CbC/CbC_gcc: gcc/cfgcleanup.c comparison

comparison gcc/cfgcleanup.c @ 111:04ced10e8804

gcc 7

author	kono
date	Fri, 27 Oct 2017 22:46:09 +0900
parents	f6334be47118
children	84e7813d76e9

comparison

equal deleted inserted replaced

-:561a7518be6b
+:04ced10e8804
 /* Control flow optimization code for GNU compiler.
-Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
+Copyright (C) 1987-2017 Free Software Foundation, Inc.
-1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2010
-Free Software Foundation, Inc.
 This file is part of GCC.
 GCC is free software; you can redistribute it and/or modify it under
 the terms of the GNU General Public License as published by the Free
 - Basic block merging.  */
 #include "config.h"
 #include "system.h"
 #include "coretypes.h"
-#include "tm.h"
+#include "backend.h"
+#include "target.h"
 #include "rtl.h"
-#include "hard-reg-set.h"
+#include "tree.h"
-#include "regs.h"
+#include "cfghooks.h"
-#include "timevar.h"
+#include "df.h"
-#include "output.h"
+#include "memmodel.h"
+#include "tm_p.h"
 #include "insn-config.h"
-#include "flags.h"
+#include "emit-rtl.h"
-#include "recog.h"
-#include "diagnostic-core.h"
 #include "cselib.h"
 #include "params.h"
-#include "tm_p.h"
-#include "target.h"
-#include "cfglayout.h"
-#include "emit-rtl.h"
 #include "tree-pass.h"
 #include "cfgloop.h"
-#include "expr.h"
+#include "cfgrtl.h"
-#include "df.h"
+#include "cfganal.h"
+#include "cfgbuild.h"
+#include "cfgcleanup.h"
 #include "dce.h"
 #include "dbgcnt.h"
+#include "rtl-iter.h"
 #define FORWARDER_BLOCK_P(BB) ((BB)->flags & BB_FORWARDER_BLOCK)
 /* Set to true when we are running first pass of try_optimize_cfg loop.  */
 static bool first_pass;
-/* Set to true if crossjumps occured in the latest run of try_optimize_cfg.  */
+/* Set to true if crossjumps occurred in the latest run of try_optimize_cfg.  */
-static bool crossjumps_occured;
+static bool crossjumps_occurred;
 /* Set to true if we couldn't run an optimization due to stale liveness
 information; we should run df_analyze to enable more opportunities.  */
 static bool block_was_dirty;
-static bool try_crossjump_to_edge (int, edge, edge);
+static bool try_crossjump_to_edge (int, edge, edge, enum replace_direction);
 static bool try_crossjump_bb (int, basic_block);
 static bool outgoing_edges_match (int, basic_block, basic_block);
-static bool old_insns_match_p (int, rtx, rtx);
+static enum replace_direction old_insns_match_p (int, rtx_insn *, rtx_insn *);
 static void merge_blocks_move_predecessor_nojumps (basic_block, basic_block);
 static void merge_blocks_move_successor_nojumps (basic_block, basic_block);
 static bool try_optimize_cfg (int);
 static bool try_simplify_condjump (basic_block);
 static bool try_forward_edges (int, basic_block);
 static edge thread_jump (edge, basic_block);
 static bool mark_effect (rtx, bitmap);
 static void notice_new_block (basic_block);
 static void update_forwarder_flag (basic_block);
-static int mentions_nonequal_regs (rtx *, void *);
 static void merge_memattrs (rtx, rtx);
 /* Set flags for newly created block.  */
 static void
 static bool
 try_simplify_condjump (basic_block cbranch_block)
 {
 basic_block jump_block, jump_dest_block, cbranch_dest_block;
 edge cbranch_jump_edge, cbranch_fallthru_edge;
-rtx cbranch_insn;
+rtx_insn *cbranch_insn;
 /* Verify that there are exactly two successors.  */
 if (EDGE_COUNT (cbranch_block->succs) != 2)
 return false;
 /* The next block must not have multiple predecessors, must not
 be the last block in the function, and must contain just the
 unconditional jump.  */
 jump_block = cbranch_fallthru_edge->dest;
 if (!single_pred_p (jump_block)
-|| jump_block->next_bb == EXIT_BLOCK_PTR
+|| jump_block->next_bb == EXIT_BLOCK_PTR_FOR_FN (cfun)
 || !FORWARDER_BLOCK_P (jump_block))
 return false;
 jump_dest_block = single_succ (jump_block);
 /* If we are partitioning hot/cold basic blocks, we don't want to
 /* The conditional branch must target the block after the
 unconditional branch.  */
 cbranch_dest_block = cbranch_jump_edge->dest;
-if (cbranch_dest_block == EXIT_BLOCK_PTR
+if (cbranch_dest_block == EXIT_BLOCK_PTR_FOR_FN (cfun)
+|| jump_dest_block == EXIT_BLOCK_PTR_FOR_FN (cfun)
 || !can_fallthru (jump_block, cbranch_dest_block))
 return false;
 /* Invert the conditional branch.  */
-if (!invert_jump (cbranch_insn, block_label (jump_dest_block), 0))
+if (!invert_jump (as_a <rtx_jump_insn *> (cbranch_insn),
+		    block_label (jump_dest_block), 0))
 return false;
 if (dump_file)
 fprintf (dump_file, "Simplifying condjump %i around jump %i\n",
 	     INSN_UID (cbranch_insn), INSN_UID (BB_END (jump_block)));
 on register.  Used by jump threading.  */
 static bool
 mark_effect (rtx exp, regset nonequal)
 {
-int regno;
 rtx dest;
 switch (GET_CODE (exp))
 {
 /* In case we do clobber the register, mark it as equal, as we know the
 	 value is dead so it don't have to match.  */
 case CLOBBER:
-if (REG_P (XEXP (exp, 0)))
+dest = XEXP (exp, 0);
-	{
+if (REG_P (dest))
-	  dest = XEXP (exp, 0);
+	bitmap_clear_range (nonequal, REGNO (dest), REG_NREGS (dest));
-	  regno = REGNO (dest);
-	  CLEAR_REGNO_REG_SET (nonequal, regno);
-	  if (regno < FIRST_PSEUDO_REGISTER)
-	    {
-	      int n = hard_regno_nregs[regno][GET_MODE (dest)];
-	      while (--n > 0)
-		CLEAR_REGNO_REG_SET (nonequal, regno + n);
-	    }
-	}
 return false;
 case SET:
 if (rtx_equal_for_cselib_p (SET_DEST (exp), SET_SRC (exp)))
 	return false;
 dest = SET_DEST (exp);
 if (dest == pc_rtx)
 	return false;
 if (!REG_P (dest))
 	return true;
-regno = REGNO (dest);
+bitmap_set_range (nonequal, REGNO (dest), REG_NREGS (dest));
-SET_REGNO_REG_SET (nonequal, regno);
-if (regno < FIRST_PSEUDO_REGISTER)
-	{
-	  int n = hard_regno_nregs[regno][GET_MODE (dest)];
-	  while (--n > 0)
-	    SET_REGNO_REG_SET (nonequal, regno + n);
-	}
 return false;
 default:
 return false;
 }
 }
-/* Return nonzero if X is a register set in regset DATA.
+/* Return true if X contains a register in NONEQUAL.  */
-Called via for_each_rtx.  */
+static bool
-static int
+mentions_nonequal_regs (const_rtx x, regset nonequal)
-mentions_nonequal_regs (rtx *x, void *data)
+{
-{
+subrtx_iterator::array_type array;
-regset nonequal = (regset) data;
+FOR_EACH_SUBRTX (iter, array, x, NONCONST)
-if (REG_P (*x))
+{
-{
+const_rtx x = *iter;
-int regno;
+if (REG_P (x))
+	{
-regno = REGNO (*x);
+	  unsigned int end_regno = END_REGNO (x);
-if (REGNO_REG_SET_P (nonequal, regno))
+	  for (unsigned int regno = REGNO (x); regno < end_regno; ++regno)
-	return 1;
+	    if (REGNO_REG_SET_P (nonequal, regno))
-if (regno < FIRST_PSEUDO_REGISTER)
+	      return true;
-	{
+	}
-	  int n = hard_regno_nregs[regno][GET_MODE (*x)];
+}
-	  while (--n > 0)
+return false;
-	    if (REGNO_REG_SET_P (nonequal, regno + n))
+}
-	      return 1;
-	}
-}
-return 0;
-}
 /* Attempt to prove that the basic block B will have no side effects and
 always continues in the same edge if reached via E.  Return the edge
 if exist, NULL otherwise.  */
 static edge
 thread_jump (edge e, basic_block b)
 {
-rtx set1, set2, cond1, cond2, insn;
+rtx set1, set2, cond1, cond2;
+rtx_insn *insn;
 enum rtx_code code1, code2, reversed_code2;
 bool reverse1 = false;
 unsigned i;
 regset nonequal;
 bool failed = false;
 goto failed_exit;
 }
 /* cond2 must not mention any register that is not equal to the
 former block.  */
-if (for_each_rtx (&cond2, mentions_nonequal_regs, nonequal))
+if (mentions_nonequal_regs (cond2, nonequal))
 goto failed_exit;
 EXECUTE_IF_SET_IN_REG_SET (nonequal, 0, i, rsi)
 goto failed_exit;
 be optimizable (or blocks that appear to be mergeable), but which really
 must be left untouched (they are required to make it safely across
 partition boundaries).  See the comments at the top of
 bb-reorder.c:partition_hot_cold_basic_blocks for complete details.  */
-if (find_reg_note (BB_END (b), REG_CROSSING_JUMP, NULL_RTX))
+if (JUMP_P (BB_END (b)) && CROSSING_JUMP_P (BB_END (b)))
 return false;
 for (ei = ei_start (b->succs); (e = ei_safe_edge (ei)); )
 {
 basic_block target, first;
-int counter, goto_locus;
+location_t goto_locus;
+int counter;
 bool threaded = false;
 int nthreaded_edges = 0;
 bool may_thread = first_pass || (b->flags & BB_MODIFIED) != 0;
 /* Skip complex edges because we don't know how to update them.
