SPIRV-Tools/source/opt/const_folding_rules.cpp
2019-09-05 13:30:03 -04:00

1182 lines
46 KiB
C++

// Copyright (c) 2018 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include "source/opt/const_folding_rules.h"
#include "source/opt/ir_context.h"
namespace spvtools {
namespace opt {
namespace {
const uint32_t kExtractCompositeIdInIdx = 0;
// Returns true if |type| is Float or a vector of Float.
bool HasFloatingPoint(const analysis::Type* type) {
if (type->AsFloat()) {
return true;
} else if (const analysis::Vector* vec_type = type->AsVector()) {
return vec_type->element_type()->AsFloat() != nullptr;
}
return false;
}
// Folds an OpcompositeExtract where input is a composite constant.
ConstantFoldingRule FoldExtractWithConstants() {
return [](IRContext* context, Instruction* inst,
const std::vector<const analysis::Constant*>& constants)
-> const analysis::Constant* {
const analysis::Constant* c = constants[kExtractCompositeIdInIdx];
if (c == nullptr) {
return nullptr;
}
for (uint32_t i = 1; i < inst->NumInOperands(); ++i) {
uint32_t element_index = inst->GetSingleWordInOperand(i);
if (c->AsNullConstant()) {
// Return Null for the return type.
analysis::ConstantManager* const_mgr = context->get_constant_mgr();
analysis::TypeManager* type_mgr = context->get_type_mgr();
return const_mgr->GetConstant(type_mgr->GetType(inst->type_id()), {});
}
auto cc = c->AsCompositeConstant();
assert(cc != nullptr);
auto components = cc->GetComponents();
// Protect against invalid IR. Refuse to fold if the index is out
// of bounds.
if (element_index >= components.size()) return nullptr;
c = components[element_index];
}
return c;
};
}
ConstantFoldingRule FoldVectorShuffleWithConstants() {
return [](IRContext* context, Instruction* inst,
const std::vector<const analysis::Constant*>& constants)
-> const analysis::Constant* {
assert(inst->opcode() == SpvOpVectorShuffle);
const analysis::Constant* c1 = constants[0];
const analysis::Constant* c2 = constants[1];
if (c1 == nullptr || c2 == nullptr) {
return nullptr;
}
analysis::ConstantManager* const_mgr = context->get_constant_mgr();
const analysis::Type* element_type = c1->type()->AsVector()->element_type();
std::vector<const analysis::Constant*> c1_components;
if (const analysis::VectorConstant* vec_const = c1->AsVectorConstant()) {
c1_components = vec_const->GetComponents();
} else {
assert(c1->AsNullConstant());
const analysis::Constant* element =
const_mgr->GetConstant(element_type, {});
c1_components.resize(c1->type()->AsVector()->element_count(), element);
}
std::vector<const analysis::Constant*> c2_components;
if (const analysis::VectorConstant* vec_const = c2->AsVectorConstant()) {
c2_components = vec_const->GetComponents();
} else {
assert(c2->AsNullConstant());
const analysis::Constant* element =
const_mgr->GetConstant(element_type, {});
c2_components.resize(c2->type()->AsVector()->element_count(), element);
}
std::vector<uint32_t> ids;
const uint32_t undef_literal_value = 0xffffffff;
for (uint32_t i = 2; i < inst->NumInOperands(); ++i) {
uint32_t index = inst->GetSingleWordInOperand(i);
if (index == undef_literal_value) {
// Don't fold shuffle with undef literal value.
return nullptr;
} else if (index < c1_components.size()) {
Instruction* member_inst =
const_mgr->GetDefiningInstruction(c1_components[index]);
ids.push_back(member_inst->result_id());
} else {
Instruction* member_inst = const_mgr->GetDefiningInstruction(
c2_components[index - c1_components.size()]);
ids.push_back(member_inst->result_id());
}
}
analysis::TypeManager* type_mgr = context->get_type_mgr();
return const_mgr->GetConstant(type_mgr->GetType(inst->type_id()), ids);
};
}
ConstantFoldingRule FoldVectorTimesScalar() {
return [](IRContext* context, Instruction* inst,
const std::vector<const analysis::Constant*>& constants)
-> const analysis::Constant* {
assert(inst->opcode() == SpvOpVectorTimesScalar);
analysis::ConstantManager* const_mgr = context->get_constant_mgr();
analysis::TypeManager* type_mgr = context->get_type_mgr();
if (!inst->IsFloatingPointFoldingAllowed()) {
if (HasFloatingPoint(type_mgr->GetType(inst->type_id()))) {
return nullptr;
}
}
const analysis::Constant* c1 = constants[0];
const analysis::Constant* c2 = constants[1];
if (c1 && c1->IsZero()) {
return c1;
}
if (c2 && c2->IsZero()) {
// Get or create the NullConstant for this type.
std::vector<uint32_t> ids;
return const_mgr->GetConstant(type_mgr->GetType(inst->type_id()), ids);
}
if (c1 == nullptr || c2 == nullptr) {
return nullptr;
}
// Check result type.
const analysis::Type* result_type = type_mgr->GetType(inst->type_id());
const analysis::Vector* vector_type = result_type->AsVector();
assert(vector_type != nullptr);
const analysis::Type* element_type = vector_type->element_type();
assert(element_type != nullptr);
const analysis::Float* float_type = element_type->AsFloat();
assert(float_type != nullptr);
// Check types of c1 and c2.
assert(c1->type()->AsVector() == vector_type);
assert(c1->type()->AsVector()->element_type() == element_type &&
c2->type() == element_type);
// Get a float vector that is the result of vector-times-scalar.
