/* -*- c++ -*- */ /* * Copyright © 2016 Intel Corporation * * Permission is hereby granted, free of charge, to any person obtaining a * copy of this software and associated documentation files (the "Software"), * to deal in the Software without restriction, including without limitation * the rights to use, copy, modify, merge, publish, distribute, sublicense, * and/or sell copies of the Software, and to permit persons to whom the * Software is furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice (including the next * paragraph) shall be included in all copies or substantial portions of the * Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS * IN THE SOFTWARE. */ #ifndef BRW_IR_ANALYSIS_H #define BRW_IR_ANALYSIS_H namespace brw { /** * Bitset of state categories that can influence the result of IR analysis * passes. */ enum analysis_dependency_class { /** * The analysis doesn't depend on the IR, its result is effectively a * constant during the compilation. */ DEPENDENCY_NOTHING = 0, /** * The analysis depends on the set of instructions in the program and * their naming. Note that because instructions are named sequentially * by IP this implies a dependency on the control flow edges between * instructions. This will be signaled whenever instructions are * inserted, removed or reordered in the program. */ DEPENDENCY_INSTRUCTION_IDENTITY = 0x1, /** * The analysis is sensitive to the detailed semantics of instructions * in the program, where "detailed" means any change in the instruction * data structures other than the linked-list pointers (which are * already covered by DEPENDENCY_INSTRUCTION_IDENTITY). E.g. changing * the negate or abs flags of an instruction source would signal this * flag alone because it would preserve all other instruction dependency * classes. */ DEPENDENCY_INSTRUCTION_DETAIL = 0x2, /** * The analysis depends on the set of data flow edges between * instructions. This will be signaled whenever the dataflow relation * between instructions has potentially changed, e.g. when the VGRF * index of an instruction source or destination changes (in which case * it will appear in combination with DEPENDENCY_INSTRUCTION_DETAIL), or * when data-dependent instructions are reordered (in which case it will * appear in combination with DEPENDENCY_INSTRUCTION_IDENTITY). */ DEPENDENCY_INSTRUCTION_DATA_FLOW = 0x4, /** * The analysis depends on all instruction dependency classes. These * will typically be signaled simultaneously when inserting or removing * instructions in the program (or if you're feeling too lazy to read * through your optimization pass to figure out which of the instruction * dependency classes above it invalidates). */ DEPENDENCY_INSTRUCTIONS = 0x7, /** * The analysis depends on the set of VGRFs in the program and their * naming. This will be signaled when VGRFs are allocated or released. */ DEPENDENCY_VARIABLES = 0x8, /** * The analysis depends on the set of basic blocks in the program, their * control flow edges and naming. */ DEPENDENCY_BLOCKS = 0x10, /** * The analysis depends on the program being literally the same (good * luck...), any change in the input invalidates previous analysis * computations. */ DEPENDENCY_EVERYTHING = ~0 }; inline analysis_dependency_class operator|(analysis_dependency_class x, analysis_dependency_class y) { return static_cast( static_cast(x) | static_cast(y)); } } /** * Instantiate a program analysis class \p L which can calculate an object of * type \p T as result. \p C is a closure that encapsulates whatever * information is required as argument to run the analysis pass. The purpose * of this class is to make sure that: * * - The analysis pass is executed lazily whenever it's needed and multiple * executions are optimized out as long as the cached result remains marked * up-to-date. * * - There is no way to access the cached analysis result without first * calling L::require(), which makes sure that the analysis pass is rerun * if necessary. * * - The cached result doesn't become inconsistent with the program for as * long as it remains marked up-to-date. (This is only enforced in debug * builds for performance reasons) * * The requirements on \p T are the following: * * - Constructible with a single argument, as in 'x = T(c)' for \p c of type * \p C. * * - 'x.dependency_class()' on const \p x returns a bitset of * brw::analysis_dependency_class specifying the set of IR objects that are * required to remain invariant for the cached analysis result to be * considered valid. * * - 'x.validate(c)' on const \p x returns a boolean result specifying * whether the analysis result \p x is consistent with the input IR. This * is currently only used for validation in debug builds. */ #define BRW_ANALYSIS(L, T, C) \ class L { \ public: \ /** \ * Construct a program analysis. \p c is an arbitrary object \ * passed as argument to the constructor of the analysis result \ * object of type \p T. \ */ \ L(C const &c) : c(c), p(NULL) {} \ \ /** \ * Destroy a program analysis. \ */ \ ~L() \ { \ delete p; \ } \ \ /** \ * Obtain the result of a program analysis. This gives a \ * guaranteed up-to-date result, the analysis pass will be \ * rerun implicitly if it has become stale. \ */ \ T & \ require() \ { \ if (p) \ assert(p->validate(c)); \ else \ p = new T(c); \ \ return *p; \ } \ \ const T & \ require() const \ { \ return const_cast(this)->require(); \ } \ \ /** \ * Report that dependencies of the analysis pass may have changed \ * since the last calculation and the cached analysis result may \ * have to be discarded. \ */ \ void \ invalidate(brw::analysis_dependency_class c) \ { \ if (p && c & p->dependency_class()) { \ delete p; \ p = NULL; \ } \ } \ \ private: \ C c; \ T *p; \ } #endif