WT-2873 Refactor CRC32 code (#3000)

* Add --enable-crc32-hardware configuration option (configured on by default), which allows CRC32 hardware support to be turned off.

* Move the CRC32 implementation in software from the x86-specific code to software/checksum.c, leave the x86-specific code in x86/crc32-x86.c.

* Move the pointer to the checksum function from a file static to the WT_PROCESS.cksum field, change the __wt_cksum_init() function to set that field.

* WT-2882 Create CRC32 Hardware implementation for ARM8

* Change "cksum" to "checksum" everywhere (hopefully) no semantic changes.

4 files changed, 30 insertions, 73 deletions

diff --git a/test/csuite/Makefile.am b/test/csuite/Makefile.am
index b8a62b69612..15db2fbcf46 100644
--- a/test/csuite/Makefile.am
+++ b/test/csuite/Makefile.am
@@ -1,6 +1,5 @@
 AM_CPPFLAGS = -I$(top_builddir) -I$(top_srcdir)/src/include \
-    -I$(top_srcdir)/test/utility \
-    -DCRC_PATH="\"$(top_srcdir)/src/checksum/x86/checksum.c\""
+    -I$(top_srcdir)/test/utility
 LDADD = $(top_builddir)/test/utility/libtest_util.la \
     $(top_builddir)/libwiredtiger.la
 AM_LDFLAGS = -static
@@ -20,7 +19,7 @@ noinst_PROGRAMS += test_wt2535_insert_race
 test_wt2447_join_main_table_SOURCES = wt2447_join_main_table/main.c
 noinst_PROGRAMS += test_wt2447_join_main_table
 
-test_wt2695_checksum_SOURCES = wt2695_checksum/main.c wt2695_checksum/sw.c
+test_wt2695_checksum_SOURCES = wt2695_checksum/main.c
 noinst_PROGRAMS += test_wt2695_checksum
 
 test_wt2592_join_schema_SOURCES = wt2592_join_schema/main.c
diff --git a/test/csuite/wt2695_checksum/main.c b/test/csuite/wt2695_checksum/main.c
index dc6f5b5cd87..df6f562f719 100644
--- a/test/csuite/wt2695_checksum/main.c
+++ b/test/csuite/wt2695_checksum/main.c
@@ -34,8 +34,6 @@
 
 void (*custom_die)(void) = NULL;
 
-uint32_t cksum_sw(const void *, size_t);
-
 static inline void
 check(uint32_t hw, uint32_t sw, size_t len, const char *msg)
 {
@@ -61,57 +59,66 @@ main(void)
 	testutil_check(__wt_random_init_seed(NULL, &rnd));
 
 	/* Initialize the WiredTiger library checksum functions. */
-	__wt_cksum_init();
+	__wt_checksum_init();
 
 	/*
 	 * Some simple known checksums.
 	 */
 	len = 1;
-	hw = __wt_cksum(data, len);
+	hw = __wt_checksum(data, len);
 	check(hw, (uint32_t)0x527d5351, len, "nul x1: hardware");
-	sw = cksum_sw(data, len);
+	sw = __wt_checksum_sw(data, len);
 	check(sw, (uint32_t)0x527d5351, len, "nul x1: software");
 
 	len = 2;
-	hw = __wt_cksum(data, len);
+	hw = __wt_checksum(data, len);
 	check(hw, (uint32_t)0xf16177d2, len, "nul x2: hardware");
-	sw = cksum_sw(data, len);
+	sw = __wt_checksum_sw(data, len);
 	check(sw, (uint32_t)0xf16177d2, len, "nul x2: software");
 
 	len = 3;
-	hw = __wt_cksum(data, len);
+	hw = __wt_checksum(data, len);
 	check(hw, (uint32_t)0x6064a37a, len, "nul x3: hardware");
-	sw = cksum_sw(data, len);
+	sw = __wt_checksum_sw(data, len);
 	check(sw, (uint32_t)0x6064a37a, len, "nul x3: software");
 
 	len = 4;
-	hw = __wt_cksum(data, len);
+	hw = __wt_checksum(data, len);
 	check(hw, (uint32_t)0x48674bc7, len, "nul x4: hardware");
-	sw = cksum_sw(data, len);
+	sw = __wt_checksum_sw(data, len);
 	check(sw, (uint32_t)0x48674bc7, len, "nul x4: software");
 
 	len = strlen("123456789");
 	memcpy(data, "123456789", len);
-	hw = __wt_cksum(data, len);
+	hw = __wt_checksum(data, len);
 	check(hw, (uint32_t)0xe3069283, len, "known string #1: hardware");
-	sw = cksum_sw(data, len);
+	sw = __wt_checksum_sw(data, len);
 	check(sw, (uint32_t)0xe3069283, len, "known string #1: software");
 
 	len = strlen("The quick brown fox jumps over the lazy dog");
 	memcpy(data, "The quick brown fox jumps over the lazy dog", len);
-	hw = __wt_cksum(data, len);
+	hw = __wt_checksum(data, len);
 	check(hw, (uint32_t)0x22620404, len, "known string #2: hardware");
-	sw = cksum_sw(data, len);
+	sw = __wt_checksum_sw(data, len);
 	check(sw, (uint32_t)0x22620404, len, "known string #2: software");
 
