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VarAction2: Avoid group variable tracking coupling through shared procs

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Output dependencies on a procedure shouldn't propagate into input
dependencies on unrelated call sites in different groups
This commit is contained in:
Jonathan G Rennison
2022-08-10 18:30:09 +01:00
parent 00e32162a1
commit 3d59c961a6
1 changed files with 43 additions and 22 deletions
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65
src/newgrf.cpp
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@@ -101,6 +101,7 @@ static const uint32 OPENTTD_GRAPHICS_BASE_GRF_ID = BSWAP32(0xFF4F5400);
struct VarAction2GroupVariableTracking {
std::bitset<256> in;
std::bitset<256> out;
std::bitset<256> proc_call_out;
};
struct VarAction2ProcedureAnnotation {
@@ -7377,10 +7378,14 @@ static bool CheckDeterministicSpriteGroupOutputVarBits(const DeterministicSprite
return true;
};
if (procedure_dse_ok()) {
std::bitset<256> new_out = bits | var_tracking->out;
if (new_out != var_tracking->out) {
var_tracking->out = new_out;
CheckDeterministicSpriteGroupOutputVarBits(sub, new_out, false);
std::bitset<256> new_proc_call_out = bits | var_tracking->proc_call_out;
if (new_proc_call_out != var_tracking->proc_call_out) {
var_tracking->proc_call_out = new_proc_call_out;
std::bitset<256> old_total = var_tracking->out | var_tracking->proc_call_out;
std::bitset<256> new_total = var_tracking->out | new_proc_call_out;
if (old_total != new_total) {
CheckDeterministicSpriteGroupOutputVarBits(sub, new_total, false);
}
}
} else {
RecursiveDisallowDSEForProcedure(sub);
@@ -7399,7 +7404,7 @@ static bool OptimiseVarAction2DeterministicSpriteGroupExpensiveVarsInner(Determi
btree::btree_map<uint64, uint32> seen_expensive_variables;
std::bitset<256> usable_vars;
if (var_tracking != nullptr) {
usable_vars = ~var_tracking->out;
usable_vars = ~(var_tracking->out | var_tracking->proc_call_out);
} else {
usable_vars.set();
}
@@ -7798,7 +7803,7 @@ static std::vector<VarAction2ProcedureCallVarReadAnnotation> _varaction2_proc_ca
static void OptimiseVarAction2DeterministicSpriteGroupPopulateLastVarReadAnnotations(DeterministicSpriteGroup *group, VarAction2GroupVariableTracking *var_tracking)
{
std::bitset<256> bits;
if (var_tracking != nullptr) bits = var_tracking->out;
if (var_tracking != nullptr) bits = (var_tracking->out | var_tracking->proc_call_out);
bool need_var1C = false;
for (int i = (int)group->adjusts.size() - 1; i >= 0; i--) {
@@ -8187,14 +8192,19 @@ static void OptimiseVarAction2DeterministicSpriteGroup(VarAction2OptimiseState &
static std::bitset<256> HandleVarAction2DeadStoreElimination(DeterministicSpriteGroup *group, VarAction2GroupVariableTracking *var_tracking, bool no_changes)
{
std::bitset<256> bits;
std::bitset<256> all_bits;
std::bitset<256> propagate_bits;
std::vector<uint> substitution_candidates;
if (var_tracking != nullptr) bits = var_tracking->out;
if (var_tracking != nullptr) {
propagate_bits = var_tracking->out;
all_bits = propagate_bits | var_tracking->proc_call_out;
}
bool need_var1C = false;
auto abandon_substitution_candidates = [&]() {
for (uint value : substitution_candidates) {
bits.set(value & 0xFF, true);
all_bits.set(value & 0xFF, true);
propagate_bits.set(value & 0xFF, true);
}
substitution_candidates.clear();
};
@@ -8234,9 +8244,11 @@ static std::bitset<256> HandleVarAction2DeadStoreElimination(DeterministicSprite
pending_restart = false;
i = (int)group->adjusts.size() - 1;
if (var_tracking != nullptr) {
bits = var_tracking->out;
propagate_bits = var_tracking->out;
all_bits = propagate_bits | var_tracking->proc_call_out;
} else {
bits.reset();
all_bits.reset();
propagate_bits.reset();
}
substitution_candidates.clear();
need_var1C = false;
@@ -8255,7 +8267,8 @@ static std::bitset<256> HandleVarAction2DeadStoreElimination(DeterministicSprite
