| // Copyright (c) 2017 Google Inc. |
| // |
| // 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/fold.h" |
| |
| #include <cassert> |
| #include <cstdint> |
| #include <vector> |
| |
| #include "source/opt/const_folding_rules.h" |
| #include "source/opt/def_use_manager.h" |
| #include "source/opt/folding_rules.h" |
| #include "source/opt/ir_builder.h" |
| #include "source/opt/ir_context.h" |
| |
| namespace spvtools { |
| namespace opt { |
| namespace { |
| |
| #ifndef INT32_MIN |
| #define INT32_MIN (-2147483648) |
| #endif |
| |
| #ifndef INT32_MAX |
| #define INT32_MAX 2147483647 |
| #endif |
| |
| #ifndef UINT32_MAX |
| #define UINT32_MAX 0xffffffff /* 4294967295U */ |
| #endif |
| |
| } // namespace |
| |
| uint32_t InstructionFolder::UnaryOperate(SpvOp opcode, uint32_t operand) const { |
| switch (opcode) { |
| // Arthimetics |
| case SpvOp::SpvOpSNegate: { |
| int32_t s_operand = static_cast<int32_t>(operand); |
| if (s_operand == std::numeric_limits<int32_t>::min()) { |
| return s_operand; |
| } |
| return -s_operand; |
| } |
| case SpvOp::SpvOpNot: |
| return ~operand; |
| case SpvOp::SpvOpLogicalNot: |
| return !static_cast<bool>(operand); |
| case SpvOp::SpvOpUConvert: |
| return operand; |
| case SpvOp::SpvOpSConvert: |
| return operand; |
| default: |
| assert(false && |
| "Unsupported unary operation for OpSpecConstantOp instruction"); |
| return 0u; |
| } |
| } |
| |
| uint32_t InstructionFolder::BinaryOperate(SpvOp opcode, uint32_t a, |
| uint32_t b) const { |
| switch (opcode) { |
| // Arthimetics |
| case SpvOp::SpvOpIAdd: |
| return a + b; |
| case SpvOp::SpvOpISub: |
| return a - b; |
| case SpvOp::SpvOpIMul: |
| return a * b; |
| case SpvOp::SpvOpUDiv: |
| if (b != 0) { |
| return a / b; |
| } else { |
| // Dividing by 0 is undefined, so we will just pick 0. |
| return 0; |
| } |
| case SpvOp::SpvOpSDiv: |
| if (b != 0u) { |
| return (static_cast<int32_t>(a)) / (static_cast<int32_t>(b)); |
| } else { |
| // Dividing by 0 is undefined, so we will just pick 0. |
| return 0; |
| } |
| case SpvOp::SpvOpSRem: { |
| // The sign of non-zero result comes from the first operand: a. This is |
| // guaranteed by C++11 rules for integer division operator. The division |
| // result is rounded toward zero, so the result of '%' has the sign of |
| // the first operand. |
| if (b != 0u) { |
| return static_cast<int32_t>(a) % static_cast<int32_t>(b); |
| } else { |
| // Remainder when dividing with 0 is undefined, so we will just pick 0. |
| return 0; |
| } |
| } |
| case SpvOp::SpvOpSMod: { |
| // The sign of non-zero result comes from the second operand: b |
| if (b != 0u) { |
| int32_t rem = BinaryOperate(SpvOp::SpvOpSRem, a, b); |
| int32_t b_prim = static_cast<int32_t>(b); |
| return (rem + b_prim) % b_prim; |
| } else { |
| // Mod with 0 is undefined, so we will just pick 0. |
| return 0; |
| } |
| } |
| case SpvOp::SpvOpUMod: |
| if (b != 0u) { |
| return (a % b); |
| } else { |
| // Mod with 0 is undefined, so we will just pick 0. |
| return 0; |
| } |
| |
| // Shifting |
| case SpvOp::SpvOpShiftRightLogical: |
| if (b >= 32) { |
| // This is undefined behaviour when |b| > 32. Choose 0 for consistency. |
| // When |b| == 32, doing the shift in C++ in undefined, but the result |
| // will be 0, so just return that value. |
| return 0; |
| } |
| return a >> b; |
| case SpvOp::SpvOpShiftRightArithmetic: |
| if (b > 32) { |
| // This is undefined behaviour. Choose 0 for consistency. |
| return 0; |
| } |
| if (b == 32) { |
| // Doing the shift in C++ is undefined, but the result is defined in the |
