From 8da1defe6986aab8506203c6e12f44d4df62672e Mon Sep 17 00:00:00 2001 From: Christophe Gisquet Date: Thu, 10 Jul 2014 20:49:06 +0200 Subject: libavutil: document side effects of macros Signed-off-by: Michael Niedermayer --- libavutil/intreadwrite.h | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'libavutil/intreadwrite.h') diff --git a/libavutil/intreadwrite.h b/libavutil/intreadwrite.h index 7ee6977554..51fbe30a23 100644 --- a/libavutil/intreadwrite.h +++ b/libavutil/intreadwrite.h @@ -50,6 +50,14 @@ typedef union { * AV_[RW][BLN](16|24|32|48|64) and AV_(COPY|SWAP|ZERO)(64|128) macros. * Preprocessor symbols must be defined, even if these are implemented * as inline functions. + * + * R/W means read/write, B/L/N means big/little/native endianness. + * The following macros require aligned access, compared to their + * unaligned variants: AV_(COPY|SWAP|ZERO)(64|128), AV_[RW]N[8-64]A. + * Incorrect usage may range from abysmal performance to crash + * depending on the platform. + * + * The unaligned variants are AV_[RW][BLN][8-64] and AV_COPY*U. */ #ifdef HAVE_AV_CONFIG_H -- cgit v1.2.3