testing: hwy testing strategies

1. Some tests are repeated, run once with hwy off and once with hwy
   on.  The "on" version append ".hwy" to the test name and set the
   OPENIMAGEIO_ENABLE_HWY=1 environment variable to force it on while
   running the test. The advantage to this approach is that the test
   itself doesn't need to change at all, we just run it separately in
   each mode.

   In this PR, I do this with oiiotool, oiiotool-xform, and
   docs-examples-cpp.

   For now, while hwy is not enabled by default, it's doing these
   extra things to enable hwy. Eventually, if/when hwy is enabled by
   default, we'll flip the sense and use the env variable to turn it
   off.

2. Some tests do certain operations both ways when hwy support was
   enabled at build time. This is more convenient for certain unit
   test executables, where perhaps we want to benchmark both ways
   and have those show up right next to each other within the run.

   In this PR, I do this with the imagebufalgo_test unit test.

Signed-off-by: Larry Gritz <lg@larrygritz.com>

Author: lgritz

CMakeLists.txt

@@ -112,7 +112,7 @@ else ()
 endif ()
 option (${PROJ_NAME}_BUILD_TOOLS "Build the command-line tools" ON)
 option (${PROJ_NAME}_BUILD_TESTS "Build the unit tests" ON)
-set_option (OIIO_USE_HWY "Enable experimental Google Highway SIMD optimizations (if Highway is available)" OFF)
+set_option (OIIO_USE_HWY "Enable experimental Google Highway SIMD optimizations (if Highway is available)" OFF VERBOSE)
 set (OIIO_LIBNAME_SUFFIX "" CACHE STRING
      "Optional name appended to ${PROJECT_NAME} libraries that are built")
 option (BUILD_OIIOUTIL_ONLY "If ON, will build *only* libOpenImageIO_Util" OFF)

src/cmake/testing.cmake

@@ -30,6 +30,7 @@ set(OIIO_TESTSUITE_IMAGEDIR "${PROJECT_BINARY_DIR}/testsuite" CACHE PATH
 #                    [ URL http://find.reference.cases.here.com ]
 #                    [ FOUNDVAR variable_name ... ]
 #                    [ ENABLEVAR variable_name ... ]
+#                    [ DISABLEVAR variable_name ... ]
 #                    [ SUFFIX suffix ]
 #                    [ ENVIRONMENT "VAR=value" ... ]
 #                  )
@@ -43,35 +44,48 @@ set(OIIO_TESTSUITE_IMAGEDIR "${PROJECT_BINARY_DIR}/testsuite" CACHE PATH
 # not existing and true, will skip the test.
 #
 # The optional ENABLEVAR introduces variables (typically ENABLE_Foo) that
-# if existing and yet false, will skip the test.
+# if existing and yet false/off/zero, will skip the test. (Not existing
+# does NOT disable the test.)
+#
+# The optional DISABLEVAR introduces variables that, if existing and
+# true/on/nonzero, will skip the test.
 #
 # The optional SUFFIX is appended to the test name.
 #
 # The optional ENVIRONMENT is a list of environment variables to set for the
 # test.
 #
 macro (oiio_add_tests)
-    cmake_parse_arguments (_ats "" "SUFFIX;TESTNAME" "URL;IMAGEDIR;LABEL;FOUNDVAR;ENABLEVAR;ENVIRONMENT" ${ARGN})
+    cmake_parse_arguments (_ats "" "SUFFIX;TESTNAME" "URL;IMAGEDIR;LABEL;FOUNDVAR;ENABLEVAR;DISABLEVAR;ENVIRONMENT" ${ARGN})
        # Arguments: <prefix> <options> <one_value_keywords> <multi_value_keywords> args...
     set (_ats_testdir "${OIIO_TESTSUITE_IMAGEDIR}/${_ats_IMAGEDIR}")
     # If there was a FOUNDVAR param specified and that variable name is
     # not defined, mark the test as broken.
     set (_test_disabled FALSE)
     set (_test_notfound FALSE)
     foreach (_var ${_ats_FOUNDVAR})
+        # FOUNDVAR entires had better exist and be true
         if (NOT ${_var})
             set (_ats_LABEL "broken")
             set (_test_notfound TRUE)
         endif ()
     endforeach ()
     set (_test_disabled 0)
     foreach (_var ${_ats_ENABLEVAR})
+        # ENABLEVAR, *if* it exists, must be true. But not existing is fine.
         if ((NOT "${${_var}}" STREQUAL "" AND NOT "${${_var}}") OR
             (NOT "$ENV{${_var}}" STREQUAL "" AND NOT "$ENV{${_var}}"))
             set (_ats_LABEL "broken")
             set (_test_disabled TRUE)
         endif ()
     endforeach ()
+    foreach (_var ${_ats_DISABLEVAR})
+        # DISABLEVAR, if true, disable the test. Not existing is fine.
+        if (${_var})
+            set (_ats_LABEL "broken")
+            set (_test_disabled TRUE)
+        endif ()
+    endforeach ()
     # For OCIO 2.2+, have the testsuite use the default built-in config
     list (APPEND _ats_ENVIRONMENT "OCIO=ocio://default"
                                   "OIIO_TESTSUITE_OCIOCONFIG=ocio://default")
@@ -238,6 +252,27 @@ macro (oiio_add_all_tests)
     oiio_add_tests (oiiotool-color
                     FOUNDVAR OpenColorIO_FOUND)
 