 	 really must be left untouched (they are required to make it safely
 	 across partition boundaries).  See the comments at the top of
 	 bb-reorder.c:partition_hot_cold_basic_blocks for complete
 	 details.  */
-if (first != EXIT_BLOCK_PTR
+if (first != EXIT_BLOCK_PTR_FOR_FN (cfun)
-	  && find_reg_note (BB_END (first), REG_CROSSING_JUMP, NULL_RTX))
+	  && JUMP_P (BB_END (first))
-	return false;
+	  && CROSSING_JUMP_P (BB_END (first)))
+	return changed;
-while (counter < n_basic_blocks)
+while (counter < n_basic_blocks_for_fn (cfun))
 	{
 	  basic_block new_target = NULL;
 	  bool new_target_threaded = false;
 	  may_thread |= (target->flags & BB_MODIFIED) != 0;
 	  if (FORWARDER_BLOCK_P (target)
 	      && !(single_succ_edge (target)->flags & EDGE_CROSSING)
-	      && single_succ (target) != EXIT_BLOCK_PTR)
+	      && single_succ (target) != EXIT_BLOCK_PTR_FOR_FN (cfun))
 	    {
 	      /* Bypass trivial infinite loops.  */
 	      new_target = single_succ (target);
 	      if (target == new_target)
-		counter = n_basic_blocks;
+		counter = n_basic_blocks_for_fn (cfun);
 	      else if (!optimize)
 		{
 		  /* When not optimizing, ensure that edges or forwarder
 		     blocks with different locus are not optimized out.  */
-		  int new_locus = single_succ_edge (target)->goto_locus;
+		  location_t new_locus = single_succ_edge (target)->goto_locus;
-		  int locus = goto_locus;
+		  location_t locus = goto_locus;
-		  if (new_locus && locus && !locator_eq (new_locus, locus))
+		  if (LOCATION_LOCUS (new_locus) != UNKNOWN_LOCATION
+		      && LOCATION_LOCUS (locus) != UNKNOWN_LOCATION
+		      && new_locus != locus)
 		    new_target = NULL;
 		  else
 		    {
-		      rtx last;
+		      if (LOCATION_LOCUS (new_locus) != UNKNOWN_LOCATION)
-		      if (new_locus)
 			locus = new_locus;
-		      last = BB_END (target);
+		      rtx_insn *last = BB_END (target);
 		      if (DEBUG_INSN_P (last))
 			last = prev_nondebug_insn (last);
+		      if (last && INSN_P (last))
-		      new_locus = last && INSN_P (last)
+			new_locus = INSN_LOCATION (last);
-				  ? INSN_LOCATOR (last) : 0;
+		      else
+			new_locus = UNKNOWN_LOCATION;
-		      if (new_locus && locus && !locator_eq (new_locus, locus))
+		      if (LOCATION_LOCUS (new_locus) != UNKNOWN_LOCATION
+			  && LOCATION_LOCUS (locus) != UNKNOWN_LOCATION
+			  && new_locus != locus)
 			new_target = NULL;
 		      else
 			{
-			  if (new_locus)
+			  if (LOCATION_LOCUS (new_locus) != UNKNOWN_LOCATION)
 			    locus = new_locus;
 			  goto_locus = locus;
 			}
 		    }
 	    {
 	      edge t = thread_jump (e, target);
 	      if (t)
 		{
 		  if (!threaded_edges)
-		    threaded_edges = XNEWVEC (edge, n_basic_blocks);
+		    threaded_edges = XNEWVEC (edge,
+					      n_basic_blocks_for_fn (cfun));
 		  else
 		    {
 		      int i;
 		      /* Detect an infinite loop across blocks not
 		      for (i = 0; i < nthreaded_edges; ++i)
 			if (threaded_edges[i] == t)
 			  break;
 		      if (i < nthreaded_edges)
 			{
-			  counter = n_basic_blocks;
+			  counter = n_basic_blocks_for_fn (cfun);
 			  break;
 			}
 		    }
 		  /* Detect an infinite loop across the start block.  */
 		  if (t->dest == b)
 		    break;
-		  gcc_assert (nthreaded_edges < n_basic_blocks - NUM_FIXED_BLOCKS);
+		  gcc_assert (nthreaded_edges
+			      < (n_basic_blocks_for_fn (cfun)
+				 - NUM_FIXED_BLOCKS));
 		  threaded_edges[nthreaded_edges++] = t;
 		  new_target = t->dest;
 		  new_target_threaded = true;
 		}
 	  counter++;
 	  target = new_target;
 	  threaded |= new_target_threaded;
 	}
-if (counter >= n_basic_blocks)
+if (counter >= n_basic_blocks_for_fn (cfun))
 	{
 	  if (dump_file)
 	    fprintf (dump_file, "Infinite loop in BB %i.\n",
 		     target->index);
 	}
 else if (target == first)
 	; /* We didn't do anything.  */
 else
 	{
 	  /* Save the values now, as the edge may get removed.  */
-	  gcov_type edge_count = e->count;
+	  profile_count edge_count = e->count ();
-	  int edge_probability = e->probability;
+	  profile_probability edge_probability = e->probability;
 	  int edge_frequency;
 	  int n = 0;
 	  e->goto_locus = goto_locus;
 	  /* Don't force if target is exit block.  */
-	  if (threaded && target != EXIT_BLOCK_PTR)
+	  if (threaded && target != EXIT_BLOCK_PTR_FOR_FN (cfun))
 	    {
 	      notice_new_block (redirect_edge_and_branch_force (e, target));
 	      if (dump_file)
 		fprintf (dump_file, "Conditionals threaded.\n");
 	    }
 	    }
 	  /* We successfully forwarded the edge.  Now update profile
 	     data: for each edge we traversed in the chain, remove
 	     the original edge's execution count.  */
-	  edge_frequency = ((edge_probability * b->frequency
+	  edge_frequency = edge_probability.apply (b->frequency);
-			     + REG_BR_PROB_BASE / 2)
-			    / REG_BR_PROB_BASE);
-	  if (!FORWARDER_BLOCK_P (b) && forwarder_block_p (b))
-	    b->flags |= BB_FORWARDER_BLOCK;
 	  do
 	    {
 	      edge t;
 		  update_br_prob_note (first);
 		}
 	      else
 		{
 		  first->count -= edge_count;
-		  if (first->count < 0)
-		    first->count = 0;
 		  first->frequency -= edge_frequency;
 		  if (first->frequency < 0)
 		    first->frequency = 0;
 		  /* It is possible that as the result of
 		     threading we've removed edge as it is
 		      && first == threaded_edges [n]->src)
 		    n++;
 		  t = single_succ_edge (first);
 		}
-	      t->count -= edge_count;
-	      if (t->count < 0)
-		t->count = 0;
 	      first = t->dest;
 	    }
 	  while (first != target);
 	  changed = true;
 	  continue;
 	}
 ei_next (&ei);
 }
-if (threaded_edges)
+free (threaded_edges);
-free (threaded_edges);
 return changed;
 }
 /* Blocks A and B are to be merged into a single block.  A has no incoming
 any jumps (aside from the jump from A to B).  */
 static void
 merge_blocks_move_predecessor_nojumps (basic_block a, basic_block b)
 {
-rtx barrier;
+rtx_insn *barrier;
 /* If we are partitioning hot/cold basic blocks, we don't want to
 mess up unconditional or indirect jumps that cross between hot
 and cold sections.
 any jumps (aside from the jump from A to B).  */
 static void
 merge_blocks_move_successor_nojumps (basic_block a, basic_block b)
 {
-rtx barrier, real_b_end;
+rtx_insn *barrier, *real_b_end;
-rtx label, table;
+rtx_insn *label;
+rtx_jump_table_data *table;
 /* If we are partitioning hot/cold basic blocks, we don't want to
 mess up unconditional or indirect jumps that cross between hot
 and cold sections.
 /* If B has a fallthru edge to C, no need to move anything.  */
 if (e->flags & EDGE_FALLTHRU)
 {
 int b_index = b->index, c_index = c->index;
+/* Protect the loop latches.  */
+if (current_loops && c->loop_father->latch == c)
+	return NULL;
 merge_blocks (b, c);
 update_forwarder_flag (b);
 if (dump_file)
 	fprintf (dump_file, "Merged %d and %d without moving.\n",
 		 b_index, c_index);
-return b->prev_bb == ENTRY_BLOCK_PTR ? b : b->prev_bb;
+return b->prev_bb == ENTRY_BLOCK_PTR_FOR_FN (cfun) ? b : b->prev_bb;
 }
 /* Otherwise we will need to move code around.  Do that only if expensive
 transformations are allowed.  */
 else if (mode & CLEANUP_EXPENSIVE)
 	 not have an outgoing fallthru, then it can be moved
 	 immediately after B without introducing or modifying jumps.  */
 if (! c_has_outgoing_fallthru)
 	{
 	  merge_blocks_move_successor_nojumps (b, c);
-	  return next == ENTRY_BLOCK_PTR ? next->next_bb : next;
+	  return next == ENTRY_BLOCK_PTR_FOR_FN (cfun) ? next->next_bb : next;
 	}
 /* If B does not have an incoming fallthru, then it can be moved
 	 immediately before C without introducing or modifying jumps.
 	 C cannot be the first block, so we do not have to worry about
 if (b_has_incoming_fallthru)
 	{
 	  basic_block bb;
-	  if (b_fallthru_edge->src == ENTRY_BLOCK_PTR)
+	  if (b_fallthru_edge->src == ENTRY_BLOCK_PTR_FOR_FN (cfun))
 	    return NULL;
 	  bb = force_nonfallthru (b_fallthru_edge);
 	  if (bb)
 	    notice_new_block (bb);
 	}
 merge_blocks_move_predecessor_nojumps (b, c);
-return next == ENTRY_BLOCK_PTR ? next->next_bb : next;
+return next == ENTRY_BLOCK_PTR_FOR_FN (cfun) ? next->next_bb : next;
 }
 return NULL;
 }
 /* Removes the memory attributes of MEM expression
 if they are not equal.  */
-void
+static void
 merge_memattrs (rtx x, rtx y)
 {
 int i;
 int j;
 enum rtx_code code;
 return;
 if (GET_MODE (x) != GET_MODE (y))
 return;
-if (code == MEM && MEM_ATTRS (x) != MEM_ATTRS (y))
+if (code == MEM && !mem_attrs_eq_p (MEM_ATTRS (x), MEM_ATTRS (y)))
 {
 if (! MEM_ATTRS (x))
 	MEM_ATTRS (y) = 0;
 else if (! MEM_ATTRS (y))
 	MEM_ATTRS (x) = 0;
 else
 	{
-	  rtx mem_size;
+	  HOST_WIDE_INT mem_size;
 	  if (MEM_ALIAS_SET (x) != MEM_ALIAS_SET (y))
 	    {
 	      set_mem_alias_set (x, 0);
 	      set_mem_alias_set (y, 0);
 	  if (! mem_expr_equal_p (MEM_EXPR (x), MEM_EXPR (y)))
 	    {
 	      set_mem_expr (x, 0);
 	      set_mem_expr (y, 0);
-	      set_mem_offset (x, 0);
+	      clear_mem_offset (x);
-	      set_mem_offset (y, 0);
+	      clear_mem_offset (y);
 	    }
-	  else if (MEM_OFFSET (x) != MEM_OFFSET (y))
+	  else if (MEM_OFFSET_KNOWN_P (x) != MEM_OFFSET_KNOWN_P (y)
+		   || (MEM_OFFSET_KNOWN_P (x)
+		       && MEM_OFFSET (x) != MEM_OFFSET (y)))
 	    {
-	      set_mem_offset (x, 0);
+	      clear_mem_offset (x);
-	      set_mem_offset (y, 0);
+	      clear_mem_offset (y);
 	    }
-	  if (!MEM_SIZE (x))
+	  if (MEM_SIZE_KNOWN_P (x) && MEM_SIZE_KNOWN_P (y))
-	    mem_size = NULL_RTX;
+	    {
-	  else if (!MEM_SIZE (y))
+	      mem_size = MAX (MEM_SIZE (x), MEM_SIZE (y));
-	    mem_size = NULL_RTX;
+	      set_mem_size (x, mem_size);
+	      set_mem_size (y, mem_size);
+	    }
 	  else
-	    mem_size = GEN_INT (MAX (INTVAL (MEM_SIZE (x)),
+	    {
-				     INTVAL (MEM_SIZE (y))));
+	      clear_mem_size (x);
-	  set_mem_size (x, mem_size);
+	      clear_mem_size (y);
-	  set_mem_size (y, mem_size);
+	    }
 	  set_mem_align (x, MIN (MEM_ALIGN (x), MEM_ALIGN (y)));
 	  set_mem_align (y, MEM_ALIGN (x));
+	}
+}
+if (code == MEM)
+{
+if (MEM_READONLY_P (x) != MEM_READONLY_P (y))
+	{
+	  MEM_READONLY_P (x) = 0;
+	  MEM_READONLY_P (y) = 0;
+	}
+if (MEM_NOTRAP_P (x) != MEM_NOTRAP_P (y))
+	{
+	  MEM_NOTRAP_P (x) = 0;
+	  MEM_NOTRAP_P (y) = 0;
+	}
+if (MEM_VOLATILE_P (x) != MEM_VOLATILE_P (y))
+	{
+	  MEM_VOLATILE_P (x) = 1;
+	  MEM_VOLATILE_P (y) = 1;
 	}
 }
 fmt = GET_RTX_FORMAT (code);
 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
 }
 return;
 }
-/* Return true if I1 and I2 are equivalent and thus can be crossjumped.  */
+/* Checks if patterns P1 and P2 are equivalent, apart from the possibly
+different single sets S1 and S2.  */
 static bool
-old_insns_match_p (int mode ATTRIBUTE_UNUSED, rtx i1, rtx i2)
+equal_different_set_p (rtx p1, rtx s1, rtx p2, rtx s2)
+{
+int i;
+rtx e1, e2;
+if (p1 == s1 && p2 == s2)
+return true;
+if (GET_CODE (p1) != PARALLEL || GET_CODE (p2) != PARALLEL)
+return false;
+if (XVECLEN (p1, 0) != XVECLEN (p2, 0))
+return false;
+for (i = 0; i < XVECLEN (p1, 0); i++)
+{
+e1 = XVECEXP (p1, 0, i);
+e2 = XVECEXP (p2, 0, i);
+if (e1 == s1 && e2 == s2)
+continue;
+if (reload_completed
+? rtx_renumbered_equal_p (e1, e2) : rtx_equal_p (e1, e2))
+continue;
+return false;
+}
+return true;
+}
+/* NOTE1 is the REG_EQUAL note, if any, attached to an insn
+that is a single_set with a SET_SRC of SRC1.  Similarly
+for NOTE2/SRC2.
