Merge topic 'find-blas-lapack-sizeof-integer'

64038fd5bc Help: Add release notes for Find{BLAS,LAPACK} BLA_SIZEOF_INTEGER option
972489ae4e Find{BLAS,LAPACK}: Provide testing of BLA_SIZEOF_INTEGER
95219365ff Find{BLAS,LAPACK}: Make possible testing of ILP64 model
2cd94f3e57 Find{BLAS,LAPACK}: Specify integer type in tests
9b69307b56 Find{BLAS,LAPACK}: De-duplicate and generalize test creation logic
91fd645d46 FindLAPACK: Stop processing if LAPACK library does not have 64-bit integer API
b8a3cea51f FindBLAS: Stop processing if BLAS library does not have 64-bit integer API
d2f5c7856f FindLAPACK: Search 32/64-bit integer API via BLA_SIZEOF_INTEGER if possible
...

Acked-by: Kitware Robot <kwrobot@kitware.com>
Merge-request: !6407

14 files changed, 526 insertions, 309 deletions

diff --git a/.gitlab/ci/configure_debian10_aarch64_ninja.cmake b/.gitlab/ci/configure_debian10_aarch64_ninja.cmake
index a6b7cb5..8e03eef 100644
--- a/.gitlab/ci/configure_debian10_aarch64_ninja.cmake
+++ b/.gitlab/ci/configure_debian10_aarch64_ninja.cmake
@@ -1,6 +1,5 @@
 set(CMake_TEST_FindALSA "ON" CACHE BOOL "")
-set(CMake_TEST_FindBLAS "All" CACHE STRING "")
-set(CMake_TEST_FindBLAS_STATIC "Generic" CACHE STRING "")
+set(CMake_TEST_FindBLAS "All;static=1;Generic" CACHE STRING "")
 set(CMake_TEST_FindBoost "ON" CACHE BOOL "")
 set(CMake_TEST_FindBoost_Python "ON" CACHE BOOL "")
 set(CMake_TEST_FindBZip2 "ON" CACHE BOOL "")
@@ -25,8 +24,7 @@ set(CMake_TEST_FindIconv "ON" CACHE BOOL "")
 set(CMake_TEST_FindIntl "ON" CACHE BOOL "")
 set(CMake_TEST_FindJPEG "ON" CACHE BOOL "")
 set(CMake_TEST_FindJsonCpp "ON" CACHE BOOL "")
-set(CMake_TEST_FindLAPACK "All" CACHE STRING "")
-set(CMake_TEST_FindLAPACK_STATIC "Generic" CACHE STRING "")
+set(CMake_TEST_FindLAPACK "All;static=1;Generic" CACHE STRING "")
 set(CMake_TEST_FindLibArchive "ON" CACHE BOOL "")
 set(CMake_TEST_FindLibinput "ON" CACHE BOOL "")
 set(CMake_TEST_FindLibLZMA "ON" CACHE BOOL "")
diff --git a/.gitlab/ci/configure_debian10_ninja.cmake b/.gitlab/ci/configure_debian10_ninja.cmake
index 10d0997..d50ab1f 100644
--- a/.gitlab/ci/configure_debian10_ninja.cmake
+++ b/.gitlab/ci/configure_debian10_ninja.cmake
@@ -1,6 +1,5 @@
 set(CMake_TEST_FindALSA "ON" CACHE BOOL "")
-set(CMake_TEST_FindBLAS "All" CACHE STRING "")
-set(CMake_TEST_FindBLAS_STATIC "Generic" CACHE STRING "")
+set(CMake_TEST_FindBLAS "All;static=1;Generic" CACHE STRING "")
 set(CMake_TEST_FindBoost "ON" CACHE BOOL "")
 set(CMake_TEST_FindBoost_Python "ON" CACHE BOOL "")
 set(CMake_TEST_FindBZip2 "ON" CACHE BOOL "")
@@ -25,8 +24,7 @@ set(CMake_TEST_FindIconv "ON" CACHE BOOL "")
 set(CMake_TEST_FindIntl "ON" CACHE BOOL "")
 set(CMake_TEST_FindJPEG "ON" CACHE BOOL "")
 set(CMake_TEST_FindJsonCpp "ON" CACHE BOOL "")
-set(CMake_TEST_FindLAPACK "All" CACHE STRING "")
-set(CMake_TEST_FindLAPACK_STATIC "Generic" CACHE STRING "")
+set(CMake_TEST_FindLAPACK "All;static=1;Generic" CACHE STRING "")
 set(CMake_TEST_FindLibArchive "ON" CACHE BOOL "")
 set(CMake_TEST_FindLibinput "ON" CACHE BOOL "")
 set(CMake_TEST_FindLibLZMA "ON" CACHE BOOL "")
diff --git a/.gitlab/ci/configure_fedora34_makefiles.cmake b/.gitlab/ci/configure_fedora34_makefiles.cmake
index d4bdb6a..a482378 100644
--- a/.gitlab/ci/configure_fedora34_makefiles.cmake
+++ b/.gitlab/ci/configure_fedora34_makefiles.cmake
@@ -1,6 +1,5 @@
 set(CMake_TEST_FindALSA "ON" CACHE BOOL "")
-set(CMake_TEST_FindBLAS "All" CACHE STRING "")
-set(CMake_TEST_FindBLAS_STATIC "Generic" CACHE STRING "")
+set(CMake_TEST_FindBLAS "All;static=1;Generic" CACHE STRING "")
 set(CMake_TEST_FindBoost "ON" CACHE BOOL "")
 set(CMake_TEST_FindBoost_Python "ON" CACHE BOOL "")
 set(CMake_TEST_FindBZip2 "ON" CACHE BOOL "")
@@ -25,8 +24,7 @@ set(CMake_TEST_FindIconv "ON" CACHE BOOL "")
 set(CMake_TEST_FindIntl "ON" CACHE BOOL "")
 set(CMake_TEST_FindJPEG "ON" CACHE BOOL "")
 set(CMake_TEST_FindJsonCpp "ON" CACHE BOOL "")
-set(CMake_TEST_FindLAPACK "All" CACHE STRING "")
-set(CMake_TEST_FindLAPACK_STATIC "Generic" CACHE STRING "")
+set(CMake_TEST_FindLAPACK "All;static=1;Generic" CACHE STRING "")
 set(CMake_TEST_FindLibArchive "ON" CACHE BOOL "")
 set(CMake_TEST_FindLibinput "ON" CACHE BOOL "")
 set(CMake_TEST_FindLibLZMA "ON" CACHE BOOL "")
diff --git a/.gitlab/ci/configure_intelcompiler_common.cmake b/.gitlab/ci/configure_intelcompiler_common.cmake
index be175e4..bd34740 100644
--- a/.gitlab/ci/configure_intelcompiler_common.cmake
+++ b/.gitlab/ci/configure_intelcompiler_common.cmake
@@ -1,10 +1,13 @@
-set(CMake_TEST_FindBLAS "All;Intel10_64lp;Intel10_64lp.gcc" CACHE STRING "")
-set(CMake_TEST_FindBLAS_All "Intel10_64lp" CACHE STRING "")
-set(CMake_TEST_FindBLAS_STATIC "All;Intel10_64lp;Intel10_64lp.gcc" CACHE STRING "")
-set(CMake_TEST_FindBLAS_STATIC_All "Intel10_64lp" CACHE STRING "")
-set(CMake_TEST_FindLAPACK "All;Intel10_64lp;Intel10_64lp.gcc" CACHE STRING "")
-set(CMake_TEST_FindLAPACK_All "Intel10_64lp" CACHE STRING "")
-set(CMake_TEST_FindLAPACK_STATIC "All;Intel10_64lp;Intel10_64lp.gcc" CACHE STRING "")
-set(CMake_TEST_FindLAPACK_STATIC_All "Intel10_64lp" CACHE STRING "")
+set(blas_lapack_cases
+  model=lp64 all=Intel10_64lp
+    static=0 All Intel10_64lp compiler=gcc Intel10_64lp compiler=
+    static=1 All Intel10_64lp compiler=gcc Intel10_64lp compiler=
+
+  model=ilp64 all=Intel10_64ilp
+    static=0 All Intel10_64ilp compiler=gcc Intel10_64ilp compiler=
+    static=1 All Intel10_64ilp compiler=gcc Intel10_64ilp compiler=
+  )
+set(CMake_TEST_FindBLAS "${blas_lapack_cases}" CACHE STRING "")
+set(CMake_TEST_FindLAPACK "${blas_lapack_cases}" CACHE STRING "")
 