 	/*
+	 * Offset the string by 1 to ensure the hardware code handles unaligned
+	 * reads.
+	 */
+	hw = __wt_checksum(data + 1, len - 1);
+	check(hw, (uint32_t)0xae11f7f5, len, "known string #2: hardware");
+	sw = __wt_checksum_sw(data + 1, len - 1);
+	check(sw, (uint32_t)0xae11f7f5, len, "known string #2: software");
+
+	/*
 	 * Checksums of power-of-two data chunks.
 	 */
 	for (i = 0, len = 512; i < 1000; ++i) {
 		for (j = 0; j < len; ++j)
 			data[j] = __wt_random(&rnd) & 0xff;
-		hw = __wt_cksum(data, len);
-		sw = cksum_sw(data, len);
+		hw = __wt_checksum(data, len);
+		sw = __wt_checksum_sw(data, len);
 		check(hw, sw, len, "random power-of-two");
 
 		len *= 2;
@@ -126,8 +133,8 @@ main(void)
 		len = __wt_random(&rnd) % DATASIZE;
 		for (j = 0; j < len; ++j)
 			data[j] = __wt_random(&rnd) & 0xff;
-		hw = __wt_cksum(data, len);
-		sw = cksum_sw(data, len);
+		hw = __wt_checksum(data, len);
+		sw = __wt_checksum_sw(data, len);
 		check(hw, sw, len, "random");
 	}
 
diff --git a/test/csuite/wt2695_checksum/sw.c b/test/csuite/wt2695_checksum/sw.c
deleted file mode 100644
index 892d9480bf3..00000000000
--- a/test/csuite/wt2695_checksum/sw.c
+++ /dev/null
@@ -1,49 +0,0 @@
-/*-
- * Public Domain 2014-2016 MongoDB, Inc.
- * Public Domain 2008-2014 WiredTiger, Inc.
- *
- * This is free and unencumbered software released into the public domain.
- *
- * Anyone is free to copy, modify, publish, use, compile, sell, or
- * distribute this software, either in source code form or as a compiled
- * binary, for any purpose, commercial or non-commercial, and by any
- * means.
- *
- * In jurisdictions that recognize copyright laws, the author or authors
- * of this software dedicate any and all copyright interest in the
- * software to the public domain. We make this dedication for the benefit
- * of the public at large and to the detriment of our heirs and
- * successors. We intend this dedication to be an overt act of
- * relinquishment in perpetuity of all present and future rights to this
- * software under copyright law.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
- * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
- * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
- * IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
- * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
- * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
- * OTHER DEALINGS IN THE SOFTWARE.
- */
-#include "test_util.h"
-
-/*
- * Build the software version of the CRC code.
- */
-#define	__wt_cksum	__wt_cksum_notused
-uint32_t __wt_cksum_notused(const void *, size_t);
-#define	__wt_cksum_init	__wt_cksum_init_notused
-void __wt_cksum_init_notused(void);
-
-#include CRC_PATH
-
-/*
- * cksum_sw --
- *      Checksum in software.
- */
-uint32_t cksum_sw(const void *, size_t);
-uint32_t
-cksum_sw(const void *chunk, size_t len)
-{
-	return (__wt_cksum_sw(chunk, len));
-}
diff --git a/test/salvage/salvage.c b/test/salvage/salvage.c
index c3349188623..bad0167ca8e 100644
--- a/test/salvage/salvage.c
+++ b/test/salvage/salvage.c
@@ -602,8 +602,8 @@ copy(u_int gen, u_int recno)
 			dsk->recno = recno;
 		dsk->write_gen = gen;
 		blk = WT_BLOCK_HEADER_REF(buf);
-		blk->cksum = 0;
-		blk->cksum = __wt_cksum(dsk, PSIZE);
+		blk->checksum = 0;
+		blk->checksum = __wt_checksum(dsk, PSIZE);
 		CHECK(fwrite(buf, 1, PSIZE, ofp) == PSIZE);
 	}