| // spir-v spec. Find that value another way. |
| if (static_cast<int32_t>(a) >= 0) { |
| return 0; |
| } else { |
| return static_cast<uint32_t>(-1); |
| } |
| } |
| return (static_cast<int32_t>(a)) >> b; |
| case SpvOp::SpvOpShiftLeftLogical: |
| if (b >= 32) { |
| // This is undefined behaviour when |b| > 32. Choose 0 for consistency. |
| // When |b| == 32, doing the shift in C++ in undefined, but the result |
| // will be 0, so just return that value. |
| return 0; |
| } |
| return a << b; |
| |
| // Bitwise operations |
| case SpvOp::SpvOpBitwiseOr: |
| return a | b; |
| case SpvOp::SpvOpBitwiseAnd: |
| return a & b; |
| case SpvOp::SpvOpBitwiseXor: |
| return a ^ b; |
| |
| // Logical |
| case SpvOp::SpvOpLogicalEqual: |
| return (static_cast<bool>(a)) == (static_cast<bool>(b)); |
| case SpvOp::SpvOpLogicalNotEqual: |
| return (static_cast<bool>(a)) != (static_cast<bool>(b)); |
| case SpvOp::SpvOpLogicalOr: |
| return (static_cast<bool>(a)) || (static_cast<bool>(b)); |
| case SpvOp::SpvOpLogicalAnd: |
| return (static_cast<bool>(a)) && (static_cast<bool>(b)); |
| |
| // Comparison |
| case SpvOp::SpvOpIEqual: |
| return a == b; |
| case SpvOp::SpvOpINotEqual: |
| return a != b; |
| case SpvOp::SpvOpULessThan: |
| return a < b; |
| case SpvOp::SpvOpSLessThan: |
| return (static_cast<int32_t>(a)) < (static_cast<int32_t>(b)); |
| case SpvOp::SpvOpUGreaterThan: |
| return a > b; |
| case SpvOp::SpvOpSGreaterThan: |
| return (static_cast<int32_t>(a)) > (static_cast<int32_t>(b)); |
| case SpvOp::SpvOpULessThanEqual: |
| return a <= b; |
| case SpvOp::SpvOpSLessThanEqual: |
| return (static_cast<int32_t>(a)) <= (static_cast<int32_t>(b)); |
| case SpvOp::SpvOpUGreaterThanEqual: |
| return a >= b; |
| case SpvOp::SpvOpSGreaterThanEqual: |
| return (static_cast<int32_t>(a)) >= (static_cast<int32_t>(b)); |
| default: |
| assert(false && |
| "Unsupported binary operation for OpSpecConstantOp instruction"); |
| return 0u; |
| } |
| } |
| |
| uint32_t InstructionFolder::TernaryOperate(SpvOp opcode, uint32_t a, uint32_t b, |
| uint32_t c) const { |
| switch (opcode) { |
| case SpvOp::SpvOpSelect: |
| return (static_cast<bool>(a)) ? b : c; |
| default: |
| assert(false && |
| "Unsupported ternary operation for OpSpecConstantOp instruction"); |
| return 0u; |
| } |
| } |
| |
| uint32_t InstructionFolder::OperateWords( |
| SpvOp opcode, const std::vector<uint32_t>& operand_words) const { |
| switch (operand_words.size()) { |
| case 1: |
| return UnaryOperate(opcode, operand_words.front()); |
| case 2: |
| return BinaryOperate(opcode, operand_words.front(), operand_words.back()); |
| case 3: |
| return TernaryOperate(opcode, operand_words[0], operand_words[1], |
| operand_words[2]); |
| default: |
| assert(false && "Invalid number of operands"); |
| return 0; |
| } |
| } |
| |
| bool InstructionFolder::FoldInstructionInternal(Instruction* inst) const { |
| auto identity_map = [](uint32_t id) { return id; }; |
| Instruction* folded_inst = FoldInstructionToConstant(inst, identity_map); |
| if (folded_inst != nullptr) { |
| inst->SetOpcode(SpvOpCopyObject); |
| inst->SetInOperands({{SPV_OPERAND_TYPE_ID, {folded_inst->result_id()}}}); |
| return true; |
| } |
| |
| analysis::ConstantManager* const_manager = context_->get_constant_mgr(); |
| std::vector<const analysis::Constant*> constants = |
| const_manager->GetOperandConstants(inst); |
| |
| for (const FoldingRule& rule : |
| GetFoldingRules().GetRulesForInstruction(inst)) { |
| if (rule(context_, inst, constants)) { |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| // Returns the result of performing an operation on scalar constant operands. |
