From: Richard Sandiford <richard.sandiford@arm.com>
To: Tamar Christina <Tamar.Christina@arm.com>
Cc: "gcc-patches\@gcc.gnu.org" <gcc-patches@gcc.gnu.org>,
nd <nd@arm.com>, Richard Earnshaw <Richard.Earnshaw@arm.com>,
Marcus Shawcroft <Marcus.Shawcroft@arm.com>,
Kyrylo Tkachov <Kyrylo.Tkachov@arm.com>
Subject: Re: [PATCH 2/2]AArch64 Perform more late folding of reg moves and shifts which arrive after expand
Date: Mon, 14 Nov 2022 21:54:18 +0000 [thread overview]
Message-ID: <mpt35almcc5.fsf@arm.com> (raw)
In-Reply-To: <VI1PR08MB53254855B4410E701B78BE89FF379@VI1PR08MB5325.eurprd08.prod.outlook.com> (Tamar Christina's message of "Mon, 31 Oct 2022 11:48:43 +0000")
Tamar Christina <Tamar.Christina@arm.com> writes:
>>
>> The same thing ought to work for smov, so it would be good to do both.
>> That would also make the split between the original and new patterns more
>> obvious: left shift for the old pattern, right shift for the new pattern.
>>
>
> Done, though because umov can do multilevel extensions I couldn't combine them
> Into a single pattern.
Hmm, but the pattern is:
(define_insn "*<optab>si3_insn2_uxtw"
[(set (match_operand:GPI 0 "register_operand" "=r,r,r")
(zero_extend:GPI (LSHIFTRT_ONLY:SI
(match_operand:SI 1 "register_operand" "w,r,r")
(match_operand:QI 2 "aarch64_reg_or_shift_imm_si" "Usl,Uss,r"))))]
GPI is just SI or DI, so in the SI case we're zero-extending SI to SI,
which isn't a valid operation. The original patch was just for extending
to DI, which seems correct. The choice between printing %x for smov and
%w for umov can then depend on the code.
>
> Bootstrapped Regtested on aarch64-none-linux-gnu and no issues.
>
> Ok for master?
>
> Thanks,
> Tamar
>
> gcc/ChangeLog:
>
> * config/aarch64/aarch64.md (*<optab>si3_insn_uxtw): Split SHIFT into
> left and right ones.
> (*aarch64_ashr_sisd_or_int_<mode>3, *<optab>si3_insn2_sxtw): Support
> smov.
> * config/aarch64/constraints.md (Usl): New.
> * config/aarch64/iterators.md (LSHIFTRT_ONLY, ASHIFTRT_ONLY): New.
>
> gcc/testsuite/ChangeLog:
>
> * gcc.target/aarch64/shift-read_1.c: New test.
> * gcc.target/aarch64/shift-read_2.c: New test.
> * gcc.target/aarch64/shift-read_3.c: New test.
