* tree-ssa-loop-im.c (determine_invariantness_stmt): Attempt to

	transform only GIMPLE_MODIFY_STMTs.
	* tree-complex.c (expand_complex_operations_1): Ditto.
	(expand_complex_div_wide): Do not create gotos in COND_EXPR branches.
	* tree-ssa-loop-manip.c (build_if_stmt): Removed.
	(tree_transform_and_unroll_loop): Do not create gotos in COND_EXPR
	branches.
	* value-prof.c (tree_divmod_fixed_value, tree_mod_pow2,
	tree_mod_subtract, tree_ic, tree_stringop_fixed_value): Ditto.
	* omp-low.c (expand_parallel_call, expand_omp_for_generic,
	expand_omp_for_static_chunk, expand_omp_for_static_nochunk): Ditto.
	* tree-vectorizer.c (slpeel_make_loop_iterate_ntimes,
	slpeel_add_loop_guard): Ditto.
	* tree-mudflap.c (mf_build_check_statement_for): Ditto.
	* lambda-code.c (perfect_nestify): Ditto.
	* tree-iterator.c (tsi_split_statement_list_before): Fix splitting
	before the first statement.
	* tree-optimize.c (execute_free_datastructures): Fix comments.
	(execute_free_cfg_annotations): Do not call disband_implicit_edges.
	* tree-flow.h (disband_implicit_edges): Declaration removed.
	* tree-cfg.c (make_cond_expr_edges): Remove gotos from COND_EXPR
	branches.
	(cleanup_dead_labels, tree_redirect_edge_and_branch): Handle COND_EXPRs
	without gotos.
	(disband_implicit_edges, has_label_p): Removed.
	(tree_verify_flow_info): Verify that COND_EXPR branches are empty.
	(tree_lv_add_condition_to_bb): Do not create gotos in COND_EXPR
	branches.
	* tree.c (build3_stat): Mark COND_EXPRs used as statements as having
	side effects.
	* tree-pretty-print.c (dump_implicit_edges): Dump implicit edges
	also for COND_EXPRs.
	* cfgexpand.c (label_rtx_for_bb): New function.
	(expand_gimple_cond_expr): Do not expect gotos in COND_EXPR branches.
	Use label_rtx_for_bb to find the labels.
	(expand_gimple_basic_block): Remove RETURN_EXPR at the end of the
	last block.  Detect fallthru edges.



git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@124214 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 82 insertions, 16 deletions

diff --git a/gcc/cfgexpand.c b/gcc/cfgexpand.c
index ab2b9d36af2..643ff207108 100644
--- a/gcc/cfgexpand.c
+++ b/gcc/cfgexpand.c
@@ -1244,6 +1244,38 @@ maybe_dump_rtl_for_tree_stmt (tree stmt, rtx since)
     }
 }
 
+/* Returns the label_rtx expression for a label starting basic block BB.  */
+
+static rtx
+label_rtx_for_bb (basic_block bb)
+{
+  tree_stmt_iterator tsi;
+  tree lab, lab_stmt;
+
+  if (bb->flags & BB_RTL)
+    return block_label (bb);
+
+  /* We cannot use tree_block_label, as we no longer have stmt annotations.
+     TODO -- avoid creating the new tree labels.  */
+  for (tsi = tsi_start (bb_stmt_list (bb)); !tsi_end_p (tsi); tsi_next (&tsi))
+    {
+      lab_stmt = tsi_stmt (tsi);
+      if (TREE_CODE (lab_stmt) != LABEL_EXPR)
+	break;
+
+      lab = LABEL_EXPR_LABEL (lab_stmt);
+      if (DECL_NONLOCAL (lab))
+	break;
+
+      return label_rtx (lab);
+    }
+
+  lab = create_artificial_label ();
+  lab_stmt = build1 (LABEL_EXPR, void_type_node, lab);
+  tsi_link_before (&tsi, lab_stmt, TSI_NEW_STMT);
+  return label_rtx (lab);
+}
+
 /* A subroutine of expand_gimple_basic_block.  Expand one COND_EXPR.
    Returns a new basic block if we've terminated the current basic
    block and created a new one.  */
@@ -1256,10 +1288,10 @@ expand_gimple_cond_expr (basic_block bb, tree stmt)
   edge true_edge;
   edge false_edge;
   tree pred = COND_EXPR_COND (stmt);
-  tree then_exp = COND_EXPR_THEN (stmt);
-  tree else_exp = COND_EXPR_ELSE (stmt);
   rtx last2, last;
 
+  gcc_assert (COND_EXPR_THEN (stmt) == NULL_TREE);
+  gcc_assert (COND_EXPR_ELSE (stmt) == NULL_TREE);
   last2 = last = get_last_insn ();
 
   extract_true_false_edges_from_block (bb, &true_edge, &false_edge);
@@ -1275,31 +1307,31 @@ expand_gimple_cond_expr (basic_block bb, tree stmt)
 
