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Fix negative shift left reported by UBSan (#758)

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Follow-up of #757

This shall have no performance impact on 2’s complement machine where
the compiler replaces the multiplication by power of two (constant) by
a left shift.
Verified at least on MacOS Xcode 7.3, same assembly generated after fix.
This commit is contained in:
Matthieu Darbois 2016-04-27 21:56:09 +02:00
parent 2296dc9e68
commit e6881e7527
2 changed files with 2 additions and 2 deletions
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2
src/lib/openjp2/t1.c
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@ -1514,7 +1514,7 @@ OPJ_BOOL opj_t1_encode_cblks( opj_t1_t *t1,
if (tccp->qmfbid == 1) {
for (j = 0; j < cblk_h; ++j) {
for (i = 0; i < cblk_w; ++i) {
tiledp[tileIndex] *= 1 << T1_NMSEDEC_FRACBITS;
tiledp[tileIndex] *= (1 << T1_NMSEDEC_FRACBITS);
tileIndex++;
}
tileIndex += tileLineAdvance;

2
src/lib/openjp2/tcd.c
View File

@ -1911,7 +1911,7 @@ static OPJ_BOOL opj_tcd_dc_level_shift_encode ( opj_tcd_t *p_tcd )
}
else {
for (i = 0; i < l_nb_elem; ++i) {
*l_current_ptr = (*l_current_ptr - l_tccp->m_dc_level_shift) << 11 ;
*l_current_ptr = (*l_current_ptr - l_tccp->m_dc_level_shift) * (1 << 11);
++l_current_ptr;
}
}