>
> --- inline copy of patch ---
>
> diff --git a/gcc/config/aarch64/aarch64.md b/gcc/config/aarch64/aarch64.md
> index c333fb1f72725992bb304c560f1245a242d5192d..2bc2684b82c35a44e0a2cea6e3aaf32d939f8cdf 100644
> --- a/gcc/config/aarch64/aarch64.md
> +++ b/gcc/config/aarch64/aarch64.md
> @@ -5370,20 +5370,42 @@ (define_split
>
> ;; Arithmetic right shift using SISD or Integer instruction
> (define_insn "*aarch64_ashr_sisd_or_int_<mode>3"
> - [(set (match_operand:GPI 0 "register_operand" "=r,r,w,&w,&w")
> + [(set (match_operand:GPI 0 "register_operand" "=r,r,w,r,&w,&w")
> (ashiftrt:GPI
> - (match_operand:GPI 1 "register_operand" "r,r,w,w,w")
> + (match_operand:GPI 1 "register_operand" "r,r,w,w,w,w")
> (match_operand:QI 2 "aarch64_reg_or_shift_imm_di"
> - "Us<cmode>,r,Us<cmode_simd>,w,0")))]
> + "Us<cmode>,r,Us<cmode_simd>,Usl,w,0")))]
> ""
> - "@
> - asr\t%<w>0, %<w>1, %2
> - asr\t%<w>0, %<w>1, %<w>2
> - sshr\t%<rtn>0<vas>, %<rtn>1<vas>, %2
> - #
> - #"
> - [(set_attr "type" "bfx,shift_reg,neon_shift_imm<q>,neon_shift_reg<q>,neon_shift_reg<q>")
> - (set_attr "arch" "*,*,simd,simd,simd")]
> + {
> + switch (which_alternative)
> + {
> + case 0:
> + return "asr\t%<w>0, %<w>1, %2";
> + case 1:
> + return "asr\t%<w>0, %<w>1, %<w>2";
> + case 2:
> + return "sshr\t%<rtn>0<vas>, %<rtn>1<vas>, %2";
> + case 3:
> + {
> + int val = INTVAL (operands[2]);
> + int size = 32 - val;
> +
> + if (size == 16)
> + return "smov\\t%w0, %1.h[1]";
> + if (size == 8)
> + return "smov\\t%w0, %1.b[3]";
This only looks right for SI, not DI. (But we can do something
similar for DI.)
Thanks,
Richard
> + gcc_unreachable ();
> + }
> + case 4:
> + return "#";
> + case 5:
> + return "#";
> + default:
> + gcc_unreachable ();
> + }
> + }
> + [(set_attr "type" "bfx,shift_reg,neon_shift_imm<q>,neon_to_gp, neon_shift_reg<q>,neon_shift_reg<q>")
> + (set_attr "arch" "*,*,simd,simd,simd,simd")]
> )
>
> (define_split
> @@ -5493,7 +5515,7 @@ (define_insn "*rol<mode>3_insn"
> ;; zero_extend version of shifts
> (define_insn "*<optab>si3_insn_uxtw"
> [(set (match_operand:DI 0 "register_operand" "=r,r")
> - (zero_extend:DI (SHIFT_no_rotate:SI
> + (zero_extend:DI (SHIFT_arith:SI
> (match_operand:SI 1 "register_operand" "r,r")
> (match_operand:QI 2 "aarch64_reg_or_shift_imm_si" "Uss,r"))))]
> ""
> @@ -5528,6 +5550,68 @@ (define_insn "*rolsi3_insn_uxtw"
> [(set_attr "type" "rotate_imm")]
> )
>
> +(define_insn "*<optab>si3_insn2_sxtw"
> + [(set (match_operand:GPI 0 "register_operand" "=r,r,r")
> + (sign_extend:GPI (ASHIFTRT_ONLY:SI
> + (match_operand:SI 1 "register_operand" "w,r,r")
> + (match_operand:QI 2 "aarch64_reg_or_shift_imm_si" "Usl,Uss,r"))))]
> + "<MODE>mode != DImode || satisfies_constraint_Usl (operands[2])"
> + {
> + switch (which_alternative)
> + {
> + case 0:
> + {
> + int val = INTVAL (operands[2]);
> + int size = 32 - val;
> +
> + if (size == 16)
> + return "smov\\t%<w>0, %1.h[1]";
> + if (size == 8)