bool substituted = try_variable_substitution(target, i - 1, idx);
if (!substituted) {
/* Not usable, mark as required so it's not eliminated */
bits.set(idx, true);
all_bits.set(idx, true);
propagate_bits.set(idx, true);
}
substitution_candidates[j] = substitution_candidates.back();
substitution_candidates.pop_back();
@@ -8263,7 +8276,7 @@ static std::bitset<256> HandleVarAction2DeadStoreElimination(DeterministicSprite
}
}
if (!bits[idx] && !no_changes) {
if (!all_bits[idx] && !no_changes) {
/* Redundant store */
erase_adjust(i);
i--;
@@ -8360,7 +8373,8 @@ static std::bitset<256> HandleVarAction2DeadStoreElimination(DeterministicSprite
continue;
} else {
/* Non-redundant store */
bits.set(idx, false);
all_bits.set(idx, false);
propagate_bits.set(idx, false);
}
} else {
/* Unpredictable store */
@@ -8369,11 +8383,12 @@ static std::bitset<256> HandleVarAction2DeadStoreElimination(DeterministicSprite
}
if (adjust.variable == 0x7B && adjust.parameter == 0x7D) {
/* Unpredictable load */
bits.set();
all_bits.set();
propagate_bits.set();
abandon_substitution_candidates();
}
if (adjust.variable == 0x7D && adjust.parameter < 0x100) {
if (i > 0 && !bits[adjust.parameter] && !no_changes) {
if (i > 0 && !all_bits[adjust.parameter] && !no_changes) {
/* See if this can be made a substitution candidate */
bool add = true;
for (size_t j = 0; j < substitution_candidates.size(); j++) {
@@ -8381,7 +8396,8 @@ static std::bitset<256> HandleVarAction2DeadStoreElimination(DeterministicSprite
/* There already is a candidate */
substitution_candidates[j] = substitution_candidates.back();
substitution_candidates.pop_back();
bits.set(adjust.parameter, true);
all_bits.set(adjust.parameter, true);
propagate_bits.set(adjust.parameter, true);
add = false;
break;
}
@@ -8390,7 +8406,8 @@ static std::bitset<256> HandleVarAction2DeadStoreElimination(DeterministicSprite
substitution_candidates.push_back(adjust.parameter | (i << 8));
}
} else {
bits.set(adjust.parameter, true);
all_bits.set(adjust.parameter, true);
propagate_bits.set(adjust.parameter, true);
}
}
if (adjust.variable == 0x1C) {
@@ -8403,7 +8420,7 @@ static std::bitset<256> HandleVarAction2DeadStoreElimination(DeterministicSprite
bool may_remove = !need_var1C;
if (may_remove && anno->unskippable) may_remove = false;
if (may_remove && (anno->stores & bits).any()) may_remove = false;
if (may_remove && (anno->stores & all_bits).any()) may_remove = false;
if (may_remove) {
if ((i + 1 < (int)group->adjusts.size() && group->adjusts[i + 1].operation == DSGA_OP_RST && group->adjusts[i + 1].variable != 0x7B) ||
@@ -8432,7 +8449,10 @@ static std::bitset<256> HandleVarAction2DeadStoreElimination(DeterministicSprite
} else if (sg->type == SGT_DETERMINISTIC) {
const DeterministicSpriteGroup *sub = static_cast<const DeterministicSpriteGroup *>(sg);
VarAction2GroupVariableTracking *var_tracking = _cur.GetVarAction2GroupVariableTracking(sub, false);
if (var_tracking != nullptr) bits |= var_tracking->in;
if (var_tracking != nullptr) {
all_bits |= var_tracking->in;
propagate_bits |= var_tracking->in;
}
if (sub->dsg_flags & DSGF_REQUIRES_VAR1C) need_var1C = true;
}
});
@@ -8444,7 +8464,8 @@ static std::bitset<256> HandleVarAction2DeadStoreElimination(DeterministicSprite
for (size_t j = 0; j < substitution_candidates.size();) {
uint8 idx = substitution_candidates[j] & 0xFF;
if (anno->stores[idx]) {
bits.set(idx, true);
all_bits.set(idx, true);
propagate_bits.set(idx, true);
substitution_candidates[j] = substitution_candidates.back();
substitution_candidates.pop_back();
} else {
@@ -8456,7 +8477,7 @@ static std::bitset<256> HandleVarAction2DeadStoreElimination(DeterministicSprite
i--;
}
abandon_substitution_candidates();
return bits;
return propagate_bits;
}
static void HandleVarAction2OptimisationPasses()