   /* We can either have a pure conditional jump with one fallthru edge or
      two-way jump that needs to be decomposed into two basic blocks.  */
-  if (TREE_CODE (then_exp) == GOTO_EXPR && IS_EMPTY_STMT (else_exp))
+  if (false_edge->dest == bb->next_bb)
     {
-      jumpif (pred, label_rtx (GOTO_DESTINATION (then_exp)));
+      jumpif (pred, label_rtx_for_bb (true_edge->dest));
       add_reg_br_prob_note (last, true_edge->probability);
       maybe_dump_rtl_for_tree_stmt (stmt, last);
-      if (EXPR_LOCUS (then_exp))
-	emit_line_note (*(EXPR_LOCUS (then_exp)));
+      if (true_edge->goto_locus)
+	emit_line_note (*true_edge->goto_locus);
+      false_edge->flags |= EDGE_FALLTHRU;
       return NULL;
     }
-  if (TREE_CODE (else_exp) == GOTO_EXPR && IS_EMPTY_STMT (then_exp))
+  if (true_edge->dest == bb->next_bb)
     {
-      jumpifnot (pred, label_rtx (GOTO_DESTINATION (else_exp)));
+      jumpifnot (pred, label_rtx_for_bb (false_edge->dest));
       add_reg_br_prob_note (last, false_edge->probability);
       maybe_dump_rtl_for_tree_stmt (stmt, last);
-      if (EXPR_LOCUS (else_exp))
-	emit_line_note (*(EXPR_LOCUS (else_exp)));
+      if (false_edge->goto_locus)
+	emit_line_note (*false_edge->goto_locus);
+      true_edge->flags |= EDGE_FALLTHRU;
       return NULL;
     }
-  gcc_assert (TREE_CODE (then_exp) == GOTO_EXPR
-	      && TREE_CODE (else_exp) == GOTO_EXPR);
 
-  jumpif (pred, label_rtx (GOTO_DESTINATION (then_exp)));
+  jumpif (pred, label_rtx_for_bb (true_edge->dest));
   add_reg_br_prob_note (last, true_edge->probability);
   last = get_last_insn ();
-  expand_expr (else_exp, const0_rtx, VOIDmode, 0);
+  emit_jump (label_rtx_for_bb (false_edge->dest));
 
   BB_END (bb) = last;
   if (BARRIER_P (BB_END (bb)))
@@ -1321,8 +1353,8 @@ expand_gimple_cond_expr (basic_block bb, tree stmt)
 
   maybe_dump_rtl_for_tree_stmt (stmt, last2);
 
-  if (EXPR_LOCUS (else_exp))
-    emit_line_note (*(EXPR_LOCUS (else_exp)));
+  if (false_edge->goto_locus)
+    emit_line_note (*false_edge->goto_locus);
 
   return new_bb;
 }
@@ -1457,6 +1489,25 @@ expand_gimple_basic_block (basic_block bb)
   init_rtl_bb_info (bb);
   bb->flags |= BB_RTL;
 
+  /* Remove the RETURN_EXPR if we may fall though to the exit
+     instead.  */
+  tsi = tsi_last (stmts);
+  if (!tsi_end_p (tsi)
+      && TREE_CODE (tsi_stmt (tsi)) == RETURN_EXPR)
+    {
+      tree ret_stmt = tsi_stmt (tsi);
+
+      gcc_assert (single_succ_p (bb));
+      gcc_assert (single_succ (bb) == EXIT_BLOCK_PTR);
+
+      if (bb->next_bb == EXIT_BLOCK_PTR
+	  && !TREE_OPERAND (ret_stmt, 0))
+	{
+	  tsi_delink (&tsi);
+	  single_succ_edge (bb)->flags |= EDGE_FALLTHRU;
+	}
+    }
+
   tsi = tsi_start (stmts);
   if (!tsi_end_p (tsi))
     stmt = tsi_stmt (tsi);
@@ -1546,6 +1597,21 @@ expand_gimple_basic_block (basic_block bb)
 	}
     }
 
+  /* Expand implicit goto.  */
+  FOR_EACH_EDGE (e, ei, bb->succs)
+    {
+      if (e->flags & EDGE_FALLTHRU)
+	break;
+    }
+
+  if (e && e->dest != bb->next_bb)
+    {
+      emit_jump (label_rtx_for_bb (e->dest));
+      if (e->goto_locus)
+	emit_line_note (*e->goto_locus);
+      e->flags &= ~EDGE_FALLTHRU;
+    }
+
   do_pending_stack_adjust ();
 
   /* Find the block tail.  The last insn in the block is the insn