[PATCH][AArch64] Set TREE_TARGET_GLOBALS in aarch64_set_current_function when new tree is the default node to recalculate optab availability

[Christophe Lyon]

On 26 February 2016 at 16:51, James Greenhalgh <james.greenhalgh@arm.com> wrote:
> On Thu, Feb 25, 2016 at 11:04:21AM +0000, Kyrill Tkachov wrote:
>> Hi all,
>>
>> Seems like aarch64 is suffering from something similar to PR 69245 as well.
>> If a target pragma sets the target state to the same as the
>> target_option_default_node the node is just a pointer to
>> target_option_default_node rather than a distinct identical node. So we must
>> still restore the target globals even when setting to
>> target_option_default_node in order to force the midend to recompute the
>> availability of various optabs.
>>
>> If we don't do it, we can get in a problem like in the testcase where the
>> isa_flags are all set correctly, but the optab HAVE_* predicates have not
>> been recomputed.
>>
>> There is also a related issue present when popping/resetting target pragmas
>> for which I'll send out a patch separately.
>>
>> Bootstrapped and tested on aarch64.
>>
>> Ok for trunk?
>
> OK.
>

Hi Kyrill,

Since this patch, I'm seeing:
  gcc.dg/torture/pr52429.c   -O2 -flto -fno-use-linker-plugin
-flto-partition=none  (internal compiler error)
on target aarch64-none-linux-gnu

The log has:
spawn -ignore SIGHUP
/aci-gcc-fsf/builds/gcc-fsf-gccsrc/obj-aarch64-none-linux-gnu/gcc3/gcc/xgcc
-B/aci-gcc-fsf/builds/gcc-fsf-gccsrc/obj-aarch64-none-linux-gnu/gcc
3/gcc/ /aci-gcc-fsf/sources/gcc-fsf/gccsrc/gcc/testsuite/gcc.dg/torture/pr52429.c
-fno-diagnostics-show-caret -fdiagnostics-color=never -O2 -flto
-fno-use-linker-pl
ugin -flto-partition=none -g -ftree-parallelize-loops=4
-DSTACK_SIZE=16384 -S -o pr52429.s
/aci-gcc-fsf/sources/gcc-fsf/gccsrc/gcc/testsuite/gcc.dg/torture/pr52429.c:
In function 'foo':
/aci-gcc-fsf/sources/gcc-fsf/gccsrc/gcc/testsuite/gcc.dg/torture/pr52429.c:24:1:
internal compiler error: Segmentation fault
0xade075 crash_signal
        /aci-gcc-fsf/sources/gcc-fsf/gccsrc/gcc/toplev.c:335
0x91f88e record_operand_costs
        /aci-gcc-fsf/sources/gcc-fsf/gccsrc/gcc/ira-costs.c:1293
0x91fdba scan_one_insn
        /aci-gcc-fsf/sources/gcc-fsf/gccsrc/gcc/ira-costs.c:1471
0x91fdba process_bb_for_costs
        /aci-gcc-fsf/sources/gcc-fsf/gccsrc/gcc/ira-costs.c:1592
0x9214e7 find_costs_and_classes
        /aci-gcc-fsf/sources/gcc-fsf/gccsrc/gcc/ira-costs.c:1699
0x922552 ira_set_pseudo_classes(bool, _IO_FILE*)
        /aci-gcc-fsf/sources/gcc-fsf/gccsrc/gcc/ira-costs.c:2239
0x1061ecd alloc_global_sched_pressure_data
        /aci-gcc-fsf/sources/gcc-fsf/gccsrc/gcc/haifa-sched.c:7244
0x1061ecd sched_init()
        /aci-gcc-fsf/sources/gcc-fsf/gccsrc/gcc/haifa-sched.c:7394
0x10679ed haifa_sched_init()
        /aci-gcc-fsf/sources/gcc-fsf/gccsrc/gcc/haifa-sched.c:7406
0xa84fae schedule_insns()
        /aci-gcc-fsf/sources/gcc-fsf/gccsrc/gcc/sched-rgn.c:3504
0xa85864 rest_of_handle_sched
        /aci-gcc-fsf/sources/gcc-fsf/gccsrc/gcc/sched-rgn.c:3717
0xa85864 execute
        /aci-gcc-fsf/sources/gcc-fsf/gccsrc/gcc/sched-rgn.c:3825

Don't you see this regression on your side?

Thanks,

Christophe.



> Thanks,
> James
>
>> Thanks,
>> Kyrill
>>
>>
>> 2016-02-25  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
>>
>>     PR target/69245
>>     * config/aarch64/aarch64.c (aarch64_set_current_function): Save/restore
>>     target globals when switching to target_option_default_node.
>>
>> 2016-02-25  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
>>
>>     PR target/69245
>>     * gcc.target/aarch64/pr69245_1.c: New test.
>
>