| // 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 "fold.h" |
| #include "def_use_manager.h" |
| |
| #include <cassert> |
| #include <vector> |
| |
| namespace spvtools { |
| namespace opt { |
| |
| namespace { |
| |
| // Returns the single-word result from performing the given unary operation on |
| // the operand value which is passed in as a 32-bit word. |
| uint32_t UnaryOperate(SpvOp opcode, uint32_t operand) { |
| switch (opcode) { |
| // Arthimetics |
| case SpvOp::SpvOpSNegate: |
| return -static_cast<int32_t>(operand); |
| case SpvOp::SpvOpNot: |
| return ~operand; |
| case SpvOp::SpvOpLogicalNot: |
| return !static_cast<bool>(operand); |
| default: |
| assert(false && |
| "Unsupported unary operation for OpSpecConstantOp instruction"); |
| return 0u; |
| } |
| } |
| |
| // Returns the single-word result from performing the given binary operation on |
| // the operand values which are passed in as two 32-bit word. |
| uint32_t BinaryOperate(SpvOp opcode, uint32_t a, uint32_t b) { |
| switch (opcode) { |
| // Arthimetics |
| case SpvOp::SpvOpIAdd: |
| return a + b; |
| case SpvOp::SpvOpISub: |
| return a - b; |
| case SpvOp::SpvOpIMul: |
| return a * b; |
| case SpvOp::SpvOpUDiv: |
| assert(b != 0); |
| return a / b; |
| case SpvOp::SpvOpSDiv: |
| assert(b != 0u); |
| return (static_cast<int32_t>(a)) / (static_cast<int32_t>(b)); |
| 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. |
| assert(b != 0u); |
| return static_cast<int32_t>(a) % static_cast<int32_t>(b); |
| } |
| case SpvOp::SpvOpSMod: { |
| // The sign of non-zero result comes from the second operand: b |
| assert(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; |
| } |
| case SpvOp::SpvOpUMod: |
| assert(b != 0u); |
| return (a % b); |
| |
| // Shifting |
| case SpvOp::SpvOpShiftRightLogical: { |
| return a >> b; |
| } |
| case SpvOp::SpvOpShiftRightArithmetic: |
| return (static_cast<int32_t>(a)) >> b; |
| case SpvOp::SpvOpShiftLeftLogical: |
| 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; |
| } |
| } |
| |
| // Returns the single-word result from performing the given ternary operation |
| // on the operand values which are passed in as three 32-bit word. |
| uint32_t TernaryOperate(SpvOp opcode, uint32_t a, uint32_t b, uint32_t c) { |
| switch (opcode) { |
| case SpvOp::SpvOpSelect: |
| return (static_cast<bool>(a)) ? b : c; |
| default: |
| assert(false && |
| "Unsupported ternary operation for OpSpecConstantOp instruction"); |
| return 0u; |
| } |
| } |
| |
| // Returns the single-word result from performing the given operation on the |
| // operand words. This only works with 32-bit operations and uses boolean |
| // convention that 0u is false, and anything else is boolean true. |
| // TODO(qining): Support operands other than 32-bit wide. |
| uint32_t OperateWords(SpvOp opcode, |
| const std::vector<uint32_t>& operand_words) { |
| 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; |
| } |
| } |
| |
| } // namespace |
| |
| // 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 FoldScalars(SpvOp opcode, |
| const std::vector<analysis::Constant*>& operands) { |
| std::vector<uint32_t> operand_values_in_raw_words; |
| for (analysis::Constant* operand : operands) { |
| if (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); |
| } |
| |
| // Returns the result of performing an operation over constant vectors. This |
| // function iterates through the given vector type constant operands and |
| // calculates the result for each element of the result vector to return. |
| // Vectors with longer than 32-bit scalar components are not accepted in this |
| // function. |
| std::vector<uint32_t> FoldVectors( |
| SpvOp opcode, uint32_t num_dims, |
| const std::vector<analysis::Constant*>& operands) { |
| std::vector<uint32_t> result; |
| for (uint32_t d = 0; d < num_dims; d++) { |
| std::vector<uint32_t> operand_values_for_one_dimension; |
| for (analysis::Constant* operand : operands) { |
| if (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 manageed 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; |
| } |
| |
| } // namespace opt |
| } // namespace spvtools |
