undo merge error

CIME/case/case.py

@@ -1301,6 +1301,9 @@ def configure(
         non_local=False,
         extra_machines_dir=None,
         case_group=None,
+        ngpus_per_node=0,
+        gpu_type=None,
+        gpu_offload=None,
     ):
         expect(
             check_name(compset_name, additional_chars="."),
@@ -1558,6 +1561,64 @@ def configure(
         if test:
             self.set_value("TEST", True)
 
+        # ----------------------------------------------------------------------------------------------------------
+        # Sanity check for a GPU run:
+        #        1. GPU_TYPE and GPU_OFFLOAD must both be defined to use GPUS
+        #        2. if ngpus_per_node argument is larger than the value of MAX_GPUS_PER_NODE, the NGPUS_PER_NODE
+        #             XML variable in the env_mach_pes.xml file would be set to MAX_GPUS_PER_NODE automatically.
+        #        3. if ngpus-per-node argument is equal to 0, it will be updated to 1 automatically.
+        # ----------------------------------------------------------------------------------------------------------
+        max_gpus_per_node = self.get_value("MAX_GPUS_PER_NODE")
+        if gpu_type and str(gpu_type).lower() != "none":
+            expect(
+                max_gpus_per_node,
+                f"GPUS are not defined for machine={machine_name} and compiler={compiler}",
+            )
+            expect(
+                gpu_offload,
+                "Both gpu-type and gpu-offload must be defined if either is defined",
+            )
+            expect(
+                compiler in ["nvhpc", "cray"],
+                f"Only nvhpc and cray compilers are expected for a GPU run; the user given compiler is {compiler}, ",
+            )
+            valid_gpu_type = self.get_value("GPU_TYPE").split(",")
+            valid_gpu_type.remove("none")
+            expect(
+                gpu_type in valid_gpu_type,
+                f"Unsupported GPU type is given: {gpu_type} ; valid values are {valid_gpu_type}",
+            )
+            valid_gpu_offload = self.get_value("GPU_OFFLOAD").split(",")
+            valid_gpu_offload.remove("none")
+            expect(
+                gpu_offload in valid_gpu_offload,
+                f"Unsupported GPU programming model is given: {gpu_offload} ; valid values are {valid_gpu_offload}",
+            )
+            self.gpu_enabled = True
+            if ngpus_per_node >= 0:
+                self.set_value(
+                    "NGPUS_PER_NODE",
+                    max(1, ngpus_per_node)
+                    if ngpus_per_node <= max_gpus_per_node
+                    else max_gpus_per_node,
+                )
+        elif gpu_offload and str(gpu_offload).lower() != "none":
+            expect(
+                False,
+                "Both gpu-type and gpu-offload must be defined if either is defined",
+            )
+        elif ngpus_per_node != 0:
+            expect(
+                False,
+                f"ngpus_per_node is expected to be 0 for a pure CPU run ; {ngpus_per_node} is provided instead ;",
+            )
+
+        # Set these two GPU XML variables here to overwrite the default values
+        # Only set them for "cesm" model
+        if self._cime_model == "cesm":
+            self.set_value("GPU_TYPE", str(gpu_type).lower())
+            self.set_value("GPU_OFFLOAD", str(gpu_offload).lower())
+
         self.initialize_derived_attributes()
 
         # --------------------------------------------
@@ -2382,6 +2443,9 @@ def create(
         non_local=False,
         extra_machines_dir=None,
         case_group=None,
+        ngpus_per_node=0,
+        gpu_type=None,
+        gpu_offload=None,
     ):
         try:
             # Set values for env_case.xml
@@ -2454,6 +2518,9 @@ def create(
                 non_local=non_local,
                 extra_machines_dir=extra_machines_dir,
                 case_group=case_group,
+                ngpus_per_node=ngpus_per_node,
+                gpu_type=gpu_type,
+                gpu_offload=gpu_offload,
             )
 
             self.create_caseroot()