| // This function extracts the operand values as 32 bit words and returns the |
| // result in 32 bit word. Scalar constants with longer than 32-bit width are |
| // not accepted in this function. |
| uint32_t InstructionFolder::FoldScalars( |
| SpvOp opcode, |
| const std::vector<const analysis::Constant*>& operands) const { |
| assert(IsFoldableOpcode(opcode) && |
| "Unhandled instruction opcode in FoldScalars"); |
| std::vector<uint32_t> operand_values_in_raw_words; |
| for (const auto& operand : operands) { |
| if (const analysis::ScalarConstant* scalar = operand->AsScalarConstant()) { |
| const auto& scalar_words = scalar->words(); |
| assert(scalar_words.size() == 1 && |
| "Scalar constants with longer than 32-bit width are not allowed " |
| "in FoldScalars()"); |
| operand_values_in_raw_words.push_back(scalar_words.front()); |
| } else if (operand->AsNullConstant()) { |
| operand_values_in_raw_words.push_back(0u); |
| } else { |
| assert(false && |
| "FoldScalars() only accepts ScalarConst or NullConst type of " |
| "constant"); |
| } |
| } |
| return OperateWords(opcode, operand_values_in_raw_words); |
| } |
| |
| bool InstructionFolder::FoldBinaryIntegerOpToConstant( |
| Instruction* inst, const std::function<uint32_t(uint32_t)>& id_map, |
| uint32_t* result) const { |
| SpvOp opcode = inst->opcode(); |
| analysis::ConstantManager* const_manger = context_->get_constant_mgr(); |
| |
| uint32_t ids[2]; |
| const analysis::IntConstant* constants[2]; |
| for (uint32_t i = 0; i < 2; i++) { |
| const Operand* operand = &inst->GetInOperand(i); |
| if (operand->type != SPV_OPERAND_TYPE_ID) { |
| return false; |
| } |
| ids[i] = id_map(operand->words[0]); |
| const analysis::Constant* constant = |
| const_manger->FindDeclaredConstant(ids[i]); |
| constants[i] = (constant != nullptr ? constant->AsIntConstant() : nullptr); |
| } |
| |
| switch (opcode) { |
| // Arthimetics |
| case SpvOp::SpvOpIMul: |
| for (uint32_t i = 0; i < 2; i++) { |
| if (constants[i] != nullptr && constants[i]->IsZero()) { |
| *result = 0; |
| return true; |
| } |
| } |
| break; |
| case SpvOp::SpvOpUDiv: |
| case SpvOp::SpvOpSDiv: |
| case SpvOp::SpvOpSRem: |
| case SpvOp::SpvOpSMod: |
| case SpvOp::SpvOpUMod: |
| // This changes undefined behaviour (ie divide by 0) into a 0. |
| for (uint32_t i = 0; i < 2; i++) { |
| if (constants[i] != nullptr && constants[i]->IsZero()) { |
| *result = 0; |
| return true; |
| } |
| } |
| break; |
| |
| // Shifting |
| case SpvOp::SpvOpShiftRightLogical: |
| case SpvOp::SpvOpShiftLeftLogical: |
| if (constants[1] != nullptr) { |
| // When shifting by a value larger than the size of the result, the |
| // result is undefined. We are setting the undefined behaviour to a |
| // result of 0. If the shift amount is the same as the size of the |
| // result, then the result is defined, and it 0. |
| uint32_t shift_amount = constants[1]->GetU32BitValue(); |
| if (shift_amount >= 32) { |
| *result = 0; |
| return true; |
| } |
| } |
| break; |
| |
| // Bitwise operations |
| case SpvOp::SpvOpBitwiseOr: |
| for (uint32_t i = 0; i < 2; i++) { |
| if (constants[i] != nullptr) { |
| // TODO: Change the mask against a value based on the bit width of the |
| // instruction result type. This way we can handle say 16-bit values |
| // as well. |
| uint32_t mask = constants[i]->GetU32BitValue(); |
| if (mask == 0xFFFFFFFF) { |
| *result = 0xFFFFFFFF; |
| return true; |
| } |
| } |
| } |
| break; |
| case SpvOp::SpvOpBitwiseAnd: |
