From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ed1-x534.google.com (mail-ed1-x534.google.com [IPv6:2a00:1450:4864:20::534]) by sourceware.org (Postfix) with ESMTPS id 9F321385781D for ; Tue, 25 May 2021 14:34:51 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 9F321385781D Received: by mail-ed1-x534.google.com with SMTP id i13so36505034edb.9 for ; Tue, 25 May 2021 07:34:51 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=Yftu3KP/FiZyrar3kKf7/XnInS1cfYCtF7Ates2YJR0=; b=VbMaKUSZ8XMzkc2Tcqbrnd1oAVuZ2+AUuXrNFeUQZwvjc/M3kMNu2qoH9/xm65bjZU yZXJuxcci6zi5yefWDeXYR5Bj0b3UuAMfgKxMBkxbW85M0Hl2pip8UHMAlBHzfPPFsue yUde0K0ogY48+RpAyWbgA1B65f8RPq0SLq2aIJPEl9UH/C0w3/PkTnLgg9hMaDQ2ko4E 7fDXWxr3/OYF+M9sHQUdG8rsBE1huWQpTU9H8bFx10PgFlVUnHBxQtwCtpg7WDasqkE+ 5+StxVzCdiv2c9M/sU11Osx9PGjwszUZHaIwKkRqmp3zCNgdh/n/3bWTK4Ee6mVjHHXw l3jQ== X-Gm-Message-State: AOAM532Rqh74YTeLHwcwviOT1EVpR9hi8h8pUFjMXYzgyDsu+BAFGXeN mEDxaN6ZRM4qexN7ycaRHc/2izKydrAMQkLAzqs= X-Google-Smtp-Source: ABdhPJz3qhVWycFhTbXZWbBMT04MJxRNGq3+OvORRSS29nCdQr3/k2mfPpKbrSMDyGwHI1Lirk28nOQfoGbXfOHGG7U= X-Received: by 2002:aa7:df90:: with SMTP id b16mr18294681edy.361.1621953290562; Tue, 25 May 2021 07:34:50 -0700 (PDT) MIME-Version: 1.0 References: <20210518191646.3071005-1-hjl.tools@gmail.com> <20210518191646.3071005-2-hjl.tools@gmail.com> In-Reply-To: From: Richard Biener Date: Tue, 25 May 2021 16:34:39 +0200 Message-ID: Subject: Re: [PATCH] Add 3 target hooks for memset To: "H.J. Lu" Cc: GCC Patches , Richard Sandiford , Uros Bizjak , Bernd Edlinger Content-Type: text/plain; charset="UTF-8" X-Spam-Status: No, score=-8.9 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, FREEMAIL_FROM, GIT_PATCH_0, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on server2.sourceware.org X-BeenThere: gcc-patches@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 25 May 2021 14:34:54 -0000 On Thu, May 20, 2021 at 10:50 PM H.J. Lu wrote: > > On Wed, May 19, 2021 at 5:55 AM H.J. Lu wrote: > > > > On Wed, May 19, 2021 at 2:25 AM Richard Biener > > wrote: > > > > > > On Tue, May 18, 2021 at 9:16 PM H.J. Lu wrote: > > > > > > > > Add TARGET_READ_MEMSET_VALUE and TARGET_GEN_MEMSET_VALUE to support > > > > target instructions to duplicate QImode value to TImode/OImode/XImode > > > > value for memmset. > > > > > > > > PR middle-end/90773 > > > > * builtins.c (builtin_memset_read_str): Call > > > > targetm.read_memset_value. > > > > (builtin_memset_gen_str): Call targetm.gen_memset_value. > > > > * target.def (read_memset_value): New hook. > > > > (gen_memset_value): Likewise. > > > > * targhooks.c: Inclue "builtins.h". > > > > (default_read_memset_value): New function. > > > > (default_gen_memset_value): Likewise. > > > > * targhooks.h (default_read_memset_value): New prototype. > > > > (default_gen_memset_value): Likewise. > > > > * doc/tm.texi.in: Add TARGET_READ_MEMSET_VALUE and > > > > TARGET_GEN_MEMSET_VALUE hooks. > > > > * doc/tm.texi: Regenerated. > > > > --- > > > > gcc/builtins.c | 47 ++++---------------------------------- > > > > gcc/doc/tm.texi | 16 +++++++++++++ > > > > gcc/doc/tm.texi.in | 4 ++++ > > > > gcc/target.def | 20 +++++++++++++++++ > > > > gcc/targhooks.c | 56 ++++++++++++++++++++++++++++++++++++++++++++++ > > > > gcc/targhooks.h | 4 ++++ > > > > 6 files changed, 104 insertions(+), 43 deletions(-) > > > > > > > > diff --git a/gcc/builtins.c b/gcc/builtins.c > > > > index e1b284846b1..f78a36478ef 100644 > > > > --- a/gcc/builtins.c > > > > +++ b/gcc/builtins.c > > > > @@ -6584,24 +6584,11 @@ expand_builtin_strncpy (tree exp, rtx target) > > > > previous iteration. */ > > > > > > > > rtx > > > > -builtin_memset_read_str (void *data, void *prevp, > > > > +builtin_memset_read_str (void *data, void *prev, > > > > HOST_WIDE_INT offset ATTRIBUTE_UNUSED, > > > > scalar_int_mode mode) > > > > { > > > > - by_pieces_prev *prev = (by_pieces_prev *) prevp; > > > > - if (prev != nullptr && prev->data != nullptr) > > > > - { > > > > - /* Use the previous data in the same mode. */ > > > > - if (prev->mode == mode) > > > > - return prev->data; > > > > - } > > > > - > > > > - const char *c = (const char *) data; > > > > - char *p = XALLOCAVEC (char, GET_MODE_SIZE (mode)); > > > > - > > > > - memset (p, *c, GET_MODE_SIZE (mode)); > > > > - > > > > - return c_readstr (p, mode); > > > > + return targetm.read_memset_value ((const char *) data, prev, mode); > > > > } > > > > > > > > /* Callback routine for store_by_pieces. Return the RTL of a register > > > > @@ -6611,37 +6598,11 @@ builtin_memset_read_str (void *data, void *prevp, > > > > nullptr, it has the RTL info from the previous iteration. */ > > > > > > > > static rtx > > > > -builtin_memset_gen_str (void *data, void *prevp, > > > > +builtin_memset_gen_str (void *data, void *prev, > > > > HOST_WIDE_INT offset ATTRIBUTE_UNUSED, > > > > scalar_int_mode mode) > > > > { > > > > - rtx target, coeff; > > > > - size_t size; > > > > - char *p; > > > > - > > > > - by_pieces_prev *prev = (by_pieces_prev *) prevp; > > > > - if (prev != nullptr && prev->data != nullptr) > > > > - { > > > > - /* Use the previous data in the same mode. */ > > > > - if (prev->mode == mode) > > > > - return prev->data; > > > > - > > > > - target = simplify_gen_subreg (mode, prev->data, prev->mode, 0); > > > > - if (target != nullptr) > > > > - return target; > > > > - } > > > > - > > > > - size = GET_MODE_SIZE (mode); > > > > - if (size == 1) > > > > - return (rtx) data; > > > > - > > > > - p = XALLOCAVEC (char, size); > > > > - memset (p, 1, size); > > > > - coeff = c_readstr (p, mode); > > > > - > > > > - target = convert_to_mode (mode, (rtx) data, 1); > > > > - target = expand_mult (mode, target, coeff, NULL_RTX, 1); > > > > - return force_reg (mode, target); > > > > + return targetm.gen_memset_value ((rtx) data, prev, mode); > > > > } > > > > > > > > /* Expand expression EXP, which is a call to the memset builtin. Return > > > > diff --git a/gcc/doc/tm.texi b/gcc/doc/tm.texi > > > > index 85ea9395560..51385044e76 100644 > > > > --- a/gcc/doc/tm.texi > > > > +++ b/gcc/doc/tm.texi > > > > @@ -11868,6 +11868,22 @@ This function prepares to emit a conditional comparison within a sequence > > > > @var{bit_code} is @code{AND} or @code{IOR}, which is the op on the compares. > > > > @end deftypefn > > > > > > > > +@deftypefn {Target Hook} rtx TARGET_READ_MEMSET_VALUE (const char *@var{c}, void *@var{prev}, scalar_int_mode @var{mode}) > > > > +This function returns the RTL of a constant integer corresponding to > > > > +target reading @code{GET_MODE_SIZE (@var{mode})} bytes from the stringn > > > > +constant @var{str}. If @var{prev} is not @samp{nullptr}, it contains > > > > +the RTL information from the previous interation. > > > > +@end deftypefn > > > > + > > > > +@deftypefn {Target Hook} rtx TARGET_GEN_MEMSET_VALUE (rtx @var{data}, void *@var{prev}, scalar_int_mode @var{mode}) > > > > +This function returns the RTL of a register containing > > > > +@code{GET_MODE_SIZE (@var{mode})} consecutive copies of the unsigned > > > > +char value given in the RTL register @var{data}. For example, if > > > > +@var{mode} is 4 bytes wide, return the RTL for 0x01010101*@var{data}. > > > > +If @var{PREV} is not @samp{nullptr}, it is the RTL information from > > > > +the previous iteration. > > > > +@end deftypefn > > > > + > > > > @deftypefn {Target Hook} unsigned TARGET_LOOP_UNROLL_ADJUST (unsigned @var{nunroll}, class loop *@var{loop}) > > > > This target hook returns a new value for the number of times @var{loop} > > > > should be unrolled. The parameter @var{nunroll} is the number of times > > > > diff --git a/gcc/doc/tm.texi.in b/gcc/doc/tm.texi.in > > > > index d8e3de14af1..8d4c3949fbf 100644 > > > > --- a/gcc/doc/tm.texi.in > > > > +++ b/gcc/doc/tm.texi.in > > > > @@ -7956,6 +7956,10 @@ lists. > > > > > > > > @hook TARGET_GEN_CCMP_NEXT > > > > > > > > +@hook TARGET_READ_MEMSET_VALUE > > > > + > > > > +@hook TARGET_GEN_MEMSET_VALUE > > > > + > > > > @hook TARGET_LOOP_UNROLL_ADJUST > > > > > > > > @defmac POWI_MAX_MULTS > > > > diff --git a/gcc/target.def b/gcc/target.def > > > > index bbaf6b4f3a0..c9aca40fa88 100644 > > > > --- a/gcc/target.def > > > > +++ b/gcc/target.def > > > > @@ -2694,6 +2694,26 @@ DEFHOOK > > > > rtx, (rtx_insn **prep_seq, rtx_insn **gen_seq, rtx prev, int cmp_code, tree op0, tree op1, int bit_code), > > > > NULL) > > > > > > > > +DEFHOOK > > > > +(read_memset_value, > > > > + "This function returns the RTL of a constant integer corresponding to\n\ > > > > +target reading @code{GET_MODE_SIZE (@var{mode})} bytes from the stringn\n\ > > > > +constant @var{str}. If @var{prev} is not @samp{nullptr}, it contains\n\ > > > > > > where is 'str' defined? I can't really tell what's the difference > > > > Fixed with > > > > diff --git a/gcc/target.def b/gcc/target.def > > index c9aca40fa88..4c3a5fcc634 100644 > > --- a/gcc/target.def > > +++ b/gcc/target.def > > @@ -2699,8 +2699,8 @@ DEFHOOK > > "This function returns the RTL of a constant integer corresponding to\n\ > > target reading @code{GET_MODE_SIZE (@var{mode})} bytes from the string\n\ > > constant @var{str}. If @var{prev} is not @samp{nullptr}, it contains\n\ > > -the RTL information from the previous interation.", > > - rtx, (const char *c, void *prev, scalar_int_mode mode), > > +the RTL information from the previous iteration.", > > + rtx, (const char *str, void *prev, scalar_int_mode mode), > > default_read_memset_value) > > > > DEFHOOK > > > > > from read_memset_value > > > and gen_memset_value. > > > > The difference is that input of read_memset_value is a string constant > > like "123" and input of gen_memset_value is an RTL register. > > > > > Somehow I feel that an optab for the "splat" operation similar > > > to vec_duplicate might be a better way to expose this - of course > > > that doesn't handle the "prev" thing. > > > > The x86 backend has ix86_expand_vector_init_duplicate () to > > broadcast QImode to TImode/OImode/XImode: > > > > /* A subroutine of ix86_expand_vector_init. Store into TARGET a vector > > with all elements equal to VAR. Return true if successful. */ > > > > bool > > ix86_expand_vector_init_duplicate (bool mmx_ok, machine_mode mode, > > rtx target, rtx val) > > > > > So how's this the right point of abstraction to the target? > > > > I can add 2 target hooks, one for scratch register and one for > > broadcasting QImode to TImode/OImode/XImode. Then I can > > move x86 codes to the middle-end. > > > > Here is the patch to add 3 target hooks: > > -- Target Hook: rtx TARGET_READ_MEMSET_VALUE (const char *C, > scalar_int_mode MODE) > This function returns the RTL of a constant integer corresponding > to target reading 'GET_MODE_SIZE (MODE)' bytes from the string > constant C. > > -- Target Hook: rtx TARGET_GEN_MEMSET_VALUE (rtx DATA, scalar_int_mode > MODE) > This function returns the RTL of a register containing > 'GET_MODE_SIZE (MODE)' consecutive copies of the unsigned char > value given in the RTL register DATA. For example, if MODE is 4 > bytes wide, return the RTL for 0x01010101*DATA. For this one I wonder if it should be an optab instead. Couldn't you use the existing vec_duplicate for this by using (paradoxical) subregs like (subreg:TI (vec_duplicate:VnQI (subreg:VnQI (reg:QI ...)))? Currently vec_duplicate is only used for SVE IIRC. > -- Target Hook: rtx TARGET_GEN_MEMSET_VALUE_FROM_PREV (void *PREV, > scalar_int_mode MODE) > This function returns the RTL of a register in MODE generated from > PREV in the previous iteration. > > with > > /* Return the RTL of a register in MODE generated from PREV in the > previous iteration. */ > > static rtx > gen_memset_value_from_prev (void *prevp, scalar_int_mode mode) > { > by_pieces_prev *prev = (by_pieces_prev *) prevp; > rtx value; > if (prev != nullptr && prev->data != nullptr) > { > /* Use the previous data in the same mode. */ > if (prev->mode == mode) > return prev->data; > > value = targetm.gen_memset_value_from_prev (prevp, mode); But why do we need a target hook here? Doesn't this just duplicate/subreg this further? > } > else > value = nullptr; > return value; > } > > /* Callback routine for store_by_pieces. Read GET_MODE_BITSIZE (MODE) > bytes from constant string DATA + OFFSET and return it as target > constant. If PREV isn't nullptr, it has the RTL info from the > previous iteration. */ > > rtx > builtin_memset_read_str (void *data, void *prev, > HOST_WIDE_INT offset ATTRIBUTE_UNUSED, > scalar_int_mode mode) > { > const char *str = (const char *) data; > > /* Don't use the previous value if size is 1. */ > if (GET_MODE_SIZE (mode) == 1) > return default_read_memset_value (str, mode); > > rtx value = gen_memset_value_from_prev (prev, mode); > if (value) > return value; > > return targetm.read_memset_value (str, mode); > } > > /* Callback routine for store_by_pieces. Return the RTL of a register > containing GET_MODE_SIZE (MODE) consecutive copies of the unsigned > char value given in the RTL register data. For example, if mode is > 4 bytes wide, return the RTL for 0x01010101*data. If PREV isn't > nullptr, it has the RTL info from the previous iteration. */ > > static rtx > builtin_memset_gen_str (void *datap, void *prev, > HOST_WIDE_INT offset ATTRIBUTE_UNUSED, > scalar_int_mode mode) > { > rtx data = (rtx) datap; > > /* Don't use the previous value if size is 1. */ > if (GET_MODE_SIZE (mode) == 1) > return data; > > rtx value = gen_memset_value_from_prev (prev, mode); > if (value) > return value; > > return targetm.gen_memset_value (data, mode); > } > > > -- > H.J.