From ee0c8f763fe7a7c7bc2f73e01630f55eadb997cc Mon Sep 17 00:00:00 2001
From: Alex Bondarev <abondarev84@gmail.com>
Date: Tue, 13 Sep 2022 18:21:10 +0300
Subject: [PATCH] fix to correctly place the autodetected flags and to activate
 SVE options

---
 CMakeLists.txt | 52 +++++++++++++++++++++++++++++++++-----------------
 1 file changed, 35 insertions(+), 17 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 57e986c9..1283dc88 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -156,6 +156,12 @@ else()
     set(ARCH_FLAG march)
 endif()
 
+set(TUNE_FLAG "mtune")
+set(CPU_FLAG "mcpu")
+set(GNUCC_CPU "")
+set(GNUCC_TUNE "")
+message(STATUS "ARCH_FLAG '${ARCH_FLAG}' '${GNUCC_ARCH}', TUNE_FLAG '${TUNE_FLAG}' '${GNUCC_TUNE}' , CPU_FLAG '${CPU_FLAG}' '${GNUCC_CPU}'")
+
 # Detect best GNUCC_ARCH to tune for
 if (CMAKE_COMPILER_IS_GNUCC AND NOT CROSS_COMPILE)
     message(STATUS "gcc version ${CMAKE_C_COMPILER_VERSION}")
@@ -167,24 +173,47 @@ if (CMAKE_COMPILER_IS_GNUCC AND NOT CROSS_COMPILE)
 
     # arg1 might exist if using ccache
     string (STRIP "${CMAKE_C_COMPILER_ARG1}" CC_ARG1)
-    set (EXEC_ARGS ${CC_ARG1} -c -Q --help=target -${ARCH_FLAG}=native -mtune=native)
+    set (EXEC_ARGS ${CC_ARG1} -c -Q --help=target -${ARCH_FLAG}=native -mtune=native -mcpu=native)
     execute_process(COMMAND ${CMAKE_C_COMPILER} ${EXEC_ARGS}
         OUTPUT_VARIABLE _GCC_OUTPUT)
+    set(_GCC_OUTPUT_TUNE ${_GCC_OUTPUT})
+    set(_GCC_OUTPUT_CPU ${_GCC_OUTPUT})
     string(FIND "${_GCC_OUTPUT}" "${ARCH_FLAG}" POS)
     string(SUBSTRING "${_GCC_OUTPUT}" ${POS} -1 _GCC_OUTPUT)
     string(REGEX REPLACE "${ARCH_FLAG}=[ \t]*([^ \n]*)[ \n].*" "\\1" GNUCC_ARCH "${_GCC_OUTPUT}")
 
