Revert:

	2007-09-05  Laurynas Biveinis  <laurynas.biveinis@gmail.com>
	* regrename.c (copyprop_hardreg_forward_1): New variable next. Use
	FOR_BB_INSNS_SAFE instead of for loop.
	* cse.c (cse_extended_basic_block): Likewise.
	* postreload.c (reload_cse_regs_1): New variable next. Make sure
	that the for loop does not invoke NEXT_INSN on a deleted insn.
	* function.c (instantiate_virtual_regs): Likewise.
	* lower-subreg.c (remove_retval_note): Likewise.
	(decompose_multiword_subregs): Use FOR_BB_INSNS_SAFE instead of
	FOR_BB_INSNS.
	* emit-rtl.c (remove_insn): Set NEXT_INSN and PREV_INSN to NULL on
	a deleted insn.
	* cfgrtl.c (delete_insn): Set JUMP_LABEL to NULL on a deleted
	insn, if it's a jump.
	(try_redirect_by_replacing_jump): New variable jump_p. Call
	tablejump_p before delete_insn_chain.
	* reload1.c (reload): New variable next. Make sure that the for
	loop does not invoke NEXT_INSN on a deleted insn.
	(fixup_eh_region_note): Make the loop terminate if i becomes NULL.
	(delete_output_reload): New variable prev. Make sure the the for
	loops do not invoke PREV_INSN on a deleted insn.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@128284 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 84 insertions, 93 deletions

diff --git a/gcc/reload1.c b/gcc/reload1.c
index 270ea0654cf..31626f57a40 100644
--- a/gcc/reload1.c
+++ b/gcc/reload1.c
@@ -702,7 +702,7 @@ int
 reload (rtx first, int global)
 {
   int i;
-  rtx insn, next;
+  rtx insn;
   struct elim_table *ep;
   basic_block bb;
 
@@ -1227,91 +1227,87 @@ reload (rtx first, int global)
      are no longer useful or accurate.  Strip and regenerate REG_INC notes
      that may have been moved around.  */
 
