From patchwork Sun Feb 4 00:27:50 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Xi Ruoyao X-Patchwork-Id: 85276 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 0CC1A3857C7D for ; Sun, 4 Feb 2024 00:28:29 +0000 (GMT) X-Original-To: libc-alpha@sourceware.org Delivered-To: libc-alpha@sourceware.org Received: from xry111.site (xry111.site [89.208.246.23]) by sourceware.org (Postfix) with ESMTPS id 04B783858403 for ; Sun, 4 Feb 2024 00:28:03 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 04B783858403 Authentication-Results: sourceware.org; dmarc=pass (p=reject dis=none) header.from=xry111.site Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=xry111.site ARC-Filter: OpenARC Filter v1.0.0 sourceware.org 04B783858403 Authentication-Results: server2.sourceware.org; arc=none smtp.remote-ip=89.208.246.23 ARC-Seal: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1707006484; cv=none; b=cOwb78DfMEY+AOWgLtsdt2aTgy6C5rBr+8UXOyh6PJyijy7y9FXBBS14n7v1QOsQAwePGqPHzz0yU+tZ8L/2c2J1x38UpJkKazmJRTc3qlhEIUxG2hpSMC8jG9s1fS4GjCMFA5TuShTBD4FKYVHkPu8fuEdgtC/fsN0N5epMcYw= ARC-Message-Signature: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1707006484; c=relaxed/simple; bh=MtPK/pxh7figZ8/Ivv5AH+meiI0FntoJSNv+8QVU1A4=; h=DKIM-Signature:From:To:Subject:Date:Message-ID:MIME-Version; b=ZaxpK/HQYhuevS/867kOJ6qE7U20Frels+TUTuFWY3koxpZ4BRkr2+eoucDYtoSAyIp+f2mf3VcNJmCO5G4xDuYtVEGt9yry8M7jk1rrwgEx6MnMBYTqZq0zGOsU7f1YN43NzsCtPdhTRdjYQ3sFDPcl0k52xOerE6J/aOdQw8o= ARC-Authentication-Results: i=1; server2.sourceware.org DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=xry111.site; s=default; t=1707006481; bh=MtPK/pxh7figZ8/Ivv5AH+meiI0FntoJSNv+8QVU1A4=; h=From:To:Cc:Subject:Date:From; b=Vic4wxZgPR+jywSMpQLt4oQYQrFz1UaKRuGKvTO/sB/TlUX6lwdwLN5NsAnB0ui6I HKbx5ZaRQ/JZ8QyzjjDNMjK3rYEVH4tBacKIFGxpbt+m9XtQCm05aGCPbggh2cCbuI E7umnr0ZjfC3XH/MDT8BWRstBtE06UNIVgD0RM50= Received: from stargazer.. (unknown [IPv6:240e:358:114e:9800:dc73:854d:832e:8]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-384) server-digest SHA384) (Client did not present a certificate) (Authenticated sender: xry111@xry111.site) by xry111.site (Postfix) with ESMTPSA id 4D89066998; Sat, 3 Feb 2024 19:27:58 -0500 (EST) From: Xi Ruoyao To: libc-alpha@sourceware.org Cc: Adhemerval Zanella Netto , caiyinyu@loongson.cn, Xi Ruoyao Subject: [PATCH] LoongArch: Use builtins for ffs and ffsll Date: Sun, 4 Feb 2024 08:27:50 +0800 Message-ID: <20240204002750.402652-1-xry111@xry111.site> X-Mailer: git-send-email 2.43.0 MIME-Version: 1.0 X-Spam-Status: No, score=-9.1 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, GIT_PATCH_0, LIKELY_SPAM_FROM, SPF_HELO_PASS, SPF_PASS, TXREP, T_SCC_BODY_TEXT_LINE 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: libc-alpha@sourceware.org X-Mailman-Version: 2.1.30 Precedence: list List-Id: Libc-alpha mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: libc-alpha-bounces+patchwork=sourceware.org@sourceware.org On LoongArch GCC compiles __builtin_ffs{,ll} to basically `(x ? __builtin_ctz (x) : -1) + 1`. Since a hardware ctz instruction is available, this is much better than the table-driven generic implementation. Tested on loongarch64. Signed-off-by: Xi Ruoyao Reviewed-by: Adhemerval Zanella --- sysdeps/loongarch/math-use-builtins-ffs.h | 2 ++ 1 file changed, 2 insertions(+) create mode 100644 sysdeps/loongarch/math-use-builtins-ffs.h diff --git a/sysdeps/loongarch/math-use-builtins-ffs.h b/sysdeps/loongarch/math-use-builtins-ffs.h new file mode 100644 index 0000000000..a83bb15414 --- /dev/null +++ b/sysdeps/loongarch/math-use-builtins-ffs.h @@ -0,0 +1,2 @@ +#define USE_FFS_BUILTIN 1 +#define USE_FFSLL_BUILTIN 1