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From: arthur.cohen@embecosm.com
To: gcc-patches@gcc.gnu.org
Cc: gcc-rust@gcc.gnu.org, Philip Herron <philip.herron@embecosm.com>
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	[thread overview]
Message-ID: <20221206101417.778807-22-arthur.cohen@embecosm.com> (raw)
In-Reply-To: <20221206101417.778807-1-arthur.cohen@embecosm.com>

From: Philip Herron <philip.herron@embecosm.com>

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
+// <http://www.gnu.org/licenses/>.
+
+#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
-- 
2.38.1


  parent reply	other threads:[~2022-12-06 10:12 UTC|newest]

Thread overview: 81+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-12-06 10:13 Rust front-end patches v4 arthur.cohen
2022-12-06 10:13 ` [PATCH Rust front-end v4 01/46] Use DW_ATE_UTF for the Rust 'char' type arthur.cohen
2022-12-06 10:13 ` [PATCH Rust front-end v4 02/46] gccrs: Add necessary hooks for a Rust front-end testsuite arthur.cohen
2022-12-06 10:13 ` [PATCH Rust front-end v4 03/46] gccrs: Add Debug info testsuite arthur.cohen
2022-12-06 10:13 ` [PATCH Rust front-end v4 04/46] gccrs: Add link cases testsuite arthur.cohen
2022-12-06 10:13 ` [PATCH Rust front-end v4 05/46] gccrs: Add general compilation test cases arthur.cohen
2022-12-06 10:13 ` [PATCH Rust front-end v4 06/46] gccrs: Add execution " arthur.cohen
2022-12-06 10:13 ` [PATCH Rust front-end v4 07/46] gccrs: Add gcc-check-target check-rust arthur.cohen
2022-12-06 10:13 ` [PATCH Rust front-end v4 08/46] gccrs: Add Rust front-end base AST data structures arthur.cohen
2022-12-06 10:13 ` [PATCH Rust front-end v4 09/46] gccrs: Add definitions of Rust Items in " arthur.cohen
2022-12-06 10:13 ` [PATCH Rust front-end v4 10/46] gccrs: Add full definitions of Rust " arthur.cohen
2022-12-06 10:13 ` [PATCH Rust front-end v4 11/46] gccrs: Add Rust AST visitors arthur.cohen
2022-12-06 10:13 ` [PATCH Rust front-end v4 12/46] gccrs: Add Lexer for Rust front-end arthur.cohen
2022-12-06 10:13 ` [PATCH Rust front-end v4 13/46] gccrs: Add Parser for Rust front-end pt.1 arthur.cohen
2022-12-06 10:13 ` [PATCH Rust front-end v4 14/46] gccrs: Add Parser for Rust front-end pt.2 arthur.cohen
2022-12-06 10:13 ` [PATCH Rust front-end v4 15/46] gccrs: Add expansion pass for the Rust front-end arthur.cohen
2022-12-06 10:13 ` [PATCH Rust front-end v4 16/46] gccrs: Add name resolution pass to " arthur.cohen
2022-12-06 10:13 ` [PATCH Rust front-end v4 17/46] gccrs: Add declarations for Rust HIR arthur.cohen
2022-12-06 10:13 ` [PATCH Rust front-end v4 18/46] gccrs: Add HIR definitions and visitor framework arthur.cohen
2022-12-06 10:13 ` [PATCH Rust front-end v4 19/46] gccrs: Add AST to HIR lowering pass arthur.cohen
2022-12-06 10:13 ` [PATCH Rust front-end v4 20/46] gccrs: Add wrapper for make_unique arthur.cohen
2022-12-07  8:50   ` Arsen Arsenović
2022-12-07  9:14     ` Thomas Schwinge
2022-12-06 10:13 ` arthur.cohen [this message]
2022-12-06 10:13 ` [PATCH Rust front-end v4 22/46] gccrs: Add Rust ABI enum helpers arthur.cohen
2022-12-06 10:13 ` [PATCH Rust front-end v4 23/46] gccrs: Add Base62 implementation arthur.cohen
2022-12-06 10:13 ` [PATCH Rust front-end v4 24/46] gccrs: Add implementation of Optional arthur.cohen
2022-12-06 10:13 ` [PATCH Rust front-end v4 25/46] gccrs: Add attributes checker arthur.cohen
2022-12-06 10:13 ` [PATCH Rust front-end v4 26/46] gccrs: Add helpers mappings canonical path and lang items arthur.cohen
2022-12-06 10:13 ` [PATCH Rust front-end v4 27/46] gccrs: Add type resolution and trait solving pass arthur.cohen
2022-12-06 10:14 ` [PATCH Rust front-end v4 28/46] gccrs: Add Rust type information arthur.cohen
2022-12-06 10:14 ` [PATCH Rust front-end v4 29/46] gccrs: Add remaining type system transformations arthur.cohen
