#include "tree-gimple.h"
#include "tree-inline.h"
#include "timevar.h"
-#include "tree-alias-common.h"
#include "hashtab.h"
#include "tree-dump.h"
#include "tree-ssa-live.h"
#include "tree-pass.h"
#include "langhooks.h"
-extern void rename_ssa_copies (void);
-
/* The following routines implement the SSA copy renaming phase.
This optimization looks for copies between 2 SSA_NAMES, either through a
Each copy is examined to determine if it is possible to rename the base
variable of one of the operands to the same variable as the other operand.
- ie.
+ i.e.
T.3_5 = <blah>
a_1 = T.3_5
{
int p1, p2, p3;
tree root1, root2;
+ tree rep1, rep2;
var_ann_t ann1, ann2, ann3;
- bool gimp1, gimp2;
+ bool ign1, ign2, abnorm;
-#ifdef ENABLE_CHECKING
- if (TREE_CODE (var1) != SSA_NAME || TREE_CODE (var2) != SSA_NAME)
- abort ();
-#endif
+ gcc_assert (TREE_CODE (var1) == SSA_NAME);
+ gcc_assert (TREE_CODE (var2) == SSA_NAME);
register_ssa_partition (map, var1, false);
register_ssa_partition (map, var2, true);
fprintf (debug, "(P%d)", p2);
}
-#ifdef ENABLE_CHECKING
- if (p1 == NO_PARTITION || p2 == NO_PARTITION)
- abort ();
-#endif
-
- root1 = SSA_NAME_VAR (partition_to_var (map, p1));
- root2 = SSA_NAME_VAR (partition_to_var (map, p2));
+ gcc_assert (p1 != NO_PARTITION);
+ gcc_assert (p2 != NO_PARTITION);
- if (DECL_HARD_REGISTER (root1) || DECL_HARD_REGISTER (root2))
- {
- if (debug)
- {
- if (DECL_HARD_REGISTER (root1))
- print_generic_expr (debug, var1, TDF_SLIM);
- else
- print_generic_expr (debug, var2, TDF_SLIM);
- fprintf (debug, " is a hardware register. No Coalescing.\n");
- }
- return;
- }
+ rep1 = partition_to_var (map, p1);
+ rep2 = partition_to_var (map, p2);
+ root1 = SSA_NAME_VAR (rep1);
+ root2 = SSA_NAME_VAR (rep2);
ann1 = var_ann (root1);
ann2 = var_ann (root2);
return;
}
+ /* Don't coalesce if one of the variables occurs in an abnormal PHI. */
+ abnorm = (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (rep1)
+ || SSA_NAME_OCCURS_IN_ABNORMAL_PHI (rep2));
+ if (abnorm)
+ {
+ if (debug)
+ fprintf (debug, " : Abnormal PHI barrier. No coalesce.\n");
+ return;
+ }
+
/* Partitions already have the same root, simply merge them. */
if (root1 == root2)
{
return;
}
- gimp1 = is_gimple_tmp_var (root1);
- gimp2 = is_gimple_tmp_var (root2);
+ ign1 = TREE_CODE (root1) == VAR_DECL && DECL_IGNORED_P (root1);
+ ign2 = TREE_CODE (root2) == VAR_DECL && DECL_IGNORED_P (root2);
/* Never attempt to coalesce 2 user variables unless one is an inline
variable. */
- if (!gimp1 && !gimp2)
+ if (!ign1 && !ign2)
{
if (DECL_FROM_INLINE (root2))
- gimp2 = true;
- else
- if (DECL_FROM_INLINE (root1))
- gimp1 = true;
- else
- {
- if (debug)
- fprintf (debug, " : 2 different USER vars. No coalesce.\n");
- return;
- }
+ ign2 = true;
+ else if (DECL_FROM_INLINE (root1))
+ ign1 = true;
+ else
+ {
+ if (debug)
+ fprintf (debug, " : 2 different USER vars. No coalesce.\n");
+ return;
+ }
}
-
/* Don't coalesce if there are two different memory tags. */
if (ann1->type_mem_tag && ann2->type_mem_tag
&& ann1->type_mem_tag != ann2->type_mem_tag)
}
else
{
- gimp2 = true;
- gimp1 = false;
+ ign2 = true;
+ ign1 = false;
}
}
- else
- if (default_def (root2))
- {
- gimp1 = true;
- gimp2 = false;
- }
+ else if (default_def (root2))
+ {
+ ign1 = true;
+ ign2 = false;
+ }
/* Don't coalesce if the two variables aren't type compatible. */
if (!lang_hooks.types_compatible_p (TREE_TYPE (root1), TREE_TYPE (root2)))
return;
}
+ /* Don't coalesce if the aliasing sets of the types are different. */
+ if (POINTER_TYPE_P (TREE_TYPE (root1))
+ && POINTER_TYPE_P (TREE_TYPE (root2))
+ && get_alias_set (TREE_TYPE (TREE_TYPE (root1)))
+ != get_alias_set (TREE_TYPE (TREE_TYPE (root2))))
+ {
+ if (debug)
+ fprintf (debug, " : 2 different alasing sets. No coalesce.\n");
+ return;
+ }
+
+
/* Merge the two partitions. */
p3 = partition_union (map->var_partition, p1, p2);
/* Set the root variable of the partition to the better choice, if there is
one. */
- if (!gimp2)
+ if (!ign2)
replace_ssa_name_symbol (partition_to_var (map, p3), root2);
- else
- if (!gimp1)
- replace_ssa_name_symbol (partition_to_var (map, p3), root1);
+ else if (!ign1)
+ replace_ssa_name_symbol (partition_to_var (map, p3), root1);
/* Update the various flag widgitry of the current base representative. */
ann3 = var_ann (SSA_NAME_VAR (partition_to_var (map, p3)));
then cause the SSA->normal pass to attempt to coalesce them all to the same
variable. */
-void
+static void
rename_ssa_copies (void)
{
var_map map;
NULL, /* next */
0, /* static_pass_number */
TV_TREE_COPY_RENAME, /* tv_id */
- PROP_cfg | PROP_ssa, /* properties_required */
+ PROP_cfg | PROP_ssa | PROP_alias, /* properties_required */
0, /* properties_provided */
0, /* properties_destroyed */
0, /* todo_flags_start */
- TODO_dump_func | TODO_verify_ssa /* todo_flags_finish */
+ TODO_dump_func | TODO_verify_ssa, /* todo_flags_finish */
+ 0 /* letter */
};