On Fri, Sep 19, 2014 at 1:43 PM, Jeff Law <l...@redhat.com> wrote:
> On 09/15/14 08:33, Jiong Wang wrote:
>>
>>
>> Jeff,
>>
>> thanks, I partially understand your meaning here.
>>
>> take the function "ira_implicitly_set_insn_hard_regs" in ira-lives.c
>> for example,
>>
>> when generating address rtl, gcc will automatically generate "const"
>> operator to prefix
>> the address expression, like the following. so a simple CONSTANT_P
>> check is enough in
>> case there is no embedded register.
>>
>> (insn 309 310 308 3 (set (reg:DI 44 r15 [orig:94 ivtmp.674 ] [94])
>> (const:DI (plus:DI (symbol_ref:DI ("recog_data") [flags 0x40]
>> <var_decl 0x2b2c2ff91510 recog_data>)
>> (const_int 480 [0x1e0])))) -1
>>
>>
>> but for architecture like aarch64, the following instruction
>> sequences to forming address
>> may be generated
>>
>> (insn 73 14 74 4 (set (reg/f:DI 20 x20 [99])
>> (high:DI (symbol_ref:DI ("global_a") [flags 0xc0] <var_decl
>> 0x7ff755a60900 stats>))) 35 {*movdi_aarch64}
>> (expr_list:REG_EQUIV (high:DI (symbol_ref:DI ("global_a") [flags
>> 0xc0] <var_decl 0x7ff755a60900 stats>))
>> (nil)))
>>
>> (insn 17 30 25 5 (set (reg/f:DI 4 x4 [83])
>> (lo_sum:DI (reg/f:DI 20 x20 [99])
>> (symbol_ref:DI ("global_a") [flags 0xc0] <var_decl
>> 0x7ff755a60900 stats>))) {add_losym_di}
>> (expr_list:REG_EQUIV (symbol_ref:DI ("global_a") [flags 0xc0]
>> <var_decl 0x7ff755a60900 stats>)
>> (nil)))
>>
>> while CONSTANT_P could not catch the latter lo_sum case, as the
>> RTX_CLASS of lo_sum is RTX_OBJ not RTX_CONST_OBJ,
>
> Hmm, it's been ~15 years since I regularly worked on a target that uses
> HIGH/LO_SUM, I thought we wrapped the LO_SUM expression inside a CONST as
> well, but reading the docs for CONST, that clearly isn't the case.
Could we add a check for lo_sum since it is an RTX_OBJ rather than
RTX_COMM_ARITH or RTX_BIN_ARITH?
I am testing the patch for that to fix the above issue. It shows up
with the testcase Jiong added but only with -mabi=ilp32 enabled.
Thanks,
Andrew Pinski
>
> Sorry for that. Can you (re) send your current patch for this for review?
>
> Jeff