+    # Tests to run with HWY enabled.
+    # Remember to add tests here as hwy enabled IBA functions are added
+    oiio_add_tests ( oiiotool
+                     oiiotool-composite
+                     oiiotool-xform
+                     docs-examples-cpp
+        FOUNDVAR hwy_FOUND
+        ENABLEVAR OIIO_USE_HWY
+        SUFFIX ".hwy"
+        ENVIRONMENT "OPENIMAGEIO_ENABLE_HWY=1"
+        )
+
+    oiio_add_tests ( python-imagebufalgo
+        FOUNDVAR hwy_FOUND
+        ENABLEVAR OIIO_USE_HWY  USE_PYTHON
+        DISABLEVAR BUILD_OIIOUTIL_ONLY SANITIZE
+        SUFFIX ".hwy"
+        ENVIRONMENT "OPENIMAGEIO_ENABLE_HWY=1"
+        IMAGEDIR oiio-images
+        )
+
     # List testsuites for specific formats or features which might be not found
     # or be intentionally disabled, or which need special external reference
     # images from the web that if not found, should skip the tests:

src/libOpenImageIO/CMakeLists.txt

@@ -282,6 +282,7 @@ if (OIIO_BUILD_TESTS AND BUILD_TESTING)
                                          ${OpenCV_LIBRARIES}
                                          ${OPENIMAGEIO_IMATH_TARGETS}
                           FOLDER "Unit Tests" NO_INSTALL)
+    target_compile_definitions (imagebufalgo_test PRIVATE OIIO_USE_HWY=${_oiio_use_hwy})
     add_test (unit_imagebufalgo ${CMAKE_RUNTIME_OUTPUT_DIRECTORY}/imagebufalgo_test)
 
     fancy_add_executable (NAME imagespec_test SRC imagespec_test.cpp

src/libOpenImageIO/imagebufalgo_test.cpp

@@ -43,6 +43,10 @@ static bool wedge         = false;
 static int threadcounts[] = { 1,  2,  4,  8,  12,  16,   20,
                               24, 28, 32, 64, 128, 1024, 1 << 30 };
 
+static const int hwy_build = OIIO_USE_HWY;
+static int hwy_on          = hwy_build;
+
+
 
 static void
 getargs(int argc, char* argv[])
@@ -403,7 +407,7 @@ test_channel_append()
 void
 test_add()
 {
-    std::cout << "test add\n";
+    print("test add{}\n", hwy_on ? " (HWY)" : "");
 
     // Create buffers
     const float Aval[] = { 0.1f, 0.2f, 0.3f, 0.4f };
@@ -429,7 +433,7 @@ test_add()
 void
 test_sub()
 {
-    std::cout << "test sub\n";
+    print("test sub{}\n", hwy_on ? " (HWY)" : "");
 
     // Create buffers
     const float Aval[] = { 0.1f, 0.2f, 0.3f, 0.4f };
@@ -455,7 +459,7 @@ test_sub()
 void
 test_mul()
 {
-    std::cout << "test mul\n";
+    print("test mul{}\n", hwy_on ? " (HWY)" : "");
 
     // Create buffers
     // Create buffers
@@ -482,7 +486,7 @@ test_mul()
 void
 test_mad()
 {
-    std::cout << "test mad\n";
+    print("test mad{}\n", hwy_on ? " (HWY)" : "");
     const int WIDTH = 4, HEIGHT = 4, CHANNELS = 4;
     ImageSpec spec(WIDTH, HEIGHT, CHANNELS, TypeDesc::FLOAT);
 
@@ -1678,6 +1682,17 @@ test_demosaic()
 }
 
 
+
+// clang-format off
+// Neat trick macro to prefix in front of the calls where we want to
+// run it in both hwy and non-hwy modes. It will loop over both settings.
+#define HWY_TEST                                    \
+    for (hwy_on = 0; hwy_on <= hwy_build; ++hwy_on) \
+        OIIO::attribute("enable_hwy", hwy_on), /* next command */
+// clang-format on
+
+
+
 int
 main(int argc, char** argv)
 {
@@ -1702,10 +1717,10 @@ main(int argc, char** argv)
     test_crop();
     test_paste();
     test_channel_append();
-    test_add();
-    test_sub();
-    test_mul();
-    test_mad();
+    HWY_TEST test_add();
+    HWY_TEST test_sub();
+    HWY_TEST test_mul();
+    HWY_TEST test_mad();
     test_hwy_strided_roi_fallback();
     test_min();
     test_max();