std::vector<const analysis::Constant*> c1_components =
c1->GetVectorComponents(const_mgr);
std::vector<uint32_t> ids;
if (float_type->width() == 32) {
float scalar = c2->GetFloat();
for (uint32_t i = 0; i < c1_components.size(); ++i) {
utils::FloatProxy<float> result(c1_components[i]->GetFloat() * scalar);
std::vector<uint32_t> words = result.GetWords();
const analysis::Constant* new_elem =
const_mgr->GetConstant(float_type, words);
ids.push_back(const_mgr->GetDefiningInstruction(new_elem)->result_id());
}
return const_mgr->GetConstant(vector_type, ids);
} else if (float_type->width() == 64) {
double scalar = c2->GetDouble();
for (uint32_t i = 0; i < c1_components.size(); ++i) {
utils::FloatProxy<double> result(c1_components[i]->GetDouble() *
scalar);
std::vector<uint32_t> words = result.GetWords();
const analysis::Constant* new_elem =
const_mgr->GetConstant(float_type, words);
ids.push_back(const_mgr->GetDefiningInstruction(new_elem)->result_id());
}
return const_mgr->GetConstant(vector_type, ids);
}
return nullptr;
};
}
ConstantFoldingRule FoldCompositeWithConstants() {
// Folds an OpCompositeConstruct where all of the inputs are constants to a
// constant. A new constant is created if necessary.
return [](IRContext* context, Instruction* inst,
const std::vector<const analysis::Constant*>& constants)
-> const analysis::Constant* {
analysis::ConstantManager* const_mgr = context->get_constant_mgr();
analysis::TypeManager* type_mgr = context->get_type_mgr();
const analysis::Type* new_type = type_mgr->GetType(inst->type_id());
Instruction* type_inst =
context->get_def_use_mgr()->GetDef(inst->type_id());
std::vector<uint32_t> ids;
for (uint32_t i = 0; i < constants.size(); ++i) {
const analysis::Constant* element_const = constants[i];
if (element_const == nullptr) {
return nullptr;
}
uint32_t component_type_id = 0;
if (type_inst->opcode() == SpvOpTypeStruct) {
component_type_id = type_inst->GetSingleWordInOperand(i);
} else if (type_inst->opcode() == SpvOpTypeArray) {
component_type_id = type_inst->GetSingleWordInOperand(0);
}
uint32_t element_id =
const_mgr->FindDeclaredConstant(element_const, component_type_id);
if (element_id == 0) {
return nullptr;
}
ids.push_back(element_id);
}
return const_mgr->GetConstant(new_type, ids);
};
}
// The interface for a function that returns the result of applying a scalar
// floating-point binary operation on |a| and |b|. The type of the return value
// will be |type|. The input constants must also be of type |type|.
using UnaryScalarFoldingRule = std::function<const analysis::Constant*(
const analysis::Type* result_type, const analysis::Constant* a,
analysis::ConstantManager*)>;
// The interface for a function that returns the result of applying a scalar
// floating-point binary operation on |a| and |b|. The type of the return value
// will be |type|. The input constants must also be of type |type|.
using BinaryScalarFoldingRule = std::function<const analysis::Constant*(
const analysis::Type* result_type, const analysis::Constant* a,
const analysis::Constant* b, analysis::ConstantManager*)>;
// Returns a |ConstantFoldingRule| that folds unary floating point scalar ops
// using |scalar_rule| and unary float point vectors ops by applying
// |scalar_rule| to the elements of the vector. The |ConstantFoldingRule|
// that is returned assumes that |constants| contains 1 entry. If they are
// not |nullptr|, then their type is either |Float| or |Integer| or a |Vector|
// whose element type is |Float| or |Integer|.
ConstantFoldingRule FoldFPUnaryOp(UnaryScalarFoldingRule scalar_rule) {
return [scalar_rule](IRContext* context, Instruction* inst,
const std::vector<const analysis::Constant*>& constants)
-> const analysis::Constant* {
analysis::ConstantManager* const_mgr = context->get_constant_mgr();
analysis::TypeManager* type_mgr = context->get_type_mgr();
const analysis::Type* result_type = type_mgr->GetType(inst->type_id());
const analysis::Vector* vector_type = result_type->AsVector();
if (!inst->IsFloatingPointFoldingAllowed()) {
return nullptr;
}
if (constants[0] == nullptr) {
return nullptr;
}
if (vector_type != nullptr) {
std::vector<const analysis::Constant*> a_components;
std::vector<const analysis::Constant*> results_components;
a_components = constants[0]->GetVectorComponents(const_mgr);
// Fold each component of the vector.
for (uint32_t i = 0; i < a_components.size(); ++i) {
results_components.push_back(scalar_rule(vector_type->element_type(),
a_components[i], const_mgr));
if (results_components[i] == nullptr) {
return nullptr;
}
}
// Build the constant object and return it.
std::vector<uint32_t> ids;
for (const analysis::Constant* member : results_components) {
ids.push_back(const_mgr->GetDefiningInstruction(member)->result_id());
}
return const_mgr->GetConstant(vector_type, ids);
} else {
return scalar_rule(result_type, constants[0], const_mgr);
}
};
}
// Returns the result of folding the constants in |constants| according the
// |scalar_rule|. If |result_type| is a vector, then |scalar_rule| is applied
// per component.
const analysis::Constant* FoldFPBinaryOp(
BinaryScalarFoldingRule scalar_rule, uint32_t result_type_id,
const std::vector<const analysis::Constant*>& constants,
IRContext* context) {
analysis::ConstantManager* const_mgr = context->get_constant_mgr();
analysis::TypeManager* type_mgr = context->get_type_mgr();
const analysis::Type* result_type = type_mgr->GetType(result_type_id);
const analysis::Vector* vector_type = result_type->AsVector();
if (constants[0] == nullptr || constants[1] == nullptr) {
return nullptr;
}
if (vector_type != nullptr) {
std::vector<const analysis::Constant*> a_components;
std::vector<const analysis::Constant*> b_components;
std::vector<const analysis::Constant*> results_components;
a_components = constants[0]->GetVectorComponents(const_mgr);
b_components = constants[1]->GetVectorComponents(const_mgr);
// Fold each component of the vector.
