Merge pull request #470 from lz4/fasterDec

Faster decoding speed

1 files changed, 8 insertions, 10 deletions

diff --git a/lib/lz4.c b/lib/lz4.c
index 7bf8677..5d4bb21 100644
--- a/lib/lz4.c
+++ b/lib/lz4.c
@@ -270,11 +270,6 @@ static void LZ4_writeLE16(void* memPtr, U16 value)
     }
 }
 
-static void LZ4_copy8(void* dst, const void* src)
-{
-    memcpy(dst,src,8);
-}
-
 /* customized variant of memcpy, which can overwrite up to 8 bytes beyond dstEnd */
 LZ4_FORCE_O2_INLINE_GCC_PPC64LE
 void LZ4_wildCopy(void* dstPtr, const void* srcPtr, void* dstEnd)
@@ -283,7 +278,7 @@ void LZ4_wildCopy(void* dstPtr, const void* srcPtr, void* dstEnd)
     const BYTE* s = (const BYTE*)srcPtr;
     BYTE* const e = (BYTE*)dstEnd;
 
-    do { LZ4_copy8(d,s); d+=8; s+=8; } while (d<e);
+    do { memcpy(d,s,8); d+=8; s+=8; } while (d<e);
 }
 
 
@@ -1220,10 +1215,13 @@ LZ4_FORCE_INLINE int LZ4_decompress_generic(
             size_t const ll = token >> ML_BITS;
             size_t const off = LZ4_readLE16(ip+ll);
             const BYTE* const matchPtr = op + ll - off;  /* pointer underflow risk ? */
-            if ((off >= 18) /* do not deal with overlapping matches */ & (matchPtr >= lowPrefix)) {
+            if ((off >= 8) /* do not deal with overlapping matches */ & (matchPtr >= lowPrefix)) {
                 size_t const ml = (token & ML_MASK) + MINMATCH;
                 memcpy(op, ip, 16); op += ll; ip += ll + 2 /*offset*/;
-                memcpy(op, matchPtr, 18); op += ml;
+                memcpy(op + 0, matchPtr + 0, 8);
+                memcpy(op + 8, matchPtr + 8, 8);
+                memcpy(op +16, matchPtr +16, 2);
+                op += ml;
                 continue;
             }
         }
@@ -1313,7 +1311,7 @@ LZ4_FORCE_INLINE int LZ4_decompress_generic(
             match += inc32table[offset];
             memcpy(op+4, match, 4);
             match -= dec64table[offset];
-        } else { LZ4_copy8(op, match); match+=8; }
+        } else { memcpy(op, match, 8); match+=8; }
         op += 8;
 
         if (unlikely(cpy>oend-12)) {
@@ -1326,7 +1324,7 @@ LZ4_FORCE_INLINE int LZ4_decompress_generic(
             }
             while (op<cpy) *op++ = *match++;
         } else {
-            LZ4_copy8(op, match);
+            memcpy(op, match, 8);
             if (length>16) LZ4_wildCopy(op+8, match+8, cpy);
         }
         op = cpy;   /* correction */