#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 ign1, ign2;
+ 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;
}
+ /* 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);
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;
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 */
};