PR middle-end/55030

	Revert:
	* stmt.c (expand_nl_goto_receiver): Remove almost-copy of
	expand_builtin_setjmp_receiver.
	(expand_label): Adjust, call expand_builtin_setjmp_receiver
	with NULL for the label parameter.
	* builtins.c (expand_builtin_setjmp_receiver): Don't clobber
	the frame-pointer.  Adjust comments.
	[HAVE_builtin_setjmp_receiver]: Emit builtin_setjmp_receiver
	only if LABEL is non-NULL.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@192701 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 73 insertions, 1 deletions

diff --git a/gcc/stmt.c b/gcc/stmt.c
index 07e7cc74159..14a28abcc58 100644
--- a/gcc/stmt.c
+++ b/gcc/stmt.c
@@ -106,6 +106,7 @@ extern basic_block label_to_block_fn (struct function *, tree);
 
 static int n_occurrences (int, const char *);
 static bool tree_conflicts_with_clobbers_p (tree, HARD_REG_SET *);
+static void expand_nl_goto_receiver (void);
 static bool check_operand_nalternatives (tree, tree);
 static bool check_unique_operand_names (tree, tree, tree);
 static char *resolve_operand_name_1 (char *, tree, tree, tree);
@@ -199,7 +200,7 @@ expand_label (tree label)
 
   if (DECL_NONLOCAL (label))
     {
-      expand_builtin_setjmp_receiver (NULL);
+      expand_nl_goto_receiver ();
       nonlocal_goto_handler_labels
 	= gen_rtx_EXPR_LIST (VOIDmode, label_r,
 			     nonlocal_goto_handler_labels);
@@ -1555,6 +1556,77 @@ expand_return (tree retval)
     }
 }
 
+/* Emit code to restore vital registers at the beginning of a nonlocal goto
+   handler.  */
+static void
+expand_nl_goto_receiver (void)
+{
+  rtx chain;
+
+  /* Clobber the FP when we get here, so we have to make sure it's
+     marked as used by this function.  */
+  emit_use (hard_frame_pointer_rtx);
+
+  /* Mark the static chain as clobbered here so life information
+     doesn't get messed up for it.  */
+  chain = targetm.calls.static_chain (current_function_decl, true);
+  if (chain && REG_P (chain))
+    emit_clobber (chain);
+
+#ifdef HAVE_nonlocal_goto
+  if (! HAVE_nonlocal_goto)
+#endif
+    /* First adjust our frame pointer to its actual value.  It was
+       previously set to the start of the virtual area corresponding to
+       the stacked variables when we branched here and now needs to be
+       adjusted to the actual hardware fp value.
+
+       Assignments are to virtual registers are converted by
+       instantiate_virtual_regs into the corresponding assignment
+       to the underlying register (fp in this case) that makes
+       the original assignment true.
+       So the following insn will actually be
+       decrementing fp by STARTING_FRAME_OFFSET.  */
+    emit_move_insn (virtual_stack_vars_rtx, hard_frame_pointer_rtx);
+
+#if !HARD_FRAME_POINTER_IS_ARG_POINTER
+  if (fixed_regs[ARG_POINTER_REGNUM])
+    {
+#ifdef ELIMINABLE_REGS
+      /* If the argument pointer can be eliminated in favor of the
+	 frame pointer, we don't need to restore it.  We assume here
+	 that if such an elimination is present, it can always be used.
+	 This is the case on all known machines; if we don't make this
+	 assumption, we do unnecessary saving on many machines.  */
+      static const struct elims {const int from, to;} elim_regs[] = ELIMINABLE_REGS;
+      size_t i;
+
+      for (i = 0; i < ARRAY_SIZE (elim_regs); i++)
+	if (elim_regs[i].from == ARG_POINTER_REGNUM
+	    && elim_regs[i].to == HARD_FRAME_POINTER_REGNUM)
+	  break;
+
+      if (i == ARRAY_SIZE (elim_regs))
+#endif
+	{
+	  /* Now restore our arg pointer from the address at which it
+	     was saved in our stack frame.  */
+	  emit_move_insn (crtl->args.internal_arg_pointer,
+			  copy_to_reg (get_arg_pointer_save_area ()));
+	}
+    }
+#endif
+
+#ifdef HAVE_nonlocal_goto_receiver
+  if (HAVE_nonlocal_goto_receiver)
+    emit_insn (gen_nonlocal_goto_receiver ());
+#endif
+
+  /* We must not allow the code we just generated to be reordered by
+     scheduling.  Specifically, the update of the frame pointer must
+     happen immediately, not later.  */
+  emit_insn (gen_blockage ());
+}
 
 /* Emit code to save the current value of stack.  */
 rtx