 include("${CMAKE_CURRENT_LIST_DIR}/configure_external_test.cmake")
diff --git a/Help/release/dev/find-blas-lapack-sizeof-integer.rst b/Help/release/dev/find-blas-lapack-sizeof-integer.rst
new file mode 100644
index 0000000..bb20654
--- /dev/null
+++ b/Help/release/dev/find-blas-lapack-sizeof-integer.rst
@@ -0,0 +1,6 @@
+find-blas-lapack-sizeof-integer
+-------------------------------
+
+* The :module:`FindBLAS` and :module:`FindLAPACK` modules gained
+  a ``BLA_SIZEOF_INTEGER`` option to find a BLAS/LAPACK whose ABI
+  uses a specific integer size.
diff --git a/Modules/FindBLAS.cmake b/Modules/FindBLAS.cmake
index a44af4d..f16d176 100644
--- a/Modules/FindBLAS.cmake
+++ b/Modules/FindBLAS.cmake
@@ -35,6 +35,19 @@ The following variables may be set to influence this module's behavior:
   if set ``pkg-config`` will be used to search for a BLAS library first
   and if one is found that is preferred
 
+``BLA_SIZEOF_INTEGER``
+  .. versionadded:: 3.22
+
+  Specify the BLAS/LAPACK library integer size:
+
+  ``4``
+    Search for a BLAS/LAPACK with 32-bit integer interfaces.
+  ``8``
+    Search for a BLAS/LAPACK with 64-bit integer interfaces.
+  ``ANY``
+    Search for any BLAS/LAPACK.
+    Most likely, a BLAS/LAPACK with 32-bit integer interfaces will be found.
+
 Imported targets
 ^^^^^^^^^^^^^^^^
 
@@ -101,10 +114,10 @@ BLAS/LAPACK Vendors
 ``FlexiBLAS``
   .. versionadded:: 3.19
 
-``Fujitsu_SSL2``, ``Fujitsu_SSL2BLAMP``
+``Fujitsu_SSL2``, ``Fujitsu_SSL2BLAMP``, ``Fujitsu_SSL2SVE``, ``Fujitsu_SSL2BLAMPSVE``
   .. versionadded:: 3.20
 
-  Fujitsu SSL2 serial and parallel blas/lapack
+  Fujitsu SSL2 serial and parallel blas/lapack with SVE instructions
 
 ``Goto``
   GotoBLAS
@@ -372,6 +385,17 @@ else()
   endif()
 endif()
 
+if(NOT BLA_SIZEOF_INTEGER)
+  # in the reality we do not know which API of BLAS/LAPACK is masked in library
+  set(_blas_sizeof_integer "ANY")
+elseif((BLA_SIZEOF_INTEGER STREQUAL "ANY") OR
+       (BLA_SIZEOF_INTEGER STREQUAL "4") OR
+       (BLA_SIZEOF_INTEGER STREQUAL "8"))
+  set(_blas_sizeof_integer ${BLA_SIZEOF_INTEGER})
+else()
+  message(FATAL_ERROR "BLA_SIZEOF_INTEGER can have only <no value>, ANY, 4, or 8 values")
+endif()
+
 # Implicitly linked BLAS libraries?
 if(BLA_VENDOR STREQUAL "All")
   if(NOT BLAS_LIBRARIES)
@@ -432,10 +456,16 @@ if(BLA_VENDOR MATCHES "Intel" OR BLA_VENDOR STREQUAL "All")
         find_package(Threads REQUIRED)
       endif()
 
-      if(BLA_VENDOR MATCHES "_64ilp")
+      if(_blas_sizeof_integer EQUAL 8)
         set(BLAS_mkl_ILP_MODE "ilp64")
-      else()
+      elseif(_blas_sizeof_integer EQUAL 4)
         set(BLAS_mkl_ILP_MODE "lp64")
+      else()
+        if(BLA_VENDOR MATCHES "_64ilp")
+          set(BLAS_mkl_ILP_MODE "ilp64")
+        else()
+          set(BLAS_mkl_ILP_MODE "lp64")
+        endif()
       endif()
 
       set(BLAS_SEARCH_LIBS "")
@@ -675,29 +705,43 @@ endif()
 
 # FlexiBLAS? (http://www.mpi-magdeburg.mpg.de/mpcsc/software/FlexiBLAS/)
 if(BLA_VENDOR STREQUAL "FlexiBLAS" OR BLA_VENDOR STREQUAL "All")
+  set(_blas_flexiblas_lib "flexiblas")
+
+  if(_blas_sizeof_integer EQUAL 8)
+    string(APPEND _blas_flexiblas_lib "64")
+  endif()
+
   if(NOT BLAS_LIBRARIES)
     check_blas_libraries(
       BLAS_LIBRARIES
       BLAS
       sgemm
       ""
-      "flexiblas"
+      "${_blas_flexiblas_lib}"
       ""
       ""
       ""
       )
   endif()
+
+  unset(_blas_flexiblas_lib)
 endif()
 
 # OpenBLAS? (http://www.openblas.net)
 if(BLA_VENDOR STREQUAL "OpenBLAS" OR BLA_VENDOR STREQUAL "All")
+  set(_blas_openblas_lib "openblas")
+
+  if(_blas_sizeof_integer EQUAL 8)
+    string(APPEND _blas_openblas_lib "64")
+  endif()
+
   if(NOT BLAS_LIBRARIES)
     check_blas_libraries(
       BLAS_LIBRARIES
       BLAS
       sgemm
       ""
-      "openblas"
+      "${_blas_openblas_lib}"
       ""
       ""
       ""
@@ -724,24 +768,32 @@ if(BLA_VENDOR STREQUAL "OpenBLAS" OR BLA_VENDOR STREQUAL "All")
       BLAS
       sgemm
       ""
-      "openblas"
+      "${_blas_openblas_lib}"
       "${_threadlibs}"
       ""
       ""
       )
     unset(_threadlibs)
   endif()
+
+  unset(_blas_openblas_lib)
 endif()
 
 # ArmPL blas library? (https://developer.arm.com/tools-and-software/server-and-hpc/compile/arm-compiler-for-linux/arm-performance-libraries)
 if(BLA_VENDOR MATCHES "Arm" OR BLA_VENDOR STREQUAL "All")
 
