Moving over WIP code from temp repo

.github/compiler_setup.py

@@ -0,0 +1,22 @@
+import os
+import sys
+
+if __name__ == "__main__":
+
+    # TODO only for ubuntu
+
+    compiler = sys.argv[1]
+    os.system("sudo apt-get update")
+
+    if "g++" in compiler and "clang" not in compiler:
+        version = compiler.split("-")[1]
+        os.system(f"sudo apt-get -y install gcc-{version} g++-{version}")
+    elif "clang" in compiler:
+        version = compiler.split("-")[1]
+        print(f"Installing clang {compiler}")
+        os.system("wget https://apt.llvm.org/llvm.sh")
+        os.system("chmod +x llvm.sh")
+        os.system(f"sudo ./llvm.sh {version}")
+        os.system(f"sudo apt-get install -y libomp-{version}-dev")
+    else:
+        raise ValueError(f"Compiler {compiler} not supported")

.github/workflows/all_push.yml

@@ -0,0 +1,46 @@
+name: All push
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+
+jobs:
+  build:
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        os: [ubuntu-latest]
+        compiler: [g++-12, clang++-17]
+        python-version: ["3.10", "3.11", "3.12"]
+    steps:
+    - uses: actions/checkout@v2
+      with:
+        submodules: recursive
+
+    - name: Setup compiler
+      run: python3 ./.github/compiler_setup.py ${{ matrix.compiler }}
+
+    - name: Setup Python
+      uses: actions/setup-python@v2
+      with:
+        python-version: ${{ matrix.python-version }}
+
+    - name: Install Python dependencies
+      run: python -m pip install numpy pytest cmake
+
+    - name: Configure CMake
+      env:
+        CXX: ${{ matrix.compiler }}
+      run: cmake -B ${{github.workspace}}/build -DCMAKE_CXX_COMPILER=${CXX} -DCMAKE_BUILD_TYPE=Release
+
+    - name: Build
+      # Build your program with the given configuration
+      run: cmake --build ${{github.workspace}}/build --parallel
+
+    - name: Test C++
+      run: ctest --test-dir build --parallel
+
+    # - name: Test Python
+      # run: PYTHONPATH=build:$PYTHONPATH pytest -v test

.gitignore

@@ -0,0 +1,81 @@
+# These are some examples of commonly ignored file patterns.
+# You should customize this list as applicable to your project.
+# Learn more about .gitignore:
+#     https://www.atlassian.com/git/tutorials/saving-changes/gitignore
+
+# Node artifact files
+node_modules/
+dist/
+build/
+
+# Compiled Java class files
+*.class
+*.prof
+# Compiled Python bytecode
+*.py[cod]
+*.egg-info
+
+# Log files
+*.log
+
+# Package files
+*.jar
+
+# Maven
+target/
+
+# JetBrains IDE
+.idea/
+
+# Unit test reports
+TEST*.xml
+
+# Generated by MacOS
+.DS_Store
+
+# Generated by Windows
+Thumbs.db
+
+# Applications
+*.app
+*.exe
+*.war
+
+# Large media files
+*.mp4
+*.tiff
+*.avi
+*.flv
+*.mov
+*.wmv
+*.svg
+
+# Python
+__pycache__
+
+# Cython compiled
+*.c
+*.so
+*.h
+
+# Latex
+*.synctex.gz
+*.toc
+*.out
+*.aux
+*.fdb_latexmk
+*.fls
+*.bbl
+*.blg
+*.xwm
+/venv/
+*.xwm
+
+# Misc
+.vscode
+.coverage
+*.zip
+*_package
+logs
+scratch
+notes

