return NULL;
}
+/* Returns true if the exit values of all loop phi nodes can be
+ determined easily (i.e. that connect_loop_phis can determine them). */
+
+static bool
+easy_exit_values (struct loop *loop)
+{
+ edge exit = single_exit (loop);
+ edge latch = loop_latch_edge (loop);
+ gphi_iterator psi;
+
+ /* Currently we regard the exit values as easy if they are the same
+ as the value over the backedge. Which is the case if the definition
+ of the backedge value dominates the exit edge. */
+ for (psi = gsi_start_phis (loop->header); !gsi_end_p (psi); gsi_next (&psi))
+ {
+ gphi *phi = psi.phi ();
+ tree next = PHI_ARG_DEF_FROM_EDGE (phi, latch);
+ basic_block bb;
+ if (TREE_CODE (next) == SSA_NAME
+ && (bb = gimple_bb (SSA_NAME_DEF_STMT (next)))
+ && !dominated_by_p (CDI_DOMINATORS, exit->src, bb))
+ return false;
+ }
+
+ return true;
+}
+
/* This function updates the SSA form after connect_loops made a new
edge NEW_E leading from LOOP1 exit to LOOP2 (via in intermediate
conditional). I.e. the second loop can now be entered either
via the original entry or via NEW_E, so the entry values of LOOP2
phi nodes are either the original ones or those at the exit
of LOOP1. Insert new phi nodes in LOOP2 pre-header reflecting
- this. */
+ this. The loops need to fulfill easy_exit_values(). */
static void
connect_loop_phis (struct loop *loop1, struct loop *loop2, edge new_e)
TREE_TYPE (controlbase),
controlbase, controlstep);
- /* Compute beg-guard_init. */
+ /* Compute end-beg. */
+ gimple_seq stmts2;
+ tree end = force_gimple_operand (niter->bound, &stmts2,
+ true, NULL_TREE);
+ gimple_seq_add_seq_without_update (stmts, stmts2);
if (POINTER_TYPE_P (TREE_TYPE (enddiff)))
{
- tree tem = gimple_convert (stmts, sizetype, guard_init);
+ tree tem = gimple_convert (stmts, sizetype, enddiff);
tem = gimple_build (stmts, NEGATE_EXPR, sizetype, tem);
enddiff = gimple_build (stmts, POINTER_PLUS_EXPR,
TREE_TYPE (enddiff),
- enddiff, tem);
+ end, tem);
}
else
enddiff = gimple_build (stmts, MINUS_EXPR, TREE_TYPE (enddiff),
- enddiff, guard_init);
+ end, enddiff);
- /* Compute end-(beg-guard_init). */
- gimple_seq stmts2;
- tree newbound = force_gimple_operand (niter->bound, &stmts2,
- true, NULL_TREE);
- gimple_seq_add_seq_without_update (stmts, stmts2);
-
- if (POINTER_TYPE_P (TREE_TYPE (enddiff))
- || POINTER_TYPE_P (TREE_TYPE (newbound)))
+ /* Compute guard_init + (end-beg). */
+ tree newbound;
+ enddiff = gimple_convert (stmts, TREE_TYPE (guard_init), enddiff);
+ if (POINTER_TYPE_P (TREE_TYPE (guard_init)))
{
enddiff = gimple_convert (stmts, sizetype, enddiff);
enddiff = gimple_build (stmts, NEGATE_EXPR, sizetype, enddiff);
newbound = gimple_build (stmts, POINTER_PLUS_EXPR,
- TREE_TYPE (newbound),
- newbound, enddiff);
+ TREE_TYPE (guard_init),
+ guard_init, enddiff);
}
else
- newbound = gimple_build (stmts, MINUS_EXPR, TREE_TYPE (enddiff),
- newbound, enddiff);
+ newbound = gimple_build (stmts, PLUS_EXPR, TREE_TYPE (guard_init),
+ guard_init, enddiff);
/* Depending on the direction of the IVs the new bound for the first
loop is the minimum or maximum of old bound and border.
build_int_cst (type2, addbound));
}
- newbound = gimple_convert (stmts, TREE_TYPE (border), newbound);
tree newend = gimple_build (stmts, minmax, TREE_TYPE (border),
border, newbound);
return newend;
original exit before. */
&& empty_block_p (loop->latch)
&& !optimize_loop_for_size_p (loop)
+ && easy_exit_values (loop)
&& number_of_iterations_exit (loop, single_exit (loop), &niter,
false, true)
&& niter.cmp != ERROR_MARK