ia64.c (spill_restore_mem): Mark iterator initialization as possibly dead.

        * config/ia64/ia64.c (spill_restore_mem): Mark iterator
        initialization as possibly dead.

From-SVN: r48030

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 2e4f175d1dbc35838996defd51274af49ad76dd5..642395bc6ce5e69f2d69f49d9d1fed5e71c75d30 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2001-12-14  Richard Henderson  <rth@redhat.com>
+
+       * config/ia64/ia64.c (spill_restore_mem): Mark iterator 
+       initialization as possibly dead.
+
 2001-12-14  Richard Henderson  <rth@redhat.com>
 
        * regrename.c (mode_change_ok): New.

diff --git a/gcc/config/ia64/ia64.c b/gcc/config/ia64/ia64.c
index b70f038390a2171e791665643d7454007fab3371..b7d3919bd4b9e4b9103824ab439a5f8907fe2ead 100644 (file)
--- a/gcc/config/ia64/ia64.c
+++ b/gcc/config/ia64/ia64.c
@@ -1771,7 +1771,7 @@ spill_restore_mem (reg, cfa_off)
     }
   else
     {
-      rtx seq;
+      rtx seq, insn;
 
       if (disp == 0)
        seq = gen_movdi (spill_fill_data.iter_reg[iter],
@@ -1797,17 +1797,26 @@ spill_restore_mem (reg, cfa_off)
 
       /* Careful for being the first insn in a sequence.  */
       if (spill_fill_data.init_after)
-       spill_fill_data.init_after
-         = emit_insn_after (seq, spill_fill_data.init_after);
+       insn = emit_insn_after (seq, spill_fill_data.init_after);
       else
        {
          rtx first = get_insns ();
          if (first)
-           spill_fill_data.init_after
-             = emit_insn_before (seq, first);
+           insn = emit_insn_before (seq, first);
          else
-           spill_fill_data.init_after = emit_insn (seq);
+           insn = emit_insn (seq);
        }
+      spill_fill_data.init_after = insn;
+
+      /* If DISP is 0, we may or may not have a further adjustment
+        afterward.  If we do, then the load/store insn may be modified
+        to be a post-modify.  If we don't, then this copy may be
+        eliminated by copyprop_hardreg_forward, which makes this
+        insn garbage, which runs afoul of the sanity check in
+        propagate_one_insn.  So mark this insn as legal to delete.  */
+      if (disp == 0)
+       REG_NOTES(insn) = gen_rtx_EXPR_LIST (REG_MAYBE_DEAD, const0_rtx,
+                                            REG_NOTES (insn));
     }
 
   mem = gen_rtx_MEM (GET_MODE (reg), spill_fill_data.iter_reg[iter]);