From: Ramana Radhakrishnan <ramana.gcc@googlemail.com>
To: Alan Lawrence <alan.lawrence@arm.com>
Cc: "gcc-patches@gcc.gnu.org" <gcc-patches@gcc.gnu.org>
Subject: Re: [PATCH,PING][ARM]Remove vec_shr and vec_shr optabs
Date: Tue, 28 Apr 2015 16:41:00 -0000 [thread overview]
Message-ID: <CAJA7tRZY4_AtBFCudHN2sYrpVM1pM7aY2yp8GJz1zeqvOY0d5w@mail.gmail.com> (raw)
In-Reply-To: <553FA400.10609@arm.com>
On Tue, Apr 28, 2015 at 4:15 PM, Alan Lawrence <alan.lawrence@arm.com> wrote:
>> No new code here ;). There is a slight change of execution path, i.e. some
>> VEC_PERM_EXPRs (e.g. those for reductions via shifts) will be expanded
>> using
>> arm_expand_vec_perm_const rather than the vec_shr pattern. This generates
>> EXT
>> instructions equivalent to the original, but using the mode of the source
>> vector, rather than always indexing in terms of 8-bit elements.
>>
>> vec_shl in contrast was never used.
>>
>> Cross-tested check-gcc on arm-none-eabi.
>>
>> gcc/ChangeLog:
>>
>> * config/arm/neon.md (vec_shl<mode>, vec_shr<mode>): Remove.
Ok if no regressions.
Thanks,
Ramana
>>
>> diff --git a/gcc/config/arm/neon.md b/gcc/config/arm/neon.md
>> index
>> 41cf913a0da2e3ec034884ebb04bff9be7db3025..4297b0cd36a660bef5e2e66e2d5030c7cb6af2d3
>> 100644
>> --- a/gcc/config/arm/neon.md
>> +++ b/gcc/config/arm/neon.md
>> @@ -1194,71 +1194,6 @@
>> [(set_attr "type" "neon_add_widen")]
>> )
>> -;; VEXT can be used to synthesize coarse whole-vector shifts with 8-bit
>> -;; shift-count granularity. That's good enough for the middle-end's
>> current
>> -;; needs.
>> -
>> -;; Note that it's not safe to perform such an operation in big-endian
>> mode,
>> -;; due to element-ordering issues.
>> -
>> -(define_expand "vec_shr_<mode>"
>> - [(match_operand:VDQ 0 "s_register_operand" "")
>> - (match_operand:VDQ 1 "s_register_operand" "")
>> - (match_operand:SI 2 "const_multiple_of_8_operand" "")]
>> - "TARGET_NEON && !BYTES_BIG_ENDIAN"
>> -{
>> - rtx zero_reg;
>> - HOST_WIDE_INT num_bits = INTVAL (operands[2]);
>> - const int width = GET_MODE_BITSIZE (<MODE>mode);
>> - const enum machine_mode bvecmode = (width == 128) ? V16QImode :
>> V8QImode;
>> - rtx (*gen_ext) (rtx, rtx, rtx, rtx) =
>> - (width == 128) ? gen_neon_vextv16qi : gen_neon_vextv8qi;
>> -
>> - if (num_bits == width)
>> - {
>> - emit_move_insn (operands[0], operands[1]);
>> - DONE;
>> - }
>> -
>> - zero_reg = force_reg (bvecmode, CONST0_RTX (bvecmode));
>> - operands[0] = gen_lowpart (bvecmode, operands[0]);
>> - operands[1] = gen_lowpart (bvecmode, operands[1]);
>> -
>> - emit_insn (gen_ext (operands[0], operands[1], zero_reg,
>> - GEN_INT (num_bits / BITS_PER_UNIT)));
>> - DONE;
>> -})
>> -
>> -(define_expand "vec_shl_<mode>"
>> - [(match_operand:VDQ 0 "s_register_operand" "")
>> - (match_operand:VDQ 1 "s_register_operand" "")
>> - (match_operand:SI 2 "const_multiple_of_8_operand" "")]
>> - "TARGET_NEON && !BYTES_BIG_ENDIAN"
>> -{
>> - rtx zero_reg;
>> - HOST_WIDE_INT num_bits = INTVAL (operands[2]);
>> - const int width = GET_MODE_BITSIZE (<MODE>mode);
>> - const enum machine_mode bvecmode = (width == 128) ? V16QImode :
>> V8QImode;
>> - rtx (*gen_ext) (rtx, rtx, rtx, rtx) =
>> - (width == 128) ? gen_neon_vextv16qi : gen_neon_vextv8qi;
>> -
>> - if (num_bits == 0)
>> - {
>> - emit_move_insn (operands[0], CONST0_RTX (<MODE>mode));
>> - DONE;
>> - }
>> -
>> - num_bits = width - num_bits;
>> -
>> - zero_reg = force_reg (bvecmode, CONST0_RTX (bvecmode));
>> - operands[0] = gen_lowpart (bvecmode, operands[0]);
>> - operands[1] = gen_lowpart (bvecmode, operands[1]);
>> -
>> - emit_insn (gen_ext (operands[0], zero_reg, operands[1],
>> - GEN_INT (num_bits / BITS_PER_UNIT)));
>> - DONE;
>> -})
>> -
>> ;; Helpers for quad-word reduction operations
>> ; Add (or smin, smax...) the low N/2 elements of the N-element vector
>
>
> Ping.
>
> --Alan
>
prev parent reply other threads:[~2015-04-28 16:22 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-04-28 15:41 Alan Lawrence
2015-04-28 16:41 ` Ramana Radhakrishnan [this message]
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