This is the mail archive of the
gcc-patches@gcc.gnu.org
mailing list for the GCC project.
Re: [PATCH, PR81430] Use finalize_options in lto1
On 07/21/2017 11:41 AM, Richard Biener wrote:
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.
I managed to get it working now. The variable tmp was only partly
initialized, which caused the problems when calling
maybe_set_param_value. I'm now using init_options_struct.
There's no note when using -O2 or "-O2 -freorder-blocks-and-partition".
But when I do "-O2 -foffload=-freorder-blocks-and-partition" I get:
...
lto1: note: '-freorder-blocks-and-partition' does not work on this
architecture
lto1: note: '-freorder-blocks-and-partition' does not support unwind
info on this architecture
...
And for "-O0 -foffload=-freorder-blocks-and-partition" I just get:
...
lto1: note: '-freorder-blocks-and-partition' does not work on this
architecture
...
Thanks,
- Tom
Call finish_options in lto1
---
gcc/tree-streamer-in.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
diff --git a/gcc/tree-streamer-in.c b/gcc/tree-streamer-in.c
index d7b6d22..eb41e75 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 +770,21 @@ 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;
+ init_options_struct (&tmp, NULL);
+ cl_optimization_restore (&tmp, TREE_OPTIMIZATION (opts));
+ finish_options (&tmp, &global_options_set, UNKNOWN_LOCATION);
+ opts = build_optimization_node (&tmp);
+ finalize_options_struct (&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