libc/arm: optimize crc32/crc32c for arm

Optimize crc32 standard(poly:0x04C11DB7) and crc32
castagnoli(poly:0x1EDC6F41) with arm crc32 extension instructions.

For example, crc32 standard caculates(lookup crc32 table) 1812 bytes data,
reduced the time from 118 us to 14 us through optimization.

Performance improved ~700%

Signed-off-by: Jinliang Li <lijinliang1@lixiang.com>

arch/Kconfig

@@ -434,6 +434,12 @@ config ARCH_HAVE_FORK
 	bool
 	default n
 
+config ARCH_HAVE_CRC32
+	bool
+	default n
+	---help---
+		Architecture supports CRC32 instruction
+
 config ARCH_HAVE_FPU
 	bool
 	default n

libs/libc/machine/arm/CMakeLists.txt

@@ -68,4 +68,8 @@ if(CONFIG_PROFILE_MINI)
   list(APPEND SRCS gnu/mcount.S)
 endif()
 
+if(CONFIG_LIBC_ARCH_CRC32)
+  list(APPEND SRCS arch_crc32.c)
+endif()
+
 target_sources(c PRIVATE ${SRCS})

libs/libc/machine/arm/Kconfig

@@ -31,3 +31,10 @@ endif
 if ARCH_ARMV8R
 source "libs/libc/machine/arm/armv8-r/Kconfig"
 endif
+
+config LIBC_ARCH_CRC32
+	bool "Enable optimized crc32 for ARM"
+	default n
+	depends on ARCH_HAVE_CRC32
+	---help---
+		Enable optimized arm neon specific crc32 library function

libs/libc/machine/arm/Make.defs

@@ -66,6 +66,10 @@ ifeq ($(CONFIG_PROFILE_MINI),y)
 ASRCS += mcount.S
 endif
 
+ifeq ($(CONFIG_LIBC_ARCH_CRC32),y)
+CSRCS += arch_crc32.c
+endif
+
 ifeq ($(CONFIG_ARCH_TOOLCHAIN_GNU),y)
 DEPPATH += --dep-path machine/arm/gnu
 VPATH += :machine/arm/gnu

libs/libc/machine/arm/arch_crc32.c

@@ -0,0 +1,115 @@
+/****************************************************************************
+ * libs/libc/machine/arm/arch_crc32.c
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.  The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <stdint.h>
+#include <sys/types.h>
+#include <arm_acle.h>
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: crc32part
+ *
+ * Description:
+ *   crc32 polynomial 0x04C11DB7 (bitreflected 0xEDB88320)
+ *
+ ****************************************************************************/
+
+uint32_t crc32part(FAR const uint8_t *src, size_t len, uint32_t crc32val)
+{
+  size_t i = 0;
+
+  for (; (i + 8) <= len; i += 8)
+    {
+      uint64_t data = *(uint64_t *)(src + i);
+      crc32val = __crc32d(crc32val, data);
+    }
+
+  if (i + 4 <= len)
+    {
+      uint32_t data = *(uint32_t *)(src + i);
+      crc32val = __crc32w(crc32val, data);
+      i += 4;
+    }
+
+  if (i + 2 <= len)
+    {
+      uint16_t data = *(uint16_t *)(src + i);
+      crc32val = __crc32h(crc32val, data);
+      i += 2;
+    }
+
+  if (i < len)
+    {
+      uint8_t data = *(uint8_t *)(src + i);
+      crc32val = __crc32b(crc32val, data);
+    }
+
+  return crc32val;
+}
+
+/****************************************************************************
+ * Name: crc32part_c
+ *
+ * Description:
+ *   crc32 Castagnoli polynomial 0x1EDC6F41
+ *
+ ****************************************************************************/
+
+uint32_t crc32part_c(FAR const uint8_t *src, size_t len, uint32_t crc32val)
+{
+  size_t i = 0;
+
+  for (; (i + 8) <= len; i += 8)
+    {
+      uint64_t data = *(uint64_t *)(src + i);
+      crc32val = __crc32cd(crc32val, data);
+    }
+
+  if (i + 4 <= len)
+    {
+      uint32_t data = *(uint32_t *)(src + i);
+      crc32val = __crc32cw(crc32val, data);
+      i += 4;
+    }
+
+  if (i + 2 <= len)
+    {
+      uint16_t data = *(uint16_t *)(src + i);
+      crc32val = __crc32ch(crc32val, data);
+      i += 2;
+    }
+
+  if (i < len)
+    {
+      uint8_t data = *(uint8_t *)(src + i);
+      crc32val = __crc32cb(crc32val, data);
+    }
+
+  return crc32val;
+}

