From patchwork Wed Oct 23 05:38:22 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "xuli1@eswincomputing.com" X-Patchwork-Id: 99357 Return-Path: X-Original-To: patchwork@sourceware.org Delivered-To: patchwork@sourceware.org Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id A33DF3858D33 for ; Wed, 23 Oct 2024 05:38:59 +0000 (GMT) X-Original-To: gcc-patches@gcc.gnu.org Delivered-To: gcc-patches@gcc.gnu.org Received: from zg8tmja2lje4os43os4xodqa.icoremail.net (zg8tmja2lje4os43os4xodqa.icoremail.net [206.189.79.184]) by sourceware.org (Postfix) with ESMTP id 6E2653858D28 for ; Wed, 23 Oct 2024 05:38:29 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 6E2653858D28 Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=eswincomputing.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=eswincomputing.com ARC-Filter: OpenARC Filter v1.0.0 sourceware.org 6E2653858D28 Authentication-Results: server2.sourceware.org; arc=none smtp.remote-ip=206.189.79.184 ARC-Seal: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1729661912; cv=none; b=hyjMpv0b/HuMRctWVbtsPIt+4YswCL3Odq55MJk1dpO2mVih22ljmcXx2/3uDGEOna7kn72HAbH0WdLTCx03PU8/3TBan49Iok5ue4UV2Cyf7kCCc7/QwgFsBjymcX2HX/phqnEXBeSh9sHjSNveC9DeOZilHWqZoQATCuck698= ARC-Message-Signature: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1729661912; c=relaxed/simple; bh=RTSVORa8spzsAjk7ZOJ3seDkDR1xKzHh3PHu5KTpcrE=; h=From:To:Subject:Date:Message-Id; b=AqqUg0qo+6mkOlCzqTFskyosgjukLXXpgp/na+azkeeZqkcbDaY1D/2pOZW2MHBmB0XE2t2cbSUd7QuR3b3S3eZclmjGFY0JLOHTUl43nI05FwacK2NuIJWJ55cFdVQ9CZG0rEneRxONyiBnf2T5i76YD7KNCsKP/Sti0USjr8E= ARC-Authentication-Results: i=1; server2.sourceware.org Received: from host014-ubuntu-1804.lxd (unknown [10.12.130.31]) by app2 (Coremail) with SMTP id TQJkCgCXWuTQixhnWvAPAA--.8395S4; Wed, 23 Oct 2024 13:38:25 +0800 (CST) From: Li Xu To: gcc-patches@gcc.gnu.org Cc: kito.cheng@gmail.com, richard.guenther@gmail.com, Tamar.Christina@arm.com, juzhe.zhong@rivai.ai, pan2.li@intel.com, jeffreyalaw@gmail.com, rdapp.gcc@gmail.com, xuli Subject: [PATCH 1/2] Match: Simplify unsigned scalar sat_sub(x -1) to (x - x != 0) Date: Wed, 23 Oct 2024 05:38:22 +0000 Message-Id: <20241023053823.14653-1-xuli1@eswincomputing.com> X-Mailer: git-send-email 2.17.1 X-CM-TRANSID: TQJkCgCXWuTQixhnWvAPAA--.8395S4 X-Coremail-Antispam: 1UD129KBjvJXoW7Kw1fJw43AFW5urW8GF43Awb_yoW5JF1xp3 y0qa4Yg34xtF1xGrs3Aay3Za13K3Zakr1UXrW3Ww1jkasay3s7KFyak3y5Cr4xGayru3Wx ZFsrKw109a15J37anT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUkI14x267AKxVW8JVW5JwAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2ocxC64kIII0Yj41l84x0c7CEw4AK67xGY2AK02 1l84ACjcxK6xIIjxv20xvE14v26w1j6s0DM28EF7xvwVC0I7IYx2IY6xkF7I0E14v26r4U JVWxJr1l84ACjcxK6I8E87Iv67AKxVW0oVCq3wA2z4x0Y4vEx4A2jsIEc7CjxVAFwI0_Gc CE3s1le2I262IYc4CY6c8Ij28IcVAaY2xG8wAqx4xG64xvF2IEw4CE5I8CrVC2j2WlYx0E 2Ix0cI8IcVAFwI0_Jr0_Jr4lYx0Ex4A2jsIE14v26r1j6r4UMcvjeVCFs4IE7xkEbVWUJV W8JwACjcxG0xvY0x0EwIxGrwACjI8F5VA0II8E6IAqYI8I648v4I1lc2xSY4AK6svPMxAI w28IcxkI7VAKI48JMxC20s026xCaFVCjc4AY6r1j6r4UMI8I3I0E5I8CrVAFwI0_Jr0_Jr 