Update unicoder.cpp (#1584)

CheckForInvalidUtf8 performance improvement

diff --git a/Src/Common/unicoder.cpp b/Src/Common/unicoder.cpp
index e499db2..37f2381 100644 (file)
--- a/Src/Common/unicoder.cpp
+++ b/Src/Common/unicoder.cpp
@@ -1134,18 +1134,19 @@ bool CheckForInvalidUtf8(const char* pBuffer, size_t size)
        for (unsigned char* pb = (unsigned char*)pBuffer, *end = pb + size; pb < end;)
        {
                unsigned c = *pb++;
-               if ((c == 0xC0) || (c == 0xC1) || (c >= 0xF5))
-                       return true;
-
+               
                if (!(c & 0x80)) continue;
+               
+               if ((c >= 0xF5) || (c == 0xC0) || (c == 0xC1))
+                       return true;
 
-               uint32_t v = 0x80808080;
+               uint32_t v = 0x80808000; //1st 0-byte covers scenario if no any next "if" fired at all
 
                if ((c & 0xE0) == 0xC0)
                {
                        if (pb == end)
                                return true;
-                       reinterpret_cast<unsigned char*>(&v)[0] = *pb++;
+                       *reinterpret_cast<unsigned char*>(&v) = *pb++;
                }
                else if ((c & 0xF0) == 0xE0)
                {
@@ -1164,8 +1165,6 @@ bool CheckForInvalidUtf8(const char* pBuffer, size_t size)
                        reinterpret_cast<uint8_t*>(&v)[2] = pb[2];
                        pb += 3;
                }
-               else
-                       return true;
 
                if ((v & (0xC0C0C0C0)) != 0x80808080)
                        return true;