[PATCH, PR81430] Use finalize_options in lto1

[Richard Biener]

On Thu, 20 Jul 2017, Tom de Vries wrote:

> On 07/20/2017 12:10 PM, Richard Biener wrote:
> > On Thu, 20 Jul 2017, Tom de Vries wrote:
> > 
> > > Hi,
> > > 
> > > this patch fixes PR81430, an ICE in the libgomp testsuite for both openmp
> > > and
> > > openacc test-cases for x86_64 with nvptx accelerator.
> > > 
> > > The scenario how we hit the ICE is as follows:
> > > - a testcase is compiled with -O2
> > > - ix86_option_optimization_table enables
> > >    OPT_freorder_blocks_and_partition at -O2
> > > - cc1 writes out the flag as part of DECL_FUNCTION_SPECIFIC_OPTIMIZATION
> > > - lto1 reads in the flag as part of DECL_FUNCTION_SPECIFIC_OPTIMIZATION
> > > - lto1 uses the flag, and runs pass_partition_blocks
> > > - pass_partition_blocks ICEs, because it generates code that is not
> > >    supported by the nvptx target.
> > > 
> > > Note that for standalone compilation for single-thread ptx execution, we
> > > don't
> > > attempt to run pass_partition_blocks. This is because for nvptx,
> > > TARGET_HAVE_NAMED_SECTIONS is set to false, and this bit in finish_options
> > > switches off pass_partition_blocks:
> > > ...
> > >     /* If the target requested unwind info, then turn off the
> > >        partitioning optimization with a different message.  Likewise, if
> > >        the target does not support named sections.  */
> > > 
> > >    if (opts->x_flag_reorder_blocks_and_partition
> > >        && (!targetm_common.have_named_sections
> > >            || (opts->x_flag_unwind_tables
> > >                && targetm_common.unwind_tables_default
> > >                && (ui_except == UI_SJLJ || ui_except >= UI_TARGET))))
> > >      {
> > >        if (opts_set->x_flag_reorder_blocks_and_partition)
> > >          inform (loc,
> > >                  "-freorder-blocks-and-partition does not work "
> > >                  "on this architecture");
> > >        opts->x_flag_reorder_blocks_and_partition = 0;
> > >        opts->x_flag_reorder_blocks = 1;
> > >      }
> > > ...
> > > 
> > > The patch fixes this by calling finish_options in lto1 after
> > > cl_optimization_restore.
> > > 
> > > Points for review:
> > > 1. I'm uncertain though about the placement of the call. Perhaps it should
> > > be
> > > in cl_optimization_restore, before targetm.override_options_after_change?
> > > 
> > > 2. I think that this is offloading specific, so perhaps this should be
> > > guarded
> > > with lto_stream_offload_p or #ifdef ACCEL_COMPILER or some such.
> > 
> > Hmm, I agree with #2.  I think it conceptually is a LTO stream adjustment
> > and thus we should do this at the time we stream in the
> > optimization/target nodes (like we remap modes for example).  Not
> > sure if it's possible to do this at that point, but it looks like
> > finish_options takes two option structs and thus we should be able to
> > call it.
> > 
> 
> With what parameters? Patch below tries with same option struct, but ...
> 
> > Do you get the inform note?  I suppose we don't really want that, no?
> > 
> 
> ... I think that way we'll get the inform note (while the previous solution
> did not).
> 
> I've also tried with a tmp2 memset to 0, but that ran into problems when doing
> a maybe_set_param_value.

Use global_options_set?  That should do what the other patch did.

> Thanks,
> - Tom
> 
> diff --git a/gcc/tree-streamer-in.c b/gcc/tree-streamer-in.c
> index 7f7ea7f..e0e792b 100644
> --- a/gcc/tree-streamer-in.c
> +++ b/gcc/tree-streamer-in.c
> @@ -33,6 +33,7 @@ along with GCC; see the file COPYING3.  If not see
>  #include "ipa-chkp.h"
>  #include "gomp-constants.h"
>  #include "asan.h"
> +#include "opts.h"
> 
> 
>  /* Read a STRING_CST from the string table in DATA_IN using input
> @@ -769,6 +770,20 @@ lto_input_ts_function_decl_tree_pointers (struct
> lto_input_block *ib,
>    DECL_FUNCTION_SPECIFIC_TARGET (expr) = stream_read_tree (ib, data_in);
>  #endif
>    DECL_FUNCTION_SPECIFIC_OPTIMIZATION (expr) = stream_read_tree (ib,
> data_in);
> +#ifdef ACCEL_COMPILER
> +  {
> +    tree opts = DECL_FUNCTION_SPECIFIC_OPTIMIZATION (expr);
> +    if (opts)
> +      {
> +       struct gcc_options tmp;
> +       cl_optimization_restore (&tmp, TREE_OPTIMIZATION (opts));
> +       finish_options (&tmp, &tmp, DECL_SOURCE_LOCATION (expr));
> +       opts = build_optimization_node (&tmp);
> +
> +       DECL_FUNCTION_SPECIFIC_OPTIMIZATION (expr) = opts;
> +      }
> +  }
> +#endif
> 
>    /* If the file contains a function with an EH personality set,
>       then it was compiled with -fexceptions.  In that case, initialize
> 
> 

-- 
Richard Biener <rguenther@suse.de>
SUSE LINUX GmbH, GF: Felix Imendoerffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nuernberg)