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VarAction2: Optimise SAR same as SHR on unsigned inputs

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Jonathan G Rennison
2022-06-06 22:47:53 +01:00
parent 9d04ebcc90
commit 236cbc4e83
1 changed files with 3 additions and 1 deletions
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4
src/newgrf.cpp
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@@ -6229,7 +6229,9 @@ static void OptimiseVarAction2Adjust(VarAction2OptimiseState &state, const GrfSp
} }
break; break;
case DSGA_OP_SHR: case DSGA_OP_SHR:
if ((prev_inference & VA2AIF_PREV_MASK_ADJUST) && adjust.variable == 0x1A && adjust.shift_num == 0 && group->adjusts.size() >= 2) { case DSGA_OP_SAR:
if ((adjust.operation == DSGA_OP_SAR || (prev_inference & VA2AIF_SIGNED_NON_NEGATIVE)) &&
((prev_inference & VA2AIF_PREV_MASK_ADJUST) && adjust.variable == 0x1A && adjust.shift_num == 0 && group->adjusts.size() >= 2)) {
/* Propagate shift right into immediately prior variable read */ /* Propagate shift right into immediately prior variable read */
DeterministicSpriteGroupAdjust &prev = group->adjusts[group->adjusts.size() - 2]; DeterministicSpriteGroupAdjust &prev = group->adjusts[group->adjusts.size() - 2];
if (prev.shift_num + adjust.and_mask < 32) { if (prev.shift_num + adjust.and_mask < 32) {