From patchwork Tue Dec 6 10:13:53 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Arthur Cohen X-Patchwork-Id: 61523 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 7F556396E863 for ; Tue, 6 Dec 2022 10:21:58 +0000 (GMT) X-Original-To: gcc-patches@gcc.gnu.org Delivered-To: gcc-patches@gcc.gnu.org Received: from mail-wr1-x42b.google.com (mail-wr1-x42b.google.com [IPv6:2a00:1450:4864:20::42b]) by sourceware.org (Postfix) with ESMTPS id 55AC5395B418 for ; Tue, 6 Dec 2022 10:12:21 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 55AC5395B418 Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=embecosm.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=embecosm.com Received: by mail-wr1-x42b.google.com with SMTP id h7so16732981wrs.6 for ; Tue, 06 Dec 2022 02:12:21 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=embecosm.com; s=google; h=content-transfer-encoding:mime-version:reply-to:references :in-reply-to:message-id:date:subject:cc:to:from:from:to:cc:subject :date:message-id:reply-to; bh=twGp41ZDbcrRhwxEEeY/B2UgHg0gvrzh9/M7dUvrgMc=; b=ZSMewC5vLh5h51BY5Ph3A1ZH3QHOQsuRT3z5KUMWMuvJ+d40jOSK+7dUzrRFdhlKwu oZbaq1kralLTycD04BjntyPKLjMBI444F6buRadNwDlXZAZqworgb1qUX4DSKSIlBNmZ U0871yg+UIb5ejGbwRjEKI7IRPxtfKlgIh83dNwbWX2cHhRtVS6ieiWiKcqPiTHiLYQr Hxjjt+L67eZzCKWPjEfeMluNYSATSReQAfS4c7/62ukLWTve8LoJlLb7y9JTJGNB/oW4 TFTdmWtPSpYjNQN8xTPyUt4M8l/JV984k2HBFop5Hddh0ZTm7wUxbkSIz2R/ZNaBaLyq M3iQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:reply-to:references :in-reply-to:message-id:date:subject:cc:to:from:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=twGp41ZDbcrRhwxEEeY/B2UgHg0gvrzh9/M7dUvrgMc=; b=7cL2bm18HVYGljm2jAiIr3b70+AUPNE9+iqIBkm1q4t0rwtHF9LAtNwzXsaepmkHxM BI6ZRuraXdGzYmiACFib+QSEGyn0PIzbTynzgotyEemTKfQz9NikrVxEfo8IiRNGljBq GlATSiGEzOmJF+uOvveHKHRIXQ5OSDvzYpAXc4MTwFAHdXf6lMsxIVImzGHr4vKs9EWC AU955Hu3N5FdVz3Bq1GcWHFkOVx3+Cg7LxDgI+Xflj4n0c2UL9rT5izHLIPBEbeAaTnd 4tUNs1cubtmEVcNiNTS1bNCVQ9pfY5DQ+xYHRlm3a+mnB8V9Yk3QKj6AvJR/R7wqHA+z 0yUA== X-Gm-Message-State: ANoB5pk4JbZfDHZ0QSXDeZ31RbFqNBBSzWllD3TxnLqGRH4gMSIokhW5 ERgdiks21G3knqI5g/QdaGgIrN9EaisCHC/qTw== X-Google-Smtp-Source: AA0mqf6cVnd5L3QBsO8mHLrDlZjD4kuiNMLMqrOECBfqXMJCT07rX41C/QSkg4ZAA7xx/wqu7PmIvg== X-Received: by 2002:adf:f98e:0:b0:242:324:ff88 with SMTP id f14-20020adff98e000000b002420324ff88mr31752712wrr.81.1670321539918; Tue, 06 Dec 2022 02:12:19 -0800 (PST) Received: from platypus.lan ([2001:861:5e4c:3bb0:6424:328a:1734:3249]) by smtp.googlemail.com with ESMTPSA id r10-20020a05600c458a00b003cfd4a50d5asm27052699wmo.34.2022.12.06.02.12.19 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 06 Dec 2022 02:12:19 -0800 (PST) From: arthur.cohen@embecosm.com To: gcc-patches@gcc.gnu.org Cc: gcc-rust@gcc.gnu.org, Philip Herron Subject: [PATCH Rust front-end v4 21/46] gccrs: Add port of FNV hash used during legacy symbol mangling Date: Tue, 6 Dec 2022 11:13:53 +0100 Message-Id: <20221206101417.778807-22-arthur.cohen@embecosm.com> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221206101417.778807-1-arthur.cohen@embecosm.com> References: <20221206101417.778807-1-arthur.cohen@embecosm.com> MIME-Version: 1.0 X-Spam-Status: No, score=-16.2 