From: Jiufu Guo <guojiufu@linux.ibm.com>
To: "Kewen.Lin" <linkw@linux.ibm.com>
Cc: segher@kernel.crashing.org, dje.gcc@gmail.com, linkw@gcc.gnu.org,
gcc-patches@gcc.gnu.org
Subject: Re: [PATCH 2/3]rs6000: NFC use sext_hwi to replace ((v&0xf..f)^0x80..0) - 0x80..0
Date: Thu, 1 Dec 2022 13:35:48 +0800 [thread overview]
Message-ID: <9cbc0b3d-0d4b-5646-0ed8-fa2d4f8dc8c3@linux.ibm.com> (raw)
In-Reply-To: <94338e4c-baf4-ec09-68a7-064a23c79327@linux.ibm.com>
Hi Kewen,
Thanks for your quick and insight review!
在 12/1/22 1:17 PM, Kewen.Lin 写道:
> Hi Jeff,
>
> on 2022/12/1 09:36, Jiufu Guo wrote:
>> Hi,
>>
>> This patch just uses sext_hwi to replace the expression like:
>> ((value & 0xf..f) ^ 0x80..0) - 0x80..0 for rs6000.cc and rs6000.md.
>>
>> Bootstrap & regtest pass on ppc64{,le}.
>> Is this ok for trunk?
>
> You didn't say it clearly but I guessed you have grepped in the whole
> config/rs6000 directory, right? I noticed there are still two places
> using this kind of expression in function constant_generates_xxspltiw,
> but I assumed it's intentional as their types are not HOST_WIDE_INT.
>
> gcc/config/rs6000/rs6000.cc: short sign_h_word = ((h_word & 0xffff) ^ 0x8000) - 0x8000;
> gcc/config/rs6000/rs6000.cc: int sign_word = ((word & 0xffffffff) ^ 0x80000000) - 0x80000000;
>
> If so, could you state it clearly in commit log like "with type
> signed/unsigned HOST_WIDE_INT" or similar?
>
Good question!
And as you said sext_hwi is more for "signed/unsigned HOST_WIDE_INT".
For these two places, it seems sext_hwi is not needed actually!
And I did see why these expressions are used, may be just an assignment
is ok.
So, this patch does not cover these two places.
BR,
Jeff (Jiufu)
> This patch is OK once the above question gets confirmed, thanks!
>
> BR,
> Kewen
>
>>
>> BR,
>> Jeff (Jiufu)
>>
>> gcc/ChangeLog:
>>
>> * config/rs6000/rs6000.cc (num_insns_constant_gpr): Use sext_hwi.
>> (darwin_rs6000_legitimate_lo_sum_const_p): Likewise.
>> (mem_operand_gpr): Likewise.
>> (mem_operand_ds_form): Likewise.
>> (rs6000_legitimize_address): Likewise.
>> (rs6000_emit_set_const): Likewise.
>> (rs6000_emit_set_long_const): Likewise.
>> (print_operand): Likewise.
>> * config/rs6000/rs6000.md: Likewise.