for (uint32_t i = 0; i < a_components.size(); ++i) {
results_components.push_back(scalar_rule(vector_type->element_type(),
a_components[i], b_components[i],
const_mgr));
if (results_components[i] == nullptr) {
return nullptr;
}
}
// Build the constant object and return it.
std::vector<uint32_t> ids;
for (const analysis::Constant* member : results_components) {
ids.push_back(const_mgr->GetDefiningInstruction(member)->result_id());
}
return const_mgr->GetConstant(vector_type, ids);
} else {
return scalar_rule(result_type, constants[0], constants[1], const_mgr);
}
}
// Returns a |ConstantFoldingRule| that folds floating point scalars using
// |scalar_rule| and vectors of floating point by applying |scalar_rule| to the
// elements of the vector. The |ConstantFoldingRule| that is returned assumes
// that |constants| contains 2 entries. If they are not |nullptr|, then their
// type is either |Float| or a |Vector| whose element type is |Float|.
ConstantFoldingRule FoldFPBinaryOp(BinaryScalarFoldingRule scalar_rule) {
return [scalar_rule](IRContext* context, Instruction* inst,
const std::vector<const analysis::Constant*>& constants)
-> const analysis::Constant* {
if (!inst->IsFloatingPointFoldingAllowed()) {
return nullptr;
}
if (inst->opcode() == SpvOpExtInst) {
return FoldFPBinaryOp(scalar_rule, inst->type_id(),
{constants[1], constants[2]}, context);
}
return FoldFPBinaryOp(scalar_rule, inst->type_id(), constants, context);
};
}
// This macro defines a |UnaryScalarFoldingRule| that performs float to
// integer conversion.
// TODO(greg-lunarg): Support for 64-bit integer types.
UnaryScalarFoldingRule FoldFToIOp() {
return [](const analysis::Type* result_type, const analysis::Constant* a,
analysis::ConstantManager* const_mgr) -> const analysis::Constant* {
assert(result_type != nullptr && a != nullptr);
const analysis::Integer* integer_type = result_type->AsInteger();
const analysis::Float* float_type = a->type()->AsFloat();
assert(float_type != nullptr);
assert(integer_type != nullptr);
if (integer_type->width() != 32) return nullptr;
if (float_type->width() == 32) {
float fa = a->GetFloat();
uint32_t result = integer_type->IsSigned()
? static_cast<uint32_t>(static_cast<int32_t>(fa))
: static_cast<uint32_t>(fa);
std::vector<uint32_t> words = {result};
return const_mgr->GetConstant(result_type, words);
} else if (float_type->width() == 64) {
double fa = a->GetDouble();
uint32_t result = integer_type->IsSigned()
? static_cast<uint32_t>(static_cast<int32_t>(fa))
: static_cast<uint32_t>(fa);
std::vector<uint32_t> words = {result};
return const_mgr->GetConstant(result_type, words);
}
return nullptr;
};
}
// This function defines a |UnaryScalarFoldingRule| that performs integer to
// float conversion.
// TODO(greg-lunarg): Support for 64-bit integer types.
UnaryScalarFoldingRule FoldIToFOp() {
return [](const analysis::Type* result_type, const analysis::Constant* a,
analysis::ConstantManager* const_mgr) -> const analysis::Constant* {
assert(result_type != nullptr && a != nullptr);
const analysis::Integer* integer_type = a->type()->AsInteger();
const analysis::Float* float_type = result_type->AsFloat();
assert(float_type != nullptr);
assert(integer_type != nullptr);
if (integer_type->width() != 32) return nullptr;
uint32_t ua = a->GetU32();
if (float_type->width() == 32) {
float result_val = integer_type->IsSigned()
? static_cast<float>(static_cast<int32_t>(ua))
: static_cast<float>(ua);
utils::FloatProxy<float> result(result_val);
std::vector<uint32_t> words = {result.data()};
return const_mgr->GetConstant(result_type, words);
} else if (float_type->width() == 64) {
double result_val = integer_type->IsSigned()
? static_cast<double>(static_cast<int32_t>(ua))
: static_cast<double>(ua);
utils::FloatProxy<double> result(result_val);
std::vector<uint32_t> words = result.GetWords();
return const_mgr->GetConstant(result_type, words);
}
return nullptr;
};
}
// This defines a |UnaryScalarFoldingRule| that performs |OpQuantizeToF16|.
UnaryScalarFoldingRule FoldQuantizeToF16Scalar() {
return [](const analysis::Type* result_type, const analysis::Constant* a,
analysis::ConstantManager* const_mgr) -> const analysis::Constant* {
assert(result_type != nullptr && a != nullptr);
const analysis::Float* float_type = a->type()->AsFloat();
assert(float_type != nullptr);
if (float_type->width() != 32) {
return nullptr;
}
float fa = a->GetFloat();
utils::HexFloat<utils::FloatProxy<float>> orignal(fa);
utils::HexFloat<utils::FloatProxy<utils::Float16>> quantized(0);
utils::HexFloat<utils::FloatProxy<float>> result(0.0f);
orignal.castTo(quantized, utils::round_direction::kToZero);
quantized.castTo(result, utils::round_direction::kToZero);
std::vector<uint32_t> words = {result.getBits()};
return const_mgr->GetConstant(result_type, words);
};
}
// This macro defines a |BinaryScalarFoldingRule| that applies |op|. The
// operator |op| must work for both float and double, and use syntax "f1 op f2".