> + return "smov\\t%<w>0, %1.b[3]";
> + gcc_unreachable ();
> + }
> + case 1:
> + return "<shift>\\t%<w>0, %<w>1, %2";
> + case 2:
> + return "<shift>\\t%<w>0, %<w>1, %<w>2";
> + default:
> + gcc_unreachable ();
> + }
> + }
> + [(set_attr "type" "neon_to_gp,bfx,shift_reg")]
> +)
> +
> +(define_insn "*<optab>si3_insn2_uxtw"
> + [(set (match_operand:GPI 0 "register_operand" "=r,r,r")
> + (zero_extend:GPI (LSHIFTRT_ONLY:SI
> + (match_operand:SI 1 "register_operand" "w,r,r")
> + (match_operand:QI 2 "aarch64_reg_or_shift_imm_si" "Usl,Uss,r"))))]
> + ""
> + {
> + switch (which_alternative)
> + {
> + case 0:
> + {
> + int val = INTVAL (operands[2]);
> + int size = 32 - val;
> +
> + if (size == 16)
> + return "umov\\t%w0, %1.h[1]";
> + if (size == 8)
> + return "umov\\t%w0, %1.b[3]";
> + gcc_unreachable ();
> + }
> + case 1:
> + return "<shift>\\t%w0, %w1, %2";
> + case 2:
> + return "<shift>\\t%w0, %w1, %w2";
> + default:
> + gcc_unreachable ();
> + }
> + }
> + [(set_attr "type" "neon_to_gp,bfx,shift_reg")]
> +)
> +
> (define_insn "*<optab><mode>3_insn"
> [(set (match_operand:SHORT 0 "register_operand" "=r")
> (ASHIFT:SHORT (match_operand:SHORT 1 "register_operand" "r")
> diff --git a/gcc/config/aarch64/constraints.md b/gcc/config/aarch64/constraints.md
> index ee7587cca1673208e2bfd6b503a21d0c8b69bf75..470510d691ee8589aec9b0a71034677534641bea 100644
> --- a/gcc/config/aarch64/constraints.md
> +++ b/gcc/config/aarch64/constraints.md
> @@ -166,6 +166,14 @@ (define_constraint "Uss"
> (and (match_code "const_int")
> (match_test "(unsigned HOST_WIDE_INT) ival < 32")))
>
> +(define_constraint "Usl"
> + "@internal
> + A constraint that matches an immediate shift constant in SImode that has an
> + exact mode available to use."
> + (and (match_code "const_int")
> + (and (match_test "satisfies_constraint_Uss (op)")
> + (match_test "(32 - ival == 8) || (32 - ival == 16)"))))
> +
> (define_constraint "Usn"
> "A constant that can be used with a CCMN operation (once negated)."
> (and (match_code "const_int")
> diff --git a/gcc/config/aarch64/iterators.md b/gcc/config/aarch64/iterators.md
> index e904407b2169e589b7007ff966b2d9347a6d0fd2..b2682acb3bb12d584613d395200c3b39c0e94d8d 100644
> --- a/gcc/config/aarch64/iterators.md
> +++ b/gcc/config/aarch64/iterators.md
> @@ -2149,8 +2149,14 @@ (define_mode_attr sve_lane_pair_con [(VNx8HF "y") (VNx4SF "x")])
> ;; This code iterator allows the various shifts supported on the core
> (define_code_iterator SHIFT [ashift ashiftrt lshiftrt rotatert rotate])
>
> -;; This code iterator allows all shifts except for rotates.
> -(define_code_iterator SHIFT_no_rotate [ashift ashiftrt lshiftrt])
> +;; This code iterator allows arithmetic shifts
> +(define_code_iterator SHIFT_arith [ashift ashiftrt])
> +
> +;; Singleton code iterator for only logical right shift.
> +(define_code_iterator LSHIFTRT_ONLY [lshiftrt])
> +
> +;; Singleton code iterator for only arithmetic right shift.
