From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lf1-x135.google.com (mail-lf1-x135.google.com [IPv6:2a00:1450:4864:20::135]) by sourceware.org (Postfix) with ESMTPS id 19B63382E521 for ; Tue, 15 Nov 2022 07:34:13 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 19B63382E521 Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=gmail.com Received: by mail-lf1-x135.google.com with SMTP id b3so23116438lfv.2 for ; Mon, 14 Nov 2022 23:34:13 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=esByPe6fV9CvHYqgkgSD305iKsRYnyiUpNu5uLGsKrc=; b=ZS3WJK9hvZ7TzV6BRlEczJ5m8SRr7qdOGpUfBQdXCyz3leejUTDSD4x6Mhe6b0AUGt nxqketQ7KrIMbis9TaHHGwJQdcZe+OeLdk8b36Qvt7p5kb/W/KSEL92pTdvjQc8ZV/u7 klTV9apsuw7VfUB6+LMXUW7wF5Xq7vpI+snyB2Ov41SjWCT0jnIpATVJ3mJOv1y2Sg1a FSvEM5xNtxgOTjNVzmRloM2NqPCcpVyNWeNkRhxphQS0B6Bo+mt4OcFFHBl3n72/R6OR +KR4IMC1L8/77nQePkLB7tal8CeamqlK3fNFCQRtBFPZGVp5unG9qHFAGMhsFlW/k5hL 28Ug== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=esByPe6fV9CvHYqgkgSD305iKsRYnyiUpNu5uLGsKrc=; b=1QuM6VwflZBSGWxgMonR3H0ilQLuMFqdgbXFouj8bat+VqEMYPAmUQkGgZdAqxbx9G 4s8A4fwQsbhtU5f93Tt00iVluaodDsDHc3PWXZFwrWnxnivpCOxPkulph+4+ikaBfp5+ VmwLllCrnx3lk1nNe+v3nJexOqB8mmG9R707eTjQmSDy+kUH9C0JSvBafmxAr/fG+u02 EZmo/7/xmiOcS47YUgCXWV0jkD1dDJwgLRfVa7KwkFJPermcLCU/k50XgriKztcGHKf6 Eadu1COQ8KpMIa7SWZOCCev0HyT8O4VbfxP7esIDi3dB8RuTWJj/GIhm5vdSx00EKUho aTYQ== X-Gm-Message-State: ANoB5pm887j0ht5ApOe8IBM62C+TwVNOWa7qj6WYozr2MayoBw8nkEFz yPVId6M7IS7PZuFL1Z01Smgg0bA0ZpXtjaR8sLE= X-Google-Smtp-Source: AA0mqf5UoZ7Qs9w32cLvBBe/2vvfCXRZE0NZ2L+IIjIEA+JeLgHyFX6sN7r8rp0iSAhs5q3sjSTvEZbKSVeRnopQ3RY= X-Received: by 2002:a05:6512:131c:b0:4b4:1177:a64c with SMTP id x28-20020a056512131c00b004b41177a64cmr5769782lfu.647.1668497651401; Mon, 14 Nov 2022 23:34:11 -0800 (PST) MIME-Version: 1.0 References: In-Reply-To: From: Richard Biener Date: Tue, 15 Nov 2022 08:33:59 +0100 Message-ID: Subject: Re: [PATCH 1/2]middle-end: Add new tbranch optab to add support for bit-test-and-branch operations To: Tamar Christina Cc: Richard Biener , Aldy Hernandez , Jeff Law , "gcc-patches@gcc.gnu.org" , nd , "MacLeod, Andrew" Content-Type: text/plain; charset="UTF-8" X-Spam-Status: No, score=-6.8 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_FROM,GIT_PATCH_0,KAM_LOTSOFHASH,RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS,TXREP autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: On Mon, Nov 14, 2022 at 4:57 PM Tamar Christina via Gcc-patches wrote: > > > -----Original Message----- > > From: Richard Biener > > Sent: Saturday, November 5, 2022 2:23 PM > > To: Aldy Hernandez > > Cc: Tamar Christina ; Jeff Law > > ; gcc-patches@gcc.gnu.org; nd ; > > MacLeod, Andrew > > Subject: Re: [PATCH 1/2]middle-end: Add new tbranch optab to add support > > for bit-test-and-branch operations > > > > On Wed, 2 Nov 2022, Aldy Hernandez wrote: > > > > > On Wed, Nov 2, 2022 at 10:55 AM Tamar Christina > > wrote: > > > > > > > > Hi Aldy, > > > > > > > > I'm trying to use Ranger to determine if a range of an expression is a > > single bit. > > > > > > > > If possible in case of a mask then also the position of the bit that's