libs/libc/misc/lib_crc32.c

@@ -1,4 +1,4 @@
-/************************************************************************************************
+/****************************************************************************
  * libs/libc/misc/lib_crc32.c
  *
  * SPDX-License-Identifier: Apache-2.0
@@ -18,110 +18,127 @@
  * License for the specific language governing permissions and limitations
  * under the License.
  *
- ***********************************************************************************************/
+ ****************************************************************************/
 
 /* The logic in this file was developed by Gary S. Brown:
  *
- *   COPYRIGHT (C) 1986 Gary S. Brown.  You may use this program, or code or tables
+ *   COPYRIGHT (C) 1986 Gary S. Brown.  You may use this program, or code or
- *   extracted from it, as desired without restriction.
+ *   tables extracted from it, as desired without restriction.
  *
- * First, the polynomial itself and its table of feedback terms.  The polynomial is:
+ * First, the polynomial itself and its table of feedback terms.  The
+ * polynomial is:
  *
  *    X^32+X^26+X^23+X^22+X^16+X^12+X^11+X^10+X^8+X^7+X^5+X^4+X^2+X^1+X^0
  *
- * Note that we take it "backwards" and put the highest-order term in the lowest-order bit.
+ * Note that we take it "backwards" and put the highest-order term in the
- * The X^32 term is "implied"; the LSB is the X^31 term, etc.  The X^0 term (usually shown
+ * lowest-order bit. The X^32 term is "implied"; the LSB is the X^31 term,
- * as "+1") results in the MSB being 1
+ * etc. The X^0 term (usually shown as "+1") results in the MSB being 1
  *
- * Note that the usual hardware shift register implementation, which is what we're using
+ * Note that the usual hardware shift register implementation, which is what
- * (we're merely optimizing it by doing eight-bit chunks at a time) shifts bits into the
+ * we're using (we're merely optimizing it by doing eight-bit chunks at a
- * lowest-order term.  In our implementation, that means shifting towards the right.  Why
+ * time) shifts bits into the lowest-order term.  In our implementation, that
- * do we do it this way?  Because the calculated CRC must be transmitted in order from
+ * means shifting towards the right.  Why do we do it this way?  Because the
- * highest-order term to lowest-order term.  UARTs transmit characters in order from LSB
+ * calculated CRC must be transmitted in order from
- * to MSB.  By storing the CRC this way we hand it to the UART in the order low-byte to
+ * highest-order term to lowest-order term.  UARTs transmit characters in
- * high-byte; the UART sends each low-bit to hight-bit; and the result is transmission bit
+ * order from LSB to MSB.  By storing the CRC this way we hand it to the UART
- * by bit from highest- to lowest-order term without requiring any bit shuffling on our
+ * in the order low-byte to high-byte; the UART sends each low-bit to
- * part.  Reception works similarly
+ * hight-bit; and the result is transmission bit by bit from highest- to
+ * lowest-order term without requiring any bit shuffling on our part.
+ * Reception works similarly
  *
  * The feedback terms table consists of 256, 32-bit entries.  Notes
  *
- * - The table can be generated at runtime if desired; code to do so is shown later.  It
+ * - The table can be generated at runtime if desired; code to do so is shown
- *   might not be obvious, but the feedback terms simply represent the results of eight
+ *   later.  It might not be obvious, but the feedback terms simply represent
- *   shift/xor operations for all combinations of data and CRC register values
+ *   the results of eight shift/xor operations for all combinations of data
+ *   and CRC register values
  *
- * - The values must be right-shifted by eight bits by the updcrc logic; the shift must
+ * - The values must be right-shifted by eight bits by the updcrc logic; the
- *   be u_(bring in zeroes).  On some hardware you could probably optimize the shift in
+ *   shift must be u_(bring in zeroes).  On some hardware you could probably
- *   assembler by using byte-swap instructions polynomial $edb88320
+ *   optimize the shift in assembler by using byte-swap instructions
- ************************************************************************************************/
+ *   polynomial $edb88320
+ ****************************************************************************/
 