    # Check for 64bit Integer support
-   if(BLA_VENDOR MATCHES "_ilp64")
-     set(_blas_armpl_lib "armpl_ilp64")
-   else()
-     set(_blas_armpl_lib "armpl_lp64")
-   endif()
+  if(_blas_sizeof_integer EQUAL 8)
+    set(_blas_armpl_lib "armpl_ilp64")
+  elseif(_blas_sizeof_integer EQUAL 4)
+    set(_blas_armpl_lib "armpl_lp64")
+  else()
+    if(BLA_VENDOR MATCHES "_ilp64")
+      set(_blas_armpl_lib "armpl_ilp64")
+    else()
+      set(_blas_armpl_lib "armpl_lp64")
+    endif()
+  endif()
 
    # Check for OpenMP support, VIA BLA_VENDOR of Arm_mp or Arm_ipl64_mp
    if(BLA_VENDOR MATCHES "_mp")
@@ -765,18 +817,26 @@ endif()
 
 # FLAME's blis library? (https://github.com/flame/blis)
 if(BLA_VENDOR STREQUAL "FLAME" OR BLA_VENDOR STREQUAL "All")
+  set(_blas_flame_lib "blis")
+
+  if(_blas_sizeof_integer EQUAL 8)
+    string(APPEND _blas_flame_lib "64")
+  endif()
+
   if(NOT BLAS_LIBRARIES)
     check_blas_libraries(
       BLAS_LIBRARIES
       BLAS
       sgemm
       ""
-      "blis"
+      "${_blas_flame_lib}"
       ""
       ""
       ""
       )
   endif()
+
+  unset(_blas_flame_lib)
 endif()
 
 # BLAS in the ATLAS library? (http://math-atlas.sourceforge.net/)
@@ -813,33 +873,45 @@ endif()
 
 # BLAS in Alpha CXML library?
 if(BLA_VENDOR STREQUAL "CXML" OR BLA_VENDOR STREQUAL "All")
-  if(NOT BLAS_LIBRARIES)
-    check_blas_libraries(
-      BLAS_LIBRARIES
-      BLAS
-      sgemm
-      ""
-      "cxml"
-      ""
-      ""
-      ""
-      )
+  if(_blas_sizeof_integer EQUAL 8)
+    if(BLA_VENDOR STREQUAL "CXML")
+      message(FATAL_ERROR "CXML does not support Int64 type")
+    endif()
+  else()
+    if(NOT BLAS_LIBRARIES)
+      check_blas_libraries(
+        BLAS_LIBRARIES
+        BLAS
+        sgemm
+        ""
+        "cxml"
+        ""
+        ""
+        ""
+        )
+    endif()
   endif()
 endif()
 
 # BLAS in Alpha DXML library? (now called CXML, see above)
 if(BLA_VENDOR STREQUAL "DXML" OR BLA_VENDOR STREQUAL "All")
-  if(NOT BLAS_LIBRARIES)
-    check_blas_libraries(
-      BLAS_LIBRARIES
-      BLAS
-      sgemm
-      ""
-      "dxml"
-      ""
-      ""
-      ""
-      )
+  if(_blas_sizeof_integer EQUAL 8)
+    if(BLA_VENDOR STREQUAL "DXML")
+      message(FATAL_ERROR "DXML does not support Int64 type")
+    endif()
+  else()
+    if(NOT BLAS_LIBRARIES)
+      check_blas_libraries(
+        BLAS_LIBRARIES
+        BLAS
+        sgemm
+        ""
+        "dxml"
+        ""
+        ""
+        ""
+        )
+    endif()
   endif()
 endif()
 
@@ -866,6 +938,9 @@ endif()
 if(BLA_VENDOR MATCHES "SCSL" OR BLA_VENDOR STREQUAL "All")
   set(_blas_scsl_lib "scs")
 
+  if(_blas_sizeof_integer EQUAL 8)
+    string(APPEND _blas_scsl_lib "_i8")
+  endif()
   if(BLA_VENDOR MATCHES "_mp")
     set(_blas_scsl_lib "${_blas_scsl_lib}_mp")
   endif()
@@ -909,6 +984,10 @@ if(BLA_VENDOR MATCHES "IBMESSL" OR BLA_VENDOR STREQUAL "All")
   if(BLA_VENDOR MATCHES "_SMP")
     set(_blas_essl_lib "${_blas_essl_lib}smp")
   endif()
+  if(_blas_sizeof_integer EQUAL 8)
+    string(APPEND _blas_essl_lib "6464")
+  endif()
+
   if(NOT BLAS_LIBRARIES)
     check_blas_libraries(
       BLAS_LIBRARIES
@@ -946,7 +1025,7 @@ if(BLA_VENDOR MATCHES "ACML" OR BLA_VENDOR STREQUAL "All")
   list(GET _ACML_GPU_ROOT 0 _ACML_GPU_ROOT)
   if(_ACML_ROOT)
     get_filename_component(_ACML_ROOT ${_ACML_ROOT} PATH)
-    if(SIZEOF_INTEGER EQUAL 8)
+    if(_blas_sizeof_integer EQUAL 8)
       set(_ACML_PATH_SUFFIX "_int64")
     else()
       set(_ACML_PATH_SUFFIX "")
@@ -1073,33 +1152,45 @@ endif() # ACML
 
 # Apple BLAS library?
 if(BLA_VENDOR STREQUAL "Apple" OR BLA_VENDOR STREQUAL "All")
-  if(NOT BLAS_LIBRARIES)
-    check_blas_libraries(
-      BLAS_LIBRARIES
-      BLAS
-      dgemm
-      ""
-      "Accelerate"
-      ""
-      ""
-      ""
-      )
+  if(_blas_sizeof_integer EQUAL 8)
+    if(BLA_VENDOR STREQUAL "Apple")
+      message(FATAL_ERROR "Accelerate Framework does not support Int64 type")
+    endif()
+  else()
+    if(NOT BLAS_LIBRARIES)
+      check_blas_libraries(
+        BLAS_LIBRARIES
+        BLAS
+        dgemm
+        ""
+        "Accelerate"
+        ""
+        ""
+        ""
+        )
+    endif()
   endif()
 endif()
 
 # Apple NAS (vecLib) library?
 if(BLA_VENDOR STREQUAL "NAS" OR BLA_VENDOR STREQUAL "All")
-  if(NOT BLAS_LIBRARIES)
-    check_blas_libraries(
-      BLAS_LIBRARIES
-      BLAS
-      dgemm
-      ""
-      "vecLib"
-      ""
-      ""
-      ""
-      )
+  if(_blas_sizeof_integer EQUAL 8)
+    if(BLA_VENDOR STREQUAL "NAS")
+      message(FATAL_ERROR "Accelerate Framework does not support Int64 type")
+    endif()
+  else()
+    if(NOT BLAS_LIBRARIES)
+      check_blas_libraries(
+        BLAS_LIBRARIES
+        BLAS
+        dgemm
+        ""
+        "vecLib"
+        ""
+        ""
+        ""
+        )
+    endif()
   endif()
 endif()
 
@@ -1108,6 +1199,9 @@ if(BLA_VENDOR MATCHES "EML" OR BLA_VENDOR STREQUAL "All")
 
    set(_blas_eml_lib "eml")
 
+   if(_blas_sizeof_integer EQUAL 8)
+     string(APPEND _blas_eml_lib "_ilp64")
+   endif()
    # Check for OpenMP support, VIA BLA_VENDOR of eml_mt
    if(BLA_VENDOR MATCHES "_mt")
      set(_blas_eml_lib "${_blas_eml_lib}_mt")
@@ -1130,45 +1224,107 @@ endif()
 