+    string(FIND "${_GCC_OUTPUT_TUNE}" "${TUNE_FLAG}" POS_TUNE)
+    string(SUBSTRING "${_GCC_OUTPUT_TUNE}" ${POS_TUNE} -1 _GCC_OUTPUT_TUNE)
+    string(REGEX REPLACE "${TUNE_FLAG}=[ \t]*([^ \n]*)[ \n].*" "\\1" GNUCC_TUNE "${_GCC_OUTPUT_TUNE}")
+
+    string(FIND "${_GCC_OUTPUT_CPU}" "${CPU_FLAG}" POS_CPU)
+    string(SUBSTRING "${_GCC_OUTPUT_CPU}" ${POS_CPU} -1 _GCC_OUTPUT_CPU)
+    string(REGEX REPLACE "${CPU_FLAG}=[ \t]*([^ \n]*)[ \n].*" "\\1" GNUCC_CPU "${_GCC_OUTPUT_CPU}")
+
+    string(FIND "${GNUCC_ARCH}" "sve" POS_SVE)
+    string(FIND "${GNUCC_ARCH}" "sve2" POS_SVE2)
+    string(FIND "${GNUCC_ARCH}" "sve2-bitperm" POS_SVE2_BITPERM)
+    if (NOT POS_SVE EQUAL 0)
+        set(BUILD_SVE 1)
+    elseif(NOT POS_SVE2 EQUAL 0)
+        set(BUILD_SVE2 1)
+    elseif(NOT POS_SVE2_BITPERM EQUAL 0)
+        set(BUILD_SVE2_BITPERM 1)
+    endif()
+
+    message(STATUS "ARCH_FLAG '${ARCH_FLAG}' '${GNUCC_ARCH}', TUNE_FLAG '${TUNE_FLAG}' '${GNUCC_TUNE}' , CPU_FLAG '${CPU_FLAG}' '${GNUCC_CPU}'")
+
     # test the parsed flag
-    set (EXEC_ARGS ${CC_ARG1} -E - -mtune=${GNUCC_ARCH})
+    set (EXEC_ARGS ${CC_ARG1} -E - -${ARCH_FLAG}=${GNUCC_ARCH} -${TUNE_FLAG}=${GNUCC_TUNE} -${CPU_FLAG}=${GNUCC_CPU})
     execute_process(COMMAND ${CMAKE_C_COMPILER} ${EXEC_ARGS}
         OUTPUT_QUIET ERROR_QUIET
         INPUT_FILE /dev/null
         RESULT_VARIABLE GNUCC_TUNE_TEST)
     if (NOT GNUCC_TUNE_TEST EQUAL 0)
         message(WARNING "Something went wrong determining gcc tune: -mtune=${GNUCC_ARCH} not valid, falling back to -mtune=native")
-        set(TUNE_FLAG native)
+        set(GNUCC_TUNE native)
     else()
-        set(TUNE_FLAG ${GNUCC_ARCH})
+        set(GNUCC_TUNE ${GNUCC_TUNE})
         message(STATUS "gcc will tune for ${GNUCC_ARCH}, ${TUNE_FLAG}")
     endif()
 elseif (CMAKE_COMPILER_IS_CLANG AND NOT CROSS_COMPILE)
@@ -225,23 +254,12 @@ if (ARCH_IA32 OR ARCH_X86_64)
     endif()
 endif()
 
-if (ARCH_AARCH64)
-    if (BUILD_SVE2_BITPERM)
-        set(GNUCC_ARCH "${GNUCC_ARCH}+sve2-bitperm")
-    elseif (BUILD_SVE2)
-        set(GNUCC_ARCH "${GNUCC_ARCH}+sve2")
-    elseif (BUILD_SVE)
-        set(GNUCC_ARCH "${GNUCC_ARCH}+sve")
-    endif ()
-endif(ARCH_AARCH64)
-
-
 message(STATUS "ARCH_C_FLAGS   : ${ARCH_C_FLAGS}")
 message(STATUS "ARCH_CXX_FLAGS : ${ARCH_CXX_FLAGS}")
 
 if (NOT FAT_RUNTIME)
-    set(ARCH_C_FLAGS "-${ARCH_FLAG}=${GNUCC_ARCH} -mtune=${TUNE_FLAG} ${ARCH_C_FLAGS}")
-    set(ARCH_CXX_FLAGS "-${ARCH_FLAG}=${GNUCC_ARCH} -mtune=${TUNE_FLAG} ${ARCH_CXX_FLAGS}")
+    set(ARCH_C_FLAGS "-${ARCH_FLAG}=${GNUCC_ARCH} -${TUNE_FLAG}=${GNUCC_TUNE} -${CPU_FLAG}=${GNUCC_CPU} ${ARCH_C_FLAGS}")
+    set(ARCH_CXX_FLAGS "-${ARCH_FLAG}=${GNUCC_ARCH} -${TUNE_FLAG}=${GNUCC_TUNE} -${CPU_FLAG}=${GNUCC_CPU} ${ARCH_CXX_FLAGS}")
 endif()
 
 #if (ARCH_IA32 OR ARCH_X86_64 OR ARCH_ARM32 OR ARCH_AARCH64)