-/************************************************************************************************
+/****************************************************************************
  * Included Files
- ************************************************************************************************/
+ ****************************************************************************/
 
 #include <sys/types.h>
 #include <stdint.h>
 
 #include <nuttx/crc32.h>
 
-/************************************************************************************************
+/****************************************************************************
  * Private Data
- ************************************************************************************************/
+ ****************************************************************************/
-
+#ifndef CONFIG_LIBC_ARCH_CRC32
 #ifdef CONFIG_LIBC_CRC32_SLOW
-#  define LIBC_CRC32_POLY 0xedb88320
+#  define LIBC_CRC32_POLY  0xedb88320
 #else
 static const uint32_t crc32_tab[] =
 {
-  0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, 0x706af48f, 0xe963a535, 0x9e6495a3,
+  0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, 0x706af48f,
-  0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988, 0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91,
+  0xe963a535, 0x9e6495a3, 0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988,
-  0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de, 0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7,
+  0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91, 0x1db71064, 0x6ab020f2,
-  0x136c9856, 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9, 0xfa0f3d63, 0x8d080df5,
+  0xf3b97148, 0x84be41de, 0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7,
-  0x3b6e20c8, 0x4c69105e, 0xd56041e4, 0xa2677172, 0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b,
+  0x136c9856, 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9,
-  0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940, 0x32d86ce3, 0x45df5c75, 0xdcd60dcf, 0xabd13d59,
+  0xfa0f3d63, 0x8d080df5, 0x3b6e20c8, 0x4c69105e, 0xd56041e4, 0xa2677172,
-  0x26d930ac, 0x51de003a, 0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423, 0xcfba9599, 0xb8bda50f,
+  0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b, 0x35b5a8fa, 0x42b2986c,
-  0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924, 0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d,
+  0xdbbbc9d6, 0xacbcf940, 0x32d86ce3, 0x45df5c75, 0xdcd60dcf, 0xabd13d59,
-  0x76dc4190, 0x01db7106, 0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f, 0x9fbfe4a5, 0xe8b8d433,
+  0x26d930ac, 0x51de003a, 0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423,
-  0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818, 0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01,
+  0xcfba9599, 0xb8bda50f, 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924,
-  0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e, 0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457,
+  0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d, 0x76dc4190, 0x01db7106,
-  0x65b0d9c6, 0x12b7e950, 0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65,
+  0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f, 0x9fbfe4a5, 0xe8b8d433,
-  0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2, 0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb,
+  0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818, 0x7f6a0dbb, 0x086d3d2d,
-  0x4369e96a, 0x346ed9fc, 0xad678846, 0xda60b8d0, 0x44042d73, 0x33031de5, 0xaa0a4c5f, 0xdd0d7cc9,
+  0x91646c97, 0xe6635c01, 0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e,
-  0x5005713c, 0x270241aa, 0xbe0b1010, 0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f,
+  0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950,
-  0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17, 0x2eb40d81, 0xb7bd5c3b, 0xc0ba6cad,
+  0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65,
-  0xedb88320, 0x9abfb3b6, 0x03b6e20c, 0x74b1d29a, 0xead54739, 0x9dd277af, 0x04db2615, 0x73dc1683,
+  0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2, 0x4adfa541, 0x3dd895d7,
-  0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8, 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1,
+  0xa4d1c46d, 0xd3d6f4fb, 0x4369e96a, 0x346ed9fc, 0xad678846, 0xda60b8d0,
-  0xf00f9344, 0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb, 0x196c3671, 0x6e6b06e7,
+  0x44042d73, 0x33031de5, 0xaa0a4c5f, 0xdd0d7cc9, 0x5005713c, 0x270241aa,
-  0xfed41b76, 0x89d32be0, 0x10da7a5a, 0x67dd4acc, 0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5,
+  0xbe0b1010, 0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f,