4lx2IqxVCjr7xvwVAFwI0_JrI_JrWlx4CE17CEb7AF67AKxVWUtVW8ZwCIc40Y0x0EwIxG rwCI42IY6xIIjxv20xvE14v26r1j6r1xMIIF0xvE2Ix0cI8IcVCY1x0267AKxVWUJVW8Jw CI42IY6xAIw20EY4v20xvaj40_Jr0_JF4lIxAIcVC2z280aVAFwI0_Jr0_Gr1lIxAIcVC2 z280aVCY1x0267AKxVW8JVW8JrUvcSsGvfC2KfnxnUUI43ZEXa7VUbXdbUUUUUU== X-CM-SenderInfo: 50xoxi46hv4xpqfrz1xxwl0woofrz/ X-Spam-Status: No, score=-12.2 required=5.0 tests=BAYES_00, GIT_PATCH_0, KAM_DMARC_STATUS, 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 X-BeenThere: gcc-patches@gcc.gnu.org X-Mailman-Version: 2.1.30 Precedence: list List-Id: Gcc-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: gcc-patches-bounces~patchwork=sourceware.org@gcc.gnu.org From: xuli When the imm operand op1=1 in the unsigned scalar sat_sub form2 below, we can simplify (x != 0 ? x + max : 0) to (x - x != 0), thereby eliminating a branch instruction. Form2: T __attribute__((noinline)) \ sat_u_sub_imm##IMM##_##T##_fmt_2 (T x) \ { \ return x >= (T)IMM ? x - (T)IMM : 0; \ } Take below form 2 as example: DEF_SAT_U_SUB_IMM_FMT_2(uint8_t, 1) Before this patch: __attribute__((noinline)) uint8_t sat_u_sub_imm1_uint8_t_fmt_2 (uint8_t x) { uint8_t _1; uint8_t _3; [local count: 1073741824]: if (x_2(D) != 0) goto ; [50.00%] else goto ; [50.00%] [local count: 536870912]: _3 = x_2(D) + 255; [local count: 1073741824]: # _1 = PHI return _1; } Assembly code: sat_u_sub_imm1_uint8_t_fmt_2: beq a0,zero,.L2 addiw a0,a0,-1 andi a0,a0,0xff .L2: ret After this patch: __attribute__((noinline)) uint8_t sat_u_sub_imm1_uint8_t_fmt_2 (uint8_t x) { _Bool _1; unsigned char _2; uint8_t _4; [local count: 1073741824]: _1 = x_3(D) != 0; _2 = (unsigned char) _1; _4 = x_3(D) - _2; return _4; } Assembly code: sat_u_sub_imm1_uint8_t_fmt_2: snez a5,a0 subw a0,a0,a5 andi a0,a0,0xff ret The below test suites are passed for this patch: 1. The rv64gcv fully regression tests. 2. The x86 bootstrap tests. 3. The x86 fully regression tests. Signed-off-by: Li Xu gcc/ChangeLog: * match.pd: Simplify (x != 0 ? x + max : 0) to (x - x != 0). --- gcc/match.pd | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/gcc/match.pd b/gcc/match.pd index 0455dfa6993..9dcb9555cc0 100644 --- a/gcc/match.pd +++ b/gcc/match.pd @@ -3383,6 +3383,22 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT) } (if (wi::eq_p (sum, wi::uhwi (0, precision))))))) +/* The boundary condition for case 10: IMM = 1: + SAT_U_SUB = X >= IMM ? (X - IMM) : 0. + simplify (X != 0 ? X + max : 0) to (X - X != 0). */ +(simplify + (cond (ne @0 integer_zerop) (plus @0 INTEGER_CST@1) integer_zerop) + (if (INTEGRAL_TYPE_P (type) && TYPE_UNSIGNED (type) + && types_match (type, @0)) + (with + { + unsigned precision = TYPE_PRECISION (type); + wide_int max = wi::mask (precision, false, precision); + wide_int c1 = wi::to_wide (@1); + } + (if (wi::eq_p (c1, max)) + (minus @0 (convert (ne @0 { build_zero_cst (type); }))))))) + /* Signed saturation sub, case 1: T minus = (T)((UT)X - (UT)Y); SAT_S_SUB = (X ^ Y) & (X ^ minus) < 0 ? (-(T)(X < 0) ^ MAX) : minus;