[U-Boot] [PATCH] crc32: minor cleanups and smaller size.

[Joakim Tjernlund]

Don't optimize for len < 4. This reduces size with
8 bytes too.

This crc32 impl is smaller that the orginal if crc32
and crc32_no_comp is impl. two separate functions(like the orginal).
That would, however, be a waste of space when both are defined.

Signed-off-by: Joakim Tjernlund <Joakim.Tjernlund at transmode.se>
---
 lib_generic/crc32.c |   44 +++++++++++++++++++++-----------------------
 1 files changed, 21 insertions(+), 23 deletions(-)

diff --git a/lib_generic/crc32.c b/lib_generic/crc32.c
index 05b1431..737587a 100644
--- a/lib_generic/crc32.c
+++ b/lib_generic/crc32.c
@@ -14,6 +14,7 @@
 #include <stdint.h>
 #endif
 #include <asm/byteorder.h>
+#include <u-boot/crc.h>
 
 #if defined(CONFIG_HW_WATCHDOG) || defined(CONFIG_WATCHDOG)
 #include <watchdog.h>
@@ -175,47 +176,44 @@ const uint32_t * ZEXPORT get_crc_table()
 /* No ones complement version. JFFS2 (and other things ?)
  * don't use ones compliment in their CRC calculations.
  */
-uint32_t ZEXPORT crc32_no_comp(uint32_t crc, const Bytef *p, uInt len)
+uint32_t ZEXPORT crc32_no_comp(uint32_t crc, const Bytef *buf, uInt len)
 {
     const uint32_t *tab = crc_table;
-    const uint32_t *b =(uint32_t *)p;
-
+    const uint32_t *b =(uint32_t *)buf;
+    size_t save_len;
 #ifdef DYNAMIC_CRC_TABLE
     if (crc_table_empty)
       make_crc_table();
 #endif
     crc = __cpu_to_le32(crc);
     /* Align it */
-    if(((long)b)&3 && len){
+    if(((long)b)&3 && len) {
 	 do {
 	      uint8_t *p = (uint8_t *)b;
 	      DO_CRC(*p++);
 	      b = (void *)p;
 	 } while ((--len) && ((long)b)&3 );
     }
-    if(len >= 4){
+
+    save_len = len & 3;
+    len = len >> 2;
+    for (--b; len; --len) {
 	 /* load data 32 bits wide, xor data 32 bits wide. */
-	 size_t save_len = len & 3;
-	 len = len >> 2;
-	 --b; /* use pre increment below(*++b) for speed */
-	 do {
-	      crc ^= *++b;
-	      DO_CRC(0);
-	      DO_CRC(0);
-	      DO_CRC(0);
-	      DO_CRC(0);
-	 } while (--len);
-	 b++; /* point to next byte(s) */
-	 len = save_len;
+	 crc ^= *++b; /* use pre increment below(*++b) for speed */
+	 DO_CRC(0);
+	 DO_CRC(0);
+	 DO_CRC(0);
+	 DO_CRC(0);
     }
+    b++; /* point to next byte(s) */
+    len = save_len;
     /* And the last few bytes */
-    if(len){
-	 do {
-	      uint8_t *p = (uint8_t *)b;
-	      DO_CRC(*p++);
-	      b = (void *)p;
-	 } while (--len);
+    for (; len; --len) {
+	 uint8_t *p = (uint8_t *)b;
+	 DO_CRC(*p++);
+	 b = (void *)p;
     }
+
     return __le32_to_cpu(crc);
 }
 #undef DO_CRC
-- 
1.6.4.4