[llvm-exegesis] Change how the native architecture is determined

[john.brawn]

Summary

Currently the llvm-exegesis native architecture is determined by comparing the llvm native architecture with X86, so to add a new target would mean adding a new check. Change this to building up a list of the targets llvm-exegesis supports then using that, as this means that when adding a new target you just add the target to the list of supported targets.

[courbet]

tools/llvm-exegesis/CMakeLists.txt

14 ↗

(On Diff #153531)

Does this work if the variable LLVM_EXEGESIS_TARGETS is never set (e.g. if llvm targets to build is just "ARM") ?

[john.brawn]

tools/llvm-exegesis/CMakeLists.txt

14 ↗

(On Diff #153531)

Yes, we get the some behaviour as we currently do (LLVM_EXEGESIS_NATIVE_ARCH is not set, so the default exegesis target is used).

llvm/trunk/tools/llvm-exegesis/CMakeLists.txt

 
 set(LLVM_LINK_COMPONENTS
   Support
   native
   )
 
 add_llvm_tool(llvm-exegesis
   llvm-exegesis.cpp
   )
 
 add_subdirectory(lib)
 
 # Link the native exegesis target if compiled and on the right host.
-if ((LLVM_TARGETS_TO_BUILD MATCHES "X86") AND ("${LLVM_NATIVE_ARCH}" STREQUAL "X86"))
-  set(LLVM_EXEGESIS_NATIVE_ARCH "X86")
+if ((LLVM_TARGETS_TO_BUILD MATCHES "${LLVM_NATIVE_ARCH}") AND (LLVM_EXEGESIS_TARGETS MATCHES "${LLVM_NATIVE_ARCH}"))
+  set(LLVM_EXEGESIS_NATIVE_ARCH "${LLVM_NATIVE_ARCH}")
 endif()
 
 if (LLVM_EXEGESIS_NATIVE_ARCH)
   set(LLVM_EXEGESIS_NATIVE_TARGET "LLVMExegesis${LLVM_EXEGESIS_NATIVE_ARCH}")
   set_source_files_properties(llvm-exegesis.cpp PROPERTIES COMPILE_FLAGS "-DLLVM_EXEGESIS_INITIALIZE_NATIVE_TARGET=Initialize${LLVM_EXEGESIS_NATIVE_ARCH}ExegesisTarget")
 endif()
 
 target_link_libraries(llvm-exegesis PRIVATE
   LLVMExegesis
   ${LLVM_EXEGESIS_NATIVE_TARGET}
   )

llvm/trunk/tools/llvm-exegesis/lib/CMakeLists.txt

 if (LLVM_TARGETS_TO_BUILD MATCHES "X86")
   add_subdirectory(X86)
+  set(LLVM_EXEGESIS_TARGETS "${LLVM_EXEGESIS_TARGETS} X86" PARENT_SCOPE)
 endif()
 
 add_library(LLVMExegesis
   STATIC
   Analysis.cpp
   Assembler.cpp
   BenchmarkResult.cpp
   BenchmarkRunner.cpp