 # Fujitsu SSL2 Library?
 if(NOT BLAS_LIBRARIES
-    AND (BLA_VENDOR MATCHES "Fujitsu_SSL2" OR BLA_VENDOR STREQUAL "All"))
-  if(BLA_VENDOR STREQUAL "Fujitsu_SSL2BLAMP")
-    set(_ssl2_suffix BLAMP)
-  else()
-    set(_ssl2_suffix)
+    AND (BLA_VENDOR MATCHES "^Fujitsu_SSL2" OR BLA_VENDOR STREQUAL "All"))
+  set(_blas_fjlapack_lib "fjlapack")
+  set(_blas_fjlapack_flags "-Kopenmp")
+
+  if(BLA_VENDOR MATCHES "BLAMP")
+    string(APPEND _blas_fjlapack_lib "ex")
   endif()
-  check_blas_libraries(
-    BLAS_LIBRARIES
-    BLAS
-    sgemm
-    "-SSL2${_ssl2_suffix}"
-    ""
-    ""
-    ""
-    ""
-    )
-  if(BLAS_LIBRARIES)
-    set(BLAS_LINKER_FLAGS "-SSL2${_ssl2_suffix}")
-    set(_blas_fphsa_req_var BLAS_LINKER_FLAGS)
+  if(BLA_VENDOR MATCHES "SVE")
+    string(APPEND _blas_fjlapack_lib "sve")
+  endif()
+  if(_blas_sizeof_integer EQUAL 8)
+    string(APPEND _blas_fjlapack_lib "_ilp64")
   endif()
-  unset(_ssl2_suffix)
+
+  if(NOT BLAS_LIBRARIES)
+    check_blas_libraries(
+      BLAS_LIBRARIES
+      BLAS
+      sgemm
+      "${_blas_fjlapack_flags}"
+      "${_blas_fjlapack_lib}"
+      ""
+      ""
+      ""
+      )
+    if(BLAS_LIBRARIES)
+      set(BLAS_LINKER_FLAGS ${_blas_fjlapack_flags})
+    endif()
+  endif()
+
+  unset(_blas_fjlapack_flags)
+  unset(_blas_fjlapack_lib)
+endif()
+
+# BLAS in nVidia HPC SDK? (https://developer.nvidia.com/hpc-sdk)
+if(BLA_VENDOR STREQUAL "NVHPC" OR BLA_VENDOR STREQUAL "All")
+  set(_blas_nvhpc_lib "blas")
+
+  if(_blas_sizeof_integer EQUAL 8)
+    string(APPEND _blas_nvhpc_lib "_ilp64")
+  elseif(_blas_sizeof_integer EQUAL 4)
+    string(APPEND _blas_nvhpc_lib "_lp64")
+  endif()
+
+  if(NOT BLAS_LIBRARIES)
+    check_blas_libraries(
+      BLAS_LIBRARIES
+      BLAS
+      sgemm
+      ""
+      "${_blas_nvhpc_lib}"
+      ""
+      ""
+      ""
+      )
+  endif()
+
+  # an additional check for NVHPC 2020
+  # which does not have differentiation
+  # between lp64 and ilp64 modes
+  if(NOT BLAS_LIBRARIES AND NOT _blas_sizeof_integer EQUAL 8)
+    set(_blas_nvhpc_lib "blas")
+
+    check_blas_libraries(
+      BLAS_LIBRARIES
+      BLAS
+      sgemm
+      ""
+      "${_blas_nvhpc_lib}"
+      ""
+      ""
+      ""
+      )
+  endif()
+
+  unset(_blas_nvhpc_lib)
 endif()
 
 # Generic BLAS library?
 if(BLA_VENDOR STREQUAL "Generic" OR
-   BLA_VENDOR STREQUAL "NVHPC" OR
    BLA_VENDOR STREQUAL "All")
+  set(_blas_generic_lib "blas")
+
+  if(_blas_sizeof_integer EQUAL 8)
+    string(APPEND _blas_generic_lib "64")
+  endif()
+
   if(NOT BLAS_LIBRARIES)
     check_blas_libraries(
       BLAS_LIBRARIES
       BLAS
       sgemm
       ""
-      "blas"
+      "${_blas_generic_lib}"
       ""
       ""
       ""
       )
   endif()
+
+  unset(_blas_generic_lib)
 endif()
 
 # On compilers that implicitly link BLAS (i.e. CrayPrgEnv) we used a
@@ -1183,4 +1339,5 @@ endif()
 
 _add_blas_target()
 unset(_blas_fphsa_req_var)
+unset(_blas_sizeof_integer)
 unset(_BLAS_LIBRARIES)
diff --git a/Modules/FindLAPACK.cmake b/Modules/FindLAPACK.cmake
index f36acfd..32d15db 100644
--- a/Modules/FindLAPACK.cmake
+++ b/Modules/FindLAPACK.cmake
@@ -35,6 +35,19 @@ The following variables may be set to influence this module's behavior:
   if set ``pkg-config`` will be used to search for a LAPACK library first
   and if one is found that is preferred
 
+``BLA_SIZEOF_INTEGER``
+  .. versionadded:: 3.22
+
+  Specify the BLAS/LAPACK library integer size:
+
+  ``4``
+    Search for a BLAS/LAPACK with 32-bit integer interfaces.
+  ``8``
+    Search for a BLAS/LAPACK with 64-bit integer interfaces.
+  ``ANY``
+    Search for any BLAS/LAPACK.
+    Most likely, a BLAS/LAPACK with 32-bit integer interfaces will be found.
+
 Imported targets
 ^^^^^^^^^^^^^^^^
 
@@ -247,6 +260,17 @@ if(NOT (CMAKE_C_COMPILER_LOADED OR CMAKE_CXX_COMPILER_LOADED OR CMAKE_Fortran_CO
     "FindLAPACK requires Fortran, C, or C++ to be enabled.")
 endif()
 
+if(NOT BLA_SIZEOF_INTEGER)
+  # in the reality we do not know which API of BLAS/LAPACK is masked in library
+  set(_lapack_sizeof_integer "ANY")
+elseif((BLA_SIZEOF_INTEGER STREQUAL "ANY") OR
+       (BLA_SIZEOF_INTEGER STREQUAL "4") OR
+       (BLA_SIZEOF_INTEGER STREQUAL "8"))
+  set(_lapack_sizeof_integer ${BLA_SIZEOF_INTEGER})
+else()
+  message(FATAL_ERROR "BLA_SIZEOF_INTEGER can have only <no value>, ANY, 4, or 8 values")
+endif()
+
 # Load BLAS
 if(NOT LAPACK_NOT_FOUND_MESSAGE)
   _lapack_find_dependency(BLAS)
@@ -288,10 +312,16 @@ if(NOT LAPACK_NOT_FOUND_MESSAGE)
 
     _lapack_find_dependency(Threads)
 