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, GIT_PATCH_0, KAM_SHORT, RCVD_IN_DNSWL_NONE, 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: 2.1.29 Precedence: list List-Id: Gcc-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: arthur.cohen@embecosm.com Errors-To: gcc-patches-bounces+patchwork=sourceware.org@gcc.gnu.org Sender: "Gcc-patches" From: Philip Herron This hash was ported from the Go runtime, as we needed a hash for the legacy symbol mangling system. All symbols in Rust contain a hash of some metadata for uniqueness on generic functions. --- gcc/rust/util/fnv-hash.h | 95 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 95 insertions(+) create mode 100644 gcc/rust/util/fnv-hash.h diff --git a/gcc/rust/util/fnv-hash.h b/gcc/rust/util/fnv-hash.h new file mode 100644 index 00000000000..78e54c99411 --- /dev/null +++ b/gcc/rust/util/fnv-hash.h @@ -0,0 +1,95 @@ +// Copyright (C) 2020-2022 Free Software Foundation, Inc. + +// This file is part of GCC. + +// GCC is free software; you can redistribute it and/or modify it under +// the terms of the GNU General Public License as published by the Free +// Software Foundation; either version 3, or (at your option) any later +// version. + +// GCC is distributed in the hope that it will be useful, but WITHOUT ANY +// WARRANTY; without even the implied warranty of MERCHANTABILITY or +// FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License +// for more details. + +// You should have received a copy of the GNU General Public License +// along with GCC; see the file COPYING3. If not see +// . + +#ifndef RUST_FNV_HASH_H +#define RUST_FNV_HASH_H + +namespace Rust { +namespace Hash { + +const uint64_t offset128Lower = 0x62b821756295c58d; +const uint64_t offset128Higher = 0x6c62272e07bb0142; +const uint64_t prime128Lower = 0x13b; +const uint64_t prime128Shift = 24; + +// ported from https://github.com/golang/go/blob/master/src/hash/fnv/fnv.go +class FNV128 +{ +public: + FNV128 () { reset (); } + + void reset () + { + buf[0] = offset128Higher; + buf[1] = offset128Lower; + } + + void write (const unsigned char *in, size_t len) + { + for (size_t i = 0; i < len; i++) + { + unsigned char c = in[i]; + + // https://stackoverflow.com/questions/28868367/getting-the-high-part-of-64-bit-integer-multiplication + uint64_t a = prime128Lower; + uint64_t b = buf[1]; + + uint64_t a_lo = (uint32_t) a; + uint64_t a_hi = a >> 32; + uint64_t b_lo = (uint32_t) b; + uint64_t b_hi = b >> 32; + + uint64_t a_x_b_hi = a_hi * b_hi; + uint64_t a_x_b_mid = a_hi * b_lo; + uint64_t b_x_a_mid = b_hi * a_lo; + uint64_t a_x_b_lo = a_lo * b_lo; + + uint64_t carry_bit + = ((uint64_t) (uint32_t) a_x_b_mid + (uint64_t) (uint32_t) b_x_a_mid + + (a_x_b_lo >> 32)) + >> 32; + + uint64_t multhi + = a_x_b_hi + (a_x_b_mid >> 32) + (b_x_a_mid >> 32) + carry_bit; + + uint64_t s0 = multhi; // high + uint64_t s1 = prime128Lower * buf[1]; // low + + s0 += buf[1] << (prime128Shift + prime128Lower * buf[0]); + + // Update the values + buf[1] = s1; + buf[0] = s0; + buf[1] ^= (uint64_t) c; + } + } + + void sum (uint64_t *hi, uint64_t *lo) const + { + *hi = buf[0]; + *lo = buf[1]; + } + +private: + uint64_t buf[2]; +}; + +} // namespace Hash +} // namespace Rust + +#endif // RUST_FNV_HASH_H