[Bug rtl-optimization/37769] internal compiler error: in reg_overlap_mentioned_for_reload_p, at reload.c:6525

[kkojima at gcc dot gnu dot org]

------- Comment #4 from kkojima at gcc dot gnu dot org  2008-10-09 04:50 -------
The regmove pass changes insns in .160r.ce2 dump

(insn 285 77 78 6 foo.C:14 (set (reg/f:SI 260)
        (reg/f:SI 269 [ ivtmp.66 ])) -1 (expr_list:REG_DEAD (reg/f:SI 269 [
ivtmp.66 ])
        (nil)))

(insn 78 285 79 6 foo.C:14 (parallel [
            (set (reg:SF 280)
                (mem:SF (post_inc:SI (reg/f:SI 260)) [2 S4 A32]))
            (use (reg/v:PSI 151 ))
            (clobber (scratch:SI))
        ]) 205 {movsf_ie} (expr_list:REG_INC (reg/f:SI 260)
        (nil)))

to

(insn:HI 285 77 78 6 foo.C:14 (set (reg/f:SI 269 [ ivtmp.66 ])
        (reg/f:SI 269 [ ivtmp.66 ])) -1 (nil))

(insn:HI 78 285 79 6 foo.C:14 (parallel [
            (set (reg:SF 280)
                (mem:SF (post_inc:SI (reg/f:SI 269 [ ivtmp.66 ])) [2 S4 A32]))
            (use (reg/v:PSI 151 ))
            (clobber (scratch:SI))
        ]) 205 {movsf_ie} (expr_list:REG_INC (reg/f:SI 260)
        (nil)))

in .162r.regmove.
It seems that regmove forgets to update the register 260 to 269
in REG_INC note of the insn 78 and this wrong REG_INC note causes
the ICE.
Now I'm testing the attached patch, for 4.3-branch.

BTW, please use the compiler based on the vanilla FSF tree
for bugzilla as Andrew has pointed out already.

--- ORIG/gcc-4_3-branch/gcc/regmove.c   2008-02-20 06:48:51.000000000 +0900
+++ LOCAL/gcc-4_3-branch/gcc/regmove.c  2008-10-09 10:50:29.000000000 +0900
@@ -687,6 +687,12 @@ optimize_reg_copy_2 (rtx insn, rtx dest,
                if (reg_mentioned_p (dest, PATTERN (q)))
                  {
                    PATTERN (q) = replace_rtx (PATTERN (q), dest, src);
+                   if (FIND_REG_INC_NOTE (q, dest))
+                     {
+                       remove_note (q, find_reg_note (q, REG_INC, dest));
+                       REG_NOTES (q)
+                         = gen_rtx_EXPR_LIST (REG_INC, src, REG_NOTES (q));
+                     }
                    df_insn_rescan (q);
                  }



-- 

kkojima at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |kkojima at gcc dot gnu dot
                   |                            |org
             Status|UNCONFIRMED                 |NEW
          Component|target                      |rtl-optimization
     Ever Confirmed|0                           |1
 GCC target triplet|sh4-*-linux                 |sh4-*-*
           Keywords|                            |ice-on-valid-code
      Known to fail|                            |4.3.2 4.4.0
      Known to work|                            |4.2.4
           Priority|P3                          |P4
   Last reconfirmed|0000-00-00 00:00:00         |2008-10-09 04:50:48
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37769