-    if(BLA_VENDOR MATCHES "_64ilp")
+    if(_lapack_sizeof_integer EQUAL 8)
       set(LAPACK_mkl_ILP_MODE "ilp64")
-    else()
+    elseif(_lapack_sizeof_integer EQUAL 4)
       set(LAPACK_mkl_ILP_MODE "lp64")
+    else()
+      if(BLA_VENDOR MATCHES "_64ilp")
+        set(LAPACK_mkl_ILP_MODE "ilp64")
+      else()
+        set(LAPACK_mkl_ILP_MODE "lp64")
+      endif()
     endif()
 
     set(LAPACK_SEARCH_LIBS "")
@@ -418,43 +448,65 @@ if(NOT LAPACK_NOT_FOUND_MESSAGE)
   # FlexiBLAS? (http://www.mpi-magdeburg.mpg.de/mpcsc/software/FlexiBLAS/)
   if(NOT LAPACK_LIBRARIES
       AND (BLA_VENDOR STREQUAL "FlexiBLAS" OR BLA_VENDOR STREQUAL "All"))
+    set(_lapack_flexiblas_lib "flexiblas")
+
+    if(_lapack_sizeof_integer EQUAL 8)
+      string(APPEND _lapack_flexiblas_lib "64")
+    endif()
+
     check_lapack_libraries(
       LAPACK_LIBRARIES
       LAPACK
       cheev
       ""
-      "flexiblas"
+      "${_lapack_flexiblas_lib}"
       ""
       ""
       ""
       "${BLAS_LIBRARIES}"
     )
+
+    unset(_lapack_flexiblas_lib)
   endif()
 
   # OpenBLAS? (http://www.openblas.net)
   if(NOT LAPACK_LIBRARIES
       AND (BLA_VENDOR STREQUAL "OpenBLAS" OR BLA_VENDOR STREQUAL "All"))
+    set(_lapack_openblas_lib "openblas")
+
+    if(_lapack_sizeof_integer EQUAL 8)
+      string(APPEND _lapack_openblas_lib "64")
+    endif()
+
     check_lapack_libraries(
       LAPACK_LIBRARIES
       LAPACK
       cheev
       ""
-      "openblas"
+      "${_lapack_openblas_lib}"
       ""
       ""
       ""
       "${BLAS_LIBRARIES}"
     )
+
+    unset(_lapack_openblas_lib)
   endif()
 
   # ArmPL? (https://developer.arm.com/tools-and-software/server-and-hpc/compile/arm-compiler-for-linux/arm-performance-libraries)
   if(NOT LAPACK_LIBRARIES
       AND (BLA_VENDOR MATCHES "Arm" OR BLA_VENDOR STREQUAL "All"))
     # Check for 64bit Integer support
-    if(BLA_VENDOR MATCHES "_ilp64")
+    if(_lapack_sizeof_integer EQUAL 8)
       set(LAPACK_armpl_LIB "armpl_ilp64")
-    else()
+    elseif(_lapack_sizeof_integer EQUAL 4)
       set(LAPACK_armpl_LIB "armpl_lp64")
+    else()
+      if(BLA_VENDOR MATCHES "_ilp64")
+        set(LAPACK_armpl_LIB "armpl_ilp64")
+      else()
+        set(LAPACK_armpl_LIB "armpl_lp64")
+      endif()
     endif()
 
     # Check for OpenMP support, VIA BLA_VENDOR of Arm_mp or Arm_ipl64_mp
@@ -478,17 +530,23 @@ if(NOT LAPACK_NOT_FOUND_MESSAGE)
   # FLAME's blis library? (https://github.com/flame/blis)
   if(NOT LAPACK_LIBRARIES
       AND (BLA_VENDOR STREQUAL "FLAME" OR BLA_VENDOR STREQUAL "All"))
-    check_lapack_libraries(
-      LAPACK_LIBRARIES
-      LAPACK
-      cheev
-      ""
-      "flame"
-      ""
-      ""
-      ""
-      "${BLAS_LIBRARIES}"
-    )
+    if(_lapack_sizeof_integer EQUAL 8)
+      if(BLA_VENDOR STREQUAL "FLAME")
+        message(FATAL_ERROR "libFLAME does not support Int64 type")
+      endif()
+    else()
+      check_lapack_libraries(
+        LAPACK_LIBRARIES
+        LAPACK
+        cheev
+        ""
+        "flame"
+        ""
+        ""
+        ""
+        "${BLAS_LIBRARIES}"
+      )
+    endif()
   endif()
 
   # LAPACK in SCSL library? (SGI/Cray Scientific Library)
@@ -496,6 +554,9 @@ if(NOT LAPACK_NOT_FOUND_MESSAGE)
       AND (BLA_VENDOR MATCHES "SCSL" OR BLA_VENDOR STREQUAL "All"))
     set(_lapack_scsl_lib "scs")
 
+    if(_lapack_sizeof_integer EQUAL 8)
+      string(APPEND _lapack_scsl_lib "_i8")
+    endif()
     # Check for OpenMP support, VIA BLA_VENDOR of scs_mp
     if(BLA_VENDOR MATCHES "_mp")
       set(_lapack_scsl_lib "${_lapack_scsl_lib}_mp")
@@ -525,129 +586,116 @@ if(NOT LAPACK_NOT_FOUND_MESSAGE)
   # Apple LAPACK library?
   if(NOT LAPACK_LIBRARIES
       AND (BLA_VENDOR STREQUAL "Apple" OR BLA_VENDOR STREQUAL "All"))
-    check_lapack_libraries(
-      LAPACK_LIBRARIES
-      LAPACK
-      cheev
-      ""
-      "Accelerate"
-      ""
-      ""
-      ""
-      "${BLAS_LIBRARIES}"
-    )
+    if(_lapack_sizeof_integer EQUAL 8)
+      if(BLA_VENDOR STREQUAL "Apple")
+        message(FATAL_ERROR "Accelerate Framework does not support Int64 type")
+      endif()
+    else()
+      check_lapack_libraries(
+        LAPACK_LIBRARIES
+        LAPACK
+        cheev
+        ""
+        "Accelerate"
+        ""
+        ""
+        ""
+        "${BLAS_LIBRARIES}"
+      )
+    endif()
   endif()
 
   # Apple NAS (vecLib) library?
   if(NOT LAPACK_LIBRARIES
       AND (BLA_VENDOR STREQUAL "NAS" OR BLA_VENDOR STREQUAL "All"))
-    check_lapack_libraries(
-      LAPACK_LIBRARIES
-      LAPACK
-      cheev
-      ""
-      "vecLib"
-      ""
-      ""
-      ""
-      "${BLAS_LIBRARIES}"
-    )
+    if(_lapack_sizeof_integer EQUAL 8)
+      if(BLA_VENDOR STREQUAL "NAS")
+        message(FATAL_ERROR "Accelerate Framework does not support Int64 type")
+      endif()
+    else()
+      check_lapack_libraries(
+        LAPACK_LIBRARIES
+        LAPACK
+        cheev
+        ""
+        "vecLib"
+        ""
+        ""
+        ""
+        "${BLAS_LIBRARIES}"
+      )
+    endif()
   endif()
 
   # Elbrus Math Library?
   if(NOT LAPACK_LIBRARIES
       AND (BLA_VENDOR MATCHES "EML" OR BLA_VENDOR STREQUAL "All"))
-
-    set(LAPACK_EML_LIB "eml")
-
-    # Check for OpenMP support, VIA BLA_VENDOR of eml_mt
-    if(BLA_VENDOR MATCHES "_mt")
-     set(LAPACK_EML_LIB "${LAPACK_EML_LIB}_mt")
+    if(BLAS_LIBRARIES MATCHES "eml.+")
+      set(LAPACK_LIBRARIES ${BLAS_LIBRARIES})
     endif()
-
-    check_lapack_libraries(
-      LAPACK_LIBRARIES
-      LAPACK
-      cheev
-      ""
-      "${LAPACK_EML_LIB}"
-      ""
-      ""
-      ""
-      "${BLAS_LIBRARIES}"
-    )
   endif()
 