-  for (insn = first; insn; insn = next)
-    {
-      next = NEXT_INSN (insn);
-      if (INSN_P (insn))
-        {
-          rtx *pnote;
-
-          if (CALL_P (insn))
-            replace_pseudos_in (& CALL_INSN_FUNCTION_USAGE (insn),
-                                VOIDmode, CALL_INSN_FUNCTION_USAGE (insn));
-
-          if ((GET_CODE (PATTERN (insn)) == USE
-               /* We mark with QImode USEs introduced by reload itself.  */
-               && (GET_MODE (insn) == QImode
-                   || find_reg_note (insn, REG_EQUAL, NULL_RTX)))
-              || (GET_CODE (PATTERN (insn)) == CLOBBER
-                  && (!MEM_P (XEXP (PATTERN (insn), 0))
-                      || GET_MODE (XEXP (PATTERN (insn), 0)) != BLKmode
-                      || (GET_CODE (XEXP (XEXP (PATTERN (insn), 0), 0))
-                          != SCRATCH
-                          && XEXP (XEXP (PATTERN (insn), 0), 0)
-                          != stack_pointer_rtx))
-                  && (!REG_P (XEXP (PATTERN (insn), 0))
-                      || ! REG_FUNCTION_VALUE_P (XEXP (PATTERN (insn), 0)))))
-            {
-              delete_insn (insn);
-              continue;
-            }
-
-          /* Some CLOBBERs may survive until here and still reference
-             unassigned pseudos with const equivalent, which may in turn cause
-             ICE in later passes if the reference remains in place.  */
-          if (GET_CODE (PATTERN (insn)) == CLOBBER)
-            replace_pseudos_in (& XEXP (PATTERN (insn), 0),
-                                VOIDmode, PATTERN (insn));
-
-          /* Discard obvious no-ops, even without -O.  This optimization
-             is fast and doesn't interfere with debugging.  */
-          if (NONJUMP_INSN_P (insn)
-              && GET_CODE (PATTERN (insn)) == SET
-              && REG_P (SET_SRC (PATTERN (insn)))
-              && REG_P (SET_DEST (PATTERN (insn)))
-              && (REGNO (SET_SRC (PATTERN (insn)))
-                  == REGNO (SET_DEST (PATTERN (insn)))))
-            {
-              delete_insn (insn);
-              continue;
-            }
-
-          pnote = &REG_NOTES (insn);
-          while (*pnote != 0)
-            {
-              if (REG_NOTE_KIND (*pnote) == REG_DEAD
-                  || REG_NOTE_KIND (*pnote) == REG_UNUSED
-                  || REG_NOTE_KIND (*pnote) == REG_INC
-                  || REG_NOTE_KIND (*pnote) == REG_RETVAL
-                  || REG_NOTE_KIND (*pnote) == REG_LIBCALL_ID
-                  || REG_NOTE_KIND (*pnote) == REG_LIBCALL)
-                *pnote = XEXP (*pnote, 1);
-              else
-                pnote = &XEXP (*pnote, 1);
-            }
+  for (insn = first; insn; insn = NEXT_INSN (insn))
+    if (INSN_P (insn))
+      {
+	rtx *pnote;
+
+	if (CALL_P (insn))
+	  replace_pseudos_in (& CALL_INSN_FUNCTION_USAGE (insn),
+			      VOIDmode, CALL_INSN_FUNCTION_USAGE (insn));
+
+	if ((GET_CODE (PATTERN (insn)) == USE
+	     /* We mark with QImode USEs introduced by reload itself.  */
+	     && (GET_MODE (insn) == QImode
+		 || find_reg_note (insn, REG_EQUAL, NULL_RTX)))
+	    || (GET_CODE (PATTERN (insn)) == CLOBBER
+		&& (!MEM_P (XEXP (PATTERN (insn), 0))
+		    || GET_MODE (XEXP (PATTERN (insn), 0)) != BLKmode
+		    || (GET_CODE (XEXP (XEXP (PATTERN (insn), 0), 0)) != SCRATCH
+			&& XEXP (XEXP (PATTERN (insn), 0), 0)
+				!= stack_pointer_rtx))
+		&& (!REG_P (XEXP (PATTERN (insn), 0))
+		    || ! REG_FUNCTION_VALUE_P (XEXP (PATTERN (insn), 0)))))
+	  {
+	    delete_insn (insn);
+	    continue;
+	  }
+
+	/* Some CLOBBERs may survive until here and still reference unassigned
+	   pseudos with const equivalent, which may in turn cause ICE in later
+	   passes if the reference remains in place.  */
+	if (GET_CODE (PATTERN (insn)) == CLOBBER)
+	  replace_pseudos_in (& XEXP (PATTERN (insn), 0),
+			      VOIDmode, PATTERN (insn));
+
+	/* Discard obvious no-ops, even without -O.  This optimization
+	   is fast and doesn't interfere with debugging.  */
+	if (NONJUMP_INSN_P (insn)
+	    && GET_CODE (PATTERN (insn)) == SET
+	    && REG_P (SET_SRC (PATTERN (insn)))
+	    && REG_P (SET_DEST (PATTERN (insn)))
+	    && (REGNO (SET_SRC (PATTERN (insn)))
+		== REGNO (SET_DEST (PATTERN (insn)))))
+	  {
+	    delete_insn (insn);
+	    continue;
+	  }
+
+	pnote = &REG_NOTES (insn);
+	while (*pnote != 0)
+	  {
+	    if (REG_NOTE_KIND (*pnote) == REG_DEAD
+		|| REG_NOTE_KIND (*pnote) == REG_UNUSED
+		|| REG_NOTE_KIND (*pnote) == REG_INC
+		|| REG_NOTE_KIND (*pnote) == REG_RETVAL
+		|| REG_NOTE_KIND (*pnote) == REG_LIBCALL_ID
+		|| REG_NOTE_KIND (*pnote) == REG_LIBCALL)
+	      *pnote = XEXP (*pnote, 1);
+	    else
+	      pnote = &XEXP (*pnote, 1);
+	  }
 
