This is the mail archive of the gcc@gcc.gnu.org mailing list for the GCC project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: Errors when invoking refs_may_alias_p_1


On 08/27/10 14:29, Richard Guenther wrote:
> On Fri, Aug 27, 2010 at 8:24 PM, Hongtao <yu171@purdue.edu> wrote:
>   
>> On 08/27/10 12:35, Richard Guenther wrote:
>>     
>>> On Fri, Aug 27, 2010 at 5:27 PM, Hongtao <yu171@purdue.edu> wrote:
>>>
>>>       
>>>> Hi all,
>>>>
>>>> I have instrumented a function call like foo(&a,&b) into the gimple SSA
>>>> representation (gcc-4.5) and the consequent optimizations can not pass
>>>> my instrumented code. The back traces are as followings. The error
>>>> occurred when the pass dse tried to test if the call I inserted may use
>>>> a memory reference. It is because the arguments &a is not a SSA_VAR or
>>>> INDIRECT_REF, so the assert in function
>>>>
>>>> bool
>>>> refs_may_alias_p_1 (ao_ref *ref1, ao_ref *ref2, bool tbaa_p)
>>>>
>>>>  gcc_assert ((!ref1->ref
>>>>           || SSA_VAR_P (ref1->ref)
>>>>           || handled_component_p (ref1->ref)
>>>>           || INDIRECT_REF_P (ref1->ref)
>>>>           || TREE_CODE (ref1->ref) == TARGET_MEM_REF
>>>>           || TREE_CODE (ref1->ref) == CONST_DECL)
>>>>          && (!ref2->ref
>>>>          || SSA_VAR_P (ref2->ref)
>>>>          || handled_component_p (ref2->ref)
>>>>          || INDIRECT_REF_P (ref2->ref)
>>>>          || TREE_CODE (ref2->ref) == TARGET_MEM_REF
>>>>          || TREE_CODE (ref2->ref) == CONST_DECL));
>>>> was violated.
>>>>
>>>> Does anyone know why the function arguments must be a SSA_VAR or
>>>> INDIRECT_REF here? Have I missed to perform any actions to maintain the
>>>> consistency of Gimple SSA?
>>>>
>>>>         
>>> Yes.  is_gimple_val () will return false for your arguments as it seems that
>>> the variables do not have function invariant addresses.
>>>
>>> Richard.
>>>
>>>
>>>       
>> Thanks. But how can I change my argument to gimple_vals, using it with
>> an assignment to a temp before and replacing my argument with the temp?
>>     
> Yes, that will work.
>
> Richard.
>
>   
OK. Do we have to rewrite it like this everytime we insert a function
call on Gimple body if the argument of that call is an expression?

