Archives/OpenTTD-patches
2
0
Fork 0
mirror of https://github.com/JGRennison/OpenTTD-patches.git synced 2024-11-16 00:12:51 +00:00
Code Issues Packages Projects Releases Wiki Activity

VarAction2: Remove constant parameter redirection via variable 7B

Browse Source
This commit is contained in:
Jonathan G Rennison 2022-05-25 04:12:44 +01:00
parent 08b83352bf
commit db5be4f92e
1 changed files with 14 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

14
src/newgrf.cpp
View File

@ -5763,6 +5763,20 @@ static void NewSpriteGroup(ByteReader *buf)
case DSGA_OP_RST:
add_inferences_from_mask(adjust.and_mask);
inference |= VA2AIF_PREV_MASK_ADJUST;
if ((prev_inference & VA2AIF_PREV_MASK_ADJUST) && adjust.variable == 0x7B) {
const DeterministicSpriteGroupAdjust &prev = group->adjusts[group->adjusts.size() - 2];
if (prev.variable == 0x1A) {
/* Extract constant to remove indirect access via variable 7B */
DeterministicSpriteGroupAdjust current = group->adjusts.back();
current.variable = current.parameter;
current.parameter = (UINT_MAX >> prev.shift_num) & prev.and_mask;
group->adjusts.pop_back();
group->adjusts.pop_back();
if (group->adjusts.empty()) current.operation = DSGA_OP_ADD;
group->adjusts.push_back(current);
break;
}
}
break;
case DSGA_OP_SHR:
if ((prev_inference & VA2AIF_PREV_MASK_ADJUST) && adjust.variable == 0x1A && adjust.shift_num == 0) {