1 files changed, 8 insertions, 1 deletions

diff --git a/lib/rbcodec/codecs/libopus/silk/arm/macros_armv5e.h b/lib/rbcodec/codecs/libopus/silk/arm/macros_armv5e.h
index aad4117e46..b14ec65ddb 100644
--- a/lib/rbcodec/codecs/libopus/silk/arm/macros_armv5e.h
+++ b/lib/rbcodec/codecs/libopus/silk/arm/macros_armv5e.h
@@ -29,6 +29,11 @@ POSSIBILITY OF SUCH DAMAGE.
 #ifndef SILK_MACROS_ARMv5E_H
 #define SILK_MACROS_ARMv5E_H
 
+/* This macro only avoids the undefined behaviour from a left shift of
+   a negative value. It should only be used in macros that can't include
+   SigProc_FIX.h. In other cases, use silk_LSHIFT32(). */
+#define SAFE_SHL(a,b) ((opus_int32)((opus_uint32)(a) << (b)))
+
 /* (a32 * (opus_int32)((opus_int16)(b32))) >> 16 output have to be 32bit int */
 #undef silk_SMULWB
 static OPUS_INLINE opus_int32 silk_SMULWB_armv5e(opus_int32 a, opus_int16 b)
@@ -190,7 +195,7 @@ static OPUS_INLINE opus_int32 silk_CLZ16_armv5(opus_int16 in16)
       "#silk_CLZ16\n\t"
       "clz %0, %1;\n"
       : "=r"(res)
-      : "r"(in16<<16|0x8000)
+      : "r"(SAFE_SHL(in16,16)|0x8000)
   );
   return res;
 }
@@ -210,4 +215,6 @@ static OPUS_INLINE opus_int32 silk_CLZ32_armv5(opus_int32 in32)
 }
 #define silk_CLZ32(in32) (silk_CLZ32_armv5(in32))
 
+#undef SAFE_SHL
+
 #endif /* SILK_MACROS_ARMv5E_H */