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Re: atomic memory operation builtins, v2
- From: Adrian Straetling <straetling at de dot ibm dot com>
- To: Richard Henderson <rth at redhat dot com>, gcc-patches at gcc dot gnu dot org
- Date: Thu, 2 Jun 2005 11:01:00 +0200
- Subject: Re: atomic memory operation builtins, v2
- References: <20050408220513.GA11088@redhat.com> <20050414233910.GA25705@redhat.com>
On Thu, Apr 14, 2005 at 04:39:10PM -0700, Richard Henderson wrote:
> I've committed the following patch. Follow on patches
> for i686 and ia64 will follow shortly.
>
> * optabs.c (init_optabs): Initialize sync optabs.
> (expand_val_compare_and_swap_1, expand_val_compare_and_swap,
> expand_bool_compare_and_swap, expand_compare_and_swap_loop,
> expand_sync_operation, expand_sync_fetch_operation,
> expand_sync_lock_test_and_set): New.
...
> Index: optabs.c
...
> +rtx
> +expand_bool_compare_and_swap (rtx mem, rtx old_val, rtx new_val, rtx target)
...
> + /* Without an appropriate setcc instruction, use a set of branches to
> + get 1 and 0 stored into target. Presumably if the target has a
> + STORE_FLAG_VALUE that isn't 1, then this will get cleaned up by ifcvt. */
> +
> + label0 = gen_label_rtx ();
> + label1 = gen_label_rtx ();
> +
> + emit_jump_insn (bcc_gen_fctn[EQ] (label0));
> + emit_move_insn (target, const0_rtx);
> + emit_jump_insn (gen_jump (label1));
> + emit_label (label0);
> + emit_move_insn (target, const1_rtx);
> + emit_label (label1);
> +
> + return target;
> +}
This sequence seems to cause 'verify_flow_info' to emit an "missing barrier"
error. The attached patch fixes that for me. Is that the way it was
meant?
With the patch bootstrap and regtest was successful.
Bye,
Adrian
2005-05-12 Adrian Straetling <straetling@de.ibm.com>
* optabs.c: (expand_bool_compare_and_swap): Emit barrier after
unconditional jump.
Index: gcc/optabs.c
===================================================================
--- gcc/optabs.c.orig 2005-05-17 16:05:19.000000000 +0200
+++ gcc/optabs.c 2005-05-31 19:04:43.000000000 +0200
@@ -5627,6 +5627,7 @@ expand_bool_compare_and_swap (rtx mem, r
emit_jump_insn (bcc_gen_fctn[EQ] (label0));
emit_move_insn (target, const0_rtx);
emit_jump_insn (gen_jump (label1));
+ emit_barrier ();
emit_label (label0);
emit_move_insn (target, const1_rtx);
emit_label (label1);