Richard Sandiford <rdsandif...@googlemail.com> writes:
> Index: gcc/auto-inc-dec.c
> ===================================================================
> --- gcc/auto-inc-dec.c 2014-06-14 20:08:31.421565177 +0100
> +++ gcc/auto-inc-dec.c 2014-06-14 20:08:33.433584004 +0100
> @@ -969,7 +969,7 @@ find_inc (bool first_try)
> rtx insn;
> basic_block bb = BLOCK_FOR_INSN (mem_insn.insn);
> rtx other_insn;
> - df_ref *def_rec;
> + df_ref def;
>
> /* Make sure this reg appears only once in this insn. */
> if (count_occurrences (PATTERN (mem_insn.insn), mem_insn.reg0, 1) != 1)
> @@ -1013,9 +1013,8 @@ find_inc (bool first_try)
>
> /* Need to assure that none of the operands of the inc instruction are
> assigned to by the mem insn. */
> - for (def_rec = DF_INSN_DEFS (mem_insn.insn); *def_rec; def_rec++)
> + FOR_EACH_INSN_DEF (def, mem_insn.insn)
> {
> - df_ref def = *def_rec;
> unsigned int regno = DF_REF_REGNO (def);
> if ((regno == REGNO (inc_insn.reg0))
> || (regno == REGNO (inc_insn.reg_res)))
> @@ -1342,7 +1341,7 @@ merge_in_block (int max_reg, basic_block
>
> FOR_BB_INSNS_REVERSE_SAFE (bb, insn, curr)
> {
> - unsigned int uid = INSN_UID (insn);
> + df_insn_info *insn_info = DF_INSN_INFO_GET (insn);
> bool insn_is_add_or_inc = true;
>
> if (!NONDEBUG_INSN_P (insn))
> @@ -1418,22 +1417,20 @@ merge_in_block (int max_reg, basic_block
>
> /* If the inc insn was merged with a mem, the inc insn is gone
> and there is noting to update. */
> - if (DF_INSN_UID_GET (uid))
> + if (insn_info)
This is wrong. As the comment explains, the insn may already be
recycled, and you use a stale pointer. Since insn_info is a local
variable, it cannot reflect that fact.
Andreas.
--
Andreas Schwab, SUSE Labs, sch...@suse.de
GPG Key fingerprint = 0196 BAD8 1CE9 1970 F4BE 1748 E4D4 88E3 0EEA B9D7
"And now for something completely different."