#define FOLD_FPARITH_OP(op) \
[](const analysis::Type* result_type_in_macro, const analysis::Constant* a, \
const analysis::Constant* b, \
analysis::ConstantManager* const_mgr_in_macro) \
-> const analysis::Constant* { \
assert(result_type_in_macro != nullptr && a != nullptr && b != nullptr); \
assert(result_type_in_macro == a->type() && \
result_type_in_macro == b->type()); \
const analysis::Float* float_type_in_macro = \
result_type_in_macro->AsFloat(); \
assert(float_type_in_macro != nullptr); \
if (float_type_in_macro->width() == 32) { \
float fa = a->GetFloat(); \
float fb = b->GetFloat(); \
utils::FloatProxy<float> result_in_macro(fa op fb); \
std::vector<uint32_t> words_in_macro = result_in_macro.GetWords(); \
return const_mgr_in_macro->GetConstant(result_type_in_macro, \
words_in_macro); \
} else if (float_type_in_macro->width() == 64) { \
double fa = a->GetDouble(); \
double fb = b->GetDouble(); \
utils::FloatProxy<double> result_in_macro(fa op fb); \
std::vector<uint32_t> words_in_macro = result_in_macro.GetWords(); \
return const_mgr_in_macro->GetConstant(result_type_in_macro, \
words_in_macro); \
} \
return nullptr; \
}
// Define the folding rule for conversion between floating point and integer
ConstantFoldingRule FoldFToI() { return FoldFPUnaryOp(FoldFToIOp()); }
ConstantFoldingRule FoldIToF() { return FoldFPUnaryOp(FoldIToFOp()); }
ConstantFoldingRule FoldQuantizeToF16() {
return FoldFPUnaryOp(FoldQuantizeToF16Scalar());
}
// Define the folding rules for subtraction, addition, multiplication, and
// division for floating point values.
ConstantFoldingRule FoldFSub() { return FoldFPBinaryOp(FOLD_FPARITH_OP(-)); }
ConstantFoldingRule FoldFAdd() { return FoldFPBinaryOp(FOLD_FPARITH_OP(+)); }
ConstantFoldingRule FoldFMul() { return FoldFPBinaryOp(FOLD_FPARITH_OP(*)); }
ConstantFoldingRule FoldFDiv() { return FoldFPBinaryOp(FOLD_FPARITH_OP(/)); }
bool CompareFloatingPoint(bool op_result, bool op_unordered,
bool need_ordered) {
if (need_ordered) {
// operands are ordered and Operand 1 is |op| Operand 2
return !op_unordered && op_result;
} else {
// operands are unordered or Operand 1 is |op| Operand 2
return op_unordered || op_result;
}
}
// This macro defines a |BinaryScalarFoldingRule| that applies |op|. The
// operator |op| must work for both float and double, and use syntax "f1 op f2".
#define FOLD_FPCMP_OP(op, ord) \
[](const analysis::Type* result_type, const analysis::Constant* a, \
const analysis::Constant* b, \
analysis::ConstantManager* const_mgr) -> const analysis::Constant* { \
assert(result_type != nullptr && a != nullptr && b != nullptr); \
assert(result_type->AsBool()); \
assert(a->type() == b->type()); \
const analysis::Float* float_type = a->type()->AsFloat(); \
assert(float_type != nullptr); \
if (float_type->width() == 32) { \
float fa = a->GetFloat(); \
float fb = b->GetFloat(); \
bool result = CompareFloatingPoint( \
fa op fb, std::isnan(fa) || std::isnan(fb), ord); \
std::vector<uint32_t> words = {uint32_t(result)}; \
return const_mgr->GetConstant(result_type, words); \
} else if (float_type->width() == 64) { \
double fa = a->GetDouble(); \
double fb = b->GetDouble(); \
bool result = CompareFloatingPoint( \
fa op fb, std::isnan(fa) || std::isnan(fb), ord); \
std::vector<uint32_t> words = {uint32_t(result)}; \
return const_mgr->GetConstant(result_type, words); \
} \
return nullptr; \
}
// Define the folding rules for ordered and unordered comparison for floating
// point values.
ConstantFoldingRule FoldFOrdEqual() {
return FoldFPBinaryOp(FOLD_FPCMP_OP(==, true));
}
ConstantFoldingRule FoldFUnordEqual() {
return FoldFPBinaryOp(FOLD_FPCMP_OP(==, false));
}
ConstantFoldingRule FoldFOrdNotEqual() {
return FoldFPBinaryOp(FOLD_FPCMP_OP(!=, true));
}
ConstantFoldingRule FoldFUnordNotEqual() {
return FoldFPBinaryOp(FOLD_FPCMP_OP(!=, false));
}
ConstantFoldingRule FoldFOrdLessThan() {
return FoldFPBinaryOp(FOLD_FPCMP_OP(<, true));
}
ConstantFoldingRule FoldFUnordLessThan() {
return FoldFPBinaryOp(FOLD_FPCMP_OP(<, false));
}
ConstantFoldingRule FoldFOrdGreaterThan() {
return FoldFPBinaryOp(FOLD_FPCMP_OP(>, true));
}
ConstantFoldingRule FoldFUnordGreaterThan() {
return FoldFPBinaryOp(FOLD_FPCMP_OP(>, false));
}
ConstantFoldingRule FoldFOrdLessThanEqual() {
return FoldFPBinaryOp(FOLD_FPCMP_OP(<=, true));
}
ConstantFoldingRule FoldFUnordLessThanEqual() {
return FoldFPBinaryOp(FOLD_FPCMP_OP(<=, false));
}
ConstantFoldingRule FoldFOrdGreaterThanEqual() {
return FoldFPBinaryOp(FOLD_FPCMP_OP(>=, true));
}
ConstantFoldingRule FoldFUnordGreaterThanEqual() {
return FoldFPBinaryOp(FOLD_FPCMP_OP(>=, false));
}
// Folds an OpDot where all of the inputs are constants to a
// constant. A new constant is created if necessary.
