* explow.c (allocate_dynamic_stack_space SETJMP_VIA_SAVE_AREA):

	Kill setjmpless_size.  current_function_calls_setjmp is completely
	computed when we are called, so just use the optimized size value
	instead of using REG_SAVE_AREA notes.
	(optimize_save_area_alloca): Delete....
	* rtl.h (optimize_save_area_alloca): Likewise...
	* passes.c (rest_of_compilation): and don't call it any more.
	* reg-notes.def (SAVE_AREA): Delete.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@98861 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 39 insertions, 134 deletions

diff --git a/gcc/explow.c b/gcc/explow.c
index 95a2931430b..6a406901e34 100644
--- a/gcc/explow.c
+++ b/gcc/explow.c
@@ -1017,83 +1017,6 @@ update_nonlocal_goto_save_area (void)
   emit_stack_save (SAVE_NONLOCAL, &r_save, NULL_RTX);
 }
 
-#ifdef SETJMP_VIA_SAVE_AREA
-/* Optimize RTL generated by allocate_dynamic_stack_space for targets
-   where SETJMP_VIA_SAVE_AREA is true.  The problem is that on these
-   platforms, the dynamic stack space used can corrupt the original
-   frame, thus causing a crash if a longjmp unwinds to it.  */
-
-void
-optimize_save_area_alloca (void)
-{
-  rtx insn;
-
-  for (insn = get_insns (); insn; insn = NEXT_INSN(insn))
-    {
-      rtx note;
-
-      if (!NONJUMP_INSN_P (insn))
-	continue;
-
-      for (note = REG_NOTES (insn); note; note = XEXP (note, 1))
-	{
-	  if (REG_NOTE_KIND (note) != REG_SAVE_AREA)
-	    continue;
-
-	  if (!current_function_calls_setjmp)
-	    {
-	      rtx pat = PATTERN (insn);
-
-	      /* If we do not see the note in a pattern matching
-		 these precise characteristics, we did something
-		 entirely wrong in allocate_dynamic_stack_space.
-
-		 Note, one way this could happen is if SETJMP_VIA_SAVE_AREA
-		 was defined on a machine where stacks grow towards higher
-		 addresses.
-
-		 Right now only supported port with stack that grow upward
-		 is the HPPA and it does not define SETJMP_VIA_SAVE_AREA.  */
-	      gcc_assert (GET_CODE (pat) == SET
-			  && SET_DEST (pat) == stack_pointer_rtx
-			  && GET_CODE (SET_SRC (pat)) == MINUS
-			  && XEXP (SET_SRC (pat), 0) == stack_pointer_rtx);
-
-	      /* This will now be transformed into a (set REG REG)
-		 so we can just blow away all the other notes.  */
-	      XEXP (SET_SRC (pat), 1) = XEXP (note, 0);
-	      REG_NOTES (insn) = NULL_RTX;
-	    }
-	  else
-	    {
-	      /* setjmp was called, we must remove the REG_SAVE_AREA
-		 note so that later passes do not get confused by its
-		 presence.  */
-	      if (note == REG_NOTES (insn))
-		{
-		  REG_NOTES (insn) = XEXP (note, 1);
-		}
-	      else
-		{
-		  rtx srch;
-
-		  for (srch = REG_NOTES (insn); srch; srch = XEXP (srch, 1))
-		    if (XEXP (srch, 1) == note)
-		      break;
-
-		  gcc_assert (srch);
-
-		  XEXP (srch, 1) = XEXP (note, 1);
-		}
-	    }
-	  /* Once we've seen the note of interest, we need not look at
-	     the rest of them.  */
-	  break;
-	}
-    }
-}
-#endif /* SETJMP_VIA_SAVE_AREA */
-
 /* Return an rtx representing the address of an area of memory dynamically
    pushed on the stack.  This region of memory is always aligned to
    a multiple of BIGGEST_ALIGNMENT.
@@ -1108,10 +1031,6 @@ optimize_save_area_alloca (void)
 rtx
 allocate_dynamic_stack_space (rtx size, rtx target, int known_align)
 {
-#ifdef SETJMP_VIA_SAVE_AREA
-  rtx setjmpless_size = NULL_RTX;
-#endif
-
   /* If we're asking for zero bytes, it doesn't matter what we point
      to since we can't dereference it.  But return a reasonable
      address anyway.  */
@@ -1160,51 +1079,47 @@ allocate_dynamic_stack_space (rtx size, rtx target, int known_align)
      avoid clobbering the reg save area.  Note that the offset of
      virtual_incoming_args_rtx includes the preallocated stack args space.
      It would be no problem to clobber that, but it's on the wrong side
-     of the old save area.  */
-  {
-    rtx dynamic_offset
-      = expand_binop (Pmode, sub_optab, virtual_stack_dynamic_rtx,
-		      stack_pointer_rtx, NULL_RTX, 1, OPTAB_LIB_WIDEN);
+     of the old save area.
+
+     What used to happen is that, since we did not know for sure
+     whether setjmp() was invoked until after RTL generation, we
+     would use reg notes to store the "optimized" size and fix things
+     up later.  These days we know this information before we ever
+     start building RTL so the reg notes are unnecessary.  */
+  if (!current_function_calls_setjmp)
+    {
+      int align = PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT;
 