   # Fujitsu SSL2 Library?
   if(NOT LAPACK_LIBRARIES
       AND (BLA_VENDOR MATCHES "Fujitsu_SSL2" OR BLA_VENDOR STREQUAL "All"))
-    if(BLA_VENDOR STREQUAL "Fujitsu_SSL2BLAMP")
-      set(_ssl2_suffix BLAMP)
-    else()
-      set(_ssl2_suffix)
-    endif()
-    set(_ssl2_blas)
-    if(BLAS_LIBRARIES STREQUAL "")
-      set(_ssl2_blas "${BLAS_LINKER_FLAGS}")
-    else()
-      set(_ssl2_blas "${BLAS_LIBRARIES} ${BLAS_LINKER_FLAGS}")
-    endif()
-    check_lapack_libraries(
-      LAPACK_LIBRARIES
-      LAPACK
-      cheev
-      "-SSL2${_ssl2_suffix}"
-      ""
-      ""
-      ""
-      ""
-      "${_ssl2_blas}"
-    )
-    if(LAPACK_LIBRARIES)
-      set(LAPACK_LINKER_FLAGS "-SSL2${_ssl2_suffix}")
-      set(_lapack_fphsa_req_var LAPACK_LINKER_FLAGS)
+    if(BLAS_LIBRARIES MATCHES "fjlapack.+")
+      set(LAPACK_LIBRARIES ${BLAS_LIBRARIES})
+      set(LAPACK_LINKER_FLAGS ${BLAS_LINKER_FLAGS})
     endif()
-    unset(_ssl2_suffix)
   endif()
 
   # LAPACK in IBM ESSL library?
   if(NOT LAPACK_LIBRARIES
       AND (BLA_VENDOR MATCHES "IBMESSL" OR BLA_VENDOR STREQUAL "All"))
-    set(_lapack_essl_lib "essl")
-
-    # Check for OpenMP support, VIA BLA_VENDOR of esslsmp
-    if(BLA_VENDOR MATCHES "_SMP")
-      set(_lapack_essl_lib "${_lapack_essl_lib}smp")
+    if(BLAS_LIBRARIES MATCHES "essl.+")
+      set(LAPACK_LIBRARIES ${BLAS_LIBRARIES})
     endif()
-
-    check_lapack_libraries(
-      LAPACK_LIBRARIES
-      LAPACK
-      cheev
-      ""
-      "${_lapack_essl_lib}"
-      ""
-      ""
-      ""
-      "${BLAS_LIBRARIES}"
-    )
-    unset(_lapack_essl_lib)
   endif()
 
   # NVHPC Library?
+
   if(NOT LAPACK_LIBRARIES
       AND (BLA_VENDOR MATCHES "NVHPC" OR BLA_VENDOR STREQUAL "All"))
+    set(_lapack_nvhpc_lib "lapack")
+
+    if(_lapack_sizeof_integer EQUAL 8)
+      string(APPEND _lapack_nvhpc_lib "_ilp64")
+    elseif(_lapack_sizeof_integer EQUAL 4)
+      string(APPEND _lapack_nvhpc_lib "_lp64")
+    endif()
+
     check_lapack_libraries(
       LAPACK_LIBRARIES
       LAPACK
       cheev
       ""
-      "lapack"
+      "${_lapack_nvhpc_lib}"
       "-fortranlibs"
       ""
       ""
       "${BLAS_LIBRARIES}"
     )
+
+    # an additional check for NVHPC 2020
+    # which does not have differentiation
+    # between lp64 and ilp64 modes
+    if(NOT LAPACK_LIBRARIES AND NOT _lapack_sizeof_integer EQUAL 8)
+      set(_lapack_nvhpc_lib "lapack")
+
+      check_lapack_libraries(
+        LAPACK_LIBRARIES
+        LAPACK
+        cheev
+        ""
+        "${_lapack_nvhpc_lib}"
+        "-fortranlibs"
+        ""
+        ""
+        "${BLAS_LIBRARIES}"
+      )
+    endif()
+
+    unset(_lapack_nvhpc_lib)
   endif()
 
   # Generic LAPACK library?
@@ -655,6 +703,7 @@ if(NOT LAPACK_NOT_FOUND_MESSAGE)
       AND (BLA_VENDOR STREQUAL "Generic"
            OR BLA_VENDOR STREQUAL "ATLAS"
            OR BLA_VENDOR STREQUAL "All"))
+    set(_lapack_generic_lib "lapack")
     if(BLA_STATIC)
       # We do not know for sure how the LAPACK reference implementation
       # is built on this host.  Guess typical dependencies.
@@ -662,18 +711,25 @@ if(NOT LAPACK_NOT_FOUND_MESSAGE)
     else()
       set(_lapack_generic_deps "")
     endif()
+
+    if(_lapack_sizeof_integer EQUAL 8)
+      string(APPEND _lapack_generic_lib "64")
+    endif()
+
     check_lapack_libraries(
       LAPACK_LIBRARIES
       LAPACK
       cheev
       ""
-      "lapack"
+      "${_lapack_generic_lib}"
       "${_lapack_generic_deps}"
       ""
       ""
       "${BLAS_LIBRARIES}"
     )
+
     unset(_lapack_generic_deps)
+    unset(_lapack_generic_lib)
   endif()
 endif()
 
@@ -701,4 +757,5 @@ endif()
 