+So effectively NOTE1/NOTE2 are an alternate form of
+SRC1/SRC2 respectively.
+Return nonzero if SRC1 or NOTE1 has the same constant
+integer value as SRC2 or NOTE2.   Else return zero.  */
+static int
+values_equal_p (rtx note1, rtx note2, rtx src1, rtx src2)
+{
+if (note1
+&& note2
+&& CONST_INT_P (XEXP (note1, 0))
+&& rtx_equal_p (XEXP (note1, 0), XEXP (note2, 0)))
+return 1;
+if (!note1
+&& !note2
+&& CONST_INT_P (src1)
+&& CONST_INT_P (src2)
+&& rtx_equal_p (src1, src2))
+return 1;
+if (note1
+&& CONST_INT_P (src2)
+&& rtx_equal_p (XEXP (note1, 0), src2))
+return 1;
+if (note2
+&& CONST_INT_P (src1)
+&& rtx_equal_p (XEXP (note2, 0), src1))
+return 1;
+return 0;
+}
+/* Examine register notes on I1 and I2 and return:
+- dir_forward if I1 can be replaced by I2, or
+- dir_backward if I2 can be replaced by I1, or
+- dir_both if both are the case.  */
+static enum replace_direction
+can_replace_by (rtx_insn *i1, rtx_insn *i2)
+{
+rtx s1, s2, d1, d2, src1, src2, note1, note2;
+bool c1, c2;
+/* Check for 2 sets.  */
+s1 = single_set (i1);
+s2 = single_set (i2);
+if (s1 == NULL_RTX || s2 == NULL_RTX)
+return dir_none;
+/* Check that the 2 sets set the same dest.  */
+d1 = SET_DEST (s1);
+d2 = SET_DEST (s2);
+if (!(reload_completed
+? rtx_renumbered_equal_p (d1, d2) : rtx_equal_p (d1, d2)))
+return dir_none;
+/* Find identical req_equiv or reg_equal note, which implies that the 2 sets
+set dest to the same value.  */
+note1 = find_reg_equal_equiv_note (i1);
+note2 = find_reg_equal_equiv_note (i2);
+src1 = SET_SRC (s1);
+src2 = SET_SRC (s2);
+if (!values_equal_p (note1, note2, src1, src2))
+return dir_none;
+if (!equal_different_set_p (PATTERN (i1), s1, PATTERN (i2), s2))
+return dir_none;
+/* Although the 2 sets set dest to the same value, we cannot replace
+(set (dest) (const_int))
+by
+(set (dest) (reg))
+because we don't know if the reg is live and has the same value at the
+location of replacement.  */
+c1 = CONST_INT_P (src1);
+c2 = CONST_INT_P (src2);
+if (c1 && c2)
+return dir_both;
+else if (c2)
+return dir_forward;
+else if (c1)
+return dir_backward;
+return dir_none;
+}
+/* Merges directions A and B.  */
+static enum replace_direction
+merge_dir (enum replace_direction a, enum replace_direction b)
+{
+/* Implements the following table:
+|bo fw bw no
+---+-----------
+bo |bo fw bw no
+fw |-- fw no no
+bw |-- -- bw no
+no |-- -- -- no.  */
+if (a == b)
+return a;
+if (a == dir_both)
+return b;
+if (b == dir_both)
+return a;
+return dir_none;
+}
+/* Array of flags indexed by reg note kind, true if the given
+reg note is CFA related.  */
+static const bool reg_note_cfa_p[] = {
+#undef REG_CFA_NOTE
+#define DEF_REG_NOTE(NAME) false,
+#define REG_CFA_NOTE(NAME) true,
+#include "reg-notes.def"
+#undef REG_CFA_NOTE
+#undef DEF_REG_NOTE
+false
+};
+/* Return true if I1 and I2 have identical CFA notes (the same order
+and equivalent content).  */
+static bool
+insns_have_identical_cfa_notes (rtx_insn *i1, rtx_insn *i2)
+{
+rtx n1, n2;
+for (n1 = REG_NOTES (i1), n2 = REG_NOTES (i2); ;
+n1 = XEXP (n1, 1), n2 = XEXP (n2, 1))
+{
+/* Skip over reg notes not related to CFI information.  */
+while (n1 && !reg_note_cfa_p[REG_NOTE_KIND (n1)])
+	n1 = XEXP (n1, 1);
+while (n2 && !reg_note_cfa_p[REG_NOTE_KIND (n2)])
+	n2 = XEXP (n2, 1);
+if (n1 == NULL_RTX && n2 == NULL_RTX)
+	return true;
+if (n1 == NULL_RTX || n2 == NULL_RTX)
+	return false;
+if (XEXP (n1, 0) == XEXP (n2, 0))
+	;
+else if (XEXP (n1, 0) == NULL_RTX || XEXP (n2, 0) == NULL_RTX)
+	return false;
+else if (!(reload_completed
+		 ? rtx_renumbered_equal_p (XEXP (n1, 0), XEXP (n2, 0))
+		 : rtx_equal_p (XEXP (n1, 0), XEXP (n2, 0))))
+	return false;
+}
+}
+/* Examine I1 and I2 and return:
+- dir_forward if I1 can be replaced by I2, or
+- dir_backward if I2 can be replaced by I1, or
+- dir_both if both are the case.  */
+static enum replace_direction
+old_insns_match_p (int mode ATTRIBUTE_UNUSED, rtx_insn *i1, rtx_insn *i2)
 {
 rtx p1, p2;
 /* Verify that I1 and I2 are equivalent.  */
 if (GET_CODE (i1) != GET_CODE (i2))
-return false;
+return dir_none;
 /* __builtin_unreachable() may lead to empty blocks (ending with
 NOTE_INSN_BASIC_BLOCK).  They may be crossjumped. */
 if (NOTE_INSN_BASIC_BLOCK_P (i1) && NOTE_INSN_BASIC_BLOCK_P (i2))
-return true;
+return dir_both;
+/* ??? Do not allow cross-jumping between different stack levels.  */
+p1 = find_reg_note (i1, REG_ARGS_SIZE, NULL);
+p2 = find_reg_note (i2, REG_ARGS_SIZE, NULL);
+if (p1 && p2)
+{
+p1 = XEXP (p1, 0);
+p2 = XEXP (p2, 0);
+if (!rtx_equal_p (p1, p2))
+return dir_none;
+/* ??? Worse, this adjustment had better be constant lest we
+have differing incoming stack levels.  */
+if (!frame_pointer_needed
+&& find_args_size_adjust (i1) == HOST_WIDE_INT_MIN)
+	return dir_none;
+}
+else if (p1 || p2)
+return dir_none;
+/* Do not allow cross-jumping between frame related insns and other
+insns.  */
+if (RTX_FRAME_RELATED_P (i1) != RTX_FRAME_RELATED_P (i2))
+return dir_none;
 p1 = PATTERN (i1);
 p2 = PATTERN (i2);
 if (GET_CODE (p1) != GET_CODE (p2))
-return false;
+return dir_none;
 /* If this is a CALL_INSN, compare register usage information.
 If we don't check this on stack register machines, the two
 CALL_INSNs might be merged leaving reg-stack.c with mismatching
 numbers of stack registers in the same basic block.
 /* Ensure the same EH region.  */
 rtx n1 = find_reg_note (i1, REG_EH_REGION, 0);
 rtx n2 = find_reg_note (i2, REG_EH_REGION, 0);
 if (!n1 && n2)
-	return false;
+	return dir_none;
 if (n1 && (!n2 || XEXP (n1, 0) != XEXP (n2, 0)))
-	return false;
+	return dir_none;
 if (!rtx_equal_p (CALL_INSN_FUNCTION_USAGE (i1),
 			CALL_INSN_FUNCTION_USAGE (i2))
 	  || SIBLING_CALL_P (i1) != SIBLING_CALL_P (i2))
-	return false;
+	return dir_none;
-}
+/* For address sanitizer, never crossjump __asan_report_* builtins,
+	 otherwise errors might be reported on incorrect lines.  */
+if (flag_sanitize & SANITIZE_ADDRESS)
+	{
+	  rtx call = get_call_rtx_from (i1);
+	  if (call && GET_CODE (XEXP (XEXP (call, 0), 0)) == SYMBOL_REF)
+	    {
+	      rtx symbol = XEXP (XEXP (call, 0), 0);
+	      if (SYMBOL_REF_DECL (symbol)
+		  && TREE_CODE (SYMBOL_REF_DECL (symbol)) == FUNCTION_DECL)
+		{
+		  if ((DECL_BUILT_IN_CLASS (SYMBOL_REF_DECL (symbol))
+		       == BUILT_IN_NORMAL)
+		      && DECL_FUNCTION_CODE (SYMBOL_REF_DECL (symbol))
+			 >= BUILT_IN_ASAN_REPORT_LOAD1
+		      && DECL_FUNCTION_CODE (SYMBOL_REF_DECL (symbol))
+			 <= BUILT_IN_ASAN_STOREN)
+		    return dir_none;
+		}
+	    }
+	}
+}
+/* If both i1 and i2 are frame related, verify all the CFA notes
+in the same order and with the same content.  */
+if (RTX_FRAME_RELATED_P (i1) && !insns_have_identical_cfa_notes (i1, i2))
+return dir_none;
 #ifdef STACK_REGS
 /* If cross_jump_death_matters is not 0, the insn's mode
 indicates whether or not the insn contains any stack-like
 regs.  */
 for (note = REG_NOTES (i2); note; note = XEXP (note, 1))
 	if (REG_NOTE_KIND (note) == REG_DEAD && STACK_REG_P (XEXP (note, 0)))
 	  SET_HARD_REG_BIT (i2_regset, REGNO (XEXP (note, 0)));
 if (!hard_reg_set_equal_p (i1_regset, i2_regset))
-	return false;
+	return dir_none;
 }
 #endif
 if (reload_completed
 ? rtx_renumbered_equal_p (p1, p2) : rtx_equal_p (p1, p2))
-return true;
+return dir_both;
-return false;
+return can_replace_by (i1, i2);
 }
 /* When comparing insns I1 and I2 in flow_find_cross_jump or
 flow_find_head_matching_sequence, ensure the notes match.  */
 static void
-merge_notes (rtx i1, rtx i2)
+merge_notes (rtx_insn *i1, rtx_insn *i2)
 {
 /* If the merged insns have different REG_EQUAL notes, then
 remove them.  */
 rtx equiv1 = find_reg_equal_equiv_note (i1);
 rtx equiv2 = find_reg_equal_equiv_note (i2);
 remove_note (i1, equiv1);
 remove_note (i2, equiv2);
 }
 }
+/* Walks from I1 in BB1 backward till the next non-debug insn, and returns the
+resulting insn in I1, and the corresponding bb in BB1.  At the head of a
+bb, if there is a predecessor bb that reaches this bb via fallthru, and
+FOLLOW_FALLTHRU, walks further in the predecessor bb and registers this in
+DID_FALLTHRU.  Otherwise, stops at the head of the bb.  */
+static void
+walk_to_nondebug_insn (rtx_insn **i1, basic_block *bb1, bool follow_fallthru,
+bool *did_fallthru)
+{
+edge fallthru;
+*did_fallthru = false;
+/* Ignore notes.  */
+while (!NONDEBUG_INSN_P (*i1))
+{
+if (*i1 != BB_HEAD (*bb1))
+{
+*i1 = PREV_INSN (*i1);
+continue;
+}
+if (!follow_fallthru)
+return;
+fallthru = find_fallthru_edge ((*bb1)->preds);
+if (!fallthru || fallthru->src == ENTRY_BLOCK_PTR_FOR_FN (cfun)
+|| !single_succ_p (fallthru->src))
+return;
+*bb1 = fallthru->src;
+*i1 = BB_END (*bb1);
+*did_fallthru = true;
+}
+}
 /* Look through the insns at the end of BB1 and BB2 and find the longest
-sequence that are equivalent.  Store the first insns for that sequence
+sequence that are either equivalent, or allow forward or backward
-in *F1 and *F2 and return the sequence length.
