[Bug rtl-optimization/34808] [4.3 Regression] ICE in prescan_insns_for_dce

["kkojima at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #5 from kkojima at gcc dot gnu dot org  2008-01-18 14:42 -------
With the patch in #4, .166r.split1 looks like:

(insn:HI 100 103 179 15 xxx.c:74 (set (subreg:SI (reg:DI 198 [ regno ]) 0)
        (reg/v:SI 159 [ regno ])) 172 {movsi_ie} (insn_list:REG_LIBCALL 180
(expr_list:REG_NO_CONFLICT (reg/v:SI 159 [ regno ])
            (nil))))

(insn 179 100 180 15 xxx.c:74 (parallel [
            (set (subreg:SI (reg:DI 198 [ regno ]) 4)
                (ashift:SI (reg/v:SI 159 [ regno ])
                    (const_int 1 [0x1])))
            (set (reg:SI 147 t)
                (lt:SI (reg/v:SI 159 [ regno ])
                    (const_int 0 [0x0])))
        ]) -1 (nil))

(insn 180 179 106 15 xxx.c:74 (set (subreg:SI (reg:DI 198 [ regno ]) 4)
        (neg:SI (reg:SI 147 t))) -1 (insn_list:REG_RETVAL 0 (nil)))

It should be REG_RETVAL 100 instead of REG_RETVAL 0, shouldn't be?
How does look the patch below?

--- ORIG/trunk/gcc/emit-rtl.c   2008-01-15 09:35:12.000000000 +0900
+++ LOCAL/trunk/gcc/emit-rtl.c  2008-01-18 21:12:39.000000000 +0900
@@ -3136,7 +3136,7 @@ try_split (rtx pat, rtx trial, int last)
   rtx before = PREV_INSN (trial);
   rtx after = NEXT_INSN (trial);
   int has_barrier = 0;
-  rtx tem, note_retval;
+  rtx tem, note_retval, note_libcall;
   rtx note, seq;
   int probability;
   rtx insn_last, insn;
@@ -3284,6 +3284,18 @@ try_split (rtx pat, rtx trial, int last)
          XEXP (note_retval, 0) = insn_last;
          break;

+       case REG_RETVAL:
+         /* Relink the insns with REG_RETVAL note and with REG_LIBCALL note
+            after split.  */
+         REG_NOTES (insn_last) 
+           = gen_rtx_INSN_LIST (REG_RETVAL,
+                                XEXP (note, 0),
+                                REG_NOTES (insn_last)); 
+
+         note_libcall = find_reg_note (XEXP (note, 0), REG_LIBCALL, NULL);
+         XEXP (note_libcall, 0) = insn_last;
+         break;
+
        default:
          break;
        }


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34808