Re: [PATCH] Sanitizing the middle-end interface to the back-end for strict alignment

[Kyrill Tkachov <kyrylo.tkachov@foss.arm.com>]

Hi Bernd,

On 8/28/19 10:36 PM, Bernd Edlinger wrote:
> On 8/28/19 2:07 PM, Christophe Lyon wrote:
>> Hi,
>>
>> This patch causes an ICE when building libgcc's unwind-arm.o
>> when configuring GCC:
>> --target  arm-none-linux-gnueabihf --with-mode thumb --with-cpu
>> cortex-a15 --with-fpu neon-vfpv4:
>>
>> The build works for the same target, but --with-mode arm --with-cpu
>> cortex a9 --with-fpu vfp
>>
>> In file included from
>> /tmp/6852788_4.tmpdir/aci-gcc-fsf/sources/gcc-fsf/gccsrc/libgcc/config/arm/unwind-arm.c:144:
>> /tmp/6852788_4.tmpdir/aci-gcc-fsf/sources/gcc-fsf/gccsrc/libgcc/unwind-arm-common.inc:
>> In function 'get_eit_entry':
>> /tmp/6852788_4.tmpdir/aci-gcc-fsf/sources/gcc-fsf/gccsrc/libgcc/unwind-arm-common.inc:245:29:
>> warning: cast discards 'const' qualifier from pointer target type
>> [-Wcast-qual]
>>    245 |       ucbp->pr_cache.ehtp = (_Unwind_EHT_Header *)&eitp->content;
>>        |                             ^
>> during RTL pass: expand
>> /tmp/6852788_4.tmpdir/aci-gcc-fsf/sources/gcc-fsf/gccsrc/libgcc/unwind-arm-common.inc:
>> In function 'unwind_phase2_forced':
>> /tmp/6852788_4.tmpdir/aci-gcc-fsf/sources/gcc-fsf/gccsrc/libgcc/unwind-arm-common.inc:319:18:
>> internal compiler error: in gen_movdi, at config/arm/arm.md:5235
>>    319 |   saved_vrs.core = entry_vrs->core;
>>        |   ~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~
>> 0x126530f gen_movdi(rtx_def*, rtx_def*)
>>          /tmp/6852788_4.tmpdir/aci-gcc-fsf/sources/gcc-fsf/gccsrc/gcc/config/arm/arm.md:5235
>> 0x896d92 insn_gen_fn::operator()(rtx_def*, rtx_def*) const
>>          /tmp/6852788_4.tmpdir/aci-gcc-fsf/sources/gcc-fsf/gccsrc/gcc/recog.h:318
>> 0x896d92 emit_move_insn_1(rtx_def*, rtx_def*)
>>          /tmp/6852788_4.tmpdir/aci-gcc-fsf/sources/gcc-fsf/gccsrc/gcc/expr.c:3694
>> 0x897083 emit_move_insn(rtx_def*, rtx_def*)
>>          /tmp/6852788_4.tmpdir/aci-gcc-fsf/sources/gcc-fsf/gccsrc/gcc/expr.c:3790
>> 0xfc25d6 gen_cpymem_ldrd_strd(rtx_def**)
>>          /tmp/6852788_4.tmpdir/aci-gcc-fsf/sources/gcc-fsf/gccsrc/gcc/config/arm/arm.c:14582
>> 0x126a1f1 gen_cpymemqi(rtx_def*, rtx_def*, rtx_def*, rtx_def*)
>>          /tmp/6852788_4.tmpdir/aci-gcc-fsf/sources/gcc-fsf/gccsrc/gcc/config/arm/arm.md:6688
>> 0xb0bc08 maybe_expand_insn(insn_code, unsigned int, expand_operand*)
>>          /tmp/6852788_4.tmpdir/aci-gcc-fsf/sources/gcc-fsf/gccsrc/gcc/optabs.c:7440
>> 0x89ba1e emit_block_move_via_cpymem
>>          /tmp/6852788_4.tmpdir/aci-gcc-fsf/sources/gcc-fsf/gccsrc/gcc/expr.c:1808
>> 0x89ba1e emit_block_move_hints(rtx_def*, rtx_def*, rtx_def*,
>> block_op_methods, unsigned int, long, unsigned long, unsigned long,
>> unsigned long, bool, bool*)
>>          /tmp/6852788_4.tmpdir/aci-gcc-fsf/sources/gcc-fsf/gccsrc/gcc/expr.c:1627
>> 0x89c383 emit_block_move(rtx_def*, rtx_def*, rtx_def*, block_op_methods)
>>          /tmp/6852788_4.tmpdir/aci-gcc-fsf/sources/gcc-fsf/gccsrc/gcc/expr.c:1667
>> 0x89fb4e store_expr(tree_node*, rtx_def*, int, bool, bool)
>>          /tmp/6852788_4.tmpdir/aci-gcc-fsf/sources/gcc-fsf/gccsrc/gcc/expr.c:5845
>> 0x88c1f9 store_field
>>          /tmp/6852788_4.tmpdir/aci-gcc-fsf/sources/gcc-fsf/gccsrc/gcc/expr.c:7149
>> 0x8a0c22 expand_assignment(tree_node*, tree_node*, bool)
>>          /tmp/6852788_4.tmpdir/aci-gcc-fsf/sources/gcc-fsf/gccsrc/gcc/expr.c:5304
>> 0x761964 expand_gimple_stmt_1
>>          /tmp/6852788_4.tmpdir/aci-gcc-fsf/sources/gcc-fsf/gccsrc/gcc/cfgexpand.c:3779
>> 0x761964 expand_gimple_stmt
>>          /tmp/6852788_4.tmpdir/aci-gcc-fsf/sources/gcc-fsf/gccsrc/gcc/cfgexpand.c:3875
>> 0x768583 expand_gimple_basic_block
>>          /tmp/6852788_4.tmpdir/aci-gcc-fsf/sources/gcc-fsf/gccsrc/gcc/cfgexpand.c:5915
>> 0x76abc6 execute
>>          /tmp/6852788_4.tmpdir/aci-gcc-fsf/sources/gcc-fsf/gccsrc/gcc/cfgexpand.c:6538
>>
>> Christophe
>>
> Okay, sorry for the breakage.
>
> What is happening in gen_cpymem_ldrd_strd is of course against the rules:
>
> It uses emit_move_insn on only 4-byte aligned DI-mode memory operands.
>
> I have a patch for this, which is able to fix the libgcc build on a cross, but have no
> possibility to bootstrap the affected target.
>
> Could you please help?