+replacement.  Store the first insns for that sequence in *F1 and *F2 and
+return the sequence length.
+DIR_P indicates the allowed replacement direction on function entry, and
+the actual replacement direction on function exit.  If NULL, only equivalent
+sequences are allowed.
 To simplify callers of this function, if the blocks match exactly,
 store the head of the blocks in *F1 and *F2.  */
 int
-flow_find_cross_jump (basic_block bb1, basic_block bb2, rtx *f1, rtx *f2)
+flow_find_cross_jump (basic_block bb1, basic_block bb2, rtx_insn **f1,
-{
+		      rtx_insn **f2, enum replace_direction *dir_p)
-rtx i1, i2, last1, last2, afterlast1, afterlast2;
+{
+rtx_insn *i1, *i2, *last1, *last2, *afterlast1, *afterlast2;
 int ninsns = 0;
+enum replace_direction dir, last_dir, afterlast_dir;
+bool follow_fallthru, did_fallthru;
+if (dir_p)
+dir = *dir_p;
+else
+dir = dir_both;
+afterlast_dir = dir;
+last_dir = afterlast_dir;
 /* Skip simple jumps at the end of the blocks.  Complex jumps still
 need to be compared for equivalence, which we'll do below.  */
 i1 = BB_END (bb1);
-last1 = afterlast1 = last2 = afterlast2 = NULL_RTX;
+last1 = afterlast1 = last2 = afterlast2 = NULL;
 if (onlyjump_p (i1)
 || (returnjump_p (i1) && !side_effects_p (PATTERN (i1))))
 {
 last1 = i1;
 i1 = PREV_INSN (i1);
 i2 = BB_END (bb2);
 if (onlyjump_p (i2)
 || (returnjump_p (i2) && !side_effects_p (PATTERN (i2))))
 {
 last2 = i2;
-/* Count everything except for unconditional jump as insn.  */
+/* Count everything except for unconditional jump as insn.
-if (!simplejump_p (i2) && !returnjump_p (i2) && last1)
+	 Don't count any jumps if dir_p is NULL.  */
+if (!simplejump_p (i2) && !returnjump_p (i2) && last1 && dir_p)
 	ninsns++;
 i2 = PREV_INSN (i2);
 }
 while (true)
 {
-/* Ignore notes.  */
+/* In the following example, we can replace all jumps to C by jumps to A.
-while (!NONDEBUG_INSN_P (i1) && i1 != BB_HEAD (bb1))
-	i1 = PREV_INSN (i1);
+This removes 4 duplicate insns.
+[bb A] insn1            [bb C] insn1
-while (!NONDEBUG_INSN_P (i2) && i2 != BB_HEAD (bb2))
+insn2                   insn2
-	i2 = PREV_INSN (i2);
+[bb B] insn3                   insn3
+insn4                   insn4
+jump_insn               jump_insn
+We could also replace all jumps to A by jumps to C, but that leaves B
+alive, and removes only 2 duplicate insns.  In a subsequent crossjump
+step, all jumps to B would be replaced with jumps to the middle of C,
+achieving the same result with more effort.
+So we allow only the first possibility, which means that we don't allow
+fallthru in the block that's being replaced.  */
+follow_fallthru = dir_p && dir != dir_forward;
+walk_to_nondebug_insn (&i1, &bb1, follow_fallthru, &did_fallthru);
+if (did_fallthru)
+dir = dir_backward;
+follow_fallthru = dir_p && dir != dir_backward;
+walk_to_nondebug_insn (&i2, &bb2, follow_fallthru, &did_fallthru);
+if (did_fallthru)
+dir = dir_forward;
 if (i1 == BB_HEAD (bb1) || i2 == BB_HEAD (bb2))
 	break;
-if (!old_insns_match_p (0, i1, i2))
+/* Do not turn corssing edge to non-crossing or vice versa after
+	 reload. */
+if (BB_PARTITION (BLOCK_FOR_INSN (i1))
+	  != BB_PARTITION (BLOCK_FOR_INSN (i2))
+	  && reload_completed)
+	break;
+dir = merge_dir (dir, old_insns_match_p (0, i1, i2));
+if (dir == dir_none || (!dir_p && dir != dir_both))
 	break;
 merge_memattrs (i1, i2);
 /* Don't begin a cross-jump with a NOTE insn.  */
 	{
 	  merge_notes (i1, i2);
 	  afterlast1 = last1, afterlast2 = last2;
 	  last1 = i1, last2 = i2;
-	  ninsns++;
+	  afterlast_dir = last_dir;
+	  last_dir = dir;
+	  if (active_insn_p (i1))
+	    ninsns++;
 	}
 i1 = PREV_INSN (i1);
 i2 = PREV_INSN (i2);
 }
-#ifdef HAVE_cc0
 /* Don't allow the insn after a compare to be shared by
 cross-jumping unless the compare is also shared.  */
-if (ninsns && reg_mentioned_p (cc0_rtx, last1) && ! sets_cc0_p (last1))
+if (HAVE_cc0 && ninsns && reg_mentioned_p (cc0_rtx, last1)
-last1 = afterlast1, last2 = afterlast2, ninsns--;
+&& ! sets_cc0_p (last1))
-#endif
+last1 = afterlast1, last2 = afterlast2, last_dir = afterlast_dir, ninsns--;
 /* Include preceding notes and labels in the cross-jump.  One,
 this may bring us to the head of the blocks as requested above.
 Two, it keeps line number notes as matched as may be.  */
 if (ninsns)
 {
+bb1 = BLOCK_FOR_INSN (last1);
 while (last1 != BB_HEAD (bb1) && !NONDEBUG_INSN_P (PREV_INSN (last1)))
 	last1 = PREV_INSN (last1);
 if (last1 != BB_HEAD (bb1) && LABEL_P (PREV_INSN (last1)))
 	last1 = PREV_INSN (last1);
+bb2 = BLOCK_FOR_INSN (last2);
 while (last2 != BB_HEAD (bb2) && !NONDEBUG_INSN_P (PREV_INSN (last2)))
 	last2 = PREV_INSN (last2);
 if (last2 != BB_HEAD (bb2) && LABEL_P (PREV_INSN (last2)))
 	last2 = PREV_INSN (last2);
 *f1 = last1;
 *f2 = last2;
 }
+if (dir_p)
+*dir_p = last_dir;
 return ninsns;
 }
 /* Like flow_find_cross_jump, except start looking for a matching sequence from
 the head of the two blocks.  Do not include jumps at the end.
 If STOP_AFTER is nonzero, stop after finding that many matching
-instructions.  */
+instructions.  If STOP_AFTER is zero, count all INSN_P insns, if it is
+non-zero, only count active insns.  */
 int
-flow_find_head_matching_sequence (basic_block bb1, basic_block bb2, rtx *f1,
+flow_find_head_matching_sequence (basic_block bb1, basic_block bb2, rtx_insn **f1,
-				  rtx *f2, int stop_after)
+				  rtx_insn **f2, int stop_after)
 {
-rtx i1, i2, last1, last2, beforelast1, beforelast2;
+rtx_insn *i1, *i2, *last1, *last2, *beforelast1, *beforelast2;
 int ninsns = 0;
 edge e;
 edge_iterator ei;
 int nehedges1 = 0, nehedges2 = 0;
 if (e->flags & EDGE_EH)
 nehedges2++;
 i1 = BB_HEAD (bb1);
 i2 = BB_HEAD (bb2);
-last1 = beforelast1 = last2 = beforelast2 = NULL_RTX;
+last1 = beforelast1 = last2 = beforelast2 = NULL;
 while (true)
 {
 /* Ignore notes, except NOTE_INSN_EPILOGUE_BEG.  */
 while (!NONDEBUG_INSN_P (i1) && i1 != BB_END (bb1))
 	      && nehedges2 > 0)
 	  || (i1 == BB_END (bb1) && i2 == BB_END (bb2)
 	      && nehedges1 != nehedges2))
 	break;
-if (!old_insns_match_p (0, i1, i2))
+if (old_insns_match_p (0, i1, i2) != dir_both)
 	break;
 merge_memattrs (i1, i2);
 /* Don't begin a cross-jump with a NOTE insn.  */
 	{
 	  merge_notes (i1, i2);
 	  beforelast1 = last1, beforelast2 = last2;
 	  last1 = i1, last2 = i2;
-	  ninsns++;
+	  if (!stop_after || active_insn_p (i1))
+	    ninsns++;
 	}
 if (i1 == BB_END (bb1) || i2 == BB_END (bb2)
 	  || (stop_after > 0 && ninsns == stop_after))
 	break;
 i1 = NEXT_INSN (i1);
 i2 = NEXT_INSN (i2);
 }
-#ifdef HAVE_cc0
 /* Don't allow a compare to be shared by cross-jumping unless the insn
 after the compare is also shared.  */
-if (ninsns && reg_mentioned_p (cc0_rtx, last1) && sets_cc0_p (last1))
+if (HAVE_cc0 && ninsns && reg_mentioned_p (cc0_rtx, last1)
+&& sets_cc0_p (last1))
 last1 = beforelast1, last2 = beforelast2, ninsns--;
-#endif
 if (ninsns)
 {
 *f1 = last1;
 *f2 = last2;
 int nehedges1 = 0, nehedges2 = 0;
 edge fallthru1 = 0, fallthru2 = 0;
 edge e1, e2;
 edge_iterator ei;
+/* If we performed shrink-wrapping, edges to the exit block can
+only be distinguished for JUMP_INSNs.  The two paths may differ in
+whether they went through the prologue.  Sibcalls are fine, we know
+that we either didn't need or inserted an epilogue before them.  */
+if (crtl->shrink_wrapped
+&& single_succ_p (bb1)
+&& single_succ (bb1) == EXIT_BLOCK_PTR_FOR_FN (cfun)
+&& !JUMP_P (BB_END (bb1))
+&& !(CALL_P (BB_END (bb1)) && SIBLING_CALL_P (BB_END (bb1))))
+return false;
 /* If BB1 has only one successor, we may be looking at either an
 unconditional jump, or a fake edge to exit.  */
 if (single_succ_p (bb1)
 && (single_succ_edge (bb1)->flags & (EDGE_COMPLEX | EDGE_FAKE)) == 0
 && (!JUMP_P (BB_END (bb1)) || simplejump_p (BB_END (bb1))))
 	 roughly similar.  */
 if (match
 	  && optimize_bb_for_speed_p (bb1)
 	  && optimize_bb_for_speed_p (bb2))
 	{
-	  int prob2;
+	  profile_probability prob2;
 	  if (b1->dest == b2->dest)
 	    prob2 = b2->probability;
 	  else
 	    /* Do not use f2 probability as f2 may be forwarded.  */
-	    prob2 = REG_BR_PROB_BASE - b2->probability;
+	    prob2 = b2->probability.invert ();
 	  /* Fail if the difference in probabilities is greater than 50%.
