Enable IPO for IntelLLVM compilers on Linux and Windows

Replicate and adapt Linux IPO options for Intel for IntelLLVM compilers
on Linux and Windows.

Signed-off-by: William R. Dieter <william.r.dieter@intel.com>

2 files changed, 60 insertions, 6 deletions

diff --git a/Modules/Compiler/IntelLLVM-FindBinUtils.cmake b/Modules/Compiler/IntelLLVM-FindBinUtils.cmake
new file mode 100644
index 0000000000..c5b1ee63d8
--- /dev/null
+++ b/Modules/Compiler/IntelLLVM-FindBinUtils.cmake
@@ -0,0 +1,45 @@
+if(NOT DEFINED _CMAKE_PROCESSING_LANGUAGE OR _CMAKE_PROCESSING_LANGUAGE STREQUAL "")
+  message(FATAL_ERROR "Internal error: _CMAKE_PROCESSING_LANGUAGE is not set")
+endif()
+
+# Ubuntu:
+# * /usr/bin/llvm-ar-9
+# * /usr/bin/llvm-ranlib-9
+string(REGEX MATCH "^([0-9]+)" __version_x
+    "${CMAKE_${_CMAKE_PROCESSING_LANGUAGE}_COMPILER_VERSION}")
+
+# Debian:
+# * /usr/bin/llvm-ar-4.0
+# * /usr/bin/llvm-ranlib-4.0
+string(REGEX MATCH "^([0-9]+\\.[0-9]+)" __version_x_y
+    "${CMAKE_${_CMAKE_PROCESSING_LANGUAGE}_COMPILER_VERSION}")
+
+# Try to find tools in the IntelLLVM Clang tools directory
+get_filename_component(__intel_llvm_hint_1 "${CMAKE_${_CMAKE_PROCESSING_LANGUAGE}_COMPILER}" DIRECTORY)
+get_filename_component(__intel_llvm_hint_1 "${__intel_llvm_hint_1}/../bin-llvm" REALPATH)
+
+get_filename_component(__intel_llvm_hint_2 "${CMAKE_${_CMAKE_PROCESSING_LANGUAGE}_COMPILER}" DIRECTORY)
+
+set(__intel_llvm_hints ${__intel_llvm_hint_1} ${__intel_llvm_hint_2})
+
+# http://manpages.ubuntu.com/manpages/precise/en/man1/llvm-ar.1.html
+find_program(CMAKE_${_CMAKE_PROCESSING_LANGUAGE}_COMPILER_AR NAMES
+    "${_CMAKE_TOOLCHAIN_PREFIX}llvm-ar-${__version_x_y}"
+    "${_CMAKE_TOOLCHAIN_PREFIX}llvm-ar-${__version_x}"
+    "${_CMAKE_TOOLCHAIN_PREFIX}llvm-ar"
+    HINTS ${__intel_llvm_hints}
+    NO_CMAKE_PATH NO_CMAKE_ENVIRONMENT_PATH
+    DOC "LLVM archiver"
+)
+mark_as_advanced(CMAKE_${_CMAKE_PROCESSING_LANGUAGE}_COMPILER_AR)
+
+# http://manpages.ubuntu.com/manpages/precise/en/man1/llvm-ranlib.1.html
+find_program(CMAKE_${_CMAKE_PROCESSING_LANGUAGE}_COMPILER_RANLIB NAMES
+    "${_CMAKE_TOOLCHAIN_PREFIX}llvm-ranlib-${__version_x_y}"
+    "${_CMAKE_TOOLCHAIN_PREFIX}llvm-ranlib-${__version_x}"
+    "${_CMAKE_TOOLCHAIN_PREFIX}llvm-ranlib"
+    HINTS ${__intel_llvm_hints}
+    NO_CMAKE_PATH NO_CMAKE_ENVIRONMENT_PATH
+    DOC "Generate index for LLVM archive"
+)
+mark_as_advanced(CMAKE_${_CMAKE_PROCESSING_LANGUAGE}_COMPILER_RANLIB)
diff --git a/Modules/Compiler/IntelLLVM.cmake b/Modules/Compiler/IntelLLVM.cmake
index c344f3259e..3f22efd8c0 100644
--- a/Modules/Compiler/IntelLLVM.cmake
+++ b/Modules/Compiler/IntelLLVM.cmake
@@ -15,6 +15,15 @@ set(__pch_header_CXX "c++-header")
 set(__pch_header_OBJC "objective-c-header")
 set(__pch_header_OBJCXX "objective-c++-header")
 