CMakeLists.txt

@@ -0,0 +1,75 @@
+#
+# Boilerplate CMakeLists.txt for C++ projects
+#
+cmake_minimum_required(VERSION 3.25)
+
+set(CMAKE_EXPORT_COMPILE_COMMANDS
+    TRUE
+    CACHE BOOL "Export compile commands to build directory" FORCE)
+
+include(cmake/CPM.cmake)
+# TODO adding a package lock to help with SBOM
+# cpmusepackagelock(package-lock.cmake)
+
+#
+# Project specific configuration
+#
+
+# Dependencies
+cpmaddpackage("gh:doctest/[email protected]")
+# cpmaddpackage("gh:p-ranav/[email protected]")
+cpmaddpackage("gh:pybind/[email protected]")
+cpmaddpackage("gh:fmtlib/fmt#10.2.1")
+cpmaddpackage("gh:kokkos/mdspan#b885a2c60ad42f9e1aaa0d317a38105b950cbed0")
+
+#
+# User Options
+#
+
+# TODO NOT WORKING YET
+
+# option(ENABLE_COVERAGE "Enable coverage reporting" OFF) if(ENABLE_COVERAGE)
+# message(STATUS "[FAST_PAULI] Enabling coverage reporting") message(STATUS
+# "[FAST_PAULI]") set(FAST_PAULI_EXTRA_CXX_COMPILE_FLAGS "-coverage")
+# set(FAST_PAULI_EXTRA_CXX_LD_FLAGS "-lgcov;--coverage") endif()
+
+#
+# Fast Pauli
+#
+
+project(fast_pauli LANGUAGES CXX)
+
+# Set C++ standard
+set(CMAKE_CXX_STANDARD 20)
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+set(CMAKE_CXX_EXTENSIONS OFF)
+
+# Set up OpenMP
+find_package(OpenMP REQUIRED)
+
+# Our primary target
+add_library(fast_pauli INTERFACE)
+target_include_directories(fast_pauli
+                           INTERFACE ${CMAKE_CURRENT_SOURCE_DIR}/include/)
+target_link_libraries(fast_pauli INTERFACE fmt::fmt mdspan OpenMP::OpenMP_CXX)
+target_compile_options(
+  fast_pauli
+  INTERFACE -g3
+            -O3
+            -march=native
+            -Wall
+            -Wextra
+            -Werror
+            # -stdlib=libc++
+            ${FAST_PAULI_EXTRA_CXX_COMPILE_FLAGS})
+target_link_options(fast_pauli INTERFACE ${FAST_PAULI_EXTRA_CXX_LD_FLAGS}
+                    -fuse-ld=mold)
+# target_compile_definitions(fast_pauli INTERFACE)
+
+# Testing
+include(CTest)
+enable_testing()
+add_subdirectory(tests)
+
+# Examples
+add_subdirectory(examples)

README.md

@@ -1 +1,44 @@
-# fast-pauli
+# Summary
+
+# TODOs
+- [ ] Figure out the tranpose non-sense or support both
+- [ ] Clean up `apply_batch` we shouldn't need to pass a coeff
+- [ ] Add docstrings
+  - [X] Pauli
+  - [X] PauliString
+  - [ ] PauliOp
+  - [ ] SummedPauliOp
+- [ ] Clean up tests
+- [X] Clean up test utils
+- [X] Add type aliases and factory functions to utils for fast_pauli
+- [X] Seach the names and make sure we don't have any overlap with other projects
+- [ ] Build out pauli decomposer
+- [X] Remove the weights argument and rename to data
+- [X] Add namespace
+- [ ] Add function equivalent of `get_state_iteration_unequal_weights` to SummedPauliOp
+- [ ] Writeup for docs
+- [ ] Add pybind11 interface and python examples
+- [ ] Change functions names over to default to parallel impl and use `_serial` for the serial implementation
+- [ ] Migrate `PauliOp` and `SummedPauliOp` to only store mdspans rather than copies of the data itself
+
+## Requirements
+
+- CMake >= 3.20
+- C++ compiler with OpenMP and C++20 support (LLVM recommended)
+  - Tested Compilers GCC@12, LLVM@17, LLVM@18
+- Python >= 3.10
+
+
+## Build and Test
+
+```bash
+cmake -B build -DCMAKE_CXX_COMPILER=<your_favorite_c++_compiler>
+cmake --build build
+ctest --test-dir build
+```
+
+## Design Choices
+
+The C++ portion of this library relies heavily on spans and views.
+These lightweight accessors are helpful and performant, but can lead to dangling spans or accessing bad memory if used improperly.
+Developers should familiarize themselves with these dangers by reviewing [this post](https://hackingcpp.com/cpp/std/span.html).

