From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 5B163C6379F for ; Wed, 8 Feb 2023 22:53:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=JVbVmWeaicideOdpe+Kbuf7uk7ZKR6KhfS51W0tQsyY=; b=dWl+MuSouxsbS9 HGs2NTSoIXlaPHRhdI9d5lGuLBdJ4slqqX6JFiChQ1oSOMO9SLbFUetRCIS5mBkLNzyftrlkYkmue mSfQrJZX4fYpg6J4JWwHEn51Wo28zYJ3gKK7QW3QprDxzKbfv1Ywi6h30GNTgSY0PECsYZ665ovbe 9isGWbC6qXJ4pRsZPatYX1WLQM5vr6iqowXIJYKBVH6rt3H9WIlOV95g75EcNHNbK0i89YA+gmI6h t99k2i9rX4dB/bkS12hLTe3NZF7ZAJAfAO1tvb3boTjYE70lWpVc56M/t/e2iC40TFD4pkV5tUHwh 9sp4x24irB3CGHOp6imw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1pPtJy-00H7t5-RO; Wed, 08 Feb 2023 22:53:46 +0000 Received: from gloria.sntech.de ([185.11.138.130]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1pPtJt-00H7qB-CR for linux-riscv@lists.infradead.org; Wed, 08 Feb 2023 22:53:43 +0000 Received: from ip5b412258.dynamic.kabel-deutschland.de ([91.65.34.88] helo=phil.lan) by gloria.sntech.de with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1pPtJi-0003OP-Vu; Wed, 08 Feb 2023 23:53:31 +0100 From: Heiko Stuebner To: palmer@rivosinc.com Cc: conor@kernel.org, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org, christoph.muellner@vrull.eu, ajones@ventanamicro.com, Heiko Stuebner Subject: [PATCH 2/2] RISC-V: improve string-function assembly Date: Wed, 8 Feb 2023 23:53:28 +0100 Message-Id: <20230208225328.1636017-3-heiko@sntech.de> X-Mailer: git-send-email 2.39.0 In-Reply-To: <20230208225328.1636017-1-heiko@sntech.de> References: <20230208225328.1636017-1-heiko@sntech.de> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230208_145341_446405_48662B8B X-CRM114-Status: GOOD ( 14.13 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org From: Heiko Stuebner Adapt the suggestions for the assembly string functions that Andrew suggested but that I didn't manage to include into the series that got applied. This includes improvements to two comments, removal of unneeded labels and moving one instruction slightly higher to contradict an explanatory comment. Suggested-by: Andrew Jones Signed-off-by: Heiko Stuebner --- arch/riscv/lib/strcmp.S | 6 ++++-- arch/riscv/lib/strlen.S | 10 +++++----- arch/riscv/lib/strncmp.S | 16 +++++++--------- 3 files changed, 16 insertions(+), 16 deletions(-) diff --git a/arch/riscv/lib/strcmp.S b/arch/riscv/lib/strcmp.S index 8148b6418f61..fb186bf28f07 100644 --- a/arch/riscv/lib/strcmp.S +++ b/arch/riscv/lib/strcmp.S @@ -40,7 +40,9 @@ SYM_FUNC_START(strcmp) ret /* - * Variant of strcmp using the ZBB extension if available + * Variant of strcmp using the ZBB extension if available. + * The code was published as part of the bitmanip manual + * in Appendix A. */ #ifdef CONFIG_RISCV_ISA_ZBB strcmp_zbb: @@ -57,7 +59,7 @@ strcmp_zbb: * a1 - string2 * * Clobbers - * t0, t1, t2, t3, t4, t5 + * t0, t1, t2, t3, t4 */ or t2, a0, a1 diff --git a/arch/riscv/lib/strlen.S b/arch/riscv/lib/strlen.S index 0f9dbf93301a..898466f67000 100644 --- a/arch/riscv/lib/strlen.S +++ b/arch/riscv/lib/strlen.S @@ -96,7 +96,7 @@ strlen_zbb: * of valid bytes in this chunk. */ srli a0, t1, 3 - bgtu t3, a0, 3f + bgtu t3, a0, 2f /* Prepare for the word comparison loop. */ addi t2, t0, SZREG @@ -112,20 +112,20 @@ strlen_zbb: addi t0, t0, SZREG orc.b t1, t1 beq t1, t3, 1b -2: + not t1, t1 CZ t1, t1 + srli t1, t1, 3 - /* Get number of processed words. */ + /* Get number of processed bytes. */ sub t2, t0, t2 /* Add number of characters in the first word. */ add a0, a0, t2 - srli t1, t1, 3 /* Add number of characters in the last word. */ add a0, a0, t1 -3: +2: ret .option pop diff --git a/arch/riscv/lib/strncmp.S b/arch/riscv/lib/strncmp.S index 7940ddab2d48..e36f5a6e1b16 100644 --- a/arch/riscv/lib/strncmp.S +++ b/arch/riscv/lib/strncmp.S @@ -70,7 +70,7 @@ strncmp_zbb: li t5, -1 and t2, t2, SZREG-1 add t4, a0, a2 - bnez t2, 4f + bnez t2, 3f /* Adjust limit for fast-path. */ andi t6, t4, -SZREG @@ -114,23 +114,21 @@ strncmp_zbb: ret /* Simple loop for misaligned strings. */ -3: - /* Restore limit for slow-path. */ .p2align 3 -4: - bge a0, t4, 6f +3: + bge a0, t4, 5f lbu t0, 0(a0) lbu t1, 0(a1) addi a0, a0, 1 addi a1, a1, 1 - bne t0, t1, 5f - bnez t0, 4b + bne t0, t1, 4f + bnez t0, 3b -5: +4: sub a0, t0, t1 ret -6: +5: li a0, 0 ret -- 2.39.0 _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 67B92C636D3 for ; Wed, 8 Feb 2023 22:53:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232505AbjBHWxi (ORCPT ); Wed, 8 Feb 2023 17:53:38 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55492 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232355AbjBHWxg (ORCPT ); Wed, 8 Feb 2023 17:53:36 -0500 Received: from gloria.sntech.de (gloria.sntech.de [185.11.138.130]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5D06525282 for ; Wed, 8 Feb 2023 14:53:33 -0800 (PST) Received: from ip5b412258.dynamic.kabel-deutschland.de ([91.65.34.88] helo=phil.lan) by gloria.sntech.de with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1pPtJi-0003OP-Vu; Wed, 08 Feb 2023 23:53:31 +0100 From: Heiko Stuebner To: palmer@rivosinc.com Cc: conor@kernel.org, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org, christoph.muellner@vrull.eu, ajones@ventanamicro.com, Heiko Stuebner Subject: [PATCH 2/2] RISC-V: improve string-function assembly Date: Wed, 8 Feb 2023 23:53:28 +0100 Message-Id: <20230208225328.1636017-3-heiko@sntech.de> X-Mailer: git-send-email 2.39.0 In-Reply-To: <20230208225328.1636017-1-heiko@sntech.de> References: <20230208225328.1636017-1-heiko@sntech.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Heiko Stuebner Adapt the suggestions for the assembly string functions that Andrew suggested but that I didn't manage to include into the series that got applied. This includes improvements to two comments, removal of unneeded labels and moving one instruction slightly higher to contradict an explanatory comment. Suggested-by: Andrew Jones Signed-off-by: Heiko Stuebner --- arch/riscv/lib/strcmp.S | 6 ++++-- arch/riscv/lib/strlen.S | 10 +++++----- arch/riscv/lib/strncmp.S | 16 +++++++--------- 3 files changed, 16 insertions(+), 16 deletions(-) diff --git a/arch/riscv/lib/strcmp.S b/arch/riscv/lib/strcmp.S index 8148b6418f61..fb186bf28f07 100644 --- a/arch/riscv/lib/strcmp.S +++ b/arch/riscv/lib/strcmp.S @@ -40,7 +40,9 @@ SYM_FUNC_START(strcmp) ret /* - * Variant of strcmp using the ZBB extension if available + * Variant of strcmp using the ZBB extension if available. + * The code was published as part of the bitmanip manual + * in Appendix A. */ #ifdef CONFIG_RISCV_ISA_ZBB strcmp_zbb: @@ -57,7 +59,7 @@ strcmp_zbb: * a1 - string2 * * Clobbers - * t0, t1, t2, t3, t4, t5 + * t0, t1, t2, t3, t4 */ or t2, a0, a1 diff --git a/arch/riscv/lib/strlen.S b/arch/riscv/lib/strlen.S index 0f9dbf93301a..898466f67000 100644 --- a/arch/riscv/lib/strlen.S +++ b/arch/riscv/lib/strlen.S @@ -96,7 +96,7 @@ strlen_zbb: * of valid bytes in this chunk. */ srli a0, t1, 3 - bgtu t3, a0, 3f + bgtu t3, a0, 2f /* Prepare for the word comparison loop. */ addi t2, t0, SZREG @@ -112,20 +112,20 @@ strlen_zbb: addi t0, t0, SZREG orc.b t1, t1 beq t1, t3, 1b -2: + not t1, t1 CZ t1, t1 + srli t1, t1, 3 - /* Get number of processed words. */ + /* Get number of processed bytes. */ sub t2, t0, t2 /* Add number of characters in the first word. */ add a0, a0, t2 - srli t1, t1, 3 /* Add number of characters in the last word. */ add a0, a0, t1 -3: +2: ret .option pop diff --git a/arch/riscv/lib/strncmp.S b/arch/riscv/lib/strncmp.S index 7940ddab2d48..e36f5a6e1b16 100644 --- a/arch/riscv/lib/strncmp.S +++ b/arch/riscv/lib/strncmp.S @@ -70,7 +70,7 @@ strncmp_zbb: li t5, -1 and t2, t2, SZREG-1 add t4, a0, a2 - bnez t2, 4f + bnez t2, 3f /* Adjust limit for fast-path. */ andi t6, t4, -SZREG @@ -114,23 +114,21 @@ strncmp_zbb: ret /* Simple loop for misaligned strings. */ -3: - /* Restore limit for slow-path. */ .p2align 3 -4: - bge a0, t4, 6f +3: + bge a0, t4, 5f lbu t0, 0(a0) lbu t1, 0(a1) addi a0, a0, 1 addi a1, a1, 1 - bne t0, t1, 5f - bnez t0, 4b + bne t0, t1, 4f + bnez t0, 3b -5: +4: sub a0, t0, t1 ret -6: +5: li a0, 0 ret -- 2.39.0