Hi, Sergey,

thanks for the patch! See my comments.

Sergey

This commit introduces CMake building scripts for the benches introduced
before. The benchmarks are enabled only if `LUAJIT_ENABLE_PERF` option
is set. For each suite (LuaJIT-benches in this patch set)
`AddBenchTarget()` macro generates 2 targets:
* Target to run all benches and store results in the
  perf/output/<suite_name> directory.
* Target to run all benches via CTest and inspect results in the
  console.

For the LuaJIT-benches there are 2 generated files:
* FASTA_5000000 -- is used as an input for <k-nukleotide.lua> and
                   <revcomp.lua>.
* SUMCOLL_5000.txt -- is used as an input for <sum-file.lua>.

These files and <perf/output> directory are added to the .gitignore files.
---
 .gitignore                         |  5 ++
 CMakeLists.txt                     | 11 ++++
 perf/CMakeLists.txt                | 99 ++++++++++++++++++++++++++++++
 perf/LuaJIT-benches/CMakeLists.txt | 52 ++++++++++++++++
 4 files changed, 167 insertions(+)
 create mode 100644 perf/CMakeLists.txt
 create mode 100644 perf/LuaJIT-benches/CMakeLists.txt

diff --git a/.gitignore b/.gitignore
index c26a7eb8..bfc7d401 100644
--- a/.gitignore
+++ b/.gitignore
@@ -28,3 +28,8 @@ luajit-parse-memprof
 luajit-parse-sysprof
 luajit.pc
 *.c_test
+
+# Generated by the performance tests.
+FASTA_5000000
+SUMCOL_5000.txt
+perf/output/
diff --git a/CMakeLists.txt b/CMakeLists.txt
index c0da4362..73f46835 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -464,6 +464,17 @@ if(LUAJIT_USE_TEST)
 endif()
 add_subdirectory(test)
 
+# --- Benchmarks source tree ---------------------------------------------------
+
+# The option to enable performance tests for the LuaJIT.
+# Disabled by default, since commonly it is used only by LuaJIT
+# developers and run in the CI with the specially set-up machine.
+option(LUAJIT_ENABLE_PERF "Generate <perf> target" OFF)
+
+if(LUAJIT_ENABLE_PERF)

option name confuses a bit due to `perf` utility.

I would rename to something like "LUAJIT_ENABLE_PERF_TESTS".

Feel free to ignore.

+  add_subdirectory(perf)
+endif()
+
 # --- Misc rules ---------------------------------------------------------------
 
 # XXX: Implement <uninstall> target using the following recipe:
diff --git a/perf/CMakeLists.txt b/perf/CMakeLists.txt
new file mode 100644
index 00000000..cc3c312f
--- /dev/null
+++ b/perf/CMakeLists.txt
@@ -0,0 +1,99 @@
+# Running various bench suites against LuaJIT.
+
+include(MakeLuaPath)
+
+if(CMAKE_BUILD_TYPE STREQUAL "Debug")
+  message(WARNING "LuaJIT and perf tests are built in the Debug mode."

s/./. /

missed whitespace after dot

+                  "Timings may be affected.")
+endif()
+
+set(PERF_OUTPUT_DIR ${PROJECT_BINARY_DIR}/perf/output)
+file(MAKE_DIRECTORY ${PERF_OUTPUT_DIR})
+
+# List of paths that will be used for each suite.
+make_lua_path(LUA_PATH_BENCH_BASE
+  PATHS
+    # Use of the bench module.
+    ${CMAKE_CURRENT_SOURCE_DIR}/utils/?.lua
+    # Simple usage with `jit.dump()`, etc.
+    ${LUAJIT_SOURCE_DIR}/?.lua
+    ${LUAJIT_BINARY_DIR}/?.lua
+)
+
+make_lua_path(LUA_CPATH
+  PATHS
+    # XXX: Some arches may have installed the cjson module here.
+    /usr/lib64/lua/5.1/?.so
+)
+
+# Produce the pair:
+# Target to run for reporting and target to inspect from the
+# console, runnable by the CTest.
+macro(AddBenchTarget perf_suite)
+  file(MAKE_DIRECTORY "${PERF_OUTPUT_DIR}/${perf_suite}/")
+  message(STATUS "Add perf suite ${perf_suite}")
+  add_custom_target(${perf_suite})
+  add_custom_target(${perf_suite}-console
+    COMMAND ${CMAKE_CTEST_COMMAND}
+      -L ${perf_suite}
+      --parallel 1
+      --verbose
+      --output-on-failure
+      --no-tests=error

