Re: Errors when invoking refs_may_alias_p_1

[Hongtao <yu171 at purdue dot edu>]

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?

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
>>
>>
>>
>>     
>