being > > checked by the mask (or the mask itself). > > > > > > Just instantiate a ranger, and ask for the range of an SSA name (or an > > > arbitrary tree expression) at a particular gimple statement (or an > > > edge): > > > > > > gimple_ranger ranger; > > > int_range_max r; > > > if (ranger.range_of_expr (r, , )) { > > > // do stuff with range "r" > > > if (r.singleton_p ()) { > > > wide_int num = r.lower_bound (); > > > // Check the bits in NUM, etc... > > > } > > > } > > > > > > You can see the full ranger API in gimple-range.h. > > > > > > Note that instantiating a new ranger is relatively lightweight, but > > > it's not free. So unless you're calling range_of_expr sporadically, > > > you probably want to have one instance for your pass. You can pass > > > around the gimple_ranger around your pass. Another way of doing this > > > is calling enable_rager() at pass start, and then doing: > > > > > > get_range_query (cfun)->range_of_expr (r, , )); > > > > > > gimple-loop-versioning.cc has an example of using enable_ranger / > > > disable_ranger. > > > > > > I am assuming you are interested in ranges for integers / pointers. > > > Otherwise (floats, etc) you'd have to use "Value_Range" instead of > > > int_range_max. I can give you examples on that if necessary. > > > > > > Let me know if that helps. > > It Did! I ended up going with Richi's suggestion, but the snippet was very helpful > for a different range based patch I'm trying a prototype for. > > Many thanks for the example! > > > > > I think you maybe just want get_nonzero_bits? > > Ah, looks like that uses range info as well. Thanks! > > Ok for master? > > Thanks, > Tamar > > gcc/ChangeLog: > > * dojump.cc (do_jump): Pass along value. > (do_jump_by_parts_greater_rtx): Likewise. > (do_jump_by_parts_zero_rtx): Likewise. > (do_jump_by_parts_equality_rtx): Likewise. > (do_compare_rtx_and_jump): Likewise. > (do_compare_and_jump): Likewise. > * dojump.h (do_compare_rtx_and_jump): New. > * optabs.cc (emit_cmp_and_jump_insn_1): Refactor to take optab to check. > (validate_test_and_branch): New. > (emit_cmp_and_jump_insns): Optiobally take a value, and when value is > supplied then check if it's suitable for tbranch. > * optabs.def (tbranch$a4): New. > * doc/md.texi (tbranch@var{mode}4): Document it. > * optabs.h (emit_cmp_and_jump_insns): > * tree.h (tree_zero_one_valued_p): New. > > --- inline copy of patch --- > diff --git a/gcc/doc/md.texi b/gcc/doc/md.texi > index 34825549ed4e315b07d36dc3d63bae0cc0a3932d..342e8c4c670de251a35689d1805acceb72a8f6bf 100644 > --- a/gcc/doc/md.texi > +++ b/gcc/doc/md.texi > @@ -6958,6 +6958,13 @@ case, you can and should make operand 1's predicate reject some operators > in the @samp{cstore@var{mode}4} pattern, or remove the pattern altogether > from the machine description. > > +@cindex @code{tbranch@var{mode}4} instruction pattern > +@item @samp{tbranch@var{mode}4} > +Conditional branch instruction combined with a bit test-and-compare > +instruction. Operand 0 is a comparison operator. Operand 1 is the > +operand of the comparison. Operand 2 is the bit position of Operand 1 to