From owner-dev-commits-src-main@freebsd.org Mon Mar 1 12:56:06 2021 Return-Path: Delivered-To: dev-commits-src-main@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id F063E55C9F7; Mon, 1 Mar 2021 12:56:05 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "R3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4Dq0cg3L9Rz4VDJ; Mon, 1 Mar 2021 12:56:03 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org (gitrepo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:5]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 5964823CCC; Mon, 1 Mar 2021 12:56:02 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org ([127.0.1.44]) by gitrepo.freebsd.org (8.16.1/8.16.1) with ESMTP id 121Cu2k9047065; Mon, 1 Mar 2021 12:56:02 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.16.1/8.16.1/Submit) id 121Cu24D047064; Mon, 1 Mar 2021 12:56:02 GMT (envelope-from git) Date: Mon, 1 Mar 2021 12:56:02 GMT Message-Id: <202103011256.121Cu24D047064@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org From: Alex Richardson Subject: git: 524b018d2004 - main - riscv: Add a soft-float implementation of fabs() MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: arichardson X-Git-Repository: src X-Git-Refname: refs/heads/main X-Git-Reftype: branch X-Git-Commit: 524b018d200408bed5eb0d2b892db5b9fb46808b Auto-Submitted: auto-generated X-BeenThere: dev-commits-src-main@freebsd.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Commit messages for the main branch of the src repository List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 01 Mar 2021 12:56:07 -0000 The branch main has been updated by arichardson: URL: https://cgit.FreeBSD.org/src/commit/?id=524b018d200408bed5eb0d2b892db5b9fb46808b commit 524b018d200408bed5eb0d2b892db5b9fb46808b Author: Alex Richardson AuthorDate: 2021-03-01 12:46:30 +0000 Commit: Alex Richardson CommitDate: 2021-03-01 12:53:46 +0000 riscv: Add a soft-float implementation of fabs() We could just use a C implementation using __builtin_fabs(), but using this assembly version guarantees that there is no additional prolog/epilog code. Additionally, clang generates worse code for masking off the top bit than GCC: https://bugs.llvm.org/show_bug.cgi?id=49377. This fixes the RISCV64 softfloat world build after cf97d2a1dab8. That commit added -fno-builtin to the msun tests which resulted in the first references to fabs (previously the compiler inlined all calls). Reviewed By: dim Reported by: mjg Differential Revision: https://reviews.freebsd.org/D28994 --- lib/libc/riscv/gen/fabs.S | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/lib/libc/riscv/gen/fabs.S b/lib/libc/riscv/gen/fabs.S index 44249252e9c1..09042af3b4c0 100644 --- a/lib/libc/riscv/gen/fabs.S +++ b/lib/libc/riscv/gen/fabs.S @@ -1,5 +1,6 @@ /*- * Copyright (c) 2015-2017 Ruslan Bukin + * Copyright (c) 2021 Alex Richardson * All rights reserved. * * Portions of this software were developed by SRI International and the @@ -10,6 +11,9 @@ * Computer Laboratory as part of the CTSRD Project, with support from the * UK Higher Education Innovation Fund (HEIF). * + * This work was supported by Innovate UK project 105694, "Digital Security + * by Design (DSbD) Technology Platform Prototype". + * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: @@ -35,9 +39,12 @@ #include __FBSDID("$FreeBSD$"); -#ifdef __riscv_float_abi_double ENTRY(fabs) +#ifdef __riscv_float_abi_double fabs.d fa0, fa0 +#else + slli a0,a0,1 + srli a0,a0,1 +#endif ret END(fabs) -#endif