Re: [02/05] Fix PR 63384

[Marek Polacek <polacek at redhat dot com>]

On Mon, Mar 14, 2016 at 12:31:24PM +0300, Andrey Belevantsev wrote:
> Hello,
> 
> Here we're looping because we decrease the counter of the insns we still can
> issue on a DEBUG_INSN thus rendering the counter negative.  The fix is to
> not count debug insns in the corresponding code.  The selective scheduling
> is known to spoil the result of var tracking, but still it is not the reason
> to hang in there.
> 
> The toggle option used in the test seems to be the equivalent of just
> enabling var-tracking-assignments which should lead to the same situation;
> however, if specified as is, var-tracking-assignments will be disabled by
> the toplev.c:1460 code.  Maybe we also need the same treatment for
> flag_var_tracking_assignments_toggle.
> 
> Ok for trunk?
> 
> gcc/
> 
> 2016-03-14  Andrey Belevantsev  <abel@ispras.ru>
> 
>     PR rtl-optimization/63384
>     * sel-sched.c (invoke_aftermath_hooks): Do not decrease issue_more on
> DEBUG_INSN_P insns.
> 
> testsuite/
> 
> 2016-03-14  Andrey Belevantsev  <abel@ispras.ru>
> 
>     PR rtl-optimization/63384
>     * testsuite/g++.dg/pr63384.C: New test.
> 
> Best,
> Andrey
> 

> diff --git a/gcc/sel-sched.c b/gcc/sel-sched.c
> index c798935..893a3e5 100644
> --- a/gcc/sel-sched.c
> +++ b/gcc/sel-sched.c
> @@ -4249,7 +4249,8 @@ invoke_aftermath_hooks (fence_t fence, rtx_insn *best_insn, int issue_more)
>                                        issue_more);
>        memcpy (FENCE_STATE (fence), curr_state, dfa_state_size);
>      }
> -  else if (GET_CODE (PATTERN (best_insn)) != USE
> +  else if (! DEBUG_INSN_P (best_insn)
> +	   && GET_CODE (PATTERN (best_insn)) != USE
>             && GET_CODE (PATTERN (best_insn)) != CLOBBER)
>      issue_more--;
>  
> diff --git a/gcc/testsuite/g++.dg/pr63384.C b/gcc/testsuite/g++.dg/pr63384.C
> new file mode 100644
> index 0000000..b4e0784
> --- /dev/null
> +++ b/gcc/testsuite/g++.dg/pr63384.C
> @@ -0,0 +1,12 @@
> +/* { dg-do compile { target powerpc*-*-* ia64-*-* i?86-*-* x86_64-*-* } } */
> +/* { dg-options "-O2 -fselective-scheduling2 -fsel-sched-pipelining  -fsel-sched-pipelining-outer-loops -fsel-sched-reschedule-pipelined -fvar-tracking-assignments-toggle -ftree-vectorize" } */
> +
> +template <class T> T **make_test_matrix() {
> + T **data = new T *;
> + for (int i = 0; i < 1000; i++)
> +    ;
> +}
> +
> +template <typename T> void test() { T **c = make_test_matrix<T>(); }
> +
> +main() { test<float>(); }

This test fails for me due to
cc1plus: warning: var-tracking-assignments changes selective scheduling

	Marek