test. > +Operand 3 is the @code{code_label} to jump to. > + > @cindex @code{cbranch@var{mode}4} instruction pattern > @item @samp{cbranch@var{mode}4} > Conditional branch instruction combined with a compare instruction. > diff --git a/gcc/dojump.h b/gcc/dojump.h > index e379cceb34bb1765cb575636e4c05b61501fc2cf..d1d79c490c420a805fe48d58740a79c1f25fb839 100644 > --- a/gcc/dojump.h > +++ b/gcc/dojump.h > @@ -71,6 +71,10 @@ extern void jumpifnot (tree exp, rtx_code_label *label, > extern void jumpifnot_1 (enum tree_code, tree, tree, rtx_code_label *, > profile_probability); > > +extern void do_compare_rtx_and_jump (rtx, rtx, enum rtx_code, int, tree, > + machine_mode, rtx, rtx_code_label *, > + rtx_code_label *, profile_probability); > + > extern void do_compare_rtx_and_jump (rtx, rtx, enum rtx_code, int, > machine_mode, rtx, rtx_code_label *, > rtx_code_label *, profile_probability); > diff --git a/gcc/dojump.cc b/gcc/dojump.cc > index 2af0cd1aca3b6af13d5d8799094ee93f18022296..190324f36f1a31990f8c49bc8c0f45c23da5c31e 100644 > --- a/gcc/dojump.cc > +++ b/gcc/dojump.cc > @@ -619,7 +619,7 @@ do_jump (tree exp, rtx_code_label *if_false_label, > } > do_compare_rtx_and_jump (temp, CONST0_RTX (GET_MODE (temp)), > NE, TYPE_UNSIGNED (TREE_TYPE (exp)), > - GET_MODE (temp), NULL_RTX, > + exp, GET_MODE (temp), NULL_RTX, > if_false_label, if_true_label, prob); > } > > @@ -687,7 +687,7 @@ do_jump_by_parts_greater_rtx (scalar_int_mode mode, int unsignedp, rtx op0, > > /* All but high-order word must be compared as unsigned. */ > do_compare_rtx_and_jump (op0_word, op1_word, code, (unsignedp || i > 0), > - word_mode, NULL_RTX, NULL, if_true_label, > + NULL, word_mode, NULL_RTX, NULL, if_true_label, > prob); > > /* Emit only one comparison for 0. Do not emit the last cond jump. */ > @@ -695,8 +695,8 @@ do_jump_by_parts_greater_rtx (scalar_int_mode mode, int unsignedp, rtx op0, > break; > > /* Consider lower words only if these are equal. */ > - do_compare_rtx_and_jump (op0_word, op1_word, NE, unsignedp, word_mode, > - NULL_RTX, NULL, if_false_label, > + do_compare_rtx_and_jump (op0_word, op1_word, NE, unsignedp, NULL, > + word_mode, NULL_RTX, NULL, if_false_label, > prob.invert ()); > } > > @@ -755,7 +755,7 @@ do_jump_by_parts_zero_rtx (scalar_int_mode mode, rtx op0, > > if (part != 0) > { > - do_compare_rtx_and_jump (part, const0_rtx, EQ, 1, word_mode, > + do_compare_rtx_and_jump (part, const0_rtx, EQ, 1, NULL, word_mode, > NULL_RTX, if_false_label, if_true_label, prob); > return; > } > @@ -766,7 +766,7 @@ do_jump_by_parts_zero_rtx (scalar_int_mode mode, rtx op0, > > for (i = 0; i < nwords; i++) > do_compare_rtx_and_jump (operand_subword_force (op0, i, mode), > - const0_rtx, EQ, 1, word_mode, NULL_RTX, > + const0_rtx, EQ, 1, NULL, word_mode, NULL_RTX, > if_false_label, NULL, prob); > > if (if_true_label) > @@ -809,8 +809,8 @@ do_jump_by_parts_equality_rtx (scalar_int_mode mode, rtx op0, rtx op1, > > for (i = 0; i < nwords; i++) > do_compare_rtx_and_jump (operand_subword_force (op0, i, mode), > - operand_subword_force (op1, i, mode), > - EQ, 0, word_mode, NULL_RTX, > + operand_subword_force (op1, i, mode), > + EQ, 0, NULL, word_mode, NULL_RTX, > if_false_label, NULL, prob); > > if (if_true_label) > @@ -962,6 +962,23 @@ do_compare_rtx_and_jump (rtx op0, rtx op1, enum rtx_code code, int unsignedp, > rtx_code_label *if_false_label, > rtx_code_label *if_true_label, > profile_probability prob) > +{ > + do_compare_rtx_and_jump (op0, op1, code, unsignedp, NULL, mode, size, > + if_false_label, if_true_label, prob); > +} > + > +/* Like do_compare_and_jump but expects the values to compare as two rtx's. > + The decision as to signed or unsigned comparison must be made by the caller. > + > + If MODE is BLKmode, SIZE is an RTX giving the size of the objects being > + compared. */ > + > +void > +do_compare_rtx_and_jump (rtx op0, rtx op1, enum rtx_code code, int unsignedp, > + tree val, machine_mode mode, rtx size, > + rtx_code_label *if_false_label, > + rtx_code_label *if_true_label, > + profile_probability prob) > { > rtx tem; > rtx_code_label *dummy_label = NULL; > @@ -1177,8 +1194,10 @@ do_compare_rtx_and_jump (rtx op0, rtx op1, enum rtx_code code, int unsignedp, > } > else > dest_label = if_false_label; > - do_compare_rtx_and_jump (op0, op1, first_code, unsignedp, mode, > - size, dest_label, NULL, first_prob); > + > + do_compare_rtx_and_jump (op0, op1, first_code, unsignedp, > + val, mode, size, dest_label, NULL, > + first_prob); > } > /* For !and_them we want to split: > if (x) goto t; // prob; > @@ -1192,8 +1211,9 @@ do_compare_rtx_and_jump (rtx op0, rtx op1, enum rtx_code code, int unsignedp, > else > { > profile_probability first_prob = prob.split (cprob); > - do_compare_rtx_and_jump (op0, op1, first_code, unsignedp, mode, > - size, NULL, if_true_label, first_prob); > + do_compare_rtx_and_jump (op0, op1, first_code, unsignedp, > + val, mode, size, NULL, > + if_true_label, first_prob); > if (orig_code == NE && can_compare_p (UNEQ, mode, ccp_jump)) > { > /* x != y can be split into x unord y || x ltgt y > @@ -1215,7 +1235,7 @@ do_compare_rtx_and_jump (rtx op0, rtx op1, enum rtx_code code, int unsignedp, > } > } > > - emit_cmp_and_jump_insns (op0, op1, code, size, mode, unsignedp, > + emit_cmp_and_jump_insns (op0, op1, code, size, mode, unsignedp, val, > if_true_label, prob); > } > > @@ -1289,9 +1309,9 @@ do_compare_and_jump (tree treeop0, tree treeop1, enum rtx_code signed_code, > op1 = new_op1; > } > > - do_compare_rtx_and_jump (op0, op1, code, unsignedp, mode, > - ((mode == BLKmode) > - ? expr_size (treeop0) : NULL_RTX), > + do_compare_rtx_and_jump (op0, op1, code, unsignedp, treeop0, mode, > + ((mode == BLKmode) > + ? expr_size (treeop0) : NULL_RTX), > if_false_label, if_true_label, prob); > } > > diff --git a/gcc/optabs.cc b/gcc/optabs.cc > index f338df410265dfe55b6896160090a453cc6a28d9..0f662ebdb818d7538bdd13fb02bcf8bcf1dbab64 100644 > --- a/gcc/optabs.cc > +++ b/gcc/optabs.cc > @@ -46,6 +46,8 @@ along with GCC; see the file COPYING3. If not see > #include "libfuncs.h" > #include "internal-fn.h" > #include "langhooks.h" > +#include "gimple.h" > +#include "ssa.h" > > static void prepare_float_lib_cmp (rtx, rtx, enum rtx_code, rtx *, > machine_mode *); > @@ -4620,7 +4622,7 @@ prepare_operand (enum insn_code icode, rtx x, int opnum, machine_mode mode, > > static void > emit_cmp_and_jump_insn_1 (rtx test, machine_mode mode, rtx label, > - profile_probability prob) > + direct_optab cmp_optab, profile_probability prob) > { > machine_mode optab_mode; > enum mode_class mclass; > @@ -4629,7 +4631,7 @@ emit_cmp_and_jump_insn_1 (rtx test, machine_mode mode, rtx label, > > mclass = GET_MODE_CLASS (mode); > optab_mode = (mclass == MODE_CC) ? CCmode : mode; > - icode = optab_handler (cbranch_optab, optab_mode); > + icode = optab_handler (cmp_optab, optab_mode); > > gcc_assert (icode != CODE_FOR_nothing); > gcc_assert (insn_operand_matches (icode, 0, test)); > @@ -4644,6 +4646,56 @@ emit_cmp_and_jump_insn_1 (rtx test, machine_mode mode, rtx label, > add_reg_br_prob_note (insn, prob); > } > > +/* Check to see if the supplied comparison in PTEST can be performed as a > + bit-test-and-branch instead. VAL must contain the original tree > + expression of the non-zero operand which will be used to rewrite the > + comparison in PTEST. > + > + Returns TRUE if operation succeeds and returns updated PMODE and PTEST, > + else FALSE. */ > + > +enum insn_code > +static validate_test_and_branch (tree val, rtx *ptest, machine_mode *pmode) > +{ > + if (!val || TREE_CODE (val) != SSA_NAME) > + return CODE_FOR_nothing; > + > + machine_mode mode = TYPE_MODE (TREE_TYPE (val)); > + rtx test = *ptest; > + > + if (GET_CODE (test) != EQ && GET_CODE (test) != NE) > + return CODE_FOR_nothing; > + > + /* If the target supports the testbit comparison directly, great. */ > + auto icode = direct_optab_handler (tbranch_optab, mode); > + if (icode == CODE_FOR_nothing) > + return icode; > + > + if (tree_zero_one_valued_p (val)) > + { > + auto pos = BYTES_BIG_ENDIAN ? GET_MODE_BITSIZE (mode) - 1 : 0; Does this work for BYTES_BIG_ENDIAN && !WORDS_BIG_ENDIAN and mode > word_mode? > + XEXP (test, 1) = gen_int_mode (pos, mode); > + *ptest = test; > + *pmode = mode; > + return icode; > + } > + > + wide_int wcst = get_nonzero_bits (val); > + if (wcst == -1) > + return CODE_FOR_nothing; > + > + int bitpos; > + > + if ((bitpos = wi::exact_log2 (wcst)) == -1) > + return CODE_FOR_nothing; > + > + auto pos = BYTES_BIG_ENDIAN ? GET_MODE_BITSIZE (mode) - 1 - bitpos : bitpos; > + XEXP (test, 1) = gen_int_mode (pos, mode); > + *ptest = test; > + *pmode = mode; > + return icode; > +} > + > /* Generate code to compare X with Y so that the condition codes are > set and to jump to LABEL if the condition is true. If X is a > constant and Y is not a constant, then the comparison is swapped to > @@ -4661,11 +4713,13 @@ emit_cmp_and_jump_insn_1 (rtx test, machine_mode mode, rtx label, > It will be potentially converted into an unsigned variant based on > UNSIGNEDP to select a proper jump instruction. > > - PROB is the probability of jumping to LABEL. */ > + PROB is the probability of jumping to LABEL. If the comparison is against > + zero then VAL contains the expression from which the non-zero RTL is > + derived. */ > > void > emit_cmp_and_jump_insns (rtx x, rtx y, enum rtx_code