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Re: Question on operand_equal_p on different type conversion expressions
- From: "Bin.Cheng" <amker dot cheng at gmail dot com>
- To: Andrew Pinski <pinskia at gmail dot com>
- Cc: "gcc at gcc dot gnu dot org" <gcc at gcc dot gnu dot org>
- Date: Tue, 21 May 2013 14:38:44 +0800
- Subject: Re: Question on operand_equal_p on different type conversion expressions
- References: <CAHFci29t23t0hDJ3y8OA_o2jJrPDCoa=3g9FwKQjnpS34EPvYg at mail dot gmail dot com> <CA+=Sn1m+M3Z3=5XybvAkVM=1CqgQ9t5_Ly2tSEDe06=Cr52yCA at mail dot gmail dot com>
On Tue, May 21, 2013 at 1:55 PM, Andrew Pinski <pinskia@gmail.com> wrote:
> On Mon, May 20, 2013 at 10:50 PM, Bin.Cheng <amker.cheng@gmail.com> wrote:
>
>
> NOP_EXPR here is a misnamed tree really. It could also be a
> CONVERT_EXPR and still have the same issue as the types are not the
> same.
>
>
>> The problem is operand_equal_q simply return false because arg0/arg1
>> have different tree code.
>
> No it returns false because the types are two different. One is
> signed and the other is unsigned.
>
>>
>> Should operand_equal_q take two kinds of conversion expression into
>> consideration, or arg0/arg1 are not equal? Thanks.
>
> Yes why would it not? Look at the resulting types again.
Thanks very much. The dumped tree codes are different (my mistake).
But the problem still exists in operand_equal_q.
For now with below tree nodes,
arg0:
<convert_expr 0xb72ddb04
type <integer_type 0xb74602a0 short int sizes-gimplified public HI
size <integer_cst 0xb744e7c4 constant 16>
unit size <integer_cst 0xb744e7e0 constant 2>
align 16 symtab 0 alias set 4 canonical type 0xb74602a0
precision 16 min <integer_cst 0xb744e770 -32768> max <integer_cst
0xb744e78c 32767> context <translation_unit_decl 0xb760dd80 D.6120>
pointer_to_this <pointer_type 0xb7241600>>
arg 0 <ssa_name 0xb72882f8
type <integer_type 0xb7460420 long int sizes-gimplified public SI
size <integer_cst 0xb744e55c constant 32>
unit size <integer_cst 0xb744e578 constant 4>
align 32 symtab 0 alias set 5 canonical type 0xb7460420
precision 32 min <integer_cst 0xb744e888 -2147483648> max <integer_cst
0xb744e8a4 2147483647> context <translation_unit_decl 0xb760dd80
D.6120>
pointer_to_this <pointer_type 0xb74677e0>>
visiteddef_stmt _23 = *_22;
version 23>>
arg1:
<nop_expr 0xb72e1b54
type <integer_type 0xb74602a0 short int sizes-gimplified public HI
size <integer_cst 0xb744e7c4 constant 16>
unit size <integer_cst 0xb744e7e0 constant 2>
align 16 symtab 0 alias set 4 canonical type 0xb74602a0
precision 16 min <integer_cst 0xb744e770 -32768> max <integer_cst
0xb744e78c 32767> context <translation_unit_decl 0xb760dd80 D.6120>
pointer_to_this <pointer_type 0xb7241600>>
arg 0 <ssa_name 0xb72882f8
type <integer_type 0xb7460420 long int sizes-gimplified public SI
size <integer_cst 0xb744e55c constant 32>
unit size <integer_cst 0xb744e578 constant 4>
align 32 symtab 0 alias set 5 canonical type 0xb7460420
precision 32 min <integer_cst 0xb744e888 -2147483648> max <integer_cst
0xb744e8a4 2147483647> context <translation_unit_decl 0xb760dd80
D.6120>
pointer_to_this <pointer_type 0xb74677e0>>
visiteddef_stmt _23 = *_22;
version 23>>
The operand_equal_p still returns false because below piece of code in it:
#if 1
if (TREE_CODE (arg0) != TREE_CODE (arg1)
/* This is needed for conversions and for COMPONENT_REF.
Might as well play it safe and always test this. */
|| TREE_CODE (TREE_TYPE (arg0)) == ERROR_MARK
|| TREE_CODE (TREE_TYPE (arg1)) == ERROR_MARK
|| TYPE_MODE (TREE_TYPE (arg0)) != TYPE_MODE (TREE_TYPE (arg1)))
#else
if ((TREE_CODE (arg0) != TREE_CODE (arg1)
&& !(CONVERT_EXPR_P (arg0) && CONVERT_EXPR_P (arg1)))
/* This is needed for conversions and for COMPONENT_REF.
Might as well play it safe and always test this. */
|| TREE_CODE (TREE_TYPE (arg0)) == ERROR_MARK
|| TREE_CODE (TREE_TYPE (arg1)) == ERROR_MARK
|| TYPE_MODE (TREE_TYPE (arg0)) != TYPE_MODE (TREE_TYPE (arg1)))
#endif
return 0;
The code in else part should be used instead, right?
Thanks.
--
Best Regards.