 _add_lapack_target()
 unset(_lapack_fphsa_req_var)
+unset(_lapack_sizeof_integer)
 unset(_LAPACK_LIBRARIES)
diff --git a/Tests/FindBLAS/CMakeLists.txt b/Tests/FindBLAS/CMakeLists.txt
index 482cee8..00b254d 100644
--- a/Tests/FindBLAS/CMakeLists.txt
+++ b/Tests/FindBLAS/CMakeLists.txt
@@ -1,49 +1,2 @@
-foreach(variant IN LISTS CMake_TEST_FindBLAS)
-  if(variant MATCHES "^([^.]+)\\.(.*)$")
-    set(vendor "${CMAKE_MATCH_1}")
-    set(alt_compiler "-DCMAKE_C_COMPILER=${CMAKE_MATCH_2}")
-  else()
-    set(vendor "${variant}")
-    set(alt_compiler "")
-  endif()
-  if(vendor STREQUAL "All" AND CMake_TEST_FindBLAS_All)
-    set(EXPECT_All "-DEXPECT_All=${CMake_TEST_FindBLAS_All}")
-  else()
-    set(EXPECT_All "")
-  endif()
-  add_test(NAME FindBLAS.Test_${variant} COMMAND
-    ${CMAKE_CTEST_COMMAND} -C $<CONFIGURATION>
-    --build-and-test
-    "${CMake_SOURCE_DIR}/Tests/FindBLAS/Test"
-    "${CMake_BINARY_DIR}/Tests/FindBLAS/Test_${variant}"
-    ${build_generator_args}
-    --build-project TestFindBLAS
-    --build-options ${build_options} ${alt_compiler} ${EXPECT_All} -DBLA_VENDOR=${vendor}
-    --test-command ${CMAKE_CTEST_COMMAND} -V -C $<CONFIGURATION>
-    )
-endforeach()
-
-foreach(variant IN LISTS CMake_TEST_FindBLAS_STATIC)
-  if(variant MATCHES "^([^.]+)\\.(.*)$")
-    set(vendor "${CMAKE_MATCH_1}")
-    set(alt_compiler "-DCMAKE_C_COMPILER=${CMAKE_MATCH_2}")
-  else()
-    set(vendor "${variant}")
-    set(alt_compiler "")
-  endif()
-  if(vendor STREQUAL "All" AND CMake_TEST_FindBLAS_STATIC_All)
-    set(EXPECT_All "-DEXPECT_All=${CMake_TEST_FindBLAS_STATIC_All}")
-  else()
-    set(EXPECT_All "")
-  endif()
-  add_test(NAME FindBLAS.Test_${variant}_Static COMMAND
-    ${CMAKE_CTEST_COMMAND} -C $<CONFIGURATION>
-    --build-and-test
-    "${CMake_SOURCE_DIR}/Tests/FindBLAS/Test"
-    "${CMake_BINARY_DIR}/Tests/FindBLAS/Test_${variant}_Static"
-    ${build_generator_args}
-    --build-project TestFindBLAS
-    --build-options ${build_options} ${alt_compiler} ${EXPECT_All} -DBLA_VENDOR=${vendor} -DBLA_STATIC=ON
-    --test-command ${CMAKE_CTEST_COMMAND} -V -C $<CONFIGURATION>
-    )
-endforeach()
+include("${CMake_SOURCE_DIR}/Tests/FindBLAS/add_BLAS_LAPACK_tests.cmake")
+add_BLAS_LAPACK_tests(CMake_TEST_FindBLAS)
diff --git a/Tests/FindBLAS/Test/CMakeLists.txt b/Tests/FindBLAS/Test/CMakeLists.txt
index 7379749..14bf19f 100644
--- a/Tests/FindBLAS/Test/CMakeLists.txt
+++ b/Tests/FindBLAS/Test/CMakeLists.txt
@@ -4,12 +4,18 @@ include(CTest)
 
 find_package(BLAS REQUIRED)
 
+if(NOT BLA_SIZEOF_INTEGER)
+  set(BLA_SIZEOF_INTEGER 4)
+endif()
+
 add_executable(test_tgt main.c)
 target_link_libraries(test_tgt BLAS::BLAS)
+target_compile_definitions(test_tgt PUBLIC BLA_SIZEOF_INTEGER=${BLA_SIZEOF_INTEGER})
 add_test(NAME test_tgt COMMAND test_tgt)
 
 add_executable(test_var main.c)
 target_link_libraries(test_var PRIVATE ${BLAS_LIBRARIES})
+target_compile_definitions(test_var PUBLIC BLA_SIZEOF_INTEGER=${BLA_SIZEOF_INTEGER})
 add_test(NAME test_var COMMAND test_var)
 
 if((BLA_VENDOR STREQUAL "Intel10_64lp") OR
@@ -17,4 +23,9 @@ if((BLA_VENDOR STREQUAL "Intel10_64lp") OR
   if(NOT BLAS_LIBRARIES MATCHES "^(-Wl,--start-group;)?[^;]*mkl_intel_lp64")
     message(FATAL_ERROR "BLAS_LIBRARIES does not start in mkl_intel_lp64:\n ${BLAS_LIBRARIES}")
   endif()
+elseif((BLA_VENDOR STREQUAL "Intel10_64ilp") OR
+   (BLA_VENDOR STREQUAL "All" AND EXPECT_All STREQUAL "Intel10_64ilp"))
+  if(NOT BLAS_LIBRARIES MATCHES "^(-Wl,--start-group;)?[^;]*mkl_intel_ilp64")
+    message(FATAL_ERROR "BLAS_LIBRARIES does not start in mkl_intel_ilp64:\n ${BLAS_LIBRARIES}")
+  endif()
 endif()
diff --git a/Tests/FindBLAS/Test/main.c b/Tests/FindBLAS/Test/main.c
index e61b02c..4fc9fe4 100644
--- a/Tests/FindBLAS/Test/main.c
+++ b/Tests/FindBLAS/Test/main.c
@@ -1,16 +1,25 @@
 #include <assert.h>
+#include <stdint.h>
 #include <string.h>
 
+#if BLA_SIZEOF_INTEGER == 4
+typedef int32_t blas_int;
+#elif BLA_SIZEOF_INTEGER == 8
+typedef int64_t blas_int;
+#else
+#  error BLA_SIZEOF_INTEGER is not declared!
+#endif
+
 // declare what parts of the blas C-API we need
-void dswap_(int* N, double* X, int* incX, double* Y, int* incY);
+void dswap_(blas_int* N, double* X, blas_int* incX, double* Y, blas_int* incY);
 