ConstantFoldingRule FoldOpDotWithConstants() {
return [](IRContext* context, Instruction* inst,
const std::vector<const analysis::Constant*>& constants)
-> const analysis::Constant* {
analysis::ConstantManager* const_mgr = context->get_constant_mgr();
analysis::TypeManager* type_mgr = context->get_type_mgr();
const analysis::Type* new_type = type_mgr->GetType(inst->type_id());
assert(new_type->AsFloat() && "OpDot should have a float return type.");
const analysis::Float* float_type = new_type->AsFloat();
if (!inst->IsFloatingPointFoldingAllowed()) {
return nullptr;
}
// If one of the operands is 0, then the result is 0.
bool has_zero_operand = false;
for (int i = 0; i < 2; ++i) {
if (constants[i]) {
if (constants[i]->AsNullConstant() ||
constants[i]->AsVectorConstant()->IsZero()) {
has_zero_operand = true;
break;
}
}
}
if (has_zero_operand) {
if (float_type->width() == 32) {
utils::FloatProxy<float> result(0.0f);
std::vector<uint32_t> words = result.GetWords();
return const_mgr->GetConstant(float_type, words);
}
if (float_type->width() == 64) {
utils::FloatProxy<double> result(0.0);
std::vector<uint32_t> words = result.GetWords();
return const_mgr->GetConstant(float_type, words);
}
return nullptr;
}
if (constants[0] == nullptr || constants[1] == nullptr) {
return nullptr;
}
std::vector<const analysis::Constant*> a_components;
std::vector<const analysis::Constant*> b_components;
a_components = constants[0]->GetVectorComponents(const_mgr);
b_components = constants[1]->GetVectorComponents(const_mgr);
utils::FloatProxy<double> result(0.0);
std::vector<uint32_t> words = result.GetWords();
const analysis::Constant* result_const =
const_mgr->GetConstant(float_type, words);
for (uint32_t i = 0; i < a_components.size() && result_const != nullptr;
++i) {
if (a_components[i] == nullptr || b_components[i] == nullptr) {
return nullptr;
}
const analysis::Constant* component = FOLD_FPARITH_OP(*)(
new_type, a_components[i], b_components[i], const_mgr);
if (component == nullptr) {
return nullptr;
}
result_const =
FOLD_FPARITH_OP(+)(new_type, result_const, component, const_mgr);
}
return result_const;
};
}
// This function defines a |UnaryScalarFoldingRule| that subtracts the constant
// from zero.
UnaryScalarFoldingRule FoldFNegateOp() {
return [](const analysis::Type* result_type, const analysis::Constant* a,
analysis::ConstantManager* const_mgr) -> const analysis::Constant* {
assert(result_type != nullptr && a != nullptr);
assert(result_type == a->type());
const analysis::Float* float_type = result_type->AsFloat();
assert(float_type != nullptr);
if (float_type->width() == 32) {
float fa = a->GetFloat();
utils::FloatProxy<float> result(-fa);
std::vector<uint32_t> words = result.GetWords();
return const_mgr->GetConstant(result_type, words);
} else if (float_type->width() == 64) {
double da = a->GetDouble();
utils::FloatProxy<double> result(-da);
std::vector<uint32_t> words = result.GetWords();
return const_mgr->GetConstant(result_type, words);
}
return nullptr;
};
}
ConstantFoldingRule FoldFNegate() { return FoldFPUnaryOp(FoldFNegateOp()); }
ConstantFoldingRule FoldFClampFeedingCompare(uint32_t cmp_opcode) {
return [cmp_opcode](IRContext* context, Instruction* inst,
const std::vector<const analysis::Constant*>& constants)
-> const analysis::Constant* {
analysis::ConstantManager* const_mgr = context->get_constant_mgr();
analysis::DefUseManager* def_use_mgr = context->get_def_use_mgr();
if (!inst->IsFloatingPointFoldingAllowed()) {
return nullptr;
}
uint32_t non_const_idx = (constants[0] ? 1 : 0);
uint32_t operand_id = inst->GetSingleWordInOperand(non_const_idx);
Instruction* operand_inst = def_use_mgr->GetDef(operand_id);
analysis::TypeManager* type_mgr = context->get_type_mgr();
const analysis::Type* operand_type =
type_mgr->GetType(operand_inst->type_id());
if (!operand_type->AsFloat()) {
return nullptr;
}
if (operand_type->AsFloat()->width() != 32 &&
operand_type->AsFloat()->width() != 64) {
return nullptr;
}
if (operand_inst->opcode() != SpvOpExtInst) {
return nullptr;
}
if (operand_inst->GetSingleWordInOperand(1) != GLSLstd450FClamp) {
return nullptr;
}
if (constants[1] == nullptr && constants[0] == nullptr) {
return nullptr;
}
uint32_t max_id = operand_inst->GetSingleWordInOperand(4);
const analysis::Constant* max_const =
const_mgr->FindDeclaredConstant(max_id);
uint32_t min_id = operand_inst->GetSingleWordInOperand(3);
const analysis::Constant* min_const =
const_mgr->FindDeclaredConstant(min_id);
bool found_result = false;
bool result = false;
switch (cmp_opcode) {
case SpvOpFOrdLessThan:
case SpvOpFUnordLessThan:
case SpvOpFOrdGreaterThanEqual:
case SpvOpFUnordGreaterThanEqual:
if (constants[0]) {
