From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on inbox.vuxu.org X-Spam-Level: X-Spam-Status: No, score=-3.1 required=5.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED,RCVD_IN_MSPIKE_H4, RCVD_IN_MSPIKE_WL,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.4 Received: from second.openwall.net (second.openwall.net [193.110.157.125]) by inbox.vuxu.org (Postfix) with SMTP id 507D628896 for ; Thu, 13 Jun 2024 10:07:37 +0200 (CEST) Received: (qmail 3355 invoked by uid 550); 13 Jun 2024 08:07:32 -0000 Mailing-List: contact musl-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Reply-To: musl@lists.openwall.com Received: (qmail 3311 invoked from network); 13 Jun 2024 08:07:32 -0000 X-QQ-mid: bizesmtpsz8t1718266039t9p41m9 X-QQ-Originating-IP: Oqm4BUCtMYkxvLx0WmqNc7jKluC/X8IYUHT6vwZ9+8I= X-QQ-SSF: 0000000000000000000000000000000 X-QQ-GoodBg: 0 X-BIZMAIL-ID: 18121992288981854812 From: Meng Zhuo To: musl@lists.openwall.com Date: Thu, 13 Jun 2024 16:07:17 +0800 Message-Id: <20240613080717.546252-1-mzh@mzh.io> X-Mailer: git-send-email 2.39.2 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-QQ-SENDSIZE: 520 Feedback-ID: bizesmtpsz:mzh.io:qybglogicsvrgz:qybglogicsvrgz5a-1 Subject: [musl] [PATCH v4] math: add riscv64 round/roundf --- v3 -> v4: * add fabs(f) to avoild overflow. * add comment on -0 copysign Thanks for review! How to implement "single cmp+branch on the bit representation of x"? I've tried Google bit hacks of it. Could you give some tip or refs? --- src/math/riscv64/round.c | 21 +++++++++++++++++++++ src/math/riscv64/roundf.c | 21 +++++++++++++++++++++ 2 files changed, 42 insertions(+) create mode 100644 src/math/riscv64/round.c create mode 100644 src/math/riscv64/roundf.c diff --git a/src/math/riscv64/round.c b/src/math/riscv64/round.c new file mode 100644 index 00000000..7d7ade9d --- /dev/null +++ b/src/math/riscv64/round.c @@ -0,0 +1,21 @@ +#include + +#if __riscv_flen >= 64 + +double round(double x) +{ + if (!isfinite(x) || fabs(x) >= 0x1p52) return x; + double tmp; + long long n; + __asm__ ("fcvt.l.d %0, %1, rmm" : "=r"(n) : "f"(x)); + __asm__ ("fcvt.d.l %0, %1" : "=f"(tmp) : "r"(n)); + // the sign bit is only copied to handle round(-0.0) + __asm__ ("fsgnj.d %0, %1, %2" : "=f"(x) : "f"(tmp), "f"(x)); + return x; +} + +#else + +#include "../round.c" + +#endif diff --git a/src/math/riscv64/roundf.c b/src/math/riscv64/roundf.c new file mode 100644 index 00000000..be588574 --- /dev/null +++ b/src/math/riscv64/roundf.c @@ -0,0 +1,21 @@ +#include + +#if __riscv_flen >= 32 + +float roundf(float x) +{ + if (!isfinite(x) || fabsf(x) >= 0x1p23) return x; + float tmp; + long n; + __asm__ ("fcvt.w.s %0, %1, rmm" : "=r"(n) : "f"(x)); + __asm__ ("fcvt.s.w %0, %1" : "=f"(tmp) : "r"(n)); + // the sign bit is only copied to handle round(-0.0) + __asm__ ("fsgnj.s %0, %1, %2" : "=f"(x) : "f"(tmp), "f"(x)); + return x; +} + +#else + +#include "../roundf.c" + +#endif -- 2.39.2