Well it's good that the sanitisation is catching the bugs!

Bootstrapping this patch I get another assert with the backtrace:

$BUILD/arm-none-linux-gnueabihf/libstdc++-v3/include/ext/concurrence.h: 
In function '(static initializers for 
$SRC/libstdc++-v3/libsupc++/eh_alloc.cc)':
$BUILD/arm-none-linux-gnueabihf/libstdc++-v3/include/ext/concurrence.h:129:5: 
internal compiler error: in gen_movv8qi, at config/arm/vec-common.md:29
   129 |     {
       |     ^
0x14155cb gen_movv8qi(rtx_def*, rtx_def*)
         $SRC/gcc/config/arm/vec-common.md:29
0x96bb89 insn_gen_fn::operator()(rtx_def*, rtx_def*) const
         $SRC/gcc/recog.h:318
0x94bc95 emit_move_insn_1(rtx_def*, rtx_def*)
         $SRC/gcc/expr.c:3694
0x94c05b emit_move_insn(rtx_def*, rtx_def*)
         $SRC/gcc/expr.c:3790
0x10d5ee5 arm_block_set_aligned_vect
         $SRC/gcc/config/arm/arm.c:30204
0x10d6b37 arm_block_set_vect
         $SRC/gcc/config/arm/arm.c:30428
0x10d6caf arm_gen_setmem(rtx_def**)
         $SRC/gcc/config/arm/arm.c:30458
0x140d7ed gen_setmemsi(rtx_def*, rtx_def*, rtx_def*, rtx_def*)
         $SRC/gcc/config/arm/arm.md:6687
0xbf0e87 insn_gen_fn::operator()(rtx_def*, rtx_def*, rtx_def*, rtx_def*) 
const
         $SRC/gcc/recog.h:320
0xbf0999 maybe_gen_insn(insn_code, unsigned int, expand_operand*)
         $SRC/gcc/optabs.c:7409
0xbf0b87 maybe_expand_insn(insn_code, unsigned int, expand_operand*)
         $SRC/gcc/optabs.c:7440
0x94a709 set_storage_via_setmem(rtx_def*, rtx_def*, rtx_def*, unsigned 
int, unsigned int, long long, unsigned long long, unsigned long long, 
unsigned long long)
         $SRC/gcc/expr.c:3168
0x94a059 clear_storage_hints(rtx_def*, rtx_def*, block_op_methods, 
unsigned int, long long, unsigned long long, unsigned long long, 
unsigned long long)
         $SRC/gcc/expr.c:3037
0x94a137 clear_storage(rtx_def*, rtx_def*, block_op_methods)
         $SRC/gcc/expr.c:3058
0x9537c5 store_constructor
         $SRC/gcc/expr.c:6333
0x957227 store_field
         $SRC/gcc/expr.c:7145
0x94fde1 expand_assignment(tree_node*, tree_node*, bool)
         $SRC/gcc/expr.c:5301
0x815e25 expand_gimple_stmt_1
         $SRC/gcc/cfgexpand.c:3777
0x81611d expand_gimple_stmt
         $SRC/gcc/cfgexpand.c:3875
0x81cd61 expand_gimple_basic_block
         $SRC/gcc/cfgexpand.c:5915

Looks to me like arm_gen_setmem needs similar fixes to gen_cpymem_ldrd_strd?

Thanks,

Kyrill


>
>
> Thanks
> Bernd.