Thanks,
Hongtao

>> Hongtao
>>     
>>>> #0  0x00007ffff6fc8ee0 in exit () from /lib/libc.so.6
>>>> #1  0x00000000005ae4ce in diagnostic_action_after_output
>>>> (context=0x1323880, diagnostic=0x7fffffffd870) at
>>>> ../../src/gcc/diagnostic.c:198
>>>> #2  0x00000000005aed54 in diagnostic_report_diagnostic
>>>> (context=0x1323880, diagnostic=0x7fffffffd870) at
>>>> ../../src/gcc/diagnostic.c:424
>>>> #3  0x00000000005afdc3 in internal_error (gmsgid=0xddfb57 "in %s, at
>>>> %s:%d") at ../../src/gcc/diagnostic.c:709
>>>> #4  0x00000000005aff4f in fancy_abort (file=0xe42670
>>>> "../../src/gcc/tree-ssa-alias.c", line=786, function=0xe427e0
>>>> "refs_may_alias_p_1")
>>>>    at ../../src/gcc/diagnostic.c:763
>>>> #5  0x00000000008a1adb in refs_may_alias_p_1 (ref1=0x7fffffffdab0,
>>>> ref2=0x7fffffffdb50, tbaa_p=1 '\001')
>>>>    at ../../src/gcc/tree-ssa-alias.c:775
>>>> #6  0x00000000008a2b12 in ref_maybe_used_by_call_p_1
>>>> (call=0x7ffff6790630, ref=0x7fffffffdb50) at
>>>> ../../src/gcc/tree-ssa-alias.c:1133
>>>> #7  0x00000000008a2d2e in ref_maybe_used_by_call_p (call=0x7ffff6790630,
>>>> ref=0x7ffff6848048) at ../../src/gcc/tree-ssa-alias.c:1147
>>>> #8  0x00000000008a2dfa in ref_maybe_used_by_stmt_p (stmt=0x7ffff6790630,
>>>> ref=0x7ffff6848048) at ../../src/gcc/tree-ssa-alias.c:1179
>>>> #9  0x00000000008bf275 in dse_possible_dead_store_p
>>>> (stmt=0x7ffff683e820, use_stmt=0x7fffffffdca8) at
>>>> ../../src/gcc/tree-ssa-dse.c:212
>>>> #10 0x00000000008bfeb9 in dse_optimize_stmt (dse_gd=0x7fffffffddd0,
>>>> bd=0x156bd30, gsi=...) at ../../src/gcc/tree-ssa-dse.c:297
>>>> #11 0x00000000008c029d in dse_enter_block (walk_data=0x7fffffffdde0,
>>>> bb=0x7ffff6a75068) at ../../src/gcc/tree-ssa-dse.c:370
>>>> #12 0x0000000000cc26a5 in walk_dominator_tree (walk_data=0x7fffffffdde0,
>>>> bb=0x7ffff6a75068) at ../../src/gcc/domwalk.c:185
>>>> #13 0x00000000008c0812 in tree_ssa_dse () at
>>>> ../../src/gcc/tree-ssa-dse.c:430
>>>> #14 0x000000000073af0a in execute_one_pass (pass=0x13cced0) at
>>>> ../../src/gcc/passes.c:1572
>>>> #15 0x000000000073b21a in execute_pass_list (pass=0x13cced0) at
>>>> ../../src/gcc/passes.c:1627
>>>> #16 0x000000000073b238 in execute_pass_list (pass=0x1312720) at
>>>> ../../src/gcc/passes.c:1628
>>>> #17 0x000000000086e372 in tree_rest_of_compilation
>>>> (fndecl=0x7ffff6b93500) at ../../src/gcc/tree-optimize.c:413
>>>> #18 0x00000000009fa7c5 in cgraph_expand_function (node=0x7ffff6be7000)
>>>> at ../../src/gcc/cgraphunit.c:1548
>>>> #19 0x00000000009faa49 in cgraph_expand_all_functions () at
>>>> ../../src/gcc/cgraphunit.c:1627
>>>> #20 0x00000000009fb07e in cgraph_optimize () at
>>>> ../../src/gcc/cgraphunit.c:1875
>>>> #21 0x00000000009f9461 in cgraph_finalize_compilation_unit () at
>>>> ../../src/gcc/cgraphunit.c:1096
>>>> #22 0x00000000004a9e93 in c_write_global_declarations () at
>>>> ../../src/gcc/c-decl.c:9519
>>>> #23 0x00000000008180d4 in compile_file () at ../../src/gcc/toplev.c:1065
>>>> #24 0x000000000081a1c5 in do_compile () at ../../src/gcc/toplev.c:2417
>>>> #25 0x000000000081a286 in toplev_main (argc=21, argv=0x7fffffffe0f8) at
>>>> ../../src/gcc/toplev.c:2459
>>>> #26 0x0000000000519c6b in main (argc=21, argv=0x7fffffffe0f8) at
>>>> ../../src/gcc/main.c:35
>>>>
>>>> Thanks,
>>>>
>>>> Hongtao
>>>> Purdue University
>>>>
>>>>
>>>>
>>>>
>>>>         
>>>       
>>
>>     
>   


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]