if (min_const) {
if (constants[0]->GetValueAsDouble() <
min_const->GetValueAsDouble()) {
found_result = true;
result = (cmp_opcode == SpvOpFOrdLessThan ||
cmp_opcode == SpvOpFUnordLessThan);
}
}
if (max_const) {
if (constants[0]->GetValueAsDouble() >=
max_const->GetValueAsDouble()) {
found_result = true;
result = !(cmp_opcode == SpvOpFOrdLessThan ||
cmp_opcode == SpvOpFUnordLessThan);
}
}
}
if (constants[1]) {
if (max_const) {
if (max_const->GetValueAsDouble() <
constants[1]->GetValueAsDouble()) {
found_result = true;
result = (cmp_opcode == SpvOpFOrdLessThan ||
cmp_opcode == SpvOpFUnordLessThan);
}
}
if (min_const) {
if (min_const->GetValueAsDouble() >=
constants[1]->GetValueAsDouble()) {
found_result = true;
result = !(cmp_opcode == SpvOpFOrdLessThan ||
cmp_opcode == SpvOpFUnordLessThan);
}
}
}
break;
case SpvOpFOrdGreaterThan:
case SpvOpFUnordGreaterThan:
case SpvOpFOrdLessThanEqual:
case SpvOpFUnordLessThanEqual:
if (constants[0]) {
if (min_const) {
if (constants[0]->GetValueAsDouble() <=
min_const->GetValueAsDouble()) {
found_result = true;
result = (cmp_opcode == SpvOpFOrdLessThanEqual ||
cmp_opcode == SpvOpFUnordLessThanEqual);
}
}
if (max_const) {
if (constants[0]->GetValueAsDouble() >
max_const->GetValueAsDouble()) {
found_result = true;
result = !(cmp_opcode == SpvOpFOrdLessThanEqual ||
cmp_opcode == SpvOpFUnordLessThanEqual);
}
}
}
if (constants[1]) {
if (max_const) {
if (max_const->GetValueAsDouble() <=
constants[1]->GetValueAsDouble()) {
found_result = true;
result = (cmp_opcode == SpvOpFOrdLessThanEqual ||
cmp_opcode == SpvOpFUnordLessThanEqual);
}
}
if (min_const) {
if (min_const->GetValueAsDouble() >
constants[1]->GetValueAsDouble()) {
found_result = true;
result = !(cmp_opcode == SpvOpFOrdLessThanEqual ||
cmp_opcode == SpvOpFUnordLessThanEqual);
}
}
}
break;
default:
return nullptr;
}
if (!found_result) {
return nullptr;
}
const analysis::Type* bool_type =
context->get_type_mgr()->GetType(inst->type_id());
const analysis::Constant* result_const =
const_mgr->GetConstant(bool_type, {static_cast<uint32_t>(result)});
assert(result_const);
return result_const;
};
}
ConstantFoldingRule FoldFMix() {
return [](IRContext* context, Instruction* inst,
const std::vector<const analysis::Constant*>& constants)
-> const analysis::Constant* {
analysis::ConstantManager* const_mgr = context->get_constant_mgr();
assert(inst->opcode() == SpvOpExtInst &&
"Expecting an extended instruction.");
assert(inst->GetSingleWordInOperand(0) ==
context->get_feature_mgr()->GetExtInstImportId_GLSLstd450() &&
"Expecting a GLSLstd450 extended instruction.");
assert(inst->GetSingleWordInOperand(1) == GLSLstd450FMix &&
"Expecting and FMix instruction.");
if (!inst->IsFloatingPointFoldingAllowed()) {
return nullptr;
}
// Make sure all FMix operands are constants.
for (uint32_t i = 1; i < 4; i++) {
if (constants[i] == nullptr) {
return nullptr;
}
}
const analysis::Constant* one;
bool is_vector = false;
const analysis::Type* result_type = constants[1]->type();
const analysis::Type* base_type = result_type;
if (base_type->AsVector()) {
is_vector = true;
base_type = base_type->AsVector()->element_type();
}
assert(base_type->AsFloat() != nullptr &&
"FMix is suppose to act on floats or vectors of floats.");
if (base_type->AsFloat()->width() == 32) {
one = const_mgr->GetConstant(base_type,
utils::FloatProxy<float>(1.0f).GetWords());
} else {
one = const_mgr->GetConstant(base_type,
utils::FloatProxy<double>(1.0).GetWords());
}
if (is_vector) {
uint32_t one_id = const_mgr->GetDefiningInstruction(one)->result_id();
one =
const_mgr->GetConstant(result_type, std::vector<uint32_t>(4, one_id));
}
const analysis::Constant* temp1 = FoldFPBinaryOp(
FOLD_FPARITH_OP(-), inst->type_id(), {one, constants[3]}, context);
if (temp1 == nullptr) {
return nullptr;
}
const analysis::Constant* temp2 = FoldFPBinaryOp(
FOLD_FPARITH_OP(*), inst->type_id(), {constants[1], temp1}, context);
if (temp2 == nullptr) {
return nullptr;
}
const analysis::Constant* temp3 =
FoldFPBinaryOp(FOLD_FPARITH_OP(*), inst->type_id(),
{constants[2], constants[3]}, context);
if (temp3 == nullptr) {
return nullptr;
}
return FoldFPBinaryOp(FOLD_FPARITH_OP(+), inst->type_id(), {temp2, temp3},
context);
};
}
template <class IntType>
IntType FoldIClamp(IntType x, IntType min_val, IntType max_val) {
if (x < min_val) {
x = min_val;
}
if (x > max_val) {
x = max_val;
}
return x;
}
const analysis::Constant* FoldMin(const analysis::Type* result_type,
const analysis::Constant* a,
const analysis::Constant* b,
analysis::ConstantManager*) {
if (const analysis::Integer* int_type = result_type->AsInteger()) {
if (int_type->width() == 32) {
if (int_type->IsSigned()) {
int32_t va = a->GetS32();
