Hi David,
David Edelsohn <dje....@gmail.com> writes:
> Hi, Jiufu
>
> This definitely seems to be a better solution.
>
> The TARGET_CONST_ANCHOR change should not be part of this patch. Also
> there is no ChangeLog for the patch.
Thanks a lot for your quick review!! And sorry for the sending this patch
in a hurry. I would update the patch accordingly.
BR,
Jeff (Jiufu Guo)
>
> This generally looks correct and consistent with other ports. I want
> to give Segher a chance to double check it, if he wishes.
>
> Thanks David
>
> On Mon, Jun 12, 2023 at 9:19 AM Jiufu Guo <guoji...@linux.ibm.com> wrote:
>>
>> Hi,
>>
>> For stack_tie, currently below insn is generated:
>> (insn 15 14 16 3 (parallel [
>> (set (mem/c:BLK (reg/f:DI 1 1) [1 A8])
>> (const_int 0 [0]))
>> ]) "/home/guojiufu/temp/gdb.c":13:3 922 {stack_tie}
>> (nil))
>>
>> It is "set (mem/c:BLK (reg/f:DI 1 1) (const_int 0 [0])". This maybe
>> looks like "a memory block is zerored", while actually stack_tie
>> may be more like a placeholder, and does not generate any thing.
>>
>> To avoid potential misunderstand, "UNPSEC:BLK [(const_int 0)].." could
>> be used here like other ports.
>>
>> This patch does this. Bootstrap®test pass on ppc64{,le}.
>> Is this ok for trunk?
>>
>> BR,
>> Jeff (Jiufu Guo)
>>
>> ---
>> gcc/config/rs6000/predicates.md | 11 +++++++----
>> gcc/config/rs6000/rs6000-logue.cc | 4 +++-
>> gcc/config/rs6000/rs6000.cc | 4 ++++
>> gcc/config/rs6000/rs6000.md | 14 ++++++++++----
>> 4 files changed, 24 insertions(+), 9 deletions(-)
>>
>> diff --git a/gcc/config/rs6000/predicates.md
>> b/gcc/config/rs6000/predicates.md
>> index a16ee30f0c0..4748cb37ce8 100644
>> --- a/gcc/config/rs6000/predicates.md
>> +++ b/gcc/config/rs6000/predicates.md
>> @@ -1854,10 +1854,13 @@ (define_predicate "stmw_operation"
>> (define_predicate "tie_operand"
>> (match_code "parallel")
>> {
>> - return (GET_CODE (XVECEXP (op, 0, 0)) == SET
>> - && MEM_P (XEXP (XVECEXP (op, 0, 0), 0))
>> - && GET_MODE (XEXP (XVECEXP (op, 0, 0), 0)) == BLKmode
>> - && XEXP (XVECEXP (op, 0, 0), 1) == const0_rtx);
>> + rtx set = XVECEXP (op, 0, 0);
>> + return (GET_CODE (set) == SET
>> + && MEM_P (SET_DEST (set))
>> + && GET_MODE (SET_DEST (set)) == BLKmode
>> + && GET_CODE (SET_SRC (set)) == UNSPEC
>> + && XINT (SET_SRC (set), 1) == UNSPEC_TIE
>> + && XVECEXP (SET_SRC (set), 0, 0) == const0_rtx);
>> })
>>
>> ;; Match a small code model toc reference (or medium and large
>> diff --git a/gcc/config/rs6000/rs6000-logue.cc
>> b/gcc/config/rs6000/rs6000-logue.cc
>> index bc6b153b59f..b99f43a8282 100644
>> --- a/gcc/config/rs6000/rs6000-logue.cc
>> +++ b/gcc/config/rs6000/rs6000-logue.cc
>> @@ -1463,7 +1463,9 @@ rs6000_emit_stack_tie (rtx fp, bool hard_frame_needed)
