Minor improvements

Similarly to NVIDIA and Intel GPUs, we now detect microarchitecture,
also with manufacturing process and specific chip name. We infer all
of this from the gfx name (in the code we use the term llvm_target),
altough it's not clear yet that this method is completely reliable (see
comments for more details). In the future we might want to replace that
with a better way. Once we have the gfx name, we *should* be able to
infer the specific chip, and from the chip we can easily infer the
microarchitecture.

This commit also includes some refactorings and code improvements on
the HSA backend.

CMakeLists.txt

@@ -27,8 +27,7 @@ if(ENABLE_CUDA_BACKEND)
 endif()
 
 if(ENABLE_HSA_BACKEND)
-  # TODO: Needs rocm-cmake, what if its not insalled?
-  find_package(ROCmCMakeBuildTools)
+  find_package(ROCmCMakeBuildTools QUIET)
   if (ROCmCMakeBuildTools_FOUND)
     find_package(hsa-runtime64 1.0 REQUIRED)    
     link_directories(hsa_backend hsa-runtime64::hsa-runtime64)
@@ -48,9 +47,22 @@ if(ENABLE_HSA_BACKEND)
       message(STATUS "${BoldYellow}HSA not found, disabling HSA backend${ColorReset}")
       set(ENABLE_HSA_BACKEND false)
     endif()
+  else()
+    # rocm-cmake is not installed, try to manually find neccesary files.
+    message(STATUS "${BoldYellow}Could NOT find HSA automatically, running manual search...${ColorReset}")
+    if (NOT DEFINED ROCM_PATH)
+      set(ROCM_PATH "/opt/rocm" CACHE PATH "Path to ROCm")
+    endif()
+
+    find_path(HSA_INCLUDE_DIR hsa/hsa.h HINTS ${ROCM_PATH}/include)
+    find_library(HSA_LIBRARY hsa-runtime64 HINTS ${ROCM_PATH}/lib ${ROCM_PATH}/lib64)
+
+    if (HSA_INCLUDE_DIR AND HSA_LIBRARY)
+      message(STATUS "${BoldYellow}HSA was found manually${ColorReset}")
     else()
       set(ENABLE_HSA_BACKEND false)
-    message(STATUS "${BoldYellow}ROCm not found${ColorReset}")
+      message(STATUS "${BoldYellow}HSA was not found manually${ColorReset}")
+    endif()
   endif()
 endif()
 
@@ -134,9 +146,13 @@ if(ENABLE_HSA_BACKEND)
   endif()
 
   target_include_directories(hsa_backend PRIVATE "${HSA_INCLUDE_DIR}")
-  message(STATUS "Found HSA: ${HSA_INCLUDE_DIR}")
 
+  if (HSA_LIBRARY)
+    target_link_libraries(hsa_backend PRIVATE ${HSA_LIBRARY})
+  else()
     target_link_libraries(hsa_backend PRIVATE hsa-runtime64::hsa-runtime64)
+  endif()
+
   target_link_libraries(gpufetch hsa_backend)
 endif()