int32_t vb = b->GetS32();
return (va < vb ? a : b);
} else {
uint32_t va = a->GetU32();
uint32_t vb = b->GetU32();
return (va < vb ? a : b);
}
} else if (int_type->width() == 64) {
if (int_type->IsSigned()) {
int64_t va = a->GetS64();
int64_t vb = b->GetS64();
return (va < vb ? a : b);
} else {
uint64_t va = a->GetU64();
uint64_t vb = b->GetU64();
return (va < vb ? a : b);
}
}
} else if (const analysis::Float* float_type = result_type->AsFloat()) {
if (float_type->width() == 32) {
float va = a->GetFloat();
float vb = b->GetFloat();
return (va < vb ? a : b);
} else if (float_type->width() == 64) {
double va = a->GetDouble();
double vb = b->GetDouble();
return (va < vb ? a : b);
}
}
return nullptr;
}
const analysis::Constant* FoldMax(const analysis::Type* result_type,
const analysis::Constant* a,
const analysis::Constant* b,
analysis::ConstantManager*) {
if (const analysis::Integer* int_type = result_type->AsInteger()) {
if (int_type->width() == 32) {
if (int_type->IsSigned()) {
int32_t va = a->GetS32();
int32_t vb = b->GetS32();
return (va > vb ? a : b);
} else {
uint32_t va = a->GetU32();
uint32_t vb = b->GetU32();
return (va > vb ? a : b);
}
} else if (int_type->width() == 64) {
if (int_type->IsSigned()) {
int64_t va = a->GetS64();
int64_t vb = b->GetS64();
return (va > vb ? a : b);
} else {
uint64_t va = a->GetU64();
uint64_t vb = b->GetU64();
return (va > vb ? a : b);
}
}
} else if (const analysis::Float* float_type = result_type->AsFloat()) {
if (float_type->width() == 32) {
float va = a->GetFloat();
float vb = b->GetFloat();
return (va > vb ? a : b);
} else if (float_type->width() == 64) {
double va = a->GetDouble();
double vb = b->GetDouble();
return (va > vb ? a : b);
}
}
return nullptr;
}
// Fold an clamp instruction when all three operands are constant.
const analysis::Constant* FoldClamp1(
IRContext* context, Instruction* inst,
const std::vector<const analysis::Constant*>& constants) {
assert(inst->opcode() == SpvOpExtInst &&
"Expecting an extended instruction.");
assert(inst->GetSingleWordInOperand(0) ==
context->get_feature_mgr()->GetExtInstImportId_GLSLstd450() &&
"Expecting a GLSLstd450 extended instruction.");
// Make sure all Clamp operands are constants.
for (uint32_t i = 1; i < 3; i++) {
if (constants[i] == nullptr) {
return nullptr;
}
}
const analysis::Constant* temp = FoldFPBinaryOp(
FoldMax, inst->type_id(), {constants[1], constants[2]}, context);
if (temp == nullptr) {
return nullptr;
}
return FoldFPBinaryOp(FoldMin, inst->type_id(), {temp, constants[3]},
context);
}
// Fold a clamp instruction when |x >= min_val|.
const analysis::Constant* FoldClamp2(
IRContext* context, Instruction* inst,
const std::vector<const analysis::Constant*>& constants) {
assert(inst->opcode() == SpvOpExtInst &&
"Expecting an extended instruction.");
assert(inst->GetSingleWordInOperand(0) ==
context->get_feature_mgr()->GetExtInstImportId_GLSLstd450() &&
"Expecting a GLSLstd450 extended instruction.");
const analysis::Constant* x = constants[1];
const analysis::Constant* min_val = constants[2];
if (x == nullptr || min_val == nullptr) {
return nullptr;
}
const analysis::Constant* temp =
FoldFPBinaryOp(FoldMax, inst->type_id(), {x, min_val}, context);
if (temp == min_val) {
// We can assume that |min_val| is less than |max_val|. Therefore, if the
// result of the max operation is |min_val|, we know the result of the min
// operation, even if |max_val| is not a constant.
return min_val;
}
return nullptr;
}
// Fold a clamp instruction when |x >= max_val|.
const analysis::Constant* FoldClamp3(
IRContext* context, Instruction* inst,
const std::vector<const analysis::Constant*>& constants) {
assert(inst->opcode() == SpvOpExtInst &&
"Expecting an extended instruction.");
assert(inst->GetSingleWordInOperand(0) ==
context->get_feature_mgr()->GetExtInstImportId_GLSLstd450() &&
"Expecting a GLSLstd450 extended instruction.");
const analysis::Constant* x = constants[1];
const analysis::Constant* max_val = constants[3];
if (x == nullptr || max_val == nullptr) {
return nullptr;
}
const analysis::Constant* temp =
FoldFPBinaryOp(FoldMin, inst->type_id(), {x, max_val}, context);
if (temp == max_val) {
// We can assume that |min_val| is less than |max_val|. Therefore, if the
// result of the max operation is |min_val|, we know the result of the min
// operation, even if |max_val| is not a constant.
return max_val;
}
return nullptr;
}
} // namespace
void ConstantFoldingRules::AddFoldingRules() {
// Add all folding rules to the list for the opcodes to which they apply.
// Note that the order in which rules are added to the list matters. If a rule
// applies to the instruction, the rest of the rules will not be attempted.
