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[Opt] Math constant folding for scalars #285

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merged 2 commits into from
Apr 10, 2021
Merged

[Opt] Math constant folding for scalars #285

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9a509e6
[Opt] Math constant folding for scalars
Apr 7, 2021
f316749
Merge branch 'master' into folding_for_scalars
weimingzha0 Apr 10, 2021
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68 changes: 25 additions & 43 deletions lib/transforms/inst_simplify.cc
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Original file line number Diff line number Diff line change
Expand Up @@ -44,9 +44,12 @@ static Constant* RunConstantFoldingOnMathBinary(const std::string& name,
const Type& ret_type, Def op0,
Def op1, OpCode opcode,
KindPredicate pred) {
if (!IsA<Constant>(op0) || !IsA<Constant>(op1) ||
op0.GetType().GetTotalNumOfElements() !=
op1.GetType().GetTotalNumOfElements()) {
if (!IsA<Constant>(op0) || !IsA<Constant>(op1)) {
return nullptr;
}
if ((op0.GetType().GetTotalNumOfElements() !=
op1.GetType().GetTotalNumOfElements() &&
op1.GetType().GetTotalNumOfElements() != 1)) {
return nullptr;
}
if (opcode == OpCode::CMP) {
Expand All @@ -58,32 +61,36 @@ static Constant* RunConstantFoldingOnMathBinary(const std::string& name,
std::swap(op0, op1);
}
}
Constant* c_lhs = DynCast<Constant>(op0.GetOwner());
Constant* c_rhs = DynCast<Constant>(op1.GetOwner());
Constant* c_lhs = DynCast<Constant>(op0);
Constant* c_rhs = DynCast<Constant>(op1);
size_t num_elements = op0.GetType().GetTotalNumOfElements();
Constant* c_ret = nullptr;
ConstantBuilder cb(DynCast<Function>(c_lhs->GetParent()));
std::vector<T> ret;
ret.reserve(num_elements);
bool rhs_is_scalar = op1.GetType().GetTotalNumOfElements() == 1;

switch (opcode) {
case OpCode::ADD: {
for (size_t i = 0; i < num_elements; ++i) {
ret.push_back(c_lhs->GetData<T>(i) + c_rhs->GetData<T>(i));
ret.push_back(c_lhs->GetData<T>(i) +
c_rhs->GetData<T>(rhs_is_scalar ? 0 : i));
}
c_ret = cb.CreateConstant(name, ret_type, ret.data());
break;
}
case OpCode::MUL: {
for (size_t i = 0; i < num_elements; ++i) {
ret.push_back(c_lhs->GetData<T>(i) * c_rhs->GetData<T>(i));
ret.push_back(c_lhs->GetData<T>(i) *
c_rhs->GetData<T>(rhs_is_scalar ? 0 : i));
}
c_ret = cb.CreateConstant(name, ret_type, ret.data());
break;
}
case OpCode::DIV: {
for (size_t i = 0; i < num_elements; ++i) {
ret.push_back(c_lhs->GetData<T>(i) / c_rhs->GetData<T>(i));
ret.push_back(c_lhs->GetData<T>(i) /
c_rhs->GetData<T>(rhs_is_scalar ? 0 : i));
}
c_ret = cb.CreateConstant(name, ret_type, ret.data());
break;
Expand All @@ -93,7 +100,8 @@ static Constant* RunConstantFoldingOnMathBinary(const std::string& name,
switch (pred) {
case KindPredicate::LT: {
for (size_t i = 0; i < num_elements; ++i) {
if (c_lhs->GetData<T>(i) < c_rhs->GetData<T>(i)) {
if (c_lhs->GetData<T>(i) <
c_rhs->GetData<T>(rhs_is_scalar ? 0 : i)) {
ret.push_back(1);
} else {
ret.push_back(0);
Expand Down Expand Up @@ -260,39 +268,14 @@ static std::pair<Def, Def> RunOnMathBinaryInstruction(Instruction* binary_inst,
const auto& op0_type = op0.GetType();
const auto& op1_type = op1.GetType();
OpCode opcode = binary_inst->GetOpCode();
/*
// Handle scalar constant
if (IsA<Constant>(op1.GetOwner())) {
Constant* c_op1 = DynCast<Constant>(op1.GetOwner());
Type ret_type = binary_inst->GetResultsTypes()[0];
HLCHECK(ret_type.IsValid());
if (c_op1->IsScalarZero()) {
if (opcode == OpCode::ADD) {
return {orig_def, op0};
}
if (opcode == OpCode::MUL) {
Constant* c_zero =
cb.SplatConstantZero(binary_inst->GetName(), ret_type);
return {orig_def, *c_zero};
}
}
if (c_op1->IsScalarOne()) {
if (opcode == OpCode::MUL) {
return {orig_def, op0};
}
}
}*/

const int64_t folding_threshold = 10;
// Both operands are constant, do constant folding
if (IsA<Constant>(op0) && IsA<Constant>(op1) &&
op0_type.GetTotalNumOfElements() == op1_type.GetTotalNumOfElements() &&
op0_type.GetTotalNumOfElements() < folding_threshold) {
Type ret_type = binary_inst->GetResultsTypes()[0];
HLCHECK(ret_type.IsValid());
// Try constant folding
const auto& ret_type = binary_inst->GetResultType();

if (ret_type.IsValid()) {
KindPredicate pred = KindPredicate::INVALID;
if (opcode == OpCode::CMP) {
pred = static_cast<CmpInst*>(binary_inst)->GetPredicator(); // NOLINT
pred = DynCast<CmpInst>(binary_inst)->GetPredicator();
}
if (has_swapped) {
std::swap(op0, op1);
Expand All @@ -301,19 +284,19 @@ static std::pair<Def, Def> RunOnMathBinaryInstruction(Instruction* binary_inst,
switch (op0_type.GetDataType()) {
case DataType::INT32: {
c_ret = RunConstantFoldingOnMathBinary<int>(
binary_inst->GetName() + "_folding", ret_type, op0, op1, opcode,
binary_inst->GetName() + "_folded", ret_type, op0, op1, opcode,
pred);
break;
}
case DataType::INT64: {
c_ret = RunConstantFoldingOnMathBinary<int64_t>(
binary_inst->GetName() + "_folding", ret_type, op0, op1, opcode,
binary_inst->GetName() + "_folded", ret_type, op0, op1, opcode,
pred);
break;
}
case DataType::FLOAT32: {
c_ret = RunConstantFoldingOnMathBinary<float>(
binary_inst->GetName() + "_folding", ret_type, op0, op1, opcode,
binary_inst->GetName() + "_folded", ret_type, op0, op1, opcode,
pred);
break;
}
Expand All @@ -323,7 +306,6 @@ static std::pair<Def, Def> RunOnMathBinaryInstruction(Instruction* binary_inst,
if (c_ret != nullptr) {
return {orig_def, *c_ret};
}
return {orig_def, orig_def};
}

// Do offline broadcasting.
Expand Down