+  )
+  add_dependencies(${perf_suite}-console luajit-main)
+endmacro()
+
+# Add the bench to the pair of targets created by the call above.
+macro(AddBench bench_name bench_path perf_suite LUA_PATH)
+  set(bench_title "perf/${perf_suite}/${bench_name}")
+  get_filename_component(bench_name_stripped  ${bench_name} NAME_WE)
+  set(bench_out_file
+    ${PERF_OUTPUT_DIR}/${perf_suite}/${bench_name_stripped}.json
+  )
+  set(bench_command "${LUAJIT_BINARY} ${bench_path}")
+  if(${ARGC} GREATER 4)
+    set(input_file ${ARGV4})
+    set(bench_command "${bench_command} < ${input_file}")
+  endif()
+  set(BENCH_FLAGS
+    "--benchmark_out_format=json --benchmark_out=${bench_out_file}"
+  )
+  set(bench_command_flags ${bench_command} ${BENCH_FLAGS})
+  separate_arguments(bench_command_separated UNIX_COMMAND ${bench_command})
+  add_custom_command(
+    COMMAND ${CMAKE_COMMAND} -E env
+      LUA_PATH="${LUA_PATH}"
+      LUA_CPATH="${LUA_CPATH}"
+        ${bench_command_separated}
+          --benchmark_out_format=json
+          --benchmark_out="${bench_out_file}"

+    OUTPUT ${bench_out_file}
+    DEPENDS luajit-main
+    COMMENT
+      "Running benchmark ${bench_title} saving results in ${bench_out_file}."
+  )
+  add_custom_target(${bench_name} DEPENDS ${bench_out_file})
+  add_dependencies(${perf_suite} ${bench_name})
+
+  # Report in the console.
+  add_test(NAME ${bench_title}
+    COMMAND sh -c "${bench_command}"
+  )
+  set_tests_properties(${bench_title} PROPERTIES
+    ENVIRONMENT "LUA_PATH=${LUA_PATH}"
+    LABELS ${perf_suite}
+    DEPENDS luajit-main
+  )
+  unset(input_file)
+endmacro()
+
+add_subdirectory(LuaJIT-benches)
+
+add_custom_target(${PROJECT_NAME}-perf
+  DEPENDS LuaJIT-benches

+)
+
+add_custom_target(${PROJECT_NAME}-perf-console
+  DEPENDS LuaJIT-benches-console

+)
diff --git a/perf/LuaJIT-benches/CMakeLists.txt b/perf/LuaJIT-benches/CMakeLists.txt
new file mode 100644
index 00000000..d9909f36
--- /dev/null
+++ b/perf/LuaJIT-benches/CMakeLists.txt
@@ -0,0 +1,52 @@
+set(PERF_SUITE_NAME LuaJIT-benches)
+set(LUA_BENCH_SUFFIX .lua)

+
+AddBenchTarget(${PERF_SUITE_NAME})
+
+# Input for the k-nucleotide and revcomp benchmarks.
+set(FASTA_NAME ${CMAKE_CURRENT_BINARY_DIR}/FASTA_5000000)
+add_custom_target(FASTA_5000000
+  COMMAND ${LUAJIT_BINARY}
+    ${CMAKE_CURRENT_SOURCE_DIR}/libs/fasta.lua 5000000 > ${FASTA_NAME}

FASTA_5000000 is a plain text file. I propose to add extension .txt for its full name and

probably postfix "_autogenerated". Like we do this for SUMCOL_5000 and SUMCOL_1.

+  OUTPUT ${FASTA_NAME}
+  DEPENDS luajit-main
+  COMMENT "Generate ${FASTA_NAME}."
+)
+
+make_lua_path(LUA_PATH
+  PATHS
+    ${LUA_PATH_BENCH_BASE}
+    ${CMAKE_CURRENT_SOURCE_DIR}/libs/?.lua
+)
+
+# Input for the <sum-file.lua> benchmark.
+set(SUM_NAME ${CMAKE_CURRENT_BINARY_DIR}/SUMCOL_5000.txt)
+# Remove possibly existing file.
+file(REMOVE ${SUM_NAME})

Why do we need generate file after every cmake configuration?

I propose to skip generation if file already exist or regenerate if SHA256 is not the same.

+
+set(SUMCOL_FILE ${CMAKE_CURRENT_SOURCE_DIR}/SUMCOL_1.txt)
+file(READ ${SUMCOL_FILE} SUMCOL_CONTENT)
+foreach(_unused RANGE 4999)
+  file(APPEND ${SUM_NAME} "${SUMCOL_CONTENT}")
+endforeach()
+
+file(GLOB benches "${CMAKE_CURRENT_SOURCE_DIR}/*${LUA_BENCH_SUFFIX}")
+foreach(bench_path ${benches})
+  file(RELATIVE_PATH bench_name ${CMAKE_CURRENT_SOURCE_DIR} ${bench_path})
+  set(bench_title "perf/${PERF_SUITE_NAME}/${bench_name}")
+  if(bench_name MATCHES "k-nucleotide" OR bench_name MATCHES "revcomp")
+    AddBench(${bench_name}
+      ${bench_path} ${PERF_SUITE_NAME} "${LUA_PATH}" ${FASTA_NAME}
+    )
+    add_dependencies(${bench_name} FASTA_5000000)
+  elseif(bench_name MATCHES "sum-file")
+    AddBench(${bench_name}
+      ${bench_path} ${PERF_SUITE_NAME} "${LUA_PATH}" ${SUM_NAME}
+    )
+  else()
+    AddBench(${bench_name} ${bench_path} ${PERF_SUITE_NAME} "${LUA_PATH}")
+  endif()
+endforeach()
+
+# We need to generate the file before we run tests.
+add_dependencies(${PERF_SUITE_NAME}-console FASTA_5000000)