From: Hans Kristian Rosbach <hk-git@circlestorm.org>
Date: Thu, 20 Jul 2023 17:26:06 +0000 (+0200)
Subject: Simplify handling of march=native in CMakeLits.txt
X-Git-Tag: 2.1.4~39
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=aec18b6b8664ed3fd16b62b6d86979dd6d748a99;p=thirdparty%2Fzlib-ng.git

Simplify handling of march=native in CMakeLits.txt
---

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 47562a343..322d7fc6d 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -168,10 +168,6 @@ if(CMAKE_C_COMPILER_ID MATCHES "^Intel")
         set(WARNFLAGS_MAINTAINER /W5)
         set(WARNFLAGS_DISABLE)
     endif()
-    if(WITH_NATIVE_INSTRUCTIONS)
-        message(STATUS "Ignoring WITH_NATIVE_INSTRUCTIONS; not supported on this configuration")
-        set(WITH_NATIVE_INSTRUCTIONS OFF)
-    endif()
 elseif(MSVC)
     # Minimum supported MSVC version is 1800 = Visual Studio 12.0/2013
     # See also https://cmake.org/cmake/help/latest/variable/MSVC_VERSION.html
@@ -190,23 +186,13 @@ elseif(MSVC)
         if(NOT "${ARCH}" MATCHES "aarch64")
             set(NEONFLAG "/arch:VFPv4")
         endif()
-        endif()
-    if(WITH_NATIVE_INSTRUCTIONS)
-        message(STATUS "Ignoring WITH_NATIVE_INSTRUCTIONS; not supported on this configuration")
-        set(WITH_NATIVE_INSTRUCTIONS OFF)
     endif()
 elseif(CMAKE_C_COMPILER_ID MATCHES "GNU" OR CMAKE_C_COMPILER_ID MATCHES "Clang")
     # Enable warnings in GCC and Clang
     set(WARNFLAGS -Wall)
     set(WARNFLAGS_MAINTAINER -Wextra)
     set(WARNFLAGS_DISABLE)
-    if(WITH_NATIVE_INSTRUCTIONS)
-        if(BASEARCH_PPC_FOUND)
-            set(NATIVEFLAG "-mcpu=native")
-        else()
-            set(NATIVEFLAG "-march=native")
-        endif()
-    else()
+    if(NOT WITH_NATIVE_INSTRUCTIONS)
         if(BASEARCH_ARM_FOUND)
             if("${ARCH}" MATCHES "arm" AND NOT CMAKE_C_FLAGS MATCHES "-mfloat-abi")
                 # Auto-detect support for ARM floating point ABI
@@ -252,14 +238,25 @@ elseif(CMAKE_C_COMPILER_ID MATCHES "GNU" OR CMAKE_C_COMPILER_ID MATCHES "Clang")
     if(MINGW)
         list(APPEND WARNFLAGS_DISABLE -Wno-pedantic-ms-format)
     endif()
-else()
-    if(WITH_NATIVE_INSTRUCTIONS)
+endif()
+
+# Set native march/mcpu
+if(WITH_NATIVE_INSTRUCTIONS)
+    if(CMAKE_C_COMPILER_ID MATCHES "GNU" OR CMAKE_C_COMPILER_ID MATCHES "Clang")
+        if(BASEARCH_PPC_FOUND)
+            set(NATIVEFLAG "-mcpu=native")
+        else()
+            set(NATIVEFLAG "-march=native")
+        endif()
+        # Apply flag to all source files and compilation checks
+        add_compile_options(${NATIVEFLAG})
+    else()
         message(STATUS "Ignoring WITH_NATIVE_INSTRUCTIONS; not implemented yet on this configuration")
         set(WITH_NATIVE_INSTRUCTIONS OFF)
     endif()
 endif()
 
-# Disable LTO
+# Force disable LTO if WITH_NATIVE_INSTRUCTIONS is not active
 if(NOT WITH_NATIVE_INSTRUCTIONS)
     set(CMAKE_INTERPROCEDURAL_OPTIMIZATION OFF)
     foreach(_cfg_name IN LISTS CMAKE_CONFIGURATION_TYPES)
@@ -292,12 +289,6 @@ if(NOT WITH_CODE_COVERAGE AND NOT MSVC AND NOT CMAKE_C_FLAGS MATCHES "([\\/\\-]O
         CMAKE_C_FLAGS_RELEASE "${CMAKE_C_FLAGS_RELEASE}")
 endif()
 
-# Set native instruction set compiler flag
-if(WITH_NATIVE_INSTRUCTIONS AND DEFINED NATIVEFLAG)
-    # Apply flag to all source files and compilation checks
-    add_compile_options(${NATIVEFLAG})
-endif()
-
 #
 # Check for standard/system includes
 #