 	     This rules out two well-predicted branches with opposite
 	     outcomes.  */
-	  if (abs (b1->probability - prob2) > REG_BR_PROB_BASE / 2)
+	  if (b1->probability.differs_lot_from_p (prob2))
 	    {
 	      if (dump_file)
-		fprintf (dump_file,
+		{
-			 "Outcomes of branch in bb %i and %i differ too much (%i %i)\n",
+		  fprintf (dump_file,
-			 bb1->index, bb2->index, b1->probability, prob2);
+			   "Outcomes of branch in bb %i and %i differ too"
+			   " much (", bb1->index, bb2->index);
+		  b1->probability.dump (dump_file);
+		  prob2.dump (dump_file);
+		  fprintf (dump_file, ")\n");
+		}
 	      return false;
 	    }
 	}
 if (dump_file && match)
 instruction.  */
 /* Check whether there are tablejumps in the end of BB1 and BB2.
 Return true if they are identical.  */
 {
-rtx label1, label2;
+rtx_insn *label1, *label2;
-rtx table1, table2;
+rtx_jump_table_data *table1, *table2;
 if (tablejump_p (BB_END (bb1), &label1, &table1)
 	  && tablejump_p (BB_END (bb2), &label2, &table2)
 	  && GET_CODE (PATTERN (table1)) == GET_CODE (PATTERN (table2)))
 	{
 		      identical = false;
 		}
 	      if (identical)
 		{
-		  replace_label_data rr;
 		  bool match;
 		  /* Temporarily replace references to LABEL1 with LABEL2
 		     in BB1->END so that we could compare the instructions.  */
-		  rr.r1 = label1;
+		  replace_label_in_insn (BB_END (bb1), label1, label2, false);
-		  rr.r2 = label2;
-		  rr.update_label_nuses = false;
+		  match = (old_insns_match_p (mode, BB_END (bb1), BB_END (bb2))
-		  for_each_rtx (&BB_END (bb1), replace_label, &rr);
+			   == dir_both);
-		  match = old_insns_match_p (mode, BB_END (bb1), BB_END (bb2));
 		  if (dump_file && match)
 		    fprintf (dump_file,
 			     "Tablejumps in bb %i and %i match.\n",
 			     bb1->index, bb2->index);
 		  /* Set the original label in BB1->END because when deleting
 		     a block whose end is a tablejump, the tablejump referenced
 		     from the instruction is deleted too.  */
-		  rr.r1 = label2;
+		  replace_label_in_insn (BB_END (bb1), label2, label1, false);
-		  rr.r2 = label1;
-		  for_each_rtx (&BB_END (bb1), replace_label, &rr);
 		  return match;
 		}
 	    }
 	  return false;
 	}
 }
+/* Find the last non-debug non-note instruction in each bb, except
+stop when we see the NOTE_INSN_BASIC_BLOCK, as old_insns_match_p
+handles that case specially. old_insns_match_p does not handle
+other types of instruction notes.  */
+rtx_insn *last1 = BB_END (bb1);
+rtx_insn *last2 = BB_END (bb2);
+while (!NOTE_INSN_BASIC_BLOCK_P (last1) &&
+(DEBUG_INSN_P (last1) || NOTE_P (last1)))
+last1 = PREV_INSN (last1);
+while (!NOTE_INSN_BASIC_BLOCK_P (last2) &&
+(DEBUG_INSN_P (last2) || NOTE_P (last2)))
+last2 = PREV_INSN (last2);
+gcc_assert (last1 && last2);
 /* First ensure that the instructions match.  There may be many outgoing
 edges so this test is generally cheaper.  */
-if (!old_insns_match_p (mode, BB_END (bb1), BB_END (bb2)))
+if (old_insns_match_p (mode, last1, last2) != dir_both)
 return false;
 /* Search the outgoing edges, ensure that the counts do match, find possible
 fallthru and exception handling edges since these needs more
 validation.  */
 if (EDGE_COUNT (bb1->succs) != EDGE_COUNT (bb2->succs))
 return false;
+bool nonfakeedges = false;
 FOR_EACH_EDGE (e1, ei, bb1->succs)
 {
 e2 = EDGE_SUCC (bb2, ei.index);
+if ((e1->flags & EDGE_FAKE) == 0)
+	nonfakeedges = true;
 if (e1->flags & EDGE_EH)
 	nehedges1++;
 if (e2->flags & EDGE_EH)
 }
 /* If number of edges of various types does not match, fail.  */
 if (nehedges1 != nehedges2
 || (fallthru1 != 0) != (fallthru2 != 0))
+return false;
+/* If !ACCUMULATE_OUTGOING_ARGS, bb1 (and bb2) have no successors
+and the last real insn doesn't have REG_ARGS_SIZE note, don't
+attempt to optimize, as the two basic blocks might have different
+REG_ARGS_SIZE depths.  For noreturn calls and unconditional
+traps there should be REG_ARG_SIZE notes, they could be missing
+for __builtin_unreachable () uses though.  */
+if (!nonfakeedges
+&& !ACCUMULATE_OUTGOING_ARGS
+&& (!INSN_P (last1)
+|| !find_reg_note (last1, REG_ARGS_SIZE, NULL)))
 return false;
 /* fallthru edges must be forwarded to the same destination.  */
 if (fallthru1)
 {
 && LABEL_PRESERVE_P (block_label (bb)));
 }
 /* E1 and E2 are edges with the same destination block.  Search their
 predecessors for common code.  If found, redirect control flow from
-(maybe the middle of) E1->SRC to (maybe the middle of) E2->SRC.  */
+(maybe the middle of) E1->SRC to (maybe the middle of) E2->SRC (dir_forward),
+or the other way around (dir_backward).  DIR specifies the allowed
+replacement direction.  */
 static bool
-try_crossjump_to_edge (int mode, edge e1, edge e2)
+try_crossjump_to_edge (int mode, edge e1, edge e2,
+enum replace_direction dir)
 {
 int nmatch;
 basic_block src1 = e1->src, src2 = e2->src;
 basic_block redirect_to, redirect_from, to_remove;
-rtx newpos1, newpos2;
+basic_block osrc1, osrc2, redirect_edges_to, tmp;
+rtx_insn *newpos1, *newpos2;
 edge s;
 edge_iterator ei;
-newpos1 = newpos2 = NULL_RTX;
+newpos1 = newpos2 = NULL;
-/* If we have partitioned hot/cold basic blocks, it is a bad idea
-to try this optimization.
-Basic block partitioning may result in some jumps that appear to
-be optimizable (or blocks that appear to be mergeable), but which really
-must be left untouched (they are required to make it safely across
-partition boundaries).  See the comments at the top of
-bb-reorder.c:partition_hot_cold_basic_blocks for complete details.  */
-if (flag_reorder_blocks_and_partition && reload_completed)
-return false;
 /* Search backward through forwarder blocks.  We don't need to worry
 about multiple entry or chained forwarders, as they will be optimized
 away.  We do this to look past the unconditional jump following a
 conditional jump that is required due to the current CFG shape.  */
 if (single_pred_p (src2)
 && FORWARDER_BLOCK_P (src2))
 e2 = single_pred_edge (src2), src2 = e2->src;
 /* Nothing to do if we reach ENTRY, or a common source block.  */
-if (src1 == ENTRY_BLOCK_PTR || src2 == ENTRY_BLOCK_PTR)
+if (src1 == ENTRY_BLOCK_PTR_FOR_FN (cfun) || src2
+== ENTRY_BLOCK_PTR_FOR_FN (cfun))
 return false;
 if (src1 == src2)
 return false;
 /* Seeing more than 1 forwarder blocks would confuse us later...  */
 /* Likewise with dead code (possibly newly created by the other optimizations
 of cfg_cleanup).  */
 if (EDGE_COUNT (src1->preds) == 0 || EDGE_COUNT (src2->preds) == 0)
 return false;
+/* Do not turn corssing edge to non-crossing or vice versa after reload.  */
+if (BB_PARTITION (src1) != BB_PARTITION (src2)
+&& reload_completed)
+return false;
 /* Look for the common insn sequence, part the first ...  */
 if (!outgoing_edges_match (mode, src1, src2))
 return false;
 /* ... and part the second.  */
-nmatch = flow_find_cross_jump (src1, src2, &newpos1, &newpos2);
+nmatch = flow_find_cross_jump (src1, src2, &newpos1, &newpos2, &dir);
+osrc1 = src1;
+osrc2 = src2;
+if (newpos1 != NULL_RTX)
+src1 = BLOCK_FOR_INSN (newpos1);
+if (newpos2 != NULL_RTX)
+src2 = BLOCK_FOR_INSN (newpos2);
+/* Check that SRC1 and SRC2 have preds again.  They may have changed
+above due to the call to flow_find_cross_jump.  */
+if (EDGE_COUNT (src1->preds) == 0 || EDGE_COUNT (src2->preds) == 0)
+return false;
+if (dir == dir_backward)
+{
+std::swap (osrc1, osrc2);
+std::swap (src1, src2);
+std::swap (e1, e2);
+std::swap (newpos1, newpos2);
+}
 /* Don't proceed with the crossjump unless we found a sufficient number
 of matching instructions or the 'from' block was totally matched
 (such that its predecessors will hopefully be redirected and the
 block removed).  */
 /* Here we know that the insns in the end of SRC1 which are common with SRC2
 will be deleted.
