From 5a7617136ab68e3fc35a6ea1094f6629109336d3 Mon Sep 17 00:00:00 2001 From: Carl Eugen Hoyos Date: Mon, 26 Nov 2018 00:43:46 +0100 Subject: lavc/jrevdct: Avoid an aliasing violation. Fixes fate on different PowerPC systems with some compilers. Analyzed-by: Lauri Kasanen --- libavcodec/jrevdct.c | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-) (limited to 'libavcodec') diff --git a/libavcodec/jrevdct.c b/libavcodec/jrevdct.c index 3b15a52677..a1a0f571ad 100644 --- a/libavcodec/jrevdct.c +++ b/libavcodec/jrevdct.c @@ -63,6 +63,7 @@ */ #include "libavutil/common.h" +#include "libavutil/intreadwrite.h" #include "dct.h" #include "idctdsp.h" @@ -234,7 +235,7 @@ void ff_j_rev_dct(DCTBLOCK data) * row DCT calculations can be simplified this way. */ - register int *idataptr = (int*)dataptr; + register uint8_t *idataptr = (uint8_t*)dataptr; /* WARNING: we do the same permutation as MMX idct to simplify the video core */ @@ -254,10 +255,10 @@ void ff_j_rev_dct(DCTBLOCK data) int16_t dcval = (int16_t) (d0 * (1 << PASS1_BITS)); register int v = (dcval & 0xffff) | ((dcval * (1 << 16)) & 0xffff0000); - idataptr[0] = v; - idataptr[1] = v; - idataptr[2] = v; - idataptr[3] = v; + AV_WN32A(&idataptr[ 0], v); + AV_WN32A(&idataptr[ 4], v); + AV_WN32A(&idataptr[ 8], v); + AV_WN32A(&idataptr[12], v); } dataptr += DCTSIZE; /* advance pointer to next row */ @@ -974,7 +975,7 @@ void ff_j_rev_dct4(DCTBLOCK data) * row DCT calculations can be simplified this way. */ - register int *idataptr = (int*)dataptr; + register uint8_t *idataptr = (uint8_t*)dataptr; d0 = dataptr[0]; d2 = dataptr[1]; @@ -988,8 +989,8 @@ void ff_j_rev_dct4(DCTBLOCK data) int16_t dcval = (int16_t) (d0 << PASS1_BITS); register int v = (dcval & 0xffff) | ((dcval << 16) & 0xffff0000); - idataptr[0] = v; - idataptr[1] = v; + AV_WN32A(&idataptr[0], v); + AV_WN32A(&idataptr[4], v); } dataptr += DCTSTRIDE; /* advance pointer to next row */ -- cgit v1.2.3