2022-12-06 10:14 ` [PATCH Rust front-end v4 30/46] gccrs: Add unsafe checks for Rust arthur.cohen
2022-12-06 10:14 ` [PATCH Rust front-end v4 31/46] gccrs: Add const checker arthur.cohen
2022-12-06 10:14 ` [PATCH Rust front-end v4 32/46] gccrs: Add privacy checks arthur.cohen
2022-12-06 10:14 ` [PATCH Rust front-end v4 33/46] gccrs: Add dead code scan on HIR arthur.cohen
2022-12-06 10:14 ` [PATCH Rust front-end v4 34/46] gccrs: Add unused variable scan arthur.cohen
2022-12-06 10:14 ` [PATCH Rust front-end v4 35/46] gccrs: Add metadata output pass arthur.cohen
2022-12-06 10:14 ` [PATCH Rust front-end v4 36/46] gccrs: Add base for HIR to GCC GENERIC lowering arthur.cohen
2022-12-06 10:14 ` [PATCH Rust front-end v4 37/46] gccrs: Add HIR to GCC GENERIC lowering for all nodes arthur.cohen
2022-12-06 10:14 ` [PATCH Rust front-end v4 38/46] gccrs: Add HIR to GCC GENERIC lowering entry point arthur.cohen
2022-12-06 10:14 ` [PATCH Rust front-end v4 39/46] gccrs: These are wrappers ported from reusing gccgo arthur.cohen
2022-12-06 10:14 ` [PATCH Rust front-end v4 40/46] gccrs: Add GCC Rust front-end Make-lang.in arthur.cohen
2022-12-06 10:14 ` [PATCH Rust front-end v4 41/46] gccrs: Add config-lang.in arthur.cohen
2022-12-06 10:14 ` [PATCH Rust front-end v4 42/46] gccrs: Add lang-spec.h arthur.cohen
2022-12-06 10:14 ` [PATCH Rust front-end v4 43/46] gccrs: Add lang.opt arthur.cohen
2022-12-06 10:14 ` [PATCH Rust front-end v4 44/46] gccrs: Add compiler driver arthur.cohen
2022-12-06 10:14 ` [PATCH Rust front-end v4 45/46] gccrs: Compiler proper interface kicks off the pipeline arthur.cohen
2022-12-06 10:14 ` [PATCH Rust front-end v4 46/46] gccrs: Add README, CONTRIBUTING and compiler logo arthur.cohen
2022-12-09 10:18   ` Martin Liška
2022-12-13  1:43     ` Joseph Myers
2022-12-13 12:59       ` Martin Liška
2022-12-13 18:46         ` Joseph Myers
2022-12-06 11:03 ` Rust front-end patches v4 Richard Biener
2022-12-06 11:09   ` John Paul Adrian Glaubitz
2022-12-06 11:40     ` Arthur Cohen
2022-12-06 11:57       ` John Paul Adrian Glaubitz
2022-12-06 12:40         ` Mark Wielaard
2022-12-06 11:41   ` Iain Buclaw
2022-12-10  6:39   ` Prepare 'contrib/gcc-changelog/git_commit.py' for GCC/Rust (was: Rust front-end patches v4) Thomas Schwinge
2022-12-10  7:37     ` Add stub 'gcc/rust/ChangeLog' (was: Prepare 'contrib/gcc-changelog/git_commit.py' for GCC/Rust) Thomas Schwinge
2022-12-13 13:26   ` Rust front-end patches v4 Arthur Cohen
2022-12-13 13:30     ` Martin Liška
2022-12-13 13:53       ` Arthur Cohen
2022-12-13 13:40     ` Arthur Cohen
2022-12-14 22:58       ` Make '-frust-incomplete-and-experimental-compiler-do-not-use' a 'Common' option (was: Rust front-end patches v4) Thomas Schwinge
2022-12-15  7:53         ` Richard Biener
2022-12-15 10:14           ` Thomas Schwinge
2022-12-15 11:16             ` Jakub Jelinek
2022-12-15 11:39               ` Iain Buclaw
2022-12-15 11:50                 ` Jakub Jelinek
2022-12-15 15:01                   ` Thomas Schwinge
2022-12-15 15:17                     ` Jakub Jelinek
2022-12-16 14:10                       ` Add '-Wno-complain-wrong-lang', and use it in 'gcc/testsuite/lib/target-supports.exp:check_compile' and elsewhere (was: Make '-frust-incomplete-and-experimental-compiler-do-not-use' a 'Common' option) Thomas Schwinge
2022-12-16 21:24                         ` Iain Buclaw
2023-01-11 11:41                         ` [PING] Add '-Wno-complain-wrong-lang', and use it in 'gcc/testsuite/lib/target-supports.exp:check_compile' and elsewhere Thomas Schwinge
2023-01-11 12:31                           ` Jakub Jelinek
2023-02-21 10:21                             ` [PING, v2] " Thomas Schwinge
2023-02-21 23:20                               ` Joseph Myers
2022-12-09 13:24 ` Rust front-end patches v4 Martin Liška
2022-12-10 21:44   ` Thomas Schwinge

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