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ff_check_alignment to warn the user about a missaligned stack

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Originally committed as revision 7249 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Michael Niedermayer 2006-12-07 18:33:00 +00:00
parent f95778f80d
commit 6dc7d5da70
3 changed files with 28 additions and 0 deletions
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20
libavcodec/dsputil.c
View File

@ -3801,11 +3801,31 @@ void dsputil_static_init(void)
for(i=0; i<64; i++) inv_zigzag_direct16[ff_zigzag_direct[i]]= i+1;
}
int ff_check_alignment(void){
static int did_fail=0;
DECLARE_ALIGNED_16(int, aligned);
if((int)&aligned & 15){
if(!did_fail){
#if defined(HAVE_MMX) || defined(HAVE_ALTIVEC)
av_log(NULL, AV_LOG_ERROR,
"Compiler did not align stack variables, your code has been misscompiled\n"
"and may crash, this is not a bug in the application but in the compiler\n"
"so reporting it anywhere but to the compiler maintainers is senseless!\n");
#endif
did_fail=1;
}
return -1;
}
return 0;
}
void dsputil_init(DSPContext* c, AVCodecContext *avctx)
{
int i;
ff_check_alignment();
#ifdef CONFIG_ENCODERS
if(avctx->dct_algo==FF_DCT_FASTINT) {
c->fdct = fdct_ifast;

2
libavcodec/dsputil.h
View File

@ -410,6 +410,8 @@ typedef struct DSPContext {
void dsputil_static_init(void);
void dsputil_init(DSPContext* p, AVCodecContext *avctx);
int ff_check_alignment(void);
/**
* permute block according to permuatation.
* @param last last non zero element in scantable order

6
libavcodec/mpegvideo.c
View File

@ -4838,6 +4838,8 @@ static int pre_estimate_motion_thread(AVCodecContext *c, void *arg){
static int estimate_motion_thread(AVCodecContext *c, void *arg){
MpegEncContext *s= arg;
ff_check_alignment();
s->me.dia_size= s->avctx->dia_size;
s->first_slice_line=1;
for(s->mb_y= s->start_mb_y; s->mb_y < s->end_mb_y; s->mb_y++) {
@ -4864,6 +4866,8 @@ static int mb_var_thread(AVCodecContext *c, void *arg){
MpegEncContext *s= arg;
int mb_x, mb_y;
ff_check_alignment();
for(mb_y=s->start_mb_y; mb_y < s->end_mb_y; mb_y++) {
for(mb_x=0; mb_x < s->mb_width; mb_x++) {
int xx = mb_x * 16;
@ -4911,6 +4915,8 @@ static int encode_thread(AVCodecContext *c, void *arg){
PutBitContext pb[2], pb2[2], tex_pb[2];
//printf("%d->%d\n", s->resync_mb_y, s->end_mb_y);
ff_check_alignment();
for(i=0; i<2; i++){
init_put_bits(&pb [i], bit_buf [i], MAX_MB_BYTES);
init_put_bits(&pb2 [i], bit_buf2 [i], MAX_MB_BYTES);