Merge pull request #3945 from Thyre/20250925142337_new_pr_lammps

change LAMMPS easyblock to check for `kokkos_arch` before generic `optarch`

Author: ocaisa

easybuild/easyblocks/l/lammps.py

@@ -270,37 +270,24 @@ def get_kokkos_arch(self, cuda_cc, kokkos_arch):
         # to the compiler flags, which may override the ones set by EasyBuild.
         # https://github.com/lammps/lammps/blob/stable_29Aug2024/lib/kokkos/cmake/kokkos_arch.cmake#L228-L531
         processor_arch = None
-        if build_option('optarch') == OPTARCH_GENERIC:
+        if kokkos_arch:
+            # If someone is trying a manual override for this case, let them
+            if kokkos_arch not in KOKKOS_CPU_ARCH_LIST:
+                warning_msg = "Specified CPU ARCH (%s) " % kokkos_arch
+                warning_msg += "was not found in listed options [%s]." % KOKKOS_CPU_ARCH_LIST
+                warning_msg += "Still might work though."
+                print_warning(warning_msg)
+            processor_arch = kokkos_arch
+        elif build_option('optarch') == OPTARCH_GENERIC:
             # For generic Arm builds we use an existing target;
             # this ensures that KOKKOS_ARCH_ARM_NEON is enabled (Neon is required for armv8-a).
             # For other architectures we set a custom/non-existent type, which will disable all optimizations,
             # and it should use the compiler (optimization) flags set by EasyBuild for this architecture.
             if get_cpu_architecture() == AARCH64:
-                if kokkos_arch:
-                    # If someone is trying a manual override for this case, let them
-                    if kokkos_arch not in KOKKOS_CPU_ARCH_LIST:
-                        warning_msg = "Specified CPU ARCH (%s) " % kokkos_arch
-                        warning_msg += "was not found in listed options [%s]." % KOKKOS_CPU_ARCH_LIST
-                        warning_msg += "Still might work though."
-                        print_warning(warning_msg)
-                    processor_arch = kokkos_arch
-                else:
-                    processor_arch = 'ARMV80'
+                processor_arch = 'ARMV80'
             else:
                 processor_arch = 'EASYBUILD_GENERIC'
-
             _log.info("Generic build requested, setting CPU ARCH to %s." % processor_arch)
-            if kokkos_arch:
-                msg = "The specified kokkos_arch (%s) will be ignored " % kokkos_arch
-                msg += "because a generic build was requested (via --optarch=GENERIC)"
-                print_warning(msg)
-        elif kokkos_arch:
-            if kokkos_arch not in KOKKOS_CPU_ARCH_LIST:
-                warning_msg = "Specified CPU ARCH (%s) " % kokkos_arch
-                warning_msg += "was not found in listed options [%s]." % KOKKOS_CPU_ARCH_LIST
-                warning_msg += "Still might work though."
-                print_warning(warning_msg)
-            processor_arch = kokkos_arch
 
         # If kokkos_arch was not set...
         elif LooseVersion(self.cur_version) >= LooseVersion(translate_lammps_version('2Aug2023')):