ggml : fix comment

Author: ggerganov

ggml.c

@@ -492,7 +492,10 @@ static inline __m128i packNibbles( __m128i bytes1, __m128i bytes2 )
 #endif
 
 #if __ARM_NEON
-// check if ARMv8 is not available
+
+// TODO: this check is wrong
+//       we have to check somehow if vaddvq_u8, vzp1q_u8, etc are available, but I don't know how
+//       at least, this works on my 32-bit RPi4
 #if !defined(__ARM_FEATURE_QRDMX)
 
 inline static uint16_t vaddvq_u8(uint8x16_t v) {