Pipedream
Pipedream reverse engineers the following performance characteristics: (1) Instruction latency – The number of cycles an instruction requires to execute. (2) Peak micro-op retirement rate – How many fused micro-ops the CPU can retire per cycle. (3) Micro-fusion – The number of fused micro-ops an instruction decomposes into. (4) Micro-op decomposition and micro-op port usage – The list of unfused micro-ops every instruction decomposes into and the list of execution ports every one of these micro-ops can execute on.
IOLB
IOLB computes a symbolic lower bound on the I/O, or data movement, complexity of a computer program, that is the amount of data that needs to be moved between cache and main memory to perform its computation. The input is a C program, and the output is a mathematical formula that depends on program parameters (array sizes…) and cache size.
Demonstrator webpage: https://iocomplexity.corse.inria.fr/
IOOpt
IOOpt takes as input an abstract representation of a tileable program. The tool generates a tractable set of relevant permutations of the tiling loops, and a symbolic I/O cost expression for each of them. It then uses a non linear problem optimizer to find the best permutations and corresponding tile sizes for a given value of machine parameters (cache sizes and bandwidths at each level). IOOop can also be used to find an upper bound on the I/O cost of a program, for a given tiling scheme.
Demonstrator webpage: https://iocomplexity.corse.inria.fr/
Palmed
PALMED computes a bipartite graph assembly instructions to abstract resources that may be used for performance prediction, targeting static analysis tools and compilers. Internally, PALMED uses PIPEDREAM as a framework for microbenchmarking code generation, and use gurobi to find a first small graph. Then, PALMED deduces from the found resources and the microbenchmarks that saturates them a mapping of every supported instruction.
Demonstrator webpage: https://palmed.corse.inria.fr/
BISM
BISM (Bytecode-level Instrumentation for Software Monitoring) is a lightweight Java bytecode instrumentation tool which features an expressive high-level control-flow-aware instrumentation language. The language follows the aspect-oriented programming paradigm by adopting the joinpoint model, advice inlining, and separate instrumentation mechanisms. BISM provides joinpoints ranging from bytecode instruction to method execution, access to comprehensive context informa\
tion, and instrumentation methods. BISM runs in two modes: build-time and load-time.
TTile
TTiLE is a code generation tool for tensor operators present in CNNs such as tensor contraction and convolution. It takes as input: 1. a kernel specification, that is, a fonctionnal description of the operator (iteration space, tensors, single assignment description of the computation), 2. an optimization scheme that describes the layered structure of the generated code. The scheme “language” allows to express loop permutation, loop tiling, vectorization, unrolling, packing (which consists in using temporary buffers making cache access better behaved) and branching. Indeed, as opposed to existing schemes that rely on partial tiles, TTile can create non-perfectly nested loops to combine several “micro-kernels” (micro-kernel stands for the innermost part of the loop nest that is fully unrolled, register promoted and vectorized here). Using a specialized search strategy that combines operational research on analytical performance model and native execution time measurement, TTile outperforms current highly optimized libraries such as Intel oneDNN and Intel MKL.
EasyTracker
EasyTracker is intended for computer science teaching. It encapsulates the execution control and monitoring of another program written in Python or any compiled language supported by GDB. It can pause execution at interest points described in a high level language (variable modified or return of recursive functions for example).
Givy
Givy is a runtime developed as part of the PhD thesis of François Gindraud. It is designed for architectures with distributed memories, with the Kalray MPPA as the main target. It will execute dynamic data-flow task graphs, annotated with memory dependencies. It will automatically handle scheduling and placement of tasks (using the memory dependency hints), and generate memory transfers between distributed memory nodes when needed by using a software cache coherence protocol. Most of the work this year was done on implementing and testing a memory allocator with specific properties that is a building block of the whole runtime. This memory allocator is also tuned to work on the MPPA and its constraints, turning with very little memory and being efficient in the context of multithreaded calls.
Tirex
Tirex is a Textual Intermediate Representation for EXchanging target-level information between compiler optimizers and whole or parts of code generators (aka compiler back-end). The first motivation for this intermediate representation is to factor target-specific compiler optimizations into a single component, in case several compilers need to be maintained for a particular target (e.g., operating system compiler and application code compiler). Another motivation is to reduce the run-time cost of JIT compilation and of mixed mode execution, since the program to compile is already in a representation lowered to the level of the target processor.
The Tirex Intermediate Representation has previously been generated from within both the Open64 and GCC compilers. In order to increase the usability of Tirex and to decrease the amount of required code maintenance that is induced by compiler evolutions a Tirex-generator has been written that is capable of creating the Tirex representation of a program based on its corresponding assembler code.
BOAST
BOAST is a metaprogramming framework to produce portable and efficient computing kernels for HPC application. BOAST offers an embedded domain specific language to describe the kernels and their possible optimization. BOAST also supplies a complete runtime to compile, run, benchmark, and check the validity of the generated kernels. BOAST is being used in two flagship HPC applications BigDFT and SPECFEM3D, to improve performance portability of those codes.
THEMIS
THEMIS consists of a library and command-line tools. It provides an API, data structures and measures for decentralized monitoring. These building blocks can be reused or extended to modify existing algorithms, design new more intricate algorithms, and elaborate new approaches to assess existing algorithms.
Verde
Interactive Debugging with a traditional debugger can be tedious. One has to manually run a program step by step and set breakpoints to track a bug. i-RV is an approach to bug fixing that aims to help developpers during their Interactive Debbugging sessions using Runtime Verification.
Verde is the reference implementation of i-RV.
Mickey
Mickey is a set of tools for profiling based performance debugging for compiled binaries. It uses a dynamic binary translator to instrument arbitrary programs as they are being run to reconstruct the control flow and track data dependencies. This information is then fed to a polyhedral optimizer that proposes structured transformations for the original code. Mickey can handle both inter- and intra-procedural control & data flow in a unified way, thus enabling inter-procedural structured transformations. It is based on QEMU to allow for portability, both in terms of targeted CPU architectures, but also in terms of programming environment and the use of third-party libraries for which no source code is available.
IPFME
Quantifier elimination is the process of removing existential variables of a given formula, obtaining one with less variables and that implies the original formula. This can also be viewed as a projection of the set of points (integer here) that satisfy the original formula onto a sub-vectorial space made up of all the non-eliminated variables. The obtained projection is an over-approximation of the exact projection. The goal of the process is to make it as tight as possible.
IPFME presents extensions to the Fourier-Motzkin quantifier elimination process. The developed techniques allow to derive more precise simplification operations when handling integer valued multivariate polynomial systems.
The implementation, in C++, uses GiNaC (https://www.ginac.de/) for the manipulation of symbolic expressions.
