Refactor cmake for setting AMD targets and fix incorrect logic

Author: ndgrigorian

CMakeLists.txt

@@ -31,7 +31,7 @@ option(DPCTL_TARGET_CUDA
 )
 set(DPCTL_TARGET_AMD
     ""
-    CACHE STRING 
+    CACHE STRING
     "Build DPCTL to target an AMD device architecture"
 )
 option(DPCTL_WITH_REDIST "Build DPCTL assuming DPC++ redistributable is installed into Python prefix" OFF)
@@ -52,21 +52,19 @@ if ("x${DPCTL_SYCL_TARGETS}" STREQUAL "x")
       endif()
    endif()
    if (NOT "x${DPCTL_TARGET_AMD}" STREQUAL "x")
+      set(_dpctl_amd_targets ${DPCTL_TARGET_AMD})
       if(_dpctl_sycl_targets)
-         set(_dpctl_sycl_targets "amdgcn-amd-amdhsa,spir64-unknown-unknown")
-         set(_dpctl_amd_targets ${DPCTL_TARGET_AMD})
-      else()
          set(_dpctl_sycl_targets "amdgcn-amd-amdhsa,${_dpctl_sycl_targets}")
-         set(_dpctl_amd_targets ${DPCTL_TARGET_AMD})
+      else()
+         set(_dpctl_sycl_targets "amdgcn-amd-amdhsa,spir64-unknown-unknown")
       endif()
    else()
       if (DEFINED ENV{DPCTL_TARGET_AMD})
+         set(_dpctl_amd_targets $ENV{DPCTL_TARGET_AMD})
          if(_dpctl_sycl_targets)
-            set(_dpctl_sycl_targets "amdgcn-amd-amdhsa,spir64-unknown-unknown")
-            set(_dpctl_amd_targets $ENV{DPCTL_TARGET_AMD})
-         else()
             set(_dpctl_sycl_targets "amdgcn-amd-amdhsa,${_dpctl_sycl_targets}")
-            set(_dpctl_amd_targets $ENV{DPCTL_TARGET_AMD})
+         else()
+            set(_dpctl_sycl_targets "amdgcn-amd-amdhsa,spir64-unknown-unknown")
          endif()
       endif()
    endif()