dave/openttd
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

VarAction2: Add helper functions for anti-commutative ops

Browse Source
This commit is contained in:
Jonathan G Rennison
2022-06-08 19:15:56 +01:00
parent 5db30e559e
commit 31e96ff5e7
2 changed files with 35 additions and 11 deletions
Download Patch File Download Diff File Expand all files Collapse all files

14
src/newgrf.cpp
View File

@@ -6941,20 +6941,12 @@ static std::bitset<256> HandleVarAction2DeadStoreElimination(DeterministicSprite
const DeterministicSpriteGroupAdjust &next2 = group->adjusts[i + 2];
if (next2.type == DSGA_TYPE_NONE && next2.variable == 0x7D && next2.shift_num == 0 &&
next2.and_mask == 0xFFFFFFFF && next2.parameter == prev.and_mask) {
bool found = false;
if (IsEvalAdjustOperationCommutative(next2.operation)) {
/* Convert: store, load var, commutative op on stored --> (dead) store, commutative op var */
next.operation = next2.operation;
if (IsEvalAdjustOperationReversable(next2.operation)) {
/* Convert: store, load var, (anti-)commutative op on stored --> (dead) store, (reversed) (anti-)commutative op var */
next.operation = ReverseEvalAdjustOperation(next2.operation);
if (IsEvalAdjustWithZeroLastValueAlwaysZero(next.operation)) {
next.adjust_flags |= DSGAF_SKIP_ON_ZERO;
}
found = true;
} else if (next2.operation == DSGA_OP_SUB || next2.operation == DSGA_OP_RSUB) {
/* Convert: store, load var, sub/rsub op on stored --> (dead) store, rsub/sub op var */
next.operation = (next2.operation == DSGA_OP_SUB) ? DSGA_OP_RSUB : DSGA_OP_SUB;
found = true;
}
if (found) {
erase_adjust(i + 2);
restart();
break;