PR debug/44694

	* dwarf2out.c (reg_loc_descriptor): For eliminated arg_pointer_rtx
	or frame_pointer_rtx use DW_OP_fbreg offset DW_OP_stack_value.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@161662 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 20 insertions, 0 deletions

diff --git a/gcc/dwarf2out.c b/gcc/dwarf2out.c
index 3faa1754859..6decc6f050e 100644
--- a/gcc/dwarf2out.c
+++ b/gcc/dwarf2out.c
@@ -12999,6 +12999,26 @@ reg_loc_descriptor (rtx rtl, enum var_init_status initialized)
   if (REGNO (rtl) >= FIRST_PSEUDO_REGISTER)
     return 0;
 
+  /* We only use "frame base" when we're sure we're talking about the
+     post-prologue local stack frame.  We do this by *not* running
+     register elimination until this point, and recognizing the special
+     argument pointer and soft frame pointer rtx's.
+     Use DW_OP_fbreg offset DW_OP_stack_value in this case.  */
+  if ((rtl == arg_pointer_rtx || rtl == frame_pointer_rtx)
+      && eliminate_regs (rtl, VOIDmode, NULL_RTX) != rtl)
+    {
+      dw_loc_descr_ref result = NULL;
+
+      if (dwarf_version >= 4 || !dwarf_strict)
+	{
+	  result = mem_loc_descriptor (rtl, VOIDmode, initialized);
+	  if (result)
+	    add_loc_descr (&result,
+			   new_loc_descr (DW_OP_stack_value, 0, 0));
+	}
+      return result;
+    }
+
   regs = targetm.dwarf_register_span (rtl);
 
   if (hard_regno_nregs[REGNO (rtl)][GET_MODE (rtl)] > 1 || regs)