>> while (--i >= 0)
>> {
>> rtx mem = gen_frame_mem (BLKmode, regs[i]);
>> - RTVEC_ELT (p, i) = gen_rtx_SET (mem, const0_rtx);
>> + RTVEC_ELT (p, i)
>> + = gen_rtx_SET (mem, gen_rtx_UNSPEC (BLKmode, gen_rtvec (1,
>> const0_rtx),
>> + UNSPEC_TIE));
>> }
>>
>> emit_insn (gen_stack_tie (gen_rtx_PARALLEL (VOIDmode, p)));
>> diff --git a/gcc/config/rs6000/rs6000.cc b/gcc/config/rs6000/rs6000.cc
>> index d197c3f3289..0c81ebea711 100644
>> --- a/gcc/config/rs6000/rs6000.cc
>> +++ b/gcc/config/rs6000/rs6000.cc
>> @@ -1760,6 +1760,10 @@ static const struct attribute_spec
>> rs6000_attribute_table[] =
>>
>> #undef TARGET_UPDATE_IPA_FN_TARGET_INFO
>> #define TARGET_UPDATE_IPA_FN_TARGET_INFO rs6000_update_ipa_fn_target_info
>> +
>> +#undef TARGET_CONST_ANCHOR
>> +#define TARGET_CONST_ANCHOR 0x8000
>> +
>>
>>
>> /* Processor table. */
>> diff --git a/gcc/config/rs6000/rs6000.md b/gcc/config/rs6000/rs6000.md
>> index b0db8ae508d..fdcf8347812 100644
>> --- a/gcc/config/rs6000/rs6000.md
>> +++ b/gcc/config/rs6000/rs6000.md
>> @@ -158,6 +158,7 @@ (define_c_enum "unspec"
>> UNSPEC_HASHCHK
>> UNSPEC_XXSPLTIDP_CONST
>> UNSPEC_XXSPLTIW_CONST
>> + UNSPEC_TIE
>> ])
>>
>> ;;
>> @@ -10828,7 +10829,9 @@ (define_expand "restore_stack_block"
>> operands[4] = gen_frame_mem (Pmode, operands[1]);
>> p = rtvec_alloc (1);
>> RTVEC_ELT (p, 0) = gen_rtx_SET (gen_frame_mem (BLKmode, operands[0]),
>> - const0_rtx);
>> + gen_rtx_UNSPEC (BLKmode,
>> + gen_rtvec (1, const0_rtx),
>> + UNSPEC_TIE));
>> operands[5] = gen_rtx_PARALLEL (VOIDmode, p);
>> })
>>
>> @@ -10866,7 +10869,9 @@ (define_expand "restore_stack_nonlocal"
>> operands[5] = gen_frame_mem (Pmode, operands[3]);
>> p = rtvec_alloc (1);
>> RTVEC_ELT (p, 0) = gen_rtx_SET (gen_frame_mem (BLKmode, operands[0]),
>> - const0_rtx);
>> + gen_rtx_UNSPEC (BLKmode,
>> + gen_rtvec (1, const0_rtx),
>> + UNSPEC_TIE));
>> operands[6] = gen_rtx_PARALLEL (VOIDmode, p);
>> })
>>
>> @@ -13898,7 +13903,8 @@ (define_insn "*save_fpregs_<mode>_r1"
>> ; not be moved over loads from or stores to stack memory.
>> (define_insn "stack_tie"
>> [(match_parallel 0 "tie_operand"
>> - [(set (mem:BLK (reg 1)) (const_int 0))])]
>> + [(set (mem:BLK (reg 1))
>> + (unspec:BLK [(const_int 0)] UNSPEC_TIE))])]
>> ""
>> ""
>> [(set_attr "length" "0")])
>> @@ -13910,7 +13916,7 @@ (define_insn "stack_restore_tie"
>> [(set (match_operand:SI 0 "gpc_reg_operand" "=r,r")
>> (plus:SI (match_operand:SI 1 "gpc_reg_operand" "r,r")
>> (match_operand:SI 2 "reg_or_cint_operand" "O,rI")))
>> - (set (mem:BLK (scratch)) (const_int 0))]
>> + (set (mem:BLK (scratch)) (unspec:BLK [(const_int 0)] UNSPEC_TIE))]
>> "TARGET_32BIT"
>> "@
>> mr %0,%1
>> --
>> 2.39.3
>>