comparison, rtx size, > - machine_mode mode, int unsignedp, rtx label, > + machine_mode mode, int unsignedp, tree val, rtx label, > profile_probability prob) > { > rtx op0 = x, op1 = y; > @@ -4690,10 +4744,32 @@ emit_cmp_and_jump_insns (rtx x, rtx y, enum rtx_code comparison, rtx size, > > prepare_cmp_insn (op0, op1, comparison, size, unsignedp, OPTAB_LIB_WIDEN, > &test, &mode); > - emit_cmp_and_jump_insn_1 (test, mode, label, prob); > + > + /* Check if we're comparing a truth type with 0, and if so check if > + the target supports tbranch. */ > + machine_mode tmode = mode; > + if (op1 == CONST0_RTX (GET_MODE (op1)) > + && validate_test_and_branch (val, &test, &tmode) != CODE_FOR_nothing) > + { > + emit_cmp_and_jump_insn_1 (test, tmode, label, tbranch_optab, prob); > + return; > + } > + > + emit_cmp_and_jump_insn_1 (test, mode, label, cbranch_optab, prob); > } > > - > > +/* Overloaded version of emit_cmp_and_jump_insns in which VAL is unknown. */ > + > +void > +emit_cmp_and_jump_insns (rtx x, rtx y, enum rtx_code comparison, rtx size, > + machine_mode mode, int unsignedp, rtx label, > + profile_probability prob) > +{ > + emit_cmp_and_jump_insns (x, y, comparison, size, mode, unsignedp, NULL, > + label, prob); > +} > + > + > /* Emit a library call comparison between floating point X and Y. > COMPARISON is the rtl operator to compare with (EQ, NE, GT, etc.). */ > > diff --git a/gcc/optabs.def b/gcc/optabs.def > index a6db2342bed6baf13ecbd84112c8432c6972e6fe..56e37d67231e1ba74ad6c5b81d74a65f315e26e2 100644 > --- a/gcc/optabs.def > +++ b/gcc/optabs.def > @@ -220,6 +220,7 @@ OPTAB_D (reload_in_optab, "reload_in$a") > OPTAB_D (reload_out_optab, "reload_out$a") > > OPTAB_DC(cbranch_optab, "cbranch$a4", COMPARE) > +OPTAB_D (tbranch_optab, "tbranch$a4") > OPTAB_D (addcc_optab, "add$acc") > OPTAB_D (negcc_optab, "neg$acc") > OPTAB_D (notcc_optab, "not$acc") > diff --git a/gcc/optabs.h b/gcc/optabs.h > index cfd7c742d2d21b0539f5227c22a94f32c793d6f7..cd55604bc3d452d7e28c5530bb4793d481766f4f 100644 > --- a/gcc/optabs.h > +++ b/gcc/optabs.h > @@ -268,6 +268,10 @@ extern void emit_cmp_and_jump_insns (rtx, rtx, enum rtx_code, rtx, > machine_mode, int, rtx, > profile_probability prob > = profile_probability::uninitialized ()); > +extern void emit_cmp_and_jump_insns (rtx, rtx, enum rtx_code, rtx, > + machine_mode, int, tree, rtx, > + profile_probability prob > + = profile_probability::uninitialized ()); > > /* Generate code to indirectly jump to a location given in the rtx LOC. */ > extern void emit_indirect_jump (rtx); > diff --git a/gcc/tree.h b/gcc/tree.h > index e6564aaccb7b69cd938ff60b6121aec41b7e8a59..f455008ceb8d91e7e073c0ad6d93dcaed65deccf 100644 > --- a/gcc/tree.h > +++ b/gcc/tree.h > @@ -4690,6 +4690,7 @@ extern tree signed_or_unsigned_type_for (int, tree); > extern tree signed_type_for (tree); > extern tree unsigned_type_for (tree); > extern bool is_truth_type_for (tree, tree); > +extern bool tree_zero_one_valued_p (tree); > extern tree truth_type_for (tree); > extern tree build_pointer_type_for_mode (tree, machine_mode, bool); > extern tree build_pointer_type (tree);