> +(define_code_iterator ASHIFTRT_ONLY [ashiftrt])
>
> ;; This code iterator allows the shifts supported in arithmetic instructions
> (define_code_iterator ASHIFT [ashift ashiftrt lshiftrt])
> diff --git a/gcc/testsuite/gcc.target/aarch64/shift-read_1.c b/gcc/testsuite/gcc.target/aarch64/shift-read_1.c
> new file mode 100644
> index 0000000000000000000000000000000000000000..e6e355224c96344fe1cdabd6b0d3d5d609cd95bd
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/aarch64/shift-read_1.c
> @@ -0,0 +1,85 @@
> +/* { dg-do compile } */
> +/* { dg-additional-options "-O2" } */
> +/* { dg-final { check-function-bodies "**" "" "" { target { le } } } } */
> +
> +#include <arm_neon.h>
> +
> +/*
> +** foor:
> +** umov w0, v0.h\[3\]
> +** ret
> +*/
> +unsigned int foor (uint32x4_t x)
> +{
> + return x[1] >> 16;
> +}
> +
> +/*
> +** fool:
> +** umov w0, v0.s\[1\]
> +** lsl w0, w0, 16
> +** ret
> +*/
> +unsigned int fool (uint32x4_t x)
> +{
> + return x[1] << 16;
> +}
> +
> +/*
> +** foor2:
> +** umov w0, v0.h\[7\]
> +** ret
> +*/
> +unsigned short foor2 (uint32x4_t x)
> +{
> + return x[3] >> 16;
> +}
> +
> +/*
> +** fool2:
> +** fmov w0, s0
> +** lsl w0, w0, 16
> +** ret
> +*/
> +unsigned int fool2 (uint32x4_t x)
> +{
> + return x[0] << 16;
> +}
> +
> +typedef int v4si __attribute__ ((vector_size (16)));
> +
> +/*
> +** bar:
> +** addv s0, v0.4s
> +** fmov w0, s0
> +** lsr w1, w0, 16
> +** add w0, w1, w0, uxth
> +** ret
> +*/
> +int bar (v4si x)
> +{
> + unsigned int sum = vaddvq_s32 (x);
> + return (((uint16_t)(sum & 0xffff)) + ((uint32_t)sum >> 16));
> +}
> +
> +/*
> +** foo:
> +** lsr w0, w0, 16
> +** ret
> +*/
> +unsigned short foo (unsigned x)
> +{
> + return x >> 16;
> +}
> +
> +/*
> +** foo2:
> +** ...
> +** umov w0, v[0-8]+.h\[1\]
> +** ret
> +*/
> +unsigned short foo2 (v4si x)
> +{
> + int y = x[0] + x[1];
> + return y >> 16;
> +}
> diff --git a/gcc/testsuite/gcc.target/aarch64/shift-read_2.c b/gcc/testsuite/gcc.target/aarch64/shift-read_2.c
> new file mode 100644
> index 0000000000000000000000000000000000000000..541dce9303382e047c3931ad58a1cbd8b3e182fb
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/aarch64/shift-read_2.c
> @@ -0,0 +1,96 @@
> +/* { dg-do compile } */
> +/* { dg-additional-options "-O2" } */
> +/* { dg-final { check-function-bodies "**" "" "" { target { le } } } } */
> +
> +#include <arm_neon.h>
> +
> +/*
> +** foor_1:
> +** smov w0, v0.h\[3\]
> +** ret
> +*/
> +int32_t foor_1 (int32x4_t x)
> +{
> + return x[1] >> 16;
> +}
> +
> +/*
> +** foor_2:
> +** smov x0, v0.h\[3\]
> +** ret
> +*/
> +int64_t foor_2 (int32x4_t x)
> +{
> + return x[1] >> 16;
> +}
> +
> +
> +/*
> +** fool:
> +** [su]mov w0, v0.s\[1\]
> +** lsl w0, w0, 16
> +** ret
> +*/
> +int fool (int32x4_t x)
> +{
> + return x[1] << 16;
> +}
> +
> +/*
> +** foor2:
> +** umov w0, v0.h\[7\]
> +** ret
> +*/
> +short foor2 (int32x4_t x)
> +{
> + return x[3] >> 16;
> +}
> +
> +/*
> +** fool2:
> +** fmov w0, s0
> +** lsl w0, w0, 16
> +** ret
> +*/
> +int fool2 (int32x4_t x)
> +{
> + return x[0] << 16;
> +}
> +
> +typedef int v4si __attribute__ ((vector_size (16)));
> +
> +/*
> +** bar:
> +** addv s0, v0.4s
> +** fmov w0, s0
> +** lsr w1, w0, 16
> +** add w0, w1, w0, uxth
> +** ret
> +*/
> +int bar (v4si x)
> +{
> + unsigned int sum = vaddvq_s32 (x);
> + return (((uint16_t)(sum & 0xffff)) + ((uint32_t)sum >> 16));
> +}
> +
> +/*
> +** foo:
> +** lsr w0, w0, 16
> +** ret
> +*/
> +short foo (int x)
> +{
> + return x >> 16;
> +}
> +
> +/*
> +** foo2:
> +** ...