-  0xd6d6a3e8, 0xa1d1937e, 0x38d8c2c4, 0x4fdff252, 0xd1bb67f1, 0xa6bc5767, 0x3fb506dd, 0x48b2364b,
+  0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17, 0x2eb40d81,
-  0xd80d2bda, 0xaf0a1b4c, 0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55, 0x316e8eef, 0x4669be79,
+  0xb7bd5c3b, 0xc0ba6cad, 0xedb88320, 0x9abfb3b6, 0x03b6e20c, 0x74b1d29a,
-  0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236, 0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f,
+  0xead54739, 0x9dd277af, 0x04db2615, 0x73dc1683, 0xe3630b12, 0x94643b84,
-  0xc5ba3bbe, 0xb2bd0b28, 0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31, 0x2cd99e8b, 0x5bdeae1d,
+  0x0d6d6a3e, 0x7a6a5aa8, 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1,
-  0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x026d930a, 0x9c0906a9, 0xeb0e363f, 0x72076785, 0x05005713,
+  0xf00f9344, 0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb,
-  0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38, 0x92d28e9b, 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21,
+  0x196c3671, 0x6e6b06e7, 0xfed41b76, 0x89d32be0, 0x10da7a5a, 0x67dd4acc,
-  0x86d3d2d4, 0xf1d4e242, 0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777,
+  0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5, 0xd6d6a3e8, 0xa1d1937e,
-  0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c, 0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45,
+  0x38d8c2c4, 0x4fdff252, 0xd1bb67f1, 0xa6bc5767, 0x3fb506dd, 0x48b2364b,
-  0xa00ae278, 0xd70dd2ee, 0x4e048354, 0x3903b3c2, 0xa7672661, 0xd06016f7, 0x4969474d, 0x3e6e77db,
+  0xd80d2bda, 0xaf0a1b4c, 0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55,
-  0xaed16a4a, 0xd9d65adc, 0x40df0b66, 0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9,
+  0x316e8eef, 0x4669be79, 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236,
-  0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605, 0xcdd70693, 0x54de5729, 0x23d967bf,
+  0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f, 0xc5ba3bbe, 0xb2bd0b28,
-  0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94, 0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d
+  0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31, 0x2cd99e8b, 0x5bdeae1d,
+  0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x026d930a, 0x9c0906a9, 0xeb0e363f,
+  0x72076785, 0x05005713, 0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38,
+  0x92d28e9b, 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21, 0x86d3d2d4, 0xf1d4e242,
+  0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777,
+  0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c, 0x8f659eff, 0xf862ae69,
+  0x616bffd3, 0x166ccf45, 0xa00ae278, 0xd70dd2ee, 0x4e048354, 0x3903b3c2,
+  0xa7672661, 0xd06016f7, 0x4969474d, 0x3e6e77db, 0xaed16a4a, 0xd9d65adc,
+  0x40df0b66, 0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9,
+  0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605, 0xcdd70693,
+  0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94,
+  0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d
 };
 #endif
 
-/************************************************************************************************
+/****************************************************************************
  * Public Functions
- ************************************************************************************************/
+ ****************************************************************************/
 
-/************************************************************************************************
+/****************************************************************************
  * Name: crc32part
  *
  * Description:
  *   Continue CRC calculation on a part of the buffer.
  *
- ************************************************************************************************/
+ ****************************************************************************/
 
 uint32_t crc32part(FAR const uint8_t *src, size_t len, uint32_t crc32val)
 {
   size_t i;
+
 #ifdef CONFIG_LIBC_CRC32_SLOW
   for (i = 0; i < len; i++)
     {
@@ -149,13 +166,15 @@ uint32_t crc32part(FAR const uint8_t *src, size_t len, uint32_t crc32val)
   return crc32val;
 }
 
-/************************************************************************************************
+#endif /* CONFIG_LIBC_ARCH_CRC32 */
+
+/****************************************************************************
  * Name: crc32
  *
  * Description:
  *   Return a 32-bit CRC of the contents of the 'src' buffer, length 'len'
  *
- ************************************************************************************************/
+ ****************************************************************************/
 
 uint32_t crc32(FAR const uint8_t *src, size_t len)
 {