From: Bimba Shrestha <bimbashrestha@fb.com>
Date: Thu, 5 Mar 2020 19:52:15 +0000 (-0800)
Subject: bitscan add undef check
X-Git-Tag: v1.4.5^2~78^2~2
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a75e5f2ffc46ac771e41a273cc2a9d932a52fc67;p=thirdparty%2Fzstd.git

bitscan add undef check
---

diff --git a/lib/common/bitstream.h b/lib/common/bitstream.h
index fe3148eeb..c84c0ed91 100644
--- a/lib/common/bitstream.h
+++ b/lib/common/bitstream.h
@@ -162,8 +162,7 @@ MEM_STATIC unsigned BIT_highbit32 (U32 val)
     {
 #   if defined(_MSC_VER)   /* Visual */
         unsigned long r=0;
-        _BitScanReverse ( &r, val );
-        return (unsigned) r;
+        _BitScanReverse ( &r, val ) ? (unsigned)r : 0;
 #   elif defined(__GNUC__) && (__GNUC__ >= 3)   /* Use GCC Intrinsic */
         return __builtin_clz (val) ^ 31;
 #   elif defined(__ICCARM__)    /* IAR Intrinsic */
diff --git a/lib/common/zstd_internal.h b/lib/common/zstd_internal.h
index d0b014358..1b0231314 100644
--- a/lib/common/zstd_internal.h
+++ b/lib/common/zstd_internal.h
@@ -298,8 +298,7 @@ MEM_STATIC U32 ZSTD_highbit32(U32 val)   /* compress, dictBuilder, decodeCorpus
     {
 #   if defined(_MSC_VER)   /* Visual */
         unsigned long r=0;
-        _BitScanReverse(&r, val);
-        return (unsigned)r;
+        _BitScanReverse(&r, val) ? (unsigned)r : 0;
 #   elif defined(__GNUC__) && (__GNUC__ >= 3)   /* GCC Intrinsic */
         return __builtin_clz (val) ^ 31;
 #   elif defined(__ICCARM__)    /* IAR Intrinsic */
diff --git a/lib/compress/zstd_compress_internal.h b/lib/compress/zstd_compress_internal.h
index 243f0e075..8fd08dad3 100644
--- a/lib/compress/zstd_compress_internal.h
+++ b/lib/compress/zstd_compress_internal.h
@@ -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