> +** umov w0, v[0-8]+.h\[1\]
> +** ret
> +*/
> +short foo2 (v4si x)
> +{
> + int y = x[0] + x[1];
> + return y >> 16;
> +}
> diff --git a/gcc/testsuite/gcc.target/aarch64/shift-read_3.c b/gcc/testsuite/gcc.target/aarch64/shift-read_3.c
> new file mode 100644
> index 0000000000000000000000000000000000000000..2ea81ff5b5af7794e062e471f46b433e1d7d87ee
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/aarch64/shift-read_3.c
> @@ -0,0 +1,60 @@
> +/* { dg-do compile } */
> +/* { dg-additional-options "-O2" } */
> +/* { dg-final { check-function-bodies "**" "" "" { target { le } } } } */
> +
> +#include <arm_neon.h>
> +
> +/*
> +** ufoo:
> +** ...
> +** umov w0, v0.h\[1\]
> +** ret
> +*/
> +uint64_t ufoo (uint32x4_t x)
> +{
> + return (x[0] + x[1]) >> 16;
> +}
> +
> +/*
> +** sfoo:
> +** ...
> +** smov x0, v0.h\[1\]
> +** ret
> +*/
> +int64_t sfoo (int32x4_t x)
> +{
> + return (x[0] + x[1]) >> 16;
> +}
> +
> +/*
> +** sfoo2:
> +** ...
> +** smov w0, v0.h\[1\]
> +** ret
> +*/
> +int32_t sfoo2 (int32x4_t x)
> +{
> + return (x[0] + x[1]) >> 16;
> +}
> +
> +/*
> +** ubar:
> +** ...
> +** umov w0, v0.b\[3\]
> +** ret
> +*/
> +uint64_t ubar (uint32x4_t x)
> +{
> + return (x[0] + x[1]) >> 24;
> +}
> +
> +/*
> +** sbar:
> +** ...
> +** smov x0, v0.b\[3\]
> +** ret
> +*/
> +int64_t sbar (int32x4_t x)
> +{
> + return (x[0] + x[1]) >> 24;
> +}
next prev parent reply other threads:[~2022-11-14 21:54 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-23 11:42 [PATCH 1/2]middle-end Fold BIT_FIELD_REF and Shifts into BIT_FIELD_REFs alone Tamar Christina
2022-09-23 11:43 ` [PATCH 2/2]AArch64 Perform more late folding of reg moves and shifts which arrive after expand Tamar Christina
2022-09-23 14:32 ` Richard Sandiford
2022-10-31 11:48 ` Tamar Christina
2022-11-14 21:54 ` Richard Sandiford [this message]
2022-11-14 21:59 ` Richard Sandiford
2022-12-01 16:25 ` Tamar Christina
2022-12-01 18:38 ` Richard Sandiford
2022-09-24 18:38 ` [PATCH 1/2]middle-end Fold BIT_FIELD_REF and Shifts into BIT_FIELD_REFs alone Jeff Law
2022-09-28 13:19 ` Tamar Christina
2022-09-28 17:25 ` Jeff Law
2022-09-24 18:57 ` Andrew Pinski
2022-09-26 4:55 ` Tamar Christina
2022-09-26 8:05 ` Richard Biener
2022-09-26 15:24 ` Andrew Pinski
2022-09-27 12:40 ` Richard Biener
2022-10-31 11:51 ` Tamar Christina
2022-10-31 16:24 ` Jeff Law
2022-11-07 13:29 ` Richard Biener
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=mpt35almcc5.fsf@arm.com \
--to=richard.sandiford@arm.com \
--cc=Kyrylo.Tkachov@arm.com \
--cc=Marcus.Shawcroft@arm.com \
--cc=Richard.Earnshaw@arm.com \
--cc=Tamar.Christina@arm.com \
--cc=gcc-patches@gcc.gnu.org \
--cc=nd@arm.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).