 #ifdef AUTO_INC_DEC
-          add_auto_inc_notes (insn, PATTERN (insn));
+	add_auto_inc_notes (insn, PATTERN (insn));
 #endif
 
-          /* Simplify (subreg (reg)) if it appears as an operand.  */
-          cleanup_subreg_operands (insn);
-
-          /* Clean up invalid ASMs so that they don't confuse later passes.
-             See PR 21299.  */
-          if (asm_noperands (PATTERN (insn)) >= 0)
-            {
-              extract_insn (insn);
-              if (!constrain_operands (1))
-	        {
-                  error_for_asm (insn,
-                                 "%<asm%> operand has impossible constraints");
-                  delete_insn (insn);
-                  continue;
-                }
-            }
-        }
-    }
+	/* Simplify (subreg (reg)) if it appears as an operand.  */
+	cleanup_subreg_operands (insn);
+
+	/* Clean up invalid ASMs so that they don't confuse later passes.
+	   See PR 21299.  */
+	if (asm_noperands (PATTERN (insn)) >= 0)
+	  {
+	    extract_insn (insn);
+	    if (!constrain_operands (1))
+	      {
+		error_for_asm (insn,
+			       "%<asm%> operand has impossible constraints");
+		delete_insn (insn);
+		continue;
+	      }
+	  }
+      }
 
   /* If we are doing stack checking, give a warning if this function's
      frame size is larger than we expect.  */
@@ -4020,7 +4016,7 @@ fixup_eh_region_note (rtx insn, rtx prev, rtx next)
       trap_count = 0;
     }
 
-  for (i = NEXT_INSN (prev); i && (i != next); i = NEXT_INSN (i))
+  for (i = NEXT_INSN (prev); i != next; i = NEXT_INSN (i))
     if (INSN_P (i) && i != insn && may_trap_p (PATTERN (i)))
       {
 	trap_count++;
@@ -8192,18 +8188,15 @@ delete_output_reload (rtx insn, int j, int last_reload_reg)
       && REG_BASIC_BLOCK (REGNO (reg)) >= NUM_FIXED_BLOCKS
       && find_regno_note (insn, REG_DEAD, REGNO (reg)))
     {
-      rtx i2, prev;
+      rtx i2;
 
       /* We know that it was used only between here and the beginning of
 	 the current basic block.  (We also know that the last use before
 	 INSN was the output reload we are thinking of deleting, but never
 	 mind that.)  Search that range; see if any ref remains.  */
-      for (i2 = PREV_INSN (insn); i2; i2 = prev)
+      for (i2 = PREV_INSN (insn); i2; i2 = PREV_INSN (i2))
 	{
-          rtx set;
-
-          prev = PREV_INSN (i2);
-          set = single_set (i2);
+	  rtx set = single_set (i2);
 
 	  /* Uses which just store in the pseudo don't count,
 	     since if they are the only uses, they are dead.  */
@@ -8225,11 +8218,9 @@ delete_output_reload (rtx insn, int j, int last_reload_reg)
 
       /* Delete the now-dead stores into this pseudo.  Note that this
 	 loop also takes care of deleting output_reload_insn.  */
-      for (i2 = PREV_INSN (insn); i2; i2 = prev)
+      for (i2 = PREV_INSN (insn); i2; i2 = PREV_INSN (i2))
 	{
-          rtx set;
-          prev = PREV_INSN (i2);
-          set = single_set (i2);
+	  rtx set = single_set (i2);
 
 	  if (set != 0 && SET_DEST (set) == reg)
 	    {