| for (uint32_t i = 0; i < 2; i++) { |
| if (constants[i] != nullptr) { |
| if (constants[i]->IsZero()) { |
| *result = 0; |
| return true; |
| } |
| } |
| } |
| break; |
| |
| // Comparison |
| case SpvOp::SpvOpULessThan: |
| if (constants[0] != nullptr && |
| constants[0]->GetU32BitValue() == UINT32_MAX) { |
| *result = false; |
| return true; |
| } |
| if (constants[1] != nullptr && constants[1]->GetU32BitValue() == 0) { |
| *result = false; |
| return true; |
| } |
| break; |
| case SpvOp::SpvOpSLessThan: |
| if (constants[0] != nullptr && |
| constants[0]->GetS32BitValue() == INT32_MAX) { |
| *result = false; |
| return true; |
| } |
| if (constants[1] != nullptr && |
| constants[1]->GetS32BitValue() == INT32_MIN) { |
| *result = false; |
| return true; |
| } |
| break; |
| case SpvOp::SpvOpUGreaterThan: |
| if (constants[0] != nullptr && constants[0]->IsZero()) { |
| *result = false; |
| return true; |
| } |
| if (constants[1] != nullptr && |
| constants[1]->GetU32BitValue() == UINT32_MAX) { |
| *result = false; |
| return true; |
| } |
| break; |
| case SpvOp::SpvOpSGreaterThan: |
| if (constants[0] != nullptr && |
| constants[0]->GetS32BitValue() == INT32_MIN) { |
| *result = false; |
| return true; |
| } |
| if (constants[1] != nullptr && |
| constants[1]->GetS32BitValue() == INT32_MAX) { |
| *result = false; |
| return true; |
| } |
| break; |
| case SpvOp::SpvOpULessThanEqual: |
| if (constants[0] != nullptr && constants[0]->IsZero()) { |
| *result = true; |
| return true; |
| } |
| if (constants[1] != nullptr && |
| constants[1]->GetU32BitValue() == UINT32_MAX) { |
| *result = true; |
| return true; |
| } |
| break; |
| case SpvOp::SpvOpSLessThanEqual: |
| if (constants[0] != nullptr && |
| constants[0]->GetS32BitValue() == INT32_MIN) { |
| *result = true; |
| return true; |
| } |
| if (constants[1] != nullptr && |
| constants[1]->GetS32BitValue() == INT32_MAX) { |
| *result = true; |
| return true; |
| } |
| break; |
| case SpvOp::SpvOpUGreaterThanEqual: |
| if (constants[0] != nullptr && |
| constants[0]->GetU32BitValue() == UINT32_MAX) { |
| *result = true; |
| return true; |
| } |
| if (constants[1] != nullptr && constants[1]->GetU32BitValue() == 0) { |
| *result = true; |
| return true; |
| } |
| break; |
| case SpvOp::SpvOpSGreaterThanEqual: |
| if (constants[0] != nullptr && |
| constants[0]->GetS32BitValue() == INT32_MAX) { |
| *result = true; |
| return true; |
| } |
| if (constants[1] != nullptr && |
| constants[1]->GetS32BitValue() == INT32_MIN) { |
| *result = true; |
| return true; |
| } |
| break; |
| default: |
| break; |
| } |
| return false; |
| } |
| |
| bool InstructionFolder::FoldBinaryBooleanOpToConstant( |
| Instruction* inst, const std::function<uint32_t(uint32_t)>& id_map, |
| uint32_t* result) const { |
| SpvOp opcode = inst->opcode(); |
| analysis::ConstantManager* const_manger = context_->get_constant_mgr(); |
| |
| uint32_t ids[2]; |
| const analysis::BoolConstant* constants[2]; |
| for (uint32_t i = 0; i < 2; i++) { |
| const Operand* operand = &inst->GetInOperand(i); |
| if (operand->type != SPV_OPERAND_TYPE_ID) { |
| return false; |
| } |
| ids[i] = id_map(operand->words[0]); |
| const analysis::Constant* constant = |
| const_manger->FindDeclaredConstant(ids[i]); |
| constants[i] = (constant != nullptr ? constant->AsBoolConstant() : nullptr); |
| } |
| |
| switch (opcode) { |
| // Logical |
| case SpvOp::SpvOpLogicalOr: |
| for (uint32_t i = 0; i < 2; i++) { |
| if (constants[i] != nullptr) { |
| if (constants[i]->value()) { |
| *result = true; |
| return true; |
