rfa: merge handling of locals and globals in remove_unused_locals
Michael Matz
matz@suse.de
Wed Aug 1 15:28:00 GMT 2012
Hi,
On Wed, 1 Aug 2012, Richard Guenther wrote:
> Ok. Would be nice to now unify global and local var handling with a
> single bitmap.
Yeah, wanted to do that as follow-up. Namely like so. Regstrapping on
x86_64-linux in progress on top of your remove-referenced-vars patches.
Okay for trunk?
Ciao,
Michael.
--
* tree-ssa-live.c (set_is_used): Return a bool.
(mark_all_vars_used): Don't take data argument.
(mark_all_vars_used_1): Adjust calls to above, merge handling
of local and global vars.
(remove_unused_scope_block_p): Don't take global_unused_vars,
merge handling of local and global vars.
(remove_unused_locals): Don't allocate/fill/pass global_unused_vars,
use is_used_p for local and global vars.
Index: gcc/tree-ssa-live.c
===================================================================
*** gcc.orig/tree-ssa-live.c 2012-08-01 17:21:39.000000000 +0200
--- gcc/tree-ssa-live.c 2012-08-01 17:22:01.000000000 +0200
*************** partition_view_bitmap (var_map map, bitm
*** 331,342 ****
static bitmap usedvars;
! /* Mark VAR as used, so that it'll be preserved during rtl expansion. */
! static inline void
set_is_used (tree var)
{
! bitmap_set_bit (usedvars, DECL_UID (var));
}
/* Return true if VAR is marked as used. */
--- 331,343 ----
static bitmap usedvars;
! /* Mark VAR as used, so that it'll be preserved during rtl expansion.
! Returns true if VAR wasn't marked before. */
! static inline bool
set_is_used (tree var)
{
! return bitmap_set_bit (usedvars, DECL_UID (var));
}
/* Return true if VAR is marked as used. */
*************** is_used_p (tree var)
*** 347,360 ****
return bitmap_bit_p (usedvars, DECL_UID (var));
}
! static inline void mark_all_vars_used (tree *, void *data);
/* Helper function for mark_all_vars_used, called via walk_tree. */
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;
--- 348,360 ----
return bitmap_bit_p (usedvars, DECL_UID (var));
}
! static inline void mark_all_vars_used (tree *);
/* Helper function for mark_all_vars_used, called via walk_tree. */
static tree
! mark_all_vars_used_1 (tree *tp, int *walk_subtrees, void *data ATTRIBUTE_UNUSED)
{
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
*** 370,378 ****
fields do not contain vars. */
if (TREE_CODE (t) == TARGET_MEM_REF)
{
! mark_all_vars_used (&TMR_BASE (t), data);
! mark_all_vars_used (&TMR_INDEX (t), data);
! mark_all_vars_used (&TMR_INDEX2 (t), data);
*walk_subtrees = 0;
return NULL;
}
--- 370,378 ----
fields do not contain vars. */
if (TREE_CODE (t) == TARGET_MEM_REF)
{
! mark_all_vars_used (&TMR_BASE (t));
! mark_all_vars_used (&TMR_INDEX (t));
! mark_all_vars_used (&TMR_INDEX2 (t));
*walk_subtrees = 0;
return NULL;
}
*************** mark_all_vars_used_1 (tree *tp, int *wal
*** 381,396 ****
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. */
--- 381,390 ----
eliminated as unused. */
if (TREE_CODE (t) == VAR_DECL)
{
! /* When a global var becomes used for the first time also walk its
! initializer (non global ones don't have any). */
! if (set_is_used (t) && is_global_var (t))
! mark_all_vars_used (&DECL_INITIAL (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. */
*************** mark_scope_block_unused (tree scope)
*** 435,441 ****
done by the inliner. */
static bool
! remove_unused_scope_block_p (tree scope, bitmap global_unused_vars)
{
tree *t, *next;
bool unused = !TREE_USED (scope);
--- 429,435 ----
done by the inliner. */
static bool
! remove_unused_scope_block_p (tree scope)
{
tree *t, *next;
bool unused = !TREE_USED (scope);
*************** remove_unused_scope_block_p (tree scope,
*** 475,483 ****
info about optimized-out variables in the scope blocks.
Exception are the scope blocks not containing any instructions
at all so user can't get into the scopes at first place. */
! else if ((is_global_var (*t)
! && !bitmap_bit_p (global_unused_vars, DECL_UID (*t)))
! || is_used_p (*t))
unused = false;
else if (TREE_CODE (*t) == LABEL_DECL && TREE_USED (*t))
/* For labels that are still used in the IL, the decision to
--- 469,475 ----
info about optimized-out variables in the scope blocks.