+# Variables that are common across front-end variants
+macro(__compiler_intel_llvm_common lang)
+  set(_CMAKE_${lang}_IPO_SUPPORTED_BY_CMAKE YES)
+  set(_CMAKE_${lang}_IPO_MAY_BE_SUPPORTED_BY_COMPILER YES)
+  set(CMAKE_${lang}_ARCHIVE_CREATE_IPO "\"${CMAKE_${lang}_COMPILER_AR}\" cr <TARGET> <LINK_FLAGS> <OBJECTS>")
+  set(CMAKE_${lang}_ARCHIVE_APPEND_IPO "\"${CMAKE_${lang}_COMPILER_AR}\" r <TARGET> <LINK_FLAGS> <OBJECTS>")
+  set(CMAKE_${lang}_ARCHIVE_FINISH_IPO "\"${CMAKE_${lang}_COMPILER_RANLIB}\" <TARGET>")
+endmacro()
+
 if(CMAKE_HOST_WIN32)
   # MSVC-like
   macro(__compiler_intel_llvm lang)
@@ -22,6 +31,9 @@ if(CMAKE_HOST_WIN32)
       set(CMAKE_${lang}_COMPILE_OPTIONS_INVALID_PCH -Winvalid-pch)
       set(CMAKE_${lang}_COMPILE_OPTIONS_WARNING_AS_ERROR "-WX")
     endif()
+    __compiler_intel_llvm_common(${lang})
+    set(CMAKE_${lang}_COMPILE_OPTIONS_IPO "-Qipo")
+    set(CMAKE_${lang}_LINK_OPTIONS_IPO "-Qipo")
   endmacro()
 else()
   # GNU-like
@@ -60,12 +72,9 @@ else()
     set(CMAKE_${lang}_LINKER_WRAPPER_FLAG "-Xlinker" " ")
     set(CMAKE_${lang}_LINKER_WRAPPER_FLAG_SEP)
 
-    set(_CMAKE_${lang}_IPO_SUPPORTED_BY_CMAKE YES)
-    set(_CMAKE_${lang}_IPO_MAY_BE_SUPPORTED_BY_COMPILER YES)
-    set(CMAKE_${lang}_COMPILE_OPTIONS_IPO "-flto=thin")
-    set(CMAKE_${lang}_ARCHIVE_CREATE_IPO "\"${CMAKE_${lang}_COMPILER_AR}\" cr <TARGET> <LINK_FLAGS> <OBJECTS>")
-    set(CMAKE_${lang}_ARCHIVE_APPEND_IPO "\"${CMAKE_${lang}_COMPILER_AR}\" r <TARGET> <LINK_FLAGS> <OBJECTS>")
-    set(CMAKE_${lang}_ARCHIVE_FINISH_IPO "\"${CMAKE_${lang}_COMPILER_RANLIB}\" <TARGET>")
+    __compiler_intel_llvm_common(${lang})
+    set(CMAKE_${lang}_COMPILE_OPTIONS_IPO "-ipo")
+    set(CMAKE_${lang}_LINK_OPTIONS_IPO "-ipo")
 
     set(CMAKE_${lang}_CREATE_PREPROCESSED_SOURCE "<CMAKE_${lang}_COMPILER> <DEFINES> <INCLUDES> <FLAGS> -E <SOURCE> > <PREPROCESSED_SOURCE>")
     set(CMAKE_${lang}_CREATE_ASSEMBLY_SOURCE "<CMAKE_${lang}_COMPILER> <DEFINES> <INCLUDES> <FLAGS> -S <SOURCE> -o <ASSEMBLY_SOURCE>")