 int main()
 {
   double x[4] = { 1, 2, 3, 4 };
   double y[4] = { 8, 7, 7, 6 };
-  int N = 4;
-  int incX = 1;
-  int incY = 1;
+  blas_int N = 4;
+  blas_int incX = 1;
+  blas_int incY = 1;
   dswap_(&N, x, &incX, y, &incY);
   return 0;
 }
diff --git a/Tests/FindBLAS/add_BLAS_LAPACK_tests.cmake b/Tests/FindBLAS/add_BLAS_LAPACK_tests.cmake
new file mode 100644
index 0000000..42fe386
--- /dev/null
+++ b/Tests/FindBLAS/add_BLAS_LAPACK_tests.cmake
@@ -0,0 +1,53 @@
+function(add_BLAS_LAPACK_tests var)
+  if(var MATCHES "^CMake_TEST_Find(BLAS|LAPACK)$")
+    set(package "${CMAKE_MATCH_1}")
+  else()
+    message(FATAL_ERROR "Test list variable '${var}' not supported.")
+  endif()
+
+  set(all "")
+  set(compiler "")
+  set(model "")
+  set(static "")
+
+  set(sizeof_int_lp64 4)
+  set(sizeof_int_ilp64 8)
+
+  foreach(variant IN LISTS ${var})
+    if(variant MATCHES "^(all|compiler|model|static)=(.*)$")
+      set("${CMAKE_MATCH_1}" "${CMAKE_MATCH_2}")
+      continue()
+    elseif(variant MATCHES "^([^=]+)=(.*)$")
+      message(FATAL_ERROR "Unknown variable '${variant}'")
+    endif()
+    set(variant_name "${variant}")
+    set(variant_options "-DBLA_VENDOR=${variant}")
+    if(variant STREQUAL "All" AND all)
+      list(APPEND variant_options "-DEXPECT_All=${all}")
+    endif()
+    if(model)
+      if(NOT variant_name MATCHES "Intel10_64")
+        string(APPEND variant_name "_${model}")
+      endif()
+      list(APPEND variant_options "-DBLA_SIZEOF_INTEGER=${sizeof_int_${model}}")
+    endif()
+    if(compiler)
+      string(APPEND variant_name "_${compiler}")
+      list(APPEND variant_options "-DCMAKE_C_COMPILER=${compiler}")
+    endif()
+    if(static)
+      string(APPEND variant_name "_Static")
+      list(APPEND variant_options "-DBLA_STATIC=ON")
+    endif()
+    add_test(NAME Find${package}.Test_${variant_name} COMMAND
+      ${CMAKE_CTEST_COMMAND} -C $<CONFIGURATION>
+      --build-and-test
+      "${CMake_SOURCE_DIR}/Tests/Find${package}/Test"
+      "${CMake_BINARY_DIR}/Tests/Find${package}/Test_${variant_name}"
+      ${build_generator_args}
+      --build-project TestFind${package}
+      --build-options ${build_options} ${variant_options}
+      --test-command ${CMAKE_CTEST_COMMAND} -V -C $<CONFIGURATION>
+      )
+  endforeach()
+endfunction()
diff --git a/Tests/FindLAPACK/CMakeLists.txt b/Tests/FindLAPACK/CMakeLists.txt
index 535c7b6..a2470ef 100644
--- a/Tests/FindLAPACK/CMakeLists.txt
+++ b/Tests/FindLAPACK/CMakeLists.txt
@@ -1,49 +1,2 @@
-foreach(variant IN LISTS CMake_TEST_FindLAPACK)
-  if(variant MATCHES "^([^.]+)\\.(.*)$")
-    set(vendor "${CMAKE_MATCH_1}")
-    set(alt_compiler "-DCMAKE_C_COMPILER=${CMAKE_MATCH_2}")
-  else()
-    set(vendor "${variant}")
-    set(alt_compiler "")
-  endif()
-  if(vendor STREQUAL "All" AND CMake_TEST_FindLAPACK_All)
-    set(EXPECT_All "-DEXPECT_All=${CMake_TEST_FindLAPACK_All}")
-  else()
-    set(EXPECT_All "")
-  endif()
-  add_test(NAME FindLAPACK.Test_${variant} COMMAND
-    ${CMAKE_CTEST_COMMAND} -C $<CONFIGURATION>
-    --build-and-test
-    "${CMake_SOURCE_DIR}/Tests/FindLAPACK/Test"
-    "${CMake_BINARY_DIR}/Tests/FindLAPACK/Test_${variant}"
-    ${build_generator_args}
-    --build-project TestFindLAPACK
-    --build-options ${build_options} ${alt_compiler} ${EXPECT_All} -DBLA_VENDOR=${vendor}
-    --test-command ${CMAKE_CTEST_COMMAND} -V -C $<CONFIGURATION>
-    )
-endforeach()
-
-foreach(variant IN LISTS CMake_TEST_FindLAPACK_STATIC)
-  if(variant MATCHES "^([^.]+)\\.(.*)$")
-    set(vendor "${CMAKE_MATCH_1}")
-    set(alt_compiler "-DCMAKE_C_COMPILER=${CMAKE_MATCH_2}")
-  else()
-    set(vendor "${variant}")
-    set(alt_compiler "")
-  endif()
-  if(vendor STREQUAL "All" AND CMake_TEST_FindLAPACK_STATIC_All)
-    set(EXPECT_All "-DEXPECT_All=${CMake_TEST_FindLAPACK_STATIC_All}")
-  else()
-    set(EXPECT_All "")
-  endif()
-  add_test(NAME FindLAPACK.Test_${variant}_Static COMMAND
-    ${CMAKE_CTEST_COMMAND} -C $<CONFIGURATION>
-    --build-and-test
-    "${CMake_SOURCE_DIR}/Tests/FindLAPACK/Test"
-    "${CMake_BINARY_DIR}/Tests/FindLAPACK/Test_${variant}_Static"
-    ${build_generator_args}
-    --build-project TestFindLAPACK
-    --build-options ${build_options} ${alt_compiler} ${EXPECT_All} -DBLA_VENDOR=${vendor} -DBLA_STATIC=ON
-    --test-command ${CMAKE_CTEST_COMMAND} -V -C $<CONFIGURATION>
-    )
-endforeach()
+include("${CMake_SOURCE_DIR}/Tests/FindBLAS/add_BLAS_LAPACK_tests.cmake")
+add_BLAS_LAPACK_tests(CMake_TEST_FindLAPACK)
diff --git a/Tests/FindLAPACK/Test/CMakeLists.txt b/Tests/FindLAPACK/Test/CMakeLists.txt
index 23a43ac..f5d5a73 100644
--- a/Tests/FindLAPACK/Test/CMakeLists.txt
+++ b/Tests/FindLAPACK/Test/CMakeLists.txt
@@ -4,12 +4,18 @@ include(CTest)
 
 find_package(LAPACK REQUIRED)
 
+if(NOT BLA_SIZEOF_INTEGER)
+  set(BLA_SIZEOF_INTEGER 4)
+endif()
+
 add_executable(test_tgt main.c)
 target_link_libraries(test_tgt LAPACK::LAPACK)
+target_compile_definitions(test_tgt PUBLIC BLA_SIZEOF_INTEGER=${BLA_SIZEOF_INTEGER})
 add_test(NAME test_tgt COMMAND test_tgt)
 
 add_executable(test_var main.c)
 target_link_libraries(test_var PRIVATE ${LAPACK_LIBRARIES})
+target_compile_definitions(test_var PUBLIC BLA_SIZEOF_INTEGER=${BLA_SIZEOF_INTEGER})
 add_test(NAME test_var COMMAND test_var)
 
 if((BLA_VENDOR STREQUAL "Intel10_64lp") OR
@@ -17,4 +23,9 @@ if((BLA_VENDOR STREQUAL "Intel10_64lp") OR
   if(NOT LAPACK_LIBRARIES MATCHES "^(-Wl,--start-group;)?[^;]*mkl_intel_lp64")
     message(FATAL_ERROR "LAPACK_LIBRARIES does not start in mkl_intel_lp64:\n ${LAPACK_LIBRARIES}")
   endif()
+elseif((BLA_VENDOR STREQUAL "Intel10_64ilp") OR
+   (BLA_VENDOR STREQUAL "All" AND EXPECT_All STREQUAL "Intel10_64ilp"))
+  if(NOT LAPACK_LIBRARIES MATCHES "^(-Wl,--start-group;)?[^;]*mkl_intel_ilp64")
+    message(FATAL_ERROR "LAPACK_LIBRARIES does not start in mkl_intel_ilp64:\n ${LAPACK_LIBRARIES}")
+  endif()
 endif()
diff --git a/Tests/FindLAPACK/Test/main.c b/Tests/FindLAPACK/Test/main.c
index 5873e7b..dd33fb3 100644
--- a/Tests/FindLAPACK/Test/main.c
+++ b/Tests/FindLAPACK/Test/main.c
@@ -1,8 +1,18 @@
 #include <assert.h>
+#include <stdint.h>
 #include <string.h>
 
+#if BLA_SIZEOF_INTEGER == 4
+typedef int32_t blas_int;
+#elif BLA_SIZEOF_INTEGER == 8
+typedef int64_t blas_int;
+#else
+#  error BLA_SIZEOF_INTEGER is not declared!
+#endif
+
 // declare what parts of the lapack C-API we need
-void dgesv_(int*, int*, double*, int*, int*, double*, int*, int*);
+void dgesv_(blas_int*, blas_int*, double*, blas_int*, blas_int*, double*,
+            blas_int*, blas_int*);
 
 int main()
 {
@@ -10,11 +20,11 @@ int main()
     0, 1, 2, 3, 4, 5, 6, 7,
   };
   double B[2] = { 0, 5 };
-  int ipiv[2] = { 0, 0 };
-  int info = 0;
+  blas_int ipiv[2] = { 0, 0 };
+  blas_int info = 0;
 
-  int dim = 2;
-  int numCols = 1;
+  blas_int dim = 2;
+  blas_int numCols = 1;
   dgesv_(&dim, &numCols, A, &dim, ipiv, B, &dim, &info);
   return 0;
 }