bitscan add undef check

This commit is contained in:
Bimba Shrestha
2020-03-05 11:52:15 -08:00
parent bc0e10ae78
commit a75e5f2ffc
3 changed files with 6 additions and 12 deletions
+4 -8
View File
@@ -448,8 +448,7 @@ static unsigned ZSTD_NbCommonBytes (size_t val)
if (MEM_64bits()) {
# if defined(_MSC_VER) && defined(_WIN64)
unsigned long r = 0;
_BitScanForward64( &r, (U64)val );
return (unsigned)(r>>3);
return _BitScanForward64( &r, (U64)val ) ? (unsigned)(r >> 3) : 0;
# elif defined(__GNUC__) && (__GNUC__ >= 4)
return (__builtin_ctzll((U64)val) >> 3);
# else
@@ -466,8 +465,7 @@ static unsigned ZSTD_NbCommonBytes (size_t val)
} else { /* 32 bits */
# if defined(_MSC_VER)
unsigned long r=0;
_BitScanForward( &r, (U32)val );
return (unsigned)(r>>3);
_BitScanForward( &r, (U32)val ) ? return (unsigned)(r >> 3) : 0;
# elif defined(__GNUC__) && (__GNUC__ >= 3)
return (__builtin_ctz((U32)val) >> 3);
# else
@@ -482,8 +480,7 @@ static unsigned ZSTD_NbCommonBytes (size_t val)
if (MEM_64bits()) {
# if defined(_MSC_VER) && defined(_WIN64)
unsigned long r = 0;
_BitScanReverse64( &r, val );
return (unsigned)(r>>3);
_BitScanReverse64( &r, val ) ? (unsigned)(r >> 3) : 0;
# elif defined(__GNUC__) && (__GNUC__ >= 4)
return (__builtin_clzll(val) >> 3);
# else
@@ -497,8 +494,7 @@ static unsigned ZSTD_NbCommonBytes (size_t val)
} else { /* 32 bits */
# if defined(_MSC_VER)
unsigned long r = 0;
_BitScanReverse( &r, (unsigned long)val );
return (unsigned)(r>>3);
_BitScanReverse( &r, (unsigned long)val ) ? (unsigned)(r >> 3) : 0;
# elif defined(__GNUC__) && (__GNUC__ >= 3)
return (__builtin_clz((U32)val) >> 3);
# else