>>
>> ---
>> gcc/config/rs6000/rs6000.cc | 30 +++++++++++++-----------------
>> gcc/config/rs6000/rs6000.md | 10 +++++-----
>> 2 files changed, 18 insertions(+), 22 deletions(-)
>>
>> diff --git a/gcc/config/rs6000/rs6000.cc b/gcc/config/rs6000/rs6000.cc
>> index 5efe9b22d8b..718072cc9a1 100644
>> --- a/gcc/config/rs6000/rs6000.cc
>> +++ b/gcc/config/rs6000/rs6000.cc
>> @@ -6021,7 +6021,7 @@ num_insns_constant_gpr (HOST_WIDE_INT value)
>>
>> else if (TARGET_POWERPC64)
>> {
>> - HOST_WIDE_INT low = ((value & 0xffffffff) ^ 0x80000000) - 0x80000000;
>> + HOST_WIDE_INT low = sext_hwi (value, 32);
>> HOST_WIDE_INT high = value >> 31;
>>
>> if (high == 0 || high == -1)
>> @@ -8456,7 +8456,7 @@ darwin_rs6000_legitimate_lo_sum_const_p (rtx x, machine_mode mode)
>> }
>>
>> /* We only care if the access(es) would cause a change to the high part. */
>> - offset = ((offset & 0xffff) ^ 0x8000) - 0x8000;
>> + offset = sext_hwi (offset, 16);
>> return SIGNED_16BIT_OFFSET_EXTRA_P (offset, extra);
>> }
>>
>> @@ -8522,7 +8522,7 @@ mem_operand_gpr (rtx op, machine_mode mode)
>> if (GET_CODE (addr) == LO_SUM)
>> /* For lo_sum addresses, we must allow any offset except one that
>> causes a wrap, so test only the low 16 bits. */
>> - offset = ((offset & 0xffff) ^ 0x8000) - 0x8000;
>> + offset = sext_hwi (offset, 16);
>>
>> return SIGNED_16BIT_OFFSET_EXTRA_P (offset, extra);
>> }
>> @@ -8562,7 +8562,7 @@ mem_operand_ds_form (rtx op, machine_mode mode)
>> if (GET_CODE (addr) == LO_SUM)
>> /* For lo_sum addresses, we must allow any offset except one that
>> causes a wrap, so test only the low 16 bits. */
>> - offset = ((offset & 0xffff) ^ 0x8000) - 0x8000;
>> + offset = sext_hwi (offset, 16);
>>
>> return SIGNED_16BIT_OFFSET_EXTRA_P (offset, extra);
>> }
>> @@ -9136,7 +9136,7 @@ rs6000_legitimize_address (rtx x, rtx oldx ATTRIBUTE_UNUSED,
>> {
>> HOST_WIDE_INT high_int, low_int;
>> rtx sum;
>> - low_int = ((INTVAL (XEXP (x, 1)) & 0xffff) ^ 0x8000) - 0x8000;
>> + low_int = sext_hwi (INTVAL (XEXP (x, 1)), 16);
>> if (low_int >= 0x8000 - extra)
>> low_int = 0;
>> high_int = INTVAL (XEXP (x, 1)) - low_int;
>> @@ -10203,7 +10203,7 @@ rs6000_emit_set_const (rtx dest, rtx source)
>> lo = operand_subword_force (dest, WORDS_BIG_ENDIAN != 0,
>> DImode);
>> emit_move_insn (hi, GEN_INT (c >> 32));
>> - c = ((c & 0xffffffff) ^ 0x80000000) - 0x80000000;
>> + c = sext_hwi (c, 32);
>> emit_move_insn (lo, GEN_INT (c));
>> }
>> else
>> @@ -10242,7 +10242,7 @@ rs6000_emit_set_long_const (rtx dest, HOST_WIDE_INT c)
>>
>> if ((ud4 == 0xffff && ud3 == 0xffff && ud2 == 0xffff && (ud1 & 0x8000))
>> || (ud4 == 0 && ud3 == 0 && ud2 == 0 && ! (ud1 & 0x8000)))
>> - emit_move_insn (dest, GEN_INT ((ud1 ^ 0x8000) - 0x8000));