Exception are the scope blocks not containing any instructions
at all so user can't get into the scopes at first place. */
! else if (is_used_p (*t))
unused = false;
else if (TREE_CODE (*t) == LABEL_DECL && TREE_USED (*t))
/* For labels that are still used in the IL, the decision to
*************** remove_unused_scope_block_p (tree scope,
*** 522,528 ****
}
for (t = &BLOCK_SUBBLOCKS (scope); *t ;)
! if (remove_unused_scope_block_p (*t, global_unused_vars))
{
if (BLOCK_SUBBLOCKS (*t))
{
--- 514,520 ----
}
for (t = &BLOCK_SUBBLOCKS (scope); *t ;)
! if (remove_unused_scope_block_p (*t))
{
if (BLOCK_SUBBLOCKS (*t))
{
*************** remove_unused_scope_block_p (tree scope,
*** 603,611 ****
eliminated during the tree->rtl conversion process. */
static inline void
! mark_all_vars_used (tree *expr_p, void *data)
{
! walk_tree (expr_p, mark_all_vars_used_1, data, NULL);
}
--- 595,603 ----
eliminated during the tree->rtl conversion process. */
static inline void
! mark_all_vars_used (tree *expr_p)
{
! walk_tree (expr_p, mark_all_vars_used_1, NULL, NULL);
}
*************** remove_unused_locals (void)
*** 693,700 ****
{
basic_block bb;
tree var;
! bitmap global_unused_vars = NULL;
! unsigned srcidx, dstidx, num, ix;
bool have_local_clobbers = false;
/* Removing declarations from lexical blocks when not optimizing is
--- 685,691 ----
{
basic_block bb;
tree var;
! unsigned srcidx, dstidx, num;
bool have_local_clobbers = false;
/* Removing declarations from lexical blocks when not optimizing is
*************** remove_unused_locals (void)
*** 709,721 ****
usedvars = BITMAP_ALLOC (NULL);
- /* 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)
{
--- 700,705 ----
*************** remove_unused_locals (void)
*** 743,750 ****
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))
--- 727,733 ----
TREE_USED (b) = true;
for (i = 0; i < gimple_num_ops (stmt); i++)
! mark_all_vars_used (gimple_op_ptr (gsi_stmt (gsi), i));
}
for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
*************** remove_unused_locals (void)
*** 758,769 ****
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);
}
}
--- 741,752 ----
continue;
def = gimple_phi_result (phi);
! mark_all_vars_used (&def);
FOR_EACH_PHI_ARG (arg_p, phi, i, SSA_OP_ALL_USES)
{
tree arg = USE_FROM_PTR (arg_p);
! mark_all_vars_used (&arg);
}
}
*************** remove_unused_locals (void)
*** 793,802 ****
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);
--- 776,782 ----
lhs = get_base_address (lhs);
if (TREE_CODE (lhs) == SSA_NAME)
lhs = SSA_NAME_VAR (lhs);
! if (TREE_CODE (lhs) == VAR_DECL && !is_used_p (lhs))
{
unlink_stmt_vdef (stmt);
gsi_remove (&gsi, true);
*************** remove_unused_locals (void)
*** 812,831 ****
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 (!is_used_p (var))
{
if (cfun->nonlocal_goto_save_area
&& TREE_OPERAND (cfun->nonlocal_goto_save_area, 0) == var)
--- 792,805 ----
cfun->has_local_explicit_reg_vars = false;
! /* Remove unmarked local and global 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) == VAR_DECL)
{
! if (!is_used_p (var))
{
if (cfun->nonlocal_goto_save_area
&& TREE_OPERAND (cfun->nonlocal_goto_save_area, 0) == var)
*************** remove_unused_locals (void)
*** 845,854 ****
if (dstidx != num)
VEC_truncate (tree, cfun->local_decls, dstidx);
! remove_unused_scope_block_p (DECL_INITIAL (current_function_decl),
! global_unused_vars);
- BITMAP_FREE (global_unused_vars);
BITMAP_FREE (usedvars);
if (dump_file && (dump_flags & TDF_DETAILS))
--- 819,826 ----
if (dstidx != num)
VEC_truncate (tree, cfun->local_decls, dstidx);
! remove_unused_scope_block_p (DECL_INITIAL (current_function_decl));
BITMAP_FREE (usedvars);
if (dump_file && (dump_flags & TDF_DETAILS))
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