| } |
| } |
| } |
| break; |
| case SpvOp::SpvOpLogicalAnd: |
| for (uint32_t i = 0; i < 2; i++) { |
| if (constants[i] != nullptr) { |
| if (!constants[i]->value()) { |
| *result = false; |
| return true; |
| } |
| } |
| } |
| break; |
| |
| default: |
| break; |
| } |
| return false; |
| } |
| |
| bool InstructionFolder::FoldIntegerOpToConstant( |
| Instruction* inst, const std::function<uint32_t(uint32_t)>& id_map, |
| uint32_t* result) const { |
| assert(IsFoldableOpcode(inst->opcode()) && |
| "Unhandled instruction opcode in FoldScalars"); |
| switch (inst->NumInOperands()) { |
| case 2: |
| return FoldBinaryIntegerOpToConstant(inst, id_map, result) || |
| FoldBinaryBooleanOpToConstant(inst, id_map, result); |
| default: |
| return false; |
| } |
| } |
| |
| std::vector<uint32_t> InstructionFolder::FoldVectors( |
| SpvOp opcode, uint32_t num_dims, |
| const std::vector<const analysis::Constant*>& operands) const { |
| assert(IsFoldableOpcode(opcode) && |
| "Unhandled instruction opcode in FoldVectors"); |
| std::vector<uint32_t> result; |
| for (uint32_t d = 0; d < num_dims; d++) { |
| std::vector<uint32_t> operand_values_for_one_dimension; |
| for (const auto& operand : operands) { |
| if (const analysis::VectorConstant* vector_operand = |
| operand->AsVectorConstant()) { |
| // Extract the raw value of the scalar component constants |
| // in 32-bit words here. The reason of not using FoldScalars() here |
| // is that we do not create temporary null constants as components |
| // when the vector operand is a NullConstant because Constant creation |
| // may need extra checks for the validity and that is not managed in |
| // here. |
| if (const analysis::ScalarConstant* scalar_component = |
| vector_operand->GetComponents().at(d)->AsScalarConstant()) { |
| const auto& scalar_words = scalar_component->words(); |
| assert( |
| scalar_words.size() == 1 && |
| "Vector components with longer than 32-bit width are not allowed " |
| "in FoldVectors()"); |
| operand_values_for_one_dimension.push_back(scalar_words.front()); |
| } else if (operand->AsNullConstant()) { |
| operand_values_for_one_dimension.push_back(0u); |
| } else { |
| assert(false && |
| "VectorConst should only has ScalarConst or NullConst as " |
| "components"); |
| } |
| } else if (operand->AsNullConstant()) { |
| operand_values_for_one_dimension.push_back(0u); |
| } else { |
| assert(false && |
| "FoldVectors() only accepts VectorConst or NullConst type of " |
| "constant"); |
| } |
| } |
| result.push_back(OperateWords(opcode, operand_values_for_one_dimension)); |
| } |
| return result; |
| } |
| |
| bool InstructionFolder::IsFoldableOpcode(SpvOp opcode) const { |
| // NOTE: Extend to more opcodes as new cases are handled in the folder |
| // functions. |
| switch (opcode) { |
| case SpvOp::SpvOpBitwiseAnd: |
| case SpvOp::SpvOpBitwiseOr: |
| case SpvOp::SpvOpBitwiseXor: |
| case SpvOp::SpvOpIAdd: |
| case SpvOp::SpvOpIEqual: |
| case SpvOp::SpvOpIMul: |
| case SpvOp::SpvOpINotEqual: |
| case SpvOp::SpvOpISub: |
| case SpvOp::SpvOpLogicalAnd: |
| case SpvOp::SpvOpLogicalEqual: |
| case SpvOp::SpvOpLogicalNot: |
| case SpvOp::SpvOpLogicalNotEqual: |
| case SpvOp::SpvOpLogicalOr: |
| case SpvOp::SpvOpNot: |
| case SpvOp::SpvOpSDiv: |
| case SpvOp::SpvOpSelect: |
| case SpvOp::SpvOpSGreaterThan: |
| case SpvOp::SpvOpSGreaterThanEqual: |
| case SpvOp::SpvOpShiftLeftLogical: |
| case SpvOp::SpvOpShiftRightArithmetic: |
| case SpvOp::SpvOpShiftRightLogical: |
| case SpvOp::SpvOpSLessThan: |
| case SpvOp::SpvOpSLessThanEqual: |
| case SpvOp::SpvOpSMod: |