cmake/CPM.cmake

@@ -0,0 +1,24 @@
+# SPDX-License-Identifier: MIT
+#
+# SPDX-FileCopyrightText: Copyright (c) 2019-2023 Lars Melchior and contributors
+
+set(CPM_DOWNLOAD_VERSION 0.39.0)
+set(CPM_HASH_SUM "66639bcac9dd2907b2918de466783554c1334446b9874e90d38e3778d404c2ef")
+
+if(CPM_SOURCE_CACHE)
+  set(CPM_DOWNLOAD_LOCATION "${CPM_SOURCE_CACHE}/cpm/CPM_${CPM_DOWNLOAD_VERSION}.cmake")
+elseif(DEFINED ENV{CPM_SOURCE_CACHE})
+  set(CPM_DOWNLOAD_LOCATION "$ENV{CPM_SOURCE_CACHE}/cpm/CPM_${CPM_DOWNLOAD_VERSION}.cmake")
+else()
+  set(CPM_DOWNLOAD_LOCATION "${CMAKE_BINARY_DIR}/cmake/CPM_${CPM_DOWNLOAD_VERSION}.cmake")
+endif()
+
+# Expand relative path. This is important if the provided path contains a tilde (~)
+get_filename_component(CPM_DOWNLOAD_LOCATION ${CPM_DOWNLOAD_LOCATION} ABSOLUTE)
+
+file(DOWNLOAD
+     https://github.com/cpm-cmake/CPM.cmake/releases/download/v${CPM_DOWNLOAD_VERSION}/CPM.cmake
+     ${CPM_DOWNLOAD_LOCATION} EXPECTED_HASH SHA256=${CPM_HASH_SUM}
+)
+
+include(${CPM_DOWNLOAD_LOCATION})

examples/01_pauli_op.cpp

@@ -0,0 +1,28 @@
+#include <algorithm>
+#include <random>
+
+#include "fast_pauli.hpp"
+
+using namespace fast_pauli;
+
+int main() {
+  std::vector<PauliString> pauli_strings(100000, "XYZXYZXYZXYZ");
+
+  std::vector<std::complex<double>> coeffs(pauli_strings.size(), 1);
+  PauliOp<double> pauli_op(coeffs, pauli_strings);
+
+  size_t const dims = pauli_strings[0].dims();
+
+  // Set up random state
+  std::random_device rd;
+  std::mt19937 gen(rd());
+  std::uniform_real_distribution<> dis(0, 1.0);
+  std::vector<std::complex<double>> state(dims, 0);
+  std::generate(state.begin(), state.end(),
+                [&]() { return std::complex<double>(dis(gen), dis(gen)); });
+
+  // Apply the PauliOp
+  std::vector<std::complex<double>> res = pauli_op.apply(state);
+
+  return 0;
+}

examples/02_pauli_op_multistate.cpp

@@ -0,0 +1,38 @@
+#include <algorithm>
+#include <experimental/mdspan>
+#include <random>
+
+#include "fast_pauli.hpp"
+
+using namespace fast_pauli;
+
+int main() {
+  using mytype = float;
+
+  // Setup PauliOp
+  std::vector<PauliString> pauli_strings(631, "XYZXYZXYZXYZ");
+  std::vector<std::complex<mytype>> coeffs(pauli_strings.size(), 1);
+  PauliOp<mytype> pauli_op(coeffs, pauli_strings);
+
+  size_t const dims = pauli_strings[0].dims();
+
+  // Set up random states
+  size_t const n_states = 10000;
+  std::random_device rd;
+  std::mt19937 gen(rd());
+  std::uniform_real_distribution<> dis(0, 1.0);
+  std::vector<std::complex<mytype>> states_raw(dims * n_states, 0);
+  std::generate(states_raw.begin(), states_raw.end(),
+                [&]() { return std::complex<mytype>(dis(gen), dis(gen)); });
+  std::mdspan<std::complex<mytype>, std::dextents<size_t, 2>> states(
+      states_raw.data(), n_states, dims);
+
+  // Apply the PauliOp
+  std::vector<std::complex<mytype>> new_states_raw(dims * n_states, 0);
+  std::mdspan<std::complex<mytype>, std::dextents<size_t, 2>> new_states(
+      new_states_raw.data(), n_states, dims);
+
+  // pauli_op.apply_naive(new_states, states);
+  pauli_op.apply(new_states, states);
+  return 0;
+}