Fix ia64-linux kernel miscompile, bad unwind info when reorder epilogue block.

[thirdparty/gcc.git] / gcc / config / ia64 / ia64.c

diff --git a/gcc/config/ia64/ia64.c b/gcc/config/ia64/ia64.c
index 3d30ff872e6bf8437a7b240b7bd21ed1f0789cef..63d830de216c2476ed0ba101672e1cd54103b4f8 100644 (file)
--- a/gcc/config/ia64/ia64.c
+++ b/gcc/config/ia64/ia64.c
@@ -6335,7 +6335,32 @@ ia64_encode_section_info (decl)
     }
 }
 \f
-/* Output assmebly directives for prologue regions.  */
+/* Output assembly directives for prologue regions.  */
+
+/* The current basic block number.  */
+
+static int block_num;
+
+/* True if we need a copy_state command at the start of the next block.  */
+
+static int need_copy_state;
+
+/* The function emits unwind directives for the start of an epilogue.  */
+
+static void
+process_epilogue ()
+{
+  /* If this isn't the last block of the function, then we need to label the
+     current state, and copy it back in at the start of the next block.  */
+
+  if (block_num != n_basic_blocks - 1)
+    {
+      fprintf (asm_out_file, "\t.label_state 1\n");
+      need_copy_state = 1;
+    }
+
+  fprintf (asm_out_file, "\t.restore sp\n");
+}
 
 /* This function processes a SET pattern looking for specific patterns
    which result in emitting an assembly directive required for unwinding.  */
@@ -6383,14 +6408,14 @@ process_set (asm_out_file, pat)
                  fputc ('\n', asm_out_file);
                }
              else
-               fprintf (asm_out_file, "\t.restore sp\n");
+               process_epilogue ();
            }
          else
            abort ();
        }
       else if (GET_CODE (src) == REG
               && REGNO (src) == HARD_FRAME_POINTER_REGNUM)
-       fprintf (asm_out_file, "\t.restore sp\n");
+       process_epilogue ();
       else
        abort ();
 
@@ -6561,12 +6586,28 @@ process_for_unwind_directive (asm_out_file, insn)
      FILE *asm_out_file;
      rtx insn;
 {
-  if ((flag_unwind_tables
-       || (flag_exceptions && !exceptions_via_longjmp))
-      && RTX_FRAME_RELATED_P (insn))
+  if (flag_unwind_tables
+      || (flag_exceptions && !exceptions_via_longjmp))
     {
       rtx pat;
 
+      if (GET_CODE (insn) == NOTE
+         && NOTE_LINE_NUMBER (insn) == NOTE_INSN_BASIC_BLOCK)
+       {
+         block_num = NOTE_BASIC_BLOCK (insn)->index;
+
+         /* Restore unwind state from immediately before the epilogue.  */
+         if (need_copy_state)
+           {
+             fprintf (asm_out_file, "\t.body\n");
+             fprintf (asm_out_file, "\t.copy_state 1\n");
+             need_copy_state = 0;
+           }
+       }
+
+      if (! RTX_FRAME_RELATED_P (insn))
+       return;
+
       pat = find_reg_note (insn, REG_FRAME_RELATED_EXPR, NULL_RTX);
       if (pat)
        pat = XEXP (pat, 0);