 If we have tablejumps in the end of SRC1 and SRC2
 they have been already compared for equivalence in outgoing_edges_match ()
 so replace the references to TABLE1 by references to TABLE2.  */
 {
-rtx label1, label2;
+rtx_insn *label1, *label2;
-rtx table1, table2;
+rtx_jump_table_data *table1, *table2;
-if (tablejump_p (BB_END (src1), &label1, &table1)
+if (tablejump_p (BB_END (osrc1), &label1, &table1)
-	  && tablejump_p (BB_END (src2), &label2, &table2)
+	  && tablejump_p (BB_END (osrc2), &label2, &table2)
 	  && label1 != label2)
 	{
-	  replace_label_data rr;
+	  rtx_insn *insn;
-	  rtx insn;
 	  /* Replace references to LABEL1 with LABEL2.  */
-	  rr.r1 = label1;
-	  rr.r2 = label2;
-	  rr.update_label_nuses = true;
 	  for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
 	    {
 	      /* Do not replace the label in SRC1->END because when deleting
 		 a block whose end is a tablejump, the tablejump referenced
 		 from the instruction is deleted too.  */
-	      if (insn != BB_END (src1))
+	      if (insn != BB_END (osrc1))
-		for_each_rtx (&insn, replace_label, &rr);
+		replace_label_in_insn (insn, label1, label2, true);
 	    }
 	}
 }
 /* Avoid splitting if possible.  We must always split when SRC2 has
 EH predecessor edges, or we may end up with basic blocks with both
 normal and EH predecessor edges.  */
 if (newpos2 == BB_HEAD (src2)
 	     src1->index, src2->index, nmatch);
 /* We may have some registers visible through the block.  */
 df_set_bb_dirty (redirect_to);
+if (osrc2 == src2)
+redirect_edges_to = redirect_to;
+else
+redirect_edges_to = osrc2;
 /* Recompute the frequencies and counts of outgoing edges.  */
-FOR_EACH_EDGE (s, ei, redirect_to->succs)
+FOR_EACH_EDGE (s, ei, redirect_edges_to->succs)
 {
 edge s2;
 edge_iterator ei;
 basic_block d = s->dest;
 	    d2 = single_succ (d2);
 	  if (d == d2)
 	    break;
 	}
-s->count += s2->count;
 /* Take care to update possible forwarder blocks.  We verified
 	 that there is no more than one in the chain, so we can't run
 	 into infinite loop.  */
 if (FORWARDER_BLOCK_P (s->dest))
 	{
-	  single_succ_edge (s->dest)->count += s2->count;
-	  s->dest->count += s2->count;
 	  s->dest->frequency += EDGE_FREQUENCY (s);
 	}
 if (FORWARDER_BLOCK_P (s2->dest))
 	{
-	  single_succ_edge (s2->dest)->count -= s2->count;
-	  if (single_succ_edge (s2->dest)->count < 0)
-	    single_succ_edge (s2->dest)->count = 0;
-	  s2->dest->count -= s2->count;
 	  s2->dest->frequency -= EDGE_FREQUENCY (s);
 	  if (s2->dest->frequency < 0)
 	    s2->dest->frequency = 0;
-	  if (s2->dest->count < 0)
+	}
-	    s2->dest->count = 0;
-	}
+if (!redirect_edges_to->frequency && !src1->frequency)
+	s->probability = s->probability.combine_with_freq
-if (!redirect_to->frequency && !src1->frequency)
+			   (redirect_edges_to->frequency,
-	s->probability = (s->probability + s2->probability) / 2;
+			    s2->probability, src1->frequency);
-else
-	s->probability
-	  = ((s->probability * redirect_to->frequency +
-	      s2->probability * src1->frequency)
-	     / (redirect_to->frequency + src1->frequency));
 }
 /* Adjust count and frequency for the block.  An earlier jump
 threading pass may have left the profile in an inconsistent
 state (see update_bb_profile_for_threading) so we must be
 prepared for overflows.  */
-redirect_to->count += src1->count;
+tmp = redirect_to;
-redirect_to->frequency += src1->frequency;
+do
-if (redirect_to->frequency > BB_FREQ_MAX)
+{
-redirect_to->frequency = BB_FREQ_MAX;
+tmp->count += src1->count;
-update_br_prob_note (redirect_to);
+tmp->frequency += src1->frequency;
+if (tmp->frequency > BB_FREQ_MAX)
+tmp->frequency = BB_FREQ_MAX;
+if (tmp == redirect_edges_to)
+break;
+tmp = find_fallthru_edge (tmp->succs)->dest;
+}
+while (true);
+update_br_prob_note (redirect_edges_to);
 /* Edit SRC1 to go to REDIRECT_TO at NEWPOS1.  */
 /* Skip possible basic block header.  */
 if (LABEL_P (newpos1))
 try_crossjump_bb (int mode, basic_block bb)
 {
 edge e, e2, fallthru;
 bool changed;
 unsigned max, ix, ix2;
-basic_block ev, ev2;
 /* Nothing to do if there is not at least two incoming edges.  */
 if (EDGE_COUNT (bb->preds) < 2)
 return false;
 /* Don't crossjump if this block ends in a computed jump,
 unless we are optimizing for size.  */
 if (optimize_bb_for_size_p (bb)
-&& bb != EXIT_BLOCK_PTR
+&& bb != EXIT_BLOCK_PTR_FOR_FN (cfun)
 && computed_jump_p (BB_END (bb)))
 return false;
 /* If we are partitioning hot/cold basic blocks, we don't want to
 mess up unconditional or indirect jumps that cross between hot
 return false;
 fallthru = find_fallthru_edge (bb->preds);
 changed = false;
-for (ix = 0, ev = bb; ix < EDGE_COUNT (ev->preds); )
+for (ix = 0; ix < EDGE_COUNT (bb->preds);)
 {
-e = EDGE_PRED (ev, ix);
+e = EDGE_PRED (bb, ix);
 ix++;
 /* As noted above, first try with the fallthru predecessor (or, a
 	 fallthru predecessor if we are in cfglayout mode).  */
 if (fallthru)
 	  if (!first_pass
 	      && !((e->src->flags & BB_MODIFIED)
 		   || (fallthru->src->flags & BB_MODIFIED)))
 	    continue;
-	  if (try_crossjump_to_edge (mode, e, fallthru))
+	  if (try_crossjump_to_edge (mode, e, fallthru, dir_forward))
 	    {
 	      changed = true;
 	      ix = 0;
-	      ev = bb;
 	      continue;
 	    }
 	}
 /* Non-obvious work limiting check: Recognize that we're going
 	 choosing to do the check from the block for which the edge
 	 in question is the first successor of A.  */
 if (EDGE_SUCC (e->src, 0) != e)
 	continue;
-for (ix2 = 0, ev2 = bb; ix2 < EDGE_COUNT (ev2->preds); )
+for (ix2 = 0; ix2 < EDGE_COUNT (bb->preds); ix2++)
 	{
-	  e2 = EDGE_PRED (ev2, ix2);
+	  e2 = EDGE_PRED (bb, ix2);
-	  ix2++;
 	  if (e2 == e)
 	    continue;
 	  /* We've already checked the fallthru edge above.  */
 	  if (!first_pass
 	      && !((e->src->flags & BB_MODIFIED)
 		   || (e2->src->flags & BB_MODIFIED)))
 	    continue;
-	  if (try_crossjump_to_edge (mode, e, e2))
+	  /* Both e and e2 are not fallthru edges, so we can crossjump in either
+	     direction.  */
+	  if (try_crossjump_to_edge (mode, e, e2, dir_both))
 	    {
 	      changed = true;
-	      ev2 = bb;
 	      ix = 0;
 	      break;
 	    }
 	}
 }
 if (changed)
-crossjumps_occured = true;
+crossjumps_occurred = true;
 return changed;
 }
 /* Search the successors of BB for common insn sequences.  When found,
 try_head_merge_bb (basic_block bb)
 {
 basic_block final_dest_bb = NULL;
 int max_match = INT_MAX;
 edge e0;
-rtx *headptr, *currptr, *nextptr;
+rtx_insn **headptr, **currptr, **nextptr;
 bool changed, moveall;
 unsigned ix;
-rtx e0_last_head, cond, move_before;
+rtx_insn *e0_last_head;
+rtx cond;
+rtx_insn *move_before;
 unsigned nedges = EDGE_COUNT (bb->succs);
-rtx jump = BB_END (bb);
+rtx_insn *jump = BB_END (bb);
 regset live, live_union;
 /* Nothing to do if there is not at least two outgoing edges.  */
 if (nedges < 2)
 return false;
 /* Don't crossjump if this block ends in a computed jump,
 unless we are optimizing for size.  */
 if (optimize_bb_for_size_p (bb)
-&& bb != EXIT_BLOCK_PTR
+&& bb != EXIT_BLOCK_PTR_FOR_FN (cfun)
 && computed_jump_p (BB_END (bb)))
 return false;
 cond = get_condition (jump, &move_before, true, false);
 if (cond == NULL_RTX)
-move_before = jump;
+{
+if (HAVE_cc0 && reg_mentioned_p (cc0_rtx, jump))
+	move_before = prev_nonnote_nondebug_insn (jump);
+else
+	move_before = jump;
+}
 for (ix = 0; ix < nedges; ix++)
-if (EDGE_SUCC (bb, ix)->dest == EXIT_BLOCK_PTR)
+if (EDGE_SUCC (bb, ix)->dest == EXIT_BLOCK_PTR_FOR_FN (cfun))
 return false;
 for (ix = 0; ix < nedges; ix++)
 {
 edge e = EDGE_SUCC (bb, ix);
 	    return false;
 	}
 }
 e0 = EDGE_SUCC (bb, 0);
-e0_last_head = NULL_RTX;
+e0_last_head = NULL;
 changed = false;
 for (ix = 1; ix < nedges; ix++)
 {
 edge e = EDGE_SUCC (bb, ix);
-rtx e0_last, e_last;
+rtx_insn *e0_last, *e_last;
 int nmatch;
 nmatch = flow_find_head_matching_sequence (e0->dest, e->dest,
 						 &e0_last, &e_last, 0);
 if (nmatch == 0)
 /* We must find a union of the live registers at each of the end points.  */
 live = BITMAP_ALLOC (NULL);
 live_union = BITMAP_ALLOC (NULL);
-currptr = XNEWVEC (rtx, nedges);
+currptr = XNEWVEC (rtx_insn *, nedges);
-headptr = XNEWVEC (rtx, nedges);
+headptr = XNEWVEC (rtx_insn *, nedges);
-nextptr = XNEWVEC (rtx, nedges);
+nextptr = XNEWVEC (rtx_insn *, nedges);
 for (ix = 0; ix < nedges; ix++)
 {
 int j;
 basic_block merge_bb = EDGE_SUCC (bb, ix)->dest;
-rtx head = BB_HEAD (merge_bb);
+rtx_insn *head = BB_HEAD (merge_bb);
 while (!NONDEBUG_INSN_P (head))
 	head = NEXT_INSN (head);
 headptr[ix] = head;
 currptr[ix] = head;
 /* If we're moving across two blocks, verify the validity of the
 first move, then adjust the target and let the loop below deal
 with the final move.  */
 if (final_dest_bb != NULL)
 {
-rtx move_upto;
+rtx_insn *move_upto;
 moveall = can_move_insns_across (currptr[0], e0_last_head, move_before,
 				       jump, e0->dest, live_union,
 				       NULL, &move_upto);
 if (!moveall)
 	goto out;
 jump = BB_END (final_dest_bb);
 cond = get_condition (jump, &move_before, true, false);
 if (cond == NULL_RTX)
-	move_before = jump;
+	{
+	  if (HAVE_cc0 && reg_mentioned_p (cc0_rtx, jump))
+	    move_before = prev_nonnote_nondebug_insn (jump);
+	  else
+	    move_before = jump;
+	}
 }
 do
 {
-rtx move_upto;
+rtx_insn *move_upto;
 moveall = can_move_insns_across (currptr[0], e0_last_head,
 				       move_before, jump, e0->dest, live_union,
 				       NULL, &move_upto);
 if (!moveall && move_upto == NULL_RTX)
 	{
 	    break;
 	  /* Try again, using a different insertion point.  */
 	  move_before = jump;
-#ifdef HAVE_cc0
 	  /* Don't try moving before a cc0 user, as that may invalidate
 	     the cc0.  */
-	  if (reg_mentioned_p (cc0_rtx, jump))
+	  if (HAVE_cc0 && reg_mentioned_p (cc0_rtx, jump))
 	    break;
-#endif
 	  continue;
 	}
 if (final_dest_bb && !moveall)
 	{
 	  if (currptr[0] == move_upto)
 	    break;
 	  for (ix = 0; ix < nedges; ix++)
