re PR debug/36977 (Incorrect debug info for stack variables with stack alignment)

2008-07-31  H.J. Lu  <hongjiu.lu@intel.com>

	PR debug/36977
	* cfgexpand.c (expand_stack_alignment): Set stack_realign_tried.

	* dwarf2out.c (based_loc_descr): Check crtl->stack_realign_tried
	for stack alignment.

	* function.h (rtl_data): Add stack_realign_tried.  Update
	comments.

From-SVN: r138438

gcc/ChangeLog

+2008-07-31  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR debug/36977
+	* cfgexpand.c (expand_stack_alignment): Set stack_realign_tried.
+
+	* dwarf2out.c (based_loc_descr): Check crtl->stack_realign_tried
+	for stack alignment.
+
+	* function.h (rtl_data): Add stack_realign_tried.  Update
+	comments.
+
 2008-07-31  Kaz Kojima  <kkojima@gcc.gnu.org>
 
 	* config/sh/sh.c (sh_canonical_va_list_type): Remove.

gcc/cfgexpand.c

@@ -2217,6 +2217,7 @@ expand_stack_alignment (void)
 
   crtl->stack_realign_needed
     = INCOMING_STACK_BOUNDARY < crtl->stack_alignment_estimated;
+  crtl->stack_realign_tried = crtl->stack_realign_needed;
 
   crtl->stack_realign_processed = true;
 

gcc/dwarf2out.c

@@ -9453,8 +9453,7 @@ based_loc_descr (rtx reg, HOST_WIDE_INT offset,
 	     pointer + offset to access stack variables.  If stack
 	     is aligned without drap, use stack pointer + offset to
 	     access stack variables.  */
-	  if (fde
-	      && fde->stack_realign
+	  if (crtl->stack_realign_tried
 	      && cfa.reg == HARD_FRAME_POINTER_REGNUM
 	      && reg == frame_pointer_rtx)
 	    {

gcc/function.h

@@ -424,13 +424,18 @@ struct rtl_data GTY(())
      The value set after reload is the accurate one and is finalized.  */
   bool stack_realign_needed;
 
+  /* Nonzero if function stack realignment is tried.  This flag is set
+     only once before reload.  It affects register elimination.  This
+     is used to generate DWARF debug info for stack variables.  */
+  bool stack_realign_tried;
+
   /* Nonzero if function being compiled needs dynamic realigned
      argument pointer (drap) if stack needs realigning.  */
   bool need_drap;
 
   /* Nonzero if function stack realignment estimation is done, namely
-     stack_realign_needed flag has been set before reload wrt
-     estimated stack alignment info.  */
+     stack_realign_needed flag has been set before reload wrt estimated
+     stack alignment info.  */
   bool stack_realign_processed;
 
   /* Nonzero if function stack realignment has been finalized, namely