) == VAR_DECL
- && is_global_var (var)
- && var_ann (var) != NULL
- && is_used_p (var)
- && DECL_CONTEXT (var) == current_function_decl)
- mark_all_vars_used (&DECL_INITIAL (var), global_unused_vars);
-
- num = VEC_length (tree, cfun->local_decls);
- for (srcidx = 0, dstidx = 0; srcidx < num; srcidx++)
- {
- var = VEC_index (tree, cfun->local_decls, srcidx);
- if (TREE_CODE (var) == VAR_DECL
- && is_global_var (var)
- && bitmap_bit_p (global_unused_vars, DECL_UID (var)))
- continue;
-
- if (srcidx != dstidx)
- VEC_replace (tree, cfun->local_decls, dstidx, var);
- dstidx++;
- }
- if (dstidx != num)
- VEC_truncate (tree, cfun->local_decls, dstidx);
- BITMAP_FREE (global_unused_vars);
- }
-
- /* Remove unused variables from REFERENCED_VARs. */
- FOR_EACH_REFERENCED_VAR (cfun, t, rvi)
- if (!is_global_var (t)
- && TREE_CODE (t) != PARM_DECL
- && TREE_CODE (t) != RESULT_DECL
- && !is_used_p (t))
- remove_referenced_var (t);
remove_unused_scope_block_p (DECL_INITIAL (current_function_decl));
if (dump_file && (dump_flags & TDF_DETAILS))
{
--- 847,854 ----
}
if (dstidx != num)
VEC_truncate (tree, cfun->local_decls, dstidx);
+ BITMAP_FREE (global_unused_vars);
remove_unused_scope_block_p (DECL_INITIAL (current_function_decl));
if (dump_file && (dump_flags & TDF_DETAILS))
{