>> + emit_move_insn (dest, GEN_INT (sext_hwi (ud1, 16)));
>>
>> else if ((ud4 == 0xffff && ud3 == 0xffff && (ud2 & 0x8000))
>> || (ud4 == 0 && ud3 == 0 && ! (ud2 & 0x8000)))
>> @@ -10250,7 +10250,7 @@ rs6000_emit_set_long_const (rtx dest, HOST_WIDE_INT c)
>> temp = !can_create_pseudo_p () ? dest : gen_reg_rtx (DImode);
>>
>> emit_move_insn (ud1 != 0 ? copy_rtx (temp) : dest,
>> - GEN_INT (((ud2 << 16) ^ 0x80000000) - 0x80000000));
>> + GEN_INT (sext_hwi (ud2 << 16, 32)));
>> if (ud1 != 0)
>> emit_move_insn (dest,
>> gen_rtx_IOR (DImode, copy_rtx (temp),
>> @@ -10261,8 +10261,7 @@ rs6000_emit_set_long_const (rtx dest, HOST_WIDE_INT c)
>> temp = !can_create_pseudo_p () ? dest : gen_reg_rtx (DImode);
>>
>> gcc_assert (ud2 & 0x8000);
>> - emit_move_insn (copy_rtx (temp),
>> - GEN_INT (((ud2 << 16) ^ 0x80000000) - 0x80000000));
>> + emit_move_insn (copy_rtx (temp), GEN_INT (sext_hwi (ud2 << 16, 32)));
>> if (ud1 != 0)
>> emit_move_insn (copy_rtx (temp),
>> gen_rtx_IOR (DImode, copy_rtx (temp),
>> @@ -10273,7 +10272,7 @@ rs6000_emit_set_long_const (rtx dest, HOST_WIDE_INT c)
>> {
>> temp = !can_create_pseudo_p () ? dest : gen_reg_rtx (DImode);
>> HOST_WIDE_INT num = (ud2 << 16) | ud1;
>> - rs6000_emit_set_long_const (temp, (num ^ 0x80000000) - 0x80000000);
>> + rs6000_emit_set_long_const (temp, sext_hwi (num, 32));
>> rtx one = gen_rtx_AND (DImode, temp, GEN_INT (0xffffffff));
>> rtx two = gen_rtx_ASHIFT (DImode, temp, GEN_INT (32));
>> emit_move_insn (dest, gen_rtx_IOR (DImode, one, two));
>> @@ -10283,8 +10282,7 @@ rs6000_emit_set_long_const (rtx dest, HOST_WIDE_INT c)
>> {
>> temp = !can_create_pseudo_p () ? dest : gen_reg_rtx (DImode);
>>
>> - emit_move_insn (copy_rtx (temp),
>> - GEN_INT (((ud3 << 16) ^ 0x80000000) - 0x80000000));
>> + emit_move_insn (copy_rtx (temp), GEN_INT (sext_hwi (ud3 << 16, 32)));
>> if (ud2 != 0)
>> emit_move_insn (copy_rtx (temp),
>> gen_rtx_IOR (DImode, copy_rtx (temp),
>> @@ -10336,8 +10334,7 @@ rs6000_emit_set_long_const (rtx dest, HOST_WIDE_INT c)
>> {
>> temp = !can_create_pseudo_p () ? dest : gen_reg_rtx (DImode);
>>
>> - emit_move_insn (copy_rtx (temp),
>> - GEN_INT (((ud4 << 16) ^ 0x80000000) - 0x80000000));
>> + emit_move_insn (copy_rtx (temp), GEN_INT (sext_hwi (ud4 << 16, 32)));
>> if (ud3 != 0)
>> emit_move_insn (copy_rtx (temp),
>> gen_rtx_IOR (DImode, copy_rtx (temp),
>> @@ -14167,8 +14164,7 @@ print_operand (FILE *file, rtx x, int code)
>> /* If constant, low-order 16 bits of constant, signed. Otherwise, write
>> normally. */
>> if (INT_P (x))
>> - fprintf (file, HOST_WIDE_INT_PRINT_DEC,
>> - ((INTVAL (x) & 0xffff) ^ 0x8000) - 0x8000);
>> + fprintf (file, HOST_WIDE_INT_PRINT_DEC, sext_hwi (INTVAL (x), 16));
>> else
>> print_operand (file, x, 0);
>> return;
