ISPC: Support generation for multiple instruction sets

Help/manual/cmake-properties.7.rst

@@ -259,6 +259,7 @@ Properties on Targets
    /prop_tgt/INTERPROCEDURAL_OPTIMIZATION
    /prop_tgt/IOS_INSTALL_COMBINED
    /prop_tgt/ISPC_HEADER_DIRECTORY
+   /prop_tgt/ISPC_INSTRUCTION_SETS
    /prop_tgt/JOB_POOL_COMPILE
    /prop_tgt/JOB_POOL_LINK
    /prop_tgt/JOB_POOL_PRECOMPILE_HEADER

Help/manual/cmake-variables.7.rst

@@ -512,6 +512,7 @@ Variables for Languages
    /variable/CMAKE_Fortran_MODDIR_FLAG
    /variable/CMAKE_Fortran_MODOUT_FLAG
    /variable/CMAKE_ISPC_HEADER_DIRECTORY
+   /variable/CMAKE_ISPC_INSTRUCTION_SETS
    /variable/CMAKE_LANG_ANDROID_TOOLCHAIN_MACHINE
    /variable/CMAKE_LANG_ANDROID_TOOLCHAIN_PREFIX
    /variable/CMAKE_LANG_ANDROID_TOOLCHAIN_SUFFIX

Help/prop_tgt/ISPC_INSTRUCTION_SETS.rst

@@ -0,0 +1,21 @@
+ISPC_INSTRUCTION_SETS
+---------------------
+
+.. versionadded:: 3.19
+
+List of instruction set architectures to generate code for.
+
+This property is initialized by the value of the :variable:`CMAKE_ISPC_INSTRUCTION_SETS`
+variable if it is set when a target is created.
+
+The ``ISPC_INSTRUCTION_SETS`` target property must be used when generating for multiple
+instruction sets so that CMake can track what object files will be generated.
+
+Examples
+^^^^^^^^
+
+.. code-block:: cmake
+
+  set_property(TARGET tgt PROPERTY ISPC_INSTRUCTION_SETS avx2-i32x4 avx512skx-i32x835)
+
+Generates code for avx2 and avx512skx target architectures.

Help/variable/CMAKE_ISPC_INSTRUCTION_SETS.rst

@@ -0,0 +1,9 @@
+CMAKE_ISPC_INSTRUCTION_SETS
+---------------------------
+
+.. versionadded:: 3.19
+
+Default value for :prop_tgt:`ISPC_INSTRUCTION_SETS` property of targets.
+
+This variable is used to initialize the :prop_tgt:`ISPC_INSTRUCTION_SETS` property
+on all targets. See the target property for additional information.