-    if (!current_function_calls_setjmp)
-      {
-	int align = PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT;
-
-	/* See optimize_save_area_alloca to understand what is being
-	   set up here.  */
-
-	/* ??? Code below assumes that the save area needs maximal
-	   alignment.  This constraint may be too strong.  */
-	gcc_assert (PREFERRED_STACK_BOUNDARY == BIGGEST_ALIGNMENT);
-
-	if (GET_CODE (size) == CONST_INT)
-	  {
-	    HOST_WIDE_INT new = INTVAL (size) / align * align;
-
-	    if (INTVAL (size) != new)
-	      setjmpless_size = GEN_INT (new);
-	    else
-	      setjmpless_size = size;
-	  }
-	else
-	  {
-	    /* Since we know overflow is not possible, we avoid using
-	       CEIL_DIV_EXPR and use TRUNC_DIV_EXPR instead.  */
-	    setjmpless_size = expand_divmod (0, TRUNC_DIV_EXPR, Pmode, size,
-					     GEN_INT (align), NULL_RTX, 1);
-	    setjmpless_size = expand_mult (Pmode, setjmpless_size,
-					   GEN_INT (align), NULL_RTX, 1);
-	  }
-	/* Our optimization works based upon being able to perform a simple
-	   transformation of this RTL into a (set REG REG) so make sure things
-	   did in fact end up in a REG.  */
-	if (!register_operand (setjmpless_size, Pmode))
-	  setjmpless_size = force_reg (Pmode, setjmpless_size);
-      }
+      /* ??? Code below assumes that the save area needs maximal
+	 alignment.  This constraint may be too strong.  */
+      gcc_assert (PREFERRED_STACK_BOUNDARY == BIGGEST_ALIGNMENT);
 
-    size = expand_binop (Pmode, add_optab, size, dynamic_offset,
-			 NULL_RTX, 1, OPTAB_LIB_WIDEN);
-  }
+      if (GET_CODE (size) == CONST_INT)
+	{
+	  HOST_WIDE_INT new = INTVAL (size) / align * align;
+
+	  if (INTVAL (size) != new)
+	    size = GEN_INT (new);
+	}
+      else
+	{
+	  /* Since we know overflow is not possible, we avoid using
+	     CEIL_DIV_EXPR and use TRUNC_DIV_EXPR instead.  */
+	  size = expand_divmod (0, TRUNC_DIV_EXPR, Pmode, size,
+				GEN_INT (align), NULL_RTX, 1);
+	  size = expand_mult (Pmode, size,
+			      GEN_INT (align), NULL_RTX, 1);
+	}
+    }
+  else
+    {
+      rtx dynamic_offset
+	= expand_binop (Pmode, sub_optab, virtual_stack_dynamic_rtx,
+			stack_pointer_rtx, NULL_RTX, 1, OPTAB_LIB_WIDEN);
+
+      size = expand_binop (Pmode, add_optab, size, dynamic_offset,
+			   NULL_RTX, 1, OPTAB_LIB_WIDEN);
+    }
 #endif /* SETJMP_VIA_SAVE_AREA */
 
   /* Round the size to a multiple of the required stack alignment.
@@ -1304,16 +1219,6 @@ allocate_dynamic_stack_space (rtx size, rtx target, int known_align)
 	}
 
       anti_adjust_stack (size);
-#ifdef SETJMP_VIA_SAVE_AREA
-      if (setjmpless_size != NULL_RTX)
-	{
-	  rtx note_target = get_last_insn ();
-
-	  REG_NOTES (note_target)
-	    = gen_rtx_EXPR_LIST (REG_SAVE_AREA, setjmpless_size,
-				 REG_NOTES (note_target));
-	}
-#endif /* SETJMP_VIA_SAVE_AREA */
 
 #ifdef STACK_GROWS_DOWNWARD
       emit_move_insn (target, virtual_stack_dynamic_rtx);