>> diff --git a/gcc/config/rs6000/rs6000.md b/gcc/config/rs6000/rs6000.md
>> index 3bae303086b..4bd1dfd3da9 100644
>> --- a/gcc/config/rs6000/rs6000.md
>> +++ b/gcc/config/rs6000/rs6000.md
>> @@ -1787,7 +1787,7 @@ (define_expand "add<mode>3"
>> }
>>
>> HOST_WIDE_INT val = INTVAL (operands[2]);
>> - HOST_WIDE_INT low = ((val & 0xffff) ^ 0x8000) - 0x8000;
>> + HOST_WIDE_INT low = sext_hwi (val, 16);
>> HOST_WIDE_INT rest = trunc_int_for_mode (val - low, <MODE>mode);
>>
>> if (<MODE>mode == DImode && !satisfies_constraint_L (GEN_INT (rest)))
>> @@ -1930,7 +1930,7 @@ (define_split
>> (set (match_dup 0) (plus:GPR (match_dup 0) (match_dup 4)))]
>> {
>> HOST_WIDE_INT val = INTVAL (operands[2]);
>> - HOST_WIDE_INT low = ((val & 0xffff) ^ 0x8000) - 0x8000;
>> + HOST_WIDE_INT low = sext_hwi (val, 16);
>> HOST_WIDE_INT rest = trunc_int_for_mode (val - low, <MODE>mode);
>>
>> operands[4] = GEN_INT (low);
>> @@ -8213,7 +8213,7 @@ (define_split
>> operands[2] = operand_subword (operands[0], endian, 0, <MODE>mode);
>> operands[3] = operand_subword (operands[0], 1 - endian, 0, <MODE>mode);
>> operands[4] = GEN_INT (value >> 32);
>> - operands[1] = GEN_INT (((value & 0xffffffff) ^ 0x80000000) - 0x80000000);
>> + operands[1] = GEN_INT (sext_hwi (value, 32));
>> })
>>
>> (define_split
>> @@ -9577,7 +9577,7 @@ (define_split
>> operands[3] = operand_subword_force (operands[0], WORDS_BIG_ENDIAN != 0,
>> DImode);
>> operands[4] = GEN_INT (value >> 32);
>> - operands[1] = GEN_INT (((value & 0xffffffff) ^ 0x80000000) - 0x80000000);
>> + operands[1] = GEN_INT (sext_hwi (value, 32));
>> })
>>
>> (define_split
>> @@ -12425,7 +12425,7 @@ (define_peephole2
>> SImode,
>> operands[1], operands[2]);
>> HOST_WIDE_INT c = INTVAL (cnst);
>> - HOST_WIDE_INT sextc = ((c & 0xffff) ^ 0x8000) - 0x8000;
>> + HOST_WIDE_INT sextc = sext_hwi (c, 16);
>> HOST_WIDE_INT xorv = c ^ sextc;
>>
>> operands[9] = GEN_INT (xorv);
next prev parent reply other threads:[~2022-12-01 5:35 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-12-01 1:36 [PATCH 1/3]rs6000: NFC use more readable pattern to clean high 32 bits Jiufu Guo
2022-12-01 1:36 ` [PATCH 2/3]rs6000: NFC use sext_hwi to replace ((v&0xf..f)^0x80..0) - 0x80..0 Jiufu Guo
2022-12-01 5:17 ` Kewen.Lin
2022-12-01 5:30 ` Kewen.Lin
2022-12-01 6:32 ` Jiufu Guo
2022-12-01 5:35 ` Jiufu Guo [this message]
2022-12-01 6:11 ` Kewen.Lin
2022-12-01 7:10 ` Jiufu Guo
2022-12-01 12:16 ` guojiufu
2022-12-02 8:56 ` Kewen.Lin
2022-12-05 6:11 ` Jiufu Guo
2022-12-09 1:51 ` Jiufu Guo
2022-12-01 1:36 ` [PATCH 3/3]rs6000: NFC no need copy_rtx in rs6000_emit_set_long_const and rs6000_emit_set_const Jiufu Guo
2022-12-01 3:31 ` Kewen.Lin
2022-12-01 4:52 ` Jiufu Guo
2022-12-09 12:25 ` Jiufu Guo
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