 	    {
-	      rtx curr = currptr[ix];
+	      rtx_insn *curr = currptr[ix];
 	      do
 		curr = NEXT_INSN (curr);
 	      while (!NONDEBUG_INSN_P (curr));
 	      currptr[ix] = curr;
 	    }
 /* If we can't currently move all of the identical insns, remember
 	 each insn after the range that we'll merge.  */
 if (!moveall)
 	for (ix = 0; ix < nedges; ix++)
 	  {
-	    rtx curr = currptr[ix];
+	    rtx_insn *curr = currptr[ix];
 	    do
 	      curr = NEXT_INSN (curr);
 	    while (!NONDEBUG_INSN_P (curr));
 	    nextptr[ix] = curr;
 	  }
 	    break;
 	  /* For the unmerged insns, try a different insertion point.  */
 	  move_before = jump;
-#ifdef HAVE_cc0
 	  /* Don't try moving before a cc0 user, as that may invalidate
 	     the cc0.  */
-	  if (reg_mentioned_p (cc0_rtx, jump))
+	  if (HAVE_cc0 && reg_mentioned_p (cc0_rtx, jump))
 	    break;
-#endif
 	  for (ix = 0; ix < nedges; ix++)
 	    currptr[ix] = headptr[ix] = nextptr[ix];
 	}
 }
 out:
 free (currptr);
 free (headptr);
 free (nextptr);
-crossjumps_occured |= changed;
+crossjumps_occurred |= changed;
 return changed;
 }
 /* Return true if BB contains just bb note, or bb note followed
 by only DEBUG_INSNs.  */
 static bool
 trivially_empty_bb_p (basic_block bb)
 {
-rtx insn = BB_END (bb);
+rtx_insn *insn = BB_END (bb);
 while (1)
 {
 if (insn == BB_HEAD (bb))
 	return true;
 	return false;
 insn = PREV_INSN (insn);
 }
 }
+/* Return true if BB contains just a return and possibly a USE of the
+return value.  Fill in *RET and *USE with the return and use insns
+if any found, otherwise NULL.  All CLOBBERs are ignored.  */
+static bool
+bb_is_just_return (basic_block bb, rtx_insn **ret, rtx_insn **use)
+{
+*ret = *use = NULL;
+rtx_insn *insn;
+if (bb == EXIT_BLOCK_PTR_FOR_FN (cfun))
+return false;
+FOR_BB_INSNS (bb, insn)
+if (NONDEBUG_INSN_P (insn))
+{
+	rtx pat = PATTERN (insn);
+	if (!*ret && ANY_RETURN_P (pat))
+	  *ret = insn;
+	else if (!*ret && !*use && GET_CODE (pat) == USE
+	    && REG_P (XEXP (pat, 0))
+	    && REG_FUNCTION_VALUE_P (XEXP (pat, 0)))
+	  *use = insn;
+	else if (GET_CODE (pat) != CLOBBER)
+	  return false;
+}
+return !!*ret;
+}
 /* Do simple CFG optimizations - basic block merging, simplifying of jump
 instructions etc.  Return nonzero if changes were made.  */
 static bool
 try_optimize_cfg (int mode)
 basic_block bb, b, next;
 if (mode & (CLEANUP_CROSSJUMP | CLEANUP_THREADING))
 clear_bb_flags ();
-crossjumps_occured = false;
+crossjumps_occurred = false;
-FOR_EACH_BB (bb)
+FOR_EACH_BB_FN (bb, cfun)
 update_forwarder_flag (bb);
 if (! targetm.cannot_modify_jumps_p ())
 {
 first_pass = true;
 	  if (dump_file)
 	    fprintf (dump_file,
 		     "\n\ntry_optimize_cfg iteration %i\n\n",
 		     iterations);
-	  for (b = ENTRY_BLOCK_PTR->next_bb; b != EXIT_BLOCK_PTR;)
+	  for (b = ENTRY_BLOCK_PTR_FOR_FN (cfun)->next_bb; b
+	       != EXIT_BLOCK_PTR_FOR_FN (cfun);)
 	    {
 	      basic_block c;
 	      edge s;
 	      bool changed_here = false;
 		 passes.  Empty blocks may result from expanding
 		 __builtin_unreachable ().  */
 	      if (EDGE_COUNT (b->preds) == 0
 		  || (EDGE_COUNT (b->succs) == 0
 		      && trivially_empty_bb_p (b)
-		      && single_succ_edge (ENTRY_BLOCK_PTR)->dest != b))
+		      && single_succ_edge (ENTRY_BLOCK_PTR_FOR_FN (cfun))->dest
+		      != b))
 		{
 		  c = b->prev_bb;
 		  if (EDGE_COUNT (b->preds) > 0)
 		    {
 		      edge e;
 		      edge_iterator ei;
 		      if (current_ir_type () == IR_RTL_CFGLAYOUT)
 			{
-			  if (b->il.rtl->footer
+			  if (BB_FOOTER (b)
-			      && BARRIER_P (b->il.rtl->footer))
+			      && BARRIER_P (BB_FOOTER (b)))
 			    FOR_EACH_EDGE (e, ei, b->preds)
 			      if ((e->flags & EDGE_FALLTHRU)
-				  && e->src->il.rtl->footer == NULL)
+				  && BB_FOOTER (e->src) == NULL)
 				{
-				  if (b->il.rtl->footer)
+				  if (BB_FOOTER (b))
 				    {
-				      e->src->il.rtl->footer = b->il.rtl->footer;
+				      BB_FOOTER (e->src) = BB_FOOTER (b);
-				      b->il.rtl->footer = NULL;
+				      BB_FOOTER (b) = NULL;
 				    }
 				  else
 				    {
 				      start_sequence ();
-				      e->src->il.rtl->footer = emit_barrier ();
+				      BB_FOOTER (e->src) = emit_barrier ();
 				      end_sequence ();
 				    }
 				}
 			}
 		      else
 			{
-			  rtx last = get_last_bb_insn (b);
+			  rtx_insn *last = get_last_bb_insn (b);
 			  if (last && BARRIER_P (last))
 			    FOR_EACH_EDGE (e, ei, b->preds)
 			      if ((e->flags & EDGE_FALLTHRU))
 				emit_barrier_after (BB_END (e->src));
 			}
 		    }
 		  delete_basic_block (b);
 		  changed = true;
-		  /* Avoid trying to remove ENTRY_BLOCK_PTR.  */
+		  /* Avoid trying to remove the exit block.  */
-		  b = (c == ENTRY_BLOCK_PTR ? c->next_bb : c);
+		  b = (c == ENTRY_BLOCK_PTR_FOR_FN (cfun) ? c->next_bb : c);
 		  continue;
 		}
 	      /* Remove code labels no longer used.  */
 	      if (single_pred_p (b)
 		  && (single_pred_edge (b)->flags & EDGE_FALLTHRU)
 		  && !(single_pred_edge (b)->flags & EDGE_COMPLEX)
 		  && LABEL_P (BB_HEAD (b))
+		  && !LABEL_PRESERVE_P (BB_HEAD (b))
 		  /* If the previous block ends with a branch to this
 		     block, we can't delete the label.  Normally this
 		     is a condjump that is yet to be simplified, but
 		     if CASE_DROPS_THRU, this can be a tablejump with
 		     some element going to the same place as the
 		     default (fallthru).  */
-		  && (single_pred (b) == ENTRY_BLOCK_PTR
+		  && (single_pred (b) == ENTRY_BLOCK_PTR_FOR_FN (cfun)
 		      || !JUMP_P (BB_END (single_pred (b)))
 		      || ! label_is_jump_target_p (BB_HEAD (b),
 						   BB_END (single_pred (b)))))
 		{
-		  rtx label = BB_HEAD (b);
+		  delete_insn (BB_HEAD (b));
-		  delete_insn_chain (label, label, false);
-		  /* If the case label is undeletable, move it after the
-		     BASIC_BLOCK note.  */
-		  if (NOTE_KIND (BB_HEAD (b)) == NOTE_INSN_DELETED_LABEL)
-		    {
-		      rtx bb_note = NEXT_INSN (BB_HEAD (b));
-		      reorder_insns_nobb (label, label, bb_note);
-		      BB_HEAD (b) = bb_note;
-		      if (BB_END (b) == bb_note)
-			BB_END (b) = label;
-		    }
 		  if (dump_file)
 		    fprintf (dump_file, "Deleted label in block %i.\n",
 			     b->index);
 		}
 	      /* If we fall through an empty block, we can remove it.  */
-	      if (!(mode & CLEANUP_CFGLAYOUT)
+	      if (!(mode & (CLEANUP_CFGLAYOUT | CLEANUP_NO_INSN_DEL))
 		  && single_pred_p (b)
 		  && (single_pred_edge (b)->flags & EDGE_FALLTHRU)
 		  && !LABEL_P (BB_HEAD (b))
 		  && FORWARDER_BLOCK_P (b)
 		  /* Note that forwarder_block_p true ensures that
 		     there is a successor for this block.  */
 		  && (single_succ_edge (b)->flags & EDGE_FALLTHRU)
-		  && n_basic_blocks > NUM_FIXED_BLOCKS + 1)
+		  && n_basic_blocks_for_fn (cfun) > NUM_FIXED_BLOCKS + 1)
 		{
 		  if (dump_file)
 		    fprintf (dump_file,
 			     "Deleting fallthru block %i.\n",
 			     b->index);
-		  c = b->prev_bb == ENTRY_BLOCK_PTR ? b->next_bb : b->prev_bb;
+		  c = ((b->prev_bb == ENTRY_BLOCK_PTR_FOR_FN (cfun))
+		       ? b->next_bb : b->prev_bb);
 		  redirect_edge_succ_nodup (single_pred_edge (b),
 					    single_succ (b));
 		  delete_basic_block (b);
 		  changed = true;
 		  b = c;
 	      /* Merge B with its single successor, if any.  */
 	      if (single_succ_p (b)
 		  && (s = single_succ_edge (b))
 		  && !(s->flags & EDGE_COMPLEX)
-		  && (c = s->dest) != EXIT_BLOCK_PTR
+		  && (c = s->dest) != EXIT_BLOCK_PTR_FOR_FN (cfun)
 		  && single_pred_p (c)
 		  && b != c)
 		{
 		  /* When not in cfg_layout mode use code aware of reordering
 		     INSN.  This code possibly creates new basic blocks so it
 			b = next;
 			changed_here = true;
 		      }
 		}
+	      /* Try to change a branch to a return to just that return.  */
+	      rtx_insn *ret, *use;
+	      if (single_succ_p (b)
+		  && onlyjump_p (BB_END (b))
+		  && bb_is_just_return (single_succ (b), &ret, &use))
+		{
+		  if (redirect_jump (as_a <rtx_jump_insn *> (BB_END (b)),
+				     PATTERN (ret), 0))
+		    {
+		      if (use)
+			emit_insn_before (copy_insn (PATTERN (use)),
+					  BB_END (b));
+		      if (dump_file)
+			fprintf (dump_file, "Changed jump %d->%d to return.\n",
+				 b->index, single_succ (b)->index);
+		      redirect_edge_succ (single_succ_edge (b),
+					  EXIT_BLOCK_PTR_FOR_FN (cfun));
+		      single_succ_edge (b)->flags &= ~EDGE_CROSSING;
+		      changed_here = true;
+		    }
+		}
+	      /* Try to change a conditional branch to a return to the
+		 respective conditional return.  */
+	      if (EDGE_COUNT (b->succs) == 2
+		  && any_condjump_p (BB_END (b))
+		  && bb_is_just_return (BRANCH_EDGE (b)->dest, &ret, &use))
+		{
+		  if (redirect_jump (as_a <rtx_jump_insn *> (BB_END (b)),
+				     PATTERN (ret), 0))
+		    {
+		      if (use)
+			emit_insn_before (copy_insn (PATTERN (use)),
+					  BB_END (b));
+		      if (dump_file)
+			fprintf (dump_file, "Changed conditional jump %d->%d "
+				 "to conditional return.\n",
+				 b->index, BRANCH_EDGE (b)->dest->index);
+		      redirect_edge_succ (BRANCH_EDGE (b),
+					  EXIT_BLOCK_PTR_FOR_FN (cfun));
+		      BRANCH_EDGE (b)->flags &= ~EDGE_CROSSING;
+		      changed_here = true;
+		    }
+		}
+	      /* Try to flip a conditional branch that falls through to
+		 a return so that it becomes a conditional return and a
+		 new jump to the original branch target.  */
+	      if (EDGE_COUNT (b->succs) == 2
+		  && BRANCH_EDGE (b)->dest != EXIT_BLOCK_PTR_FOR_FN (cfun)
+		  && any_condjump_p (BB_END (b))
+		  && bb_is_just_return (FALLTHRU_EDGE (b)->dest, &ret, &use))
+		{
+		  if (invert_jump (as_a <rtx_jump_insn *> (BB_END (b)),
+				   JUMP_LABEL (BB_END (b)), 0))
+		    {
+		      basic_block new_ft = BRANCH_EDGE (b)->dest;
+		      if (redirect_jump (as_a <rtx_jump_insn *> (BB_END (b)),
+					 PATTERN (ret), 0))
+			{
+			  if (use)
+			    emit_insn_before (copy_insn (PATTERN (use)),
+					      BB_END (b));