// Take that into consideration.
rules_[SpvOpCompositeConstruct].push_back(FoldCompositeWithConstants());
rules_[SpvOpCompositeExtract].push_back(FoldExtractWithConstants());
rules_[SpvOpConvertFToS].push_back(FoldFToI());
rules_[SpvOpConvertFToU].push_back(FoldFToI());
rules_[SpvOpConvertSToF].push_back(FoldIToF());
rules_[SpvOpConvertUToF].push_back(FoldIToF());
rules_[SpvOpDot].push_back(FoldOpDotWithConstants());
rules_[SpvOpFAdd].push_back(FoldFAdd());
rules_[SpvOpFDiv].push_back(FoldFDiv());
rules_[SpvOpFMul].push_back(FoldFMul());
rules_[SpvOpFSub].push_back(FoldFSub());
rules_[SpvOpFOrdEqual].push_back(FoldFOrdEqual());
rules_[SpvOpFUnordEqual].push_back(FoldFUnordEqual());
rules_[SpvOpFOrdNotEqual].push_back(FoldFOrdNotEqual());
rules_[SpvOpFUnordNotEqual].push_back(FoldFUnordNotEqual());
rules_[SpvOpFOrdLessThan].push_back(FoldFOrdLessThan());
rules_[SpvOpFOrdLessThan].push_back(
FoldFClampFeedingCompare(SpvOpFOrdLessThan));
rules_[SpvOpFUnordLessThan].push_back(FoldFUnordLessThan());
rules_[SpvOpFUnordLessThan].push_back(
FoldFClampFeedingCompare(SpvOpFUnordLessThan));
rules_[SpvOpFOrdGreaterThan].push_back(FoldFOrdGreaterThan());
rules_[SpvOpFOrdGreaterThan].push_back(
FoldFClampFeedingCompare(SpvOpFOrdGreaterThan));
rules_[SpvOpFUnordGreaterThan].push_back(FoldFUnordGreaterThan());
rules_[SpvOpFUnordGreaterThan].push_back(
FoldFClampFeedingCompare(SpvOpFUnordGreaterThan));
rules_[SpvOpFOrdLessThanEqual].push_back(FoldFOrdLessThanEqual());
rules_[SpvOpFOrdLessThanEqual].push_back(
FoldFClampFeedingCompare(SpvOpFOrdLessThanEqual));
rules_[SpvOpFUnordLessThanEqual].push_back(FoldFUnordLessThanEqual());
rules_[SpvOpFUnordLessThanEqual].push_back(
FoldFClampFeedingCompare(SpvOpFUnordLessThanEqual));
rules_[SpvOpFOrdGreaterThanEqual].push_back(FoldFOrdGreaterThanEqual());
rules_[SpvOpFOrdGreaterThanEqual].push_back(
FoldFClampFeedingCompare(SpvOpFOrdGreaterThanEqual));
rules_[SpvOpFUnordGreaterThanEqual].push_back(FoldFUnordGreaterThanEqual());
rules_[SpvOpFUnordGreaterThanEqual].push_back(
FoldFClampFeedingCompare(SpvOpFUnordGreaterThanEqual));
rules_[SpvOpVectorShuffle].push_back(FoldVectorShuffleWithConstants());
rules_[SpvOpVectorTimesScalar].push_back(FoldVectorTimesScalar());
rules_[SpvOpFNegate].push_back(FoldFNegate());
rules_[SpvOpQuantizeToF16].push_back(FoldQuantizeToF16());
// Add rules for GLSLstd450
FeatureManager* feature_manager = context_->get_feature_mgr();
uint32_t ext_inst_glslstd450_id =
feature_manager->GetExtInstImportId_GLSLstd450();
if (ext_inst_glslstd450_id != 0) {
ext_rules_[{ext_inst_glslstd450_id, GLSLstd450FMix}].push_back(FoldFMix());
ext_rules_[{ext_inst_glslstd450_id, GLSLstd450SMin}].push_back(
FoldFPBinaryOp(FoldMin));
ext_rules_[{ext_inst_glslstd450_id, GLSLstd450UMin}].push_back(
FoldFPBinaryOp(FoldMin));
ext_rules_[{ext_inst_glslstd450_id, GLSLstd450FMin}].push_back(
FoldFPBinaryOp(FoldMin));
ext_rules_[{ext_inst_glslstd450_id, GLSLstd450SMax}].push_back(
FoldFPBinaryOp(FoldMax));
ext_rules_[{ext_inst_glslstd450_id, GLSLstd450UMax}].push_back(
FoldFPBinaryOp(FoldMax));
ext_rules_[{ext_inst_glslstd450_id, GLSLstd450FMax}].push_back(
FoldFPBinaryOp(FoldMax));
ext_rules_[{ext_inst_glslstd450_id, GLSLstd450UClamp}].push_back(
FoldClamp1);
ext_rules_[{ext_inst_glslstd450_id, GLSLstd450UClamp}].push_back(
FoldClamp2);
ext_rules_[{ext_inst_glslstd450_id, GLSLstd450UClamp}].push_back(
FoldClamp3);
ext_rules_[{ext_inst_glslstd450_id, GLSLstd450SClamp}].push_back(
FoldClamp1);
ext_rules_[{ext_inst_glslstd450_id, GLSLstd450SClamp}].push_back(
FoldClamp2);
ext_rules_[{ext_inst_glslstd450_id, GLSLstd450SClamp}].push_back(
FoldClamp3);
ext_rules_[{ext_inst_glslstd450_id, GLSLstd450FClamp}].push_back(
FoldClamp1);
ext_rules_[{ext_inst_glslstd450_id, GLSLstd450FClamp}].push_back(
FoldClamp2);
ext_rules_[{ext_inst_glslstd450_id, GLSLstd450FClamp}].push_back(
FoldClamp3);
}
}
} // namespace opt
} // namespace spvtools