On Thu, Aug 4, 2016 at 1:31 PM, Prasad Ghangal <prasad.ghan...@gmail.com> wrote:
> On 2 August 2016 at 14:29, Richard Biener <richard.guent...@gmail.com> wrote:
>> On Mon, Aug 1, 2016 at 4:52 PM, Prasad Ghangal <prasad.ghan...@gmail.com>
>> wrote:
>>> Hi,
>>>
>>> I am trying to replace c_parser_paren_condition (parser) in
>>> c_parser_gimple_if_stmt by c_parser_gimple_paren_condition (parser) as
>>> described in the patch
>>>
>>> I am trying test case
>>> void __GIMPLE () foo ()
>>> {
>>> int a;
>>> bb_2:
>>> if (a == 2)
>>> goto bb_3;
>>> else
>>> goto bb_4;
>>> bb_3:
>>> a_2 = 4;
>>> bb_4:
>>> return;
>>> }
>>>
>>> but it fails to parse gimple expression and produces error as
>>> /home/prasad/test3.c: In function ‘foo’:
>>> /home/prasad/test3.c:1:18: error: invalid operands in gimple comparison
>>> void __GIMPLE () foo ()
>>> ^~~
>>> if (<<< Unknown tree: c_maybe_const_expr
>>>
>>> a >>> == 2) goto bb_3; else goto bb_4;
>>> /home/prasad/test3.c:1:18: internal compiler error: verify_gimple failed
>>>
>>> I failed to debug where it is setting to C_MAYBE_CONST_EXPR
>>
>> It's in parsing the binary expression. Btw, you don't need lvalue_to_rvalue
>> conversion or truthvalue conversion - source that would require this would
>> not be valid GIMPLE. Let me try to debug:
>>
>>
>> (gdb) p debug_tree (cond.value)
>> <eq_expr 0x7ffff6997960
>> type <integer_type 0x7ffff688b7e0 int public SI
>> size <integer_cst 0x7ffff6887ee8 constant 32>
>> unit size <integer_cst 0x7ffff6887f00 constant 4>
>> align 32 symtab 0 alias set -1 canonical type 0x7ffff688b7e0
>> precision 32 min <integer_cst 0x7ffff6887ea0 -2147483648> max
>> <integer_cst 0x7ffff6887eb8 2147483647>
>> pointer_to_this <pointer_type 0x7ffff68a5930>>
>>
>> arg 0 <c_maybe_const_expr 0x7ffff6997938 type <integer_type
>> 0x7ffff688b7e0 int>
>>
>> arg 1 <var_decl 0x7ffff7fefcf0 a type <integer_type 0x7ffff688b7e0
>> int>
>> used SI file t.c line 3 col 7 size <integer_cst
>> 0x7ffff6887ee8 32> unit size <integer_cst 0x7ffff6887f00 4>
>> align 32 context <function_decl 0x7ffff699c500 foo>>>
>> arg 1 <integer_cst 0x7ffff68a4318 type <integer_type
>> 0x7ffff688b7e0 int> constant 2>
>> t.c:5:9 start: t.c:5:7 finish: t.c:5:12>
>> $5 = void
>> (gdb) b ggc-page.c:1444 if result == 0x7ffff6997938
>> Breakpoint 6 at 0x8a0d3e: file
>> /space/rguenther/src/gcc_gimple_fe/gcc/ggc-page.c, line 1444.
>> (gdb) run
>>
>> Breakpoint 6, ggc_internal_alloc (size=40, f=0x0, s=0, n=1)
>> at /space/rguenther/src/gcc_gimple_fe/gcc/ggc-page.c:1444
>> 1444 return result;
>> (gdb) fin (a few times)
>> Run till exit from #0 0x00000000011821b7 in build2_stat (
>> code=C_MAYBE_CONST_EXPR, tt=<integer_type 0x7ffff688b7e0 int>,
>> arg0=<tree 0x0>, arg1=<var_decl 0x7ffff7fefcf0 a>)
>> at /space/rguenther/src/gcc_gimple_fe/gcc/tree.c:4466
>> 0x000000000081d263 in c_wrap_maybe_const (expr=<var_decl 0x7ffff7fefcf0 a>,
>> non_const=false)
>> at /space/rguenther/src/gcc_gimple_fe/gcc/c-family/c-common.c:4359
>> 4359 expr = build2 (C_MAYBE_CONST_EXPR, TREE_TYPE (expr), NULL, expr);
>> Value returned is $11 = (tree_node *) 0x7ffff6997938
>> (gdb) up
>> #1 0x00000000007b8e81 in build_binary_op (location=176833, code=EQ_EXPR,
>> orig_op0=<var_decl 0x7ffff7fefcf0 a>,
>> orig_op1=<integer_cst 0x7ffff68a4318>, convert_p=1)
>> at /space/rguenther/src/gcc_gimple_fe/gcc/c/c-typeck.c:11549
>> 11549 op0 = c_wrap_maybe_const (op0, !op0_maybe_const);
>>
>> and this is guarded by !in_late_binary_op (which also seems to guard
>> folding).
>> So I suggest to somewhere at the start of parsing to set in_late_binary_op to
>> true for -fgimple. Not sure if it works for everything, but you
>> should have accumulated
>> quite some tests for -fgimple in the testsuite to make sure it doesn't
>> regress anything.
>>
> I did bootstrap build for the trunk and testing is in progress. How
> can I test with -fgimple flag enabled?
You can do
make check-gcc RUNTESTFLAGS="--target_board=unix/-fgimple"
Richard.
>
> Thanks,
> Prasad
>> The following works for me:
>>
>> diff --git a/gcc/c/c-parser.c b/gcc/c/c-parser.c
>> index 70800a2..c8c087a 100644
>> --- a/gcc/c/c-parser.c
>> +++ b/gcc/c/c-parser.c
>> @@ -2158,7 +2159,10 @@ c_parser_declaration_or_fndef (c_parser
>> *parser, bool fndef_ok,
>>
>> if (gimple_body_p && flag_gimple)
>> {
>> + bool saved = in_late_binary_op;
>> + in_late_binary_op = true;
>> c_parser_parse_gimple_body (parser);
>> + in_late_binary_op = saved;
>> cgraph_node::finalize_function (current_function_decl, false);
>> timevar_pop (tv);
>> return;
>>
>>
>> Richard.
>>
>>>
>>> Thanks,
>>> Prasad