| case SpvOp::SpvOpSNegate: |
| case SpvOp::SpvOpSRem: |
| case SpvOp::SpvOpSConvert: |
| case SpvOp::SpvOpUConvert: |
| case SpvOp::SpvOpUDiv: |
| case SpvOp::SpvOpUGreaterThan: |
| case SpvOp::SpvOpUGreaterThanEqual: |
| case SpvOp::SpvOpULessThan: |
| case SpvOp::SpvOpULessThanEqual: |
| case SpvOp::SpvOpUMod: |
| return true; |
| default: |
| return false; |
| } |
| } |
| |
| bool InstructionFolder::IsFoldableConstant( |
| const analysis::Constant* cst) const { |
| // Currently supported constants are 32-bit values or null constants. |
| if (const analysis::ScalarConstant* scalar = cst->AsScalarConstant()) |
| return scalar->words().size() == 1; |
| else |
| return cst->AsNullConstant() != nullptr; |
| } |
| |
| Instruction* InstructionFolder::FoldInstructionToConstant( |
| Instruction* inst, std::function<uint32_t(uint32_t)> id_map) const { |
| analysis::ConstantManager* const_mgr = context_->get_constant_mgr(); |
| |
| if (!inst->IsFoldableByFoldScalar() && |
| !GetConstantFoldingRules().HasFoldingRule(inst)) { |
| return nullptr; |
| } |
| // Collect the values of the constant parameters. |
| std::vector<const analysis::Constant*> constants; |
| bool missing_constants = false; |
| inst->ForEachInId([&constants, &missing_constants, const_mgr, |
| &id_map](uint32_t* op_id) { |
| uint32_t id = id_map(*op_id); |
| const analysis::Constant* const_op = const_mgr->FindDeclaredConstant(id); |
| if (!const_op) { |
| constants.push_back(nullptr); |
| missing_constants = true; |
| } else { |
| constants.push_back(const_op); |
| } |
| }); |
| |
| const analysis::Constant* folded_const = nullptr; |
| for (auto rule : GetConstantFoldingRules().GetRulesForInstruction(inst)) { |
| folded_const = rule(context_, inst, constants); |
| if (folded_const != nullptr) { |
| Instruction* const_inst = |
| const_mgr->GetDefiningInstruction(folded_const, inst->type_id()); |
| if (const_inst == nullptr) { |
| return nullptr; |
| } |
| assert(const_inst->type_id() == inst->type_id()); |
| // May be a new instruction that needs to be analysed. |
| context_->UpdateDefUse(const_inst); |
| return const_inst; |
| } |
| } |
| |
| uint32_t result_val = 0; |
| bool successful = false; |
| // If all parameters are constant, fold the instruction to a constant. |
| if (!missing_constants && inst->IsFoldableByFoldScalar()) { |
| result_val = FoldScalars(inst->opcode(), constants); |
| successful = true; |
| } |
| |
| if (!successful && inst->IsFoldableByFoldScalar()) { |
| successful = FoldIntegerOpToConstant(inst, id_map, &result_val); |
| } |
| |
| if (successful) { |
| const analysis::Constant* result_const = |
| const_mgr->GetConstant(const_mgr->GetType(inst), {result_val}); |
| Instruction* folded_inst = |
| const_mgr->GetDefiningInstruction(result_const, inst->type_id()); |
| return folded_inst; |
| } |
| return nullptr; |
| } |
| |
| bool InstructionFolder::IsFoldableType(Instruction* type_inst) const { |
| // Support 32-bit integers. |
| if (type_inst->opcode() == SpvOpTypeInt) { |
| return type_inst->GetSingleWordInOperand(0) == 32; |
| } |
| // Support booleans. |
| if (type_inst->opcode() == SpvOpTypeBool) { |
| return true; |
| } |
| // Nothing else yet. |
| return false; |
| } |
| |
| bool InstructionFolder::FoldInstruction(Instruction* inst) const { |
| bool modified = false; |
| Instruction* folded_inst(inst); |
| while (folded_inst->opcode() != SpvOpCopyObject && |
| FoldInstructionInternal(&*folded_inst)) { |
| modified = true; |
| } |
| return modified; |
| } |
| |
| } // namespace opt |
| } // namespace spvtools |