+			  if (dump_file)
+			    fprintf (dump_file, "Changed conditional jump "
+				     "%d->%d to conditional return, adding "
+				     "fall-through jump.\n",
+				     b->index, BRANCH_EDGE (b)->dest->index);
+			  redirect_edge_succ (BRANCH_EDGE (b),
+					      EXIT_BLOCK_PTR_FOR_FN (cfun));
+			  BRANCH_EDGE (b)->flags &= ~EDGE_CROSSING;
+			  std::swap (BRANCH_EDGE (b)->probability,
+				     FALLTHRU_EDGE (b)->probability);
+			  update_br_prob_note (b);
+			  basic_block jb = force_nonfallthru (FALLTHRU_EDGE (b));
+			  notice_new_block (jb);
+			  if (!redirect_jump (as_a <rtx_jump_insn *> (BB_END (jb)),
+					      block_label (new_ft), 0))
+			    gcc_unreachable ();
+			  redirect_edge_succ (single_succ_edge (jb), new_ft);
+			  changed_here = true;
+			}
+		      else
+			{
+			  /* Invert the jump back to what it was.  This should
+			     never fail.  */
+			  if (!invert_jump (as_a <rtx_jump_insn *> (BB_END (b)),
+					    JUMP_LABEL (BB_END (b)), 0))
+			    gcc_unreachable ();
+			}
+		    }
+		}
 	      /* Simplify branch over branch.  */
 	      if ((mode & CLEANUP_EXPENSIVE)
 		   && !(mode & CLEANUP_CFGLAYOUT)
 		   && try_simplify_condjump (b))
 		changed_here = true;
 	      /* If B has a single outgoing edge, but uses a
 		 non-trivial jump instruction without side-effects, we
 		 can either delete the jump entirely, or replace it
 		 with a simple unconditional jump.  */
 	      if (single_succ_p (b)
-		  && single_succ (b) != EXIT_BLOCK_PTR
+		  && single_succ (b) != EXIT_BLOCK_PTR_FOR_FN (cfun)
 		  && onlyjump_p (BB_END (b))
-		  && !find_reg_note (BB_END (b), REG_CROSSING_JUMP, NULL_RTX)
+		  && !CROSSING_JUMP_P (BB_END (b))
 		  && try_redirect_by_replacing_jump (single_succ_edge (b),
 						     single_succ (b),
 						     (mode & CLEANUP_CFGLAYOUT) != 0))
 		{
 		  update_forwarder_flag (b);
 		  changed_here = true;
 		}
 	      /* Simplify branch to branch.  */
 	      if (try_forward_edges (mode, b))
-		changed_here = true;
+		{
+		  update_forwarder_flag (b);
+		  changed_here = true;
+		}
 	      /* Look for shared code between blocks.  */
 	      if ((mode & CLEANUP_CROSSJUMP)
 		  && try_crossjump_bb (mode, b))
 		changed_here = true;
 	      else
 		changed = true;
 	    }
 	  if ((mode & CLEANUP_CROSSJUMP)
-	      && try_crossjump_bb (mode, EXIT_BLOCK_PTR))
+	      && try_crossjump_bb (mode, EXIT_BLOCK_PTR_FOR_FN (cfun)))
 	    changed = true;
 	  if (block_was_dirty)
 	    {
 	      /* This should only be set by head-merging.  */
 	      gcc_assert (mode & CLEANUP_CROSSJUMP);
 	      df_analyze ();
 	    }
-#ifdef ENABLE_CHECKING
 	  if (changed)
-	    verify_flow_info ();
+{
-#endif
+/* Edge forwarding in particular can cause hot blocks previously
+reached by both hot and cold blocks to become dominated only
+by cold blocks. This will cause the verification below to fail,
+and lead to now cold code in the hot section. This is not easy
+to detect and fix during edge forwarding, and in some cases
+is only visible after newly unreachable blocks are deleted,
+which will be done in fixup_partitions.  */
+	      fixup_partitions ();
+	      checking_verify_flow_info ();
+}
 	  changed_overall |= changed;
 	  first_pass = false;
 	}
 while (changed);
 }
-FOR_ALL_BB (b)
+FOR_ALL_BB_FN (b, cfun)
 b->flags &= ~(BB_FORWARDER_BLOCK | BB_NONTHREADABLE_BLOCK);
 return changed_overall;
 }
 delete blocks in reverse dominator order, so as to get a chance
 to substitute all released DEFs into debug stmts.  If we don't
 have dominators information, walking blocks backward gets us a
 better chance of retaining most debug information than
 otherwise.  */
-if (MAY_HAVE_DEBUG_STMTS && current_ir_type () == IR_GIMPLE
+if (MAY_HAVE_DEBUG_INSNS && current_ir_type () == IR_GIMPLE
 && dom_info_available_p (CDI_DOMINATORS))
 {
-for (b = EXIT_BLOCK_PTR->prev_bb; b != ENTRY_BLOCK_PTR; b = prev_bb)
+for (b = EXIT_BLOCK_PTR_FOR_FN (cfun)->prev_bb;
+	   b != ENTRY_BLOCK_PTR_FOR_FN (cfun); b = prev_bb)
 	{
 	  prev_bb = b->prev_bb;
 	  if (!(b->flags & BB_REACHABLE))
 	    {
 		 case.  */
 	      if (!first_dom_son (CDI_DOMINATORS, b))
 		delete_basic_block (b);
 	      else
 		{
-		  VEC (basic_block, heap) *h
+		  vec<basic_block> h
 		    = get_all_dominated_blocks (CDI_DOMINATORS, b);
-		  while (VEC_length (basic_block, h))
+		  while (h.length ())
 		    {
-		      b = VEC_pop (basic_block, h);
+		      b = h.pop ();
 		      prev_bb = b->prev_bb;
 		      gcc_assert (!(b->flags & BB_REACHABLE));
 		      delete_basic_block (b);
 		    }
-		  VEC_free (basic_block, heap, h);
+		  h.release ();
 		}
 	      changed = true;
 	    }
 	}
 }
 else
 {
-for (b = EXIT_BLOCK_PTR->prev_bb; b != ENTRY_BLOCK_PTR; b = prev_bb)
+for (b = EXIT_BLOCK_PTR_FOR_FN (cfun)->prev_bb;
+	   b != ENTRY_BLOCK_PTR_FOR_FN (cfun); b = prev_bb)
 	{
 	  prev_bb = b->prev_bb;
 	  if (!(b->flags & BB_REACHABLE))
 	    {
 {
 basic_block bb;
 /* A dead jump table does not belong to any basic block.  Scan insns
 between two adjacent basic blocks.  */
-FOR_EACH_BB (bb)
+FOR_EACH_BB_FN (bb, cfun)
 {
-rtx insn, next;
+rtx_insn *insn, *next;
 for (insn = NEXT_INSN (BB_END (bb));
 	   insn && !NOTE_INSN_BASIC_BLOCK_P (insn);
 	   insn = next)
 	{
 	  next = NEXT_INSN (insn);
 	  if (LABEL_P (insn)
 	      && LABEL_NUSES (insn) == LABEL_PRESERVE_P (insn)
 	      && JUMP_TABLE_DATA_P (next))
 	    {
-	      rtx label = insn, jump = next;
+	      rtx_insn *label = insn, *jump = next;
 	      if (dump_file)
 		fprintf (dump_file, "Dead jumptable %i removed\n",
 			 INSN_UID (insn));
 	     code, so delete_trivially_dead_insns or even doing nothing at all
 	     is good enough.  */
 	  if ((mode & CLEANUP_EXPENSIVE) && !reload_completed
 	      && !delete_trivially_dead_insns (get_insns (), max_reg_num ()))
 	    break;
-	  if ((mode & CLEANUP_CROSSJUMP) && crossjumps_occured)
+	  if ((mode & CLEANUP_CROSSJUMP) && crossjumps_occurred)
 	    run_fast_dce ();
 	}
 else
 	break;
 }
 not in a basic block.  Dead jumptables are cleaned up when
 going out of cfglayout mode.  */
 if (!(mode & CLEANUP_CFGLAYOUT))
 delete_dead_jumptables ();
+/* ???  We probably do this way too often.  */
+if (current_loops
+&& (changed
+	  || (mode & CLEANUP_CFG_CHANGED)))
+{
+timevar_push (TV_REPAIR_LOOPS);
+/* The above doesn't preserve dominance info if available.  */
+gcc_assert (!dom_info_available_p (CDI_DOMINATORS));
+calculate_dominance_info (CDI_DOMINATORS);
+fix_loop_structure (NULL);
+free_dominance_info (CDI_DOMINATORS);
+timevar_pop (TV_REPAIR_LOOPS);
+}
 timevar_pop (TV_CLEANUP_CFG);
 return changed;
 }
-static unsigned int
+namespace {
-rest_of_handle_jump (void)
-{
+const pass_data pass_data_jump =
-if (crtl->tail_call_emit)
+{
-fixup_tail_calls ();
+RTL_PASS, /* type */
-return 0;
+"jump", /* name */
-}
+OPTGROUP_NONE, /* optinfo_flags */
+TV_JUMP, /* tv_id */
-struct rtl_opt_pass pass_jump =
+0, /* properties_required */
-{
+0, /* properties_provided */
-{
+0, /* properties_destroyed */
-RTL_PASS,
+0, /* todo_flags_start */
-"sibling",                            /* name */
+0, /* todo_flags_finish */
-NULL,                                 /* gate */
-rest_of_handle_jump,			/* execute */
-NULL,                                 /* sub */
-NULL,                                 /* next */
-0,                                    /* static_pass_number */
-TV_JUMP,                              /* tv_id */
-0,                                    /* properties_required */
-0,                                    /* properties_provided */
-0,                                    /* properties_destroyed */
-TODO_ggc_collect,                     /* todo_flags_start */
-TODO_verify_flow,                     /* todo_flags_finish */
-}
 };
+class pass_jump : public rtl_opt_pass
-static unsigned int
+{
-rest_of_handle_jump2 (void)
+public:
+pass_jump (gcc::context *ctxt)
+: rtl_opt_pass (pass_data_jump, ctxt)
+{}
+/* opt_pass methods: */
+virtual unsigned int execute (function *);
+}; // class pass_jump
+unsigned int
+pass_jump::execute (function *)
 {
 delete_trivially_dead_insns (get_insns (), max_reg_num ());
 if (dump_file)
 dump_flow_info (dump_file, dump_flags);
 cleanup_cfg ((optimize ? CLEANUP_EXPENSIVE : 0)
 	       | (flag_thread_jumps ? CLEANUP_THREADING : 0));
 return 0;
 }
+} // anon namespace
-struct rtl_opt_pass pass_jump2 =
-{
+rtl_opt_pass *
-{
+make_pass_jump (gcc::context *ctxt)
-RTL_PASS,
+{
-"jump",                               /* name */
+return new pass_jump (ctxt);
-NULL,                                 /* gate */
+}
-rest_of_handle_jump2,			/* execute */
-NULL,                                 /* sub */
+namespace {
-NULL,                                 /* next */
-0,                                    /* static_pass_number */
+const pass_data pass_data_jump2 =
-TV_JUMP,                              /* tv_id */
+{
-0,                                    /* properties_required */
+RTL_PASS, /* type */
-0,                                    /* properties_provided */
+"jump2", /* name */
-0,                                    /* properties_destroyed */
+OPTGROUP_NONE, /* optinfo_flags */
-TODO_ggc_collect,                     /* todo_flags_start */
+TV_JUMP, /* tv_id */
-TODO_dump_func | TODO_verify_rtl_sharing,/* todo_flags_finish */
+0, /* properties_required */
-}
+0, /* properties_provided */
+0, /* properties_destroyed */
+0, /* todo_flags_start */
+0, /* todo_flags_finish */
 };
+class pass_jump2 : public rtl_opt_pass
+{
+public:
+pass_jump2 (gcc::context *ctxt)
+: rtl_opt_pass (pass_data_jump2, ctxt)
+{}
+/* opt_pass methods: */
+virtual unsigned int execute (function *)
+{
+cleanup_cfg (flag_crossjumping ? CLEANUP_CROSSJUMP : 0);
+return 0;
+}
+}; // class pass_jump2
+} // anon namespace
+rtl_opt_pass *
+make_pass_jump2 (gcc::context *ctxt)
+{
+return new pass_jump2 (ctxt);
+}

Mercurial > hg > CbC > CbC_gcc

comparison gcc/cfgcleanup.c @ 111:04ced10e8804