buildlib: Use -msse if the compiler does not support target(sse)

Some older compilers (eg gcc 4.7) support the attribute syntax, but don't allow use of the xmmintrin.h header file. Instead they require full modules to be compiled with the -msse flag. Detect this and provide the flag if required. Cc: [email protected] # v15 Signed-off-by: Nicolas Morey-Chaisemartin <[email protected]> Signed-off-by: Jason Gunthorpe <[email protected]> # Conflicts: # CMakeLists.txt # buildlib/RDMA_EnableCStd.cmake
linux-rdma · Jun 11, 2018 · c880199 · c880199
1 parent 7bdca36
commit c880199
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Showing 3 changed files with 49 additions and 0 deletions.
diff --git a/CMakeLists.txt b/CMakeLists.txt
@@ -256,6 +256,8 @@ if (NOT HAVE_SPARSE)
   RDMA_DoFixup("${HAVE_STDATOMIC}" "stdatomic.h")
 endif()
 
+RDMA_Check_SSE(HAVE_TARGET_SSE)
+
 # Enable development support features
 # Prune unneeded shared libraries during linking
 RDMA_AddOptLDFlag(CMAKE_EXE_LINKER_FLAGS SUPPORTS_AS_NEEDED "-Wl,--as-needed")
@@ -524,3 +526,6 @@ endif()
 if (NOT HAVE_C_WREDUNDANT_DECLS)
   message(STATUS " -Wredundant-decls does NOT work")
 endif()
+if (NOT HAVE_TARGET_SSE)
+  message(STATUS " attribute(target(\"sse\")) does NOT work")
+endif()
diff --git a/buildlib/RDMA_EnableCStd.cmake b/buildlib/RDMA_EnableCStd.cmake
@@ -55,3 +55,46 @@ function(RDMA_EnableCStd)
     set(CMAKE_C_STANDARD 11 PARENT_SCOPE)
   endif()
 endfunction()
+
+function(RDMA_Check_SSE TO_VAR)
+  set(SSE_CHECK_PROGRAM "
+    #include <string.h>
+    #if defined(__i386__)
+      #include <xmmintrin.h>
+    #endif
+    int __attribute__((target(\"sse\"))) main(int argc, char *argv[])
+    {
+        int ret = 0;
+
+        #if defined(__i386__)
+	__m128 tmp = {};
+	tmp = _mm_loadl_pi(tmp, (__m64 *)&main);
+	_mm_storel_pi((__m64 *)&main, tmp);
+        ret = memchr(&tmp, 0, sizeof(tmp)) == &tmp;
+        #endif
+        return ret;
+    }")
+
+  CHECK_C_SOURCE_COMPILES(
+    "${SSE_CHECK_PROGRAM}"
+    HAVE_TARGET_SSE
+    FAIL_REGEX "warning")
+
+  if(NOT HAVE_TARGET_SSE)
+    # Older compiler, we can work around this by adding -msse instead of
+    # relying on the function attribute.
+    set(CMAKE_REQUIRED_FLAGS "-msse")
+    CHECK_C_SOURCE_COMPILES(
+      "${SSE_CHECK_PROGRAM}"
+      NEED_MSSE_FLAG
+      FAIL_REGEX "warning")
+    set(CMAKE_REQUIRED_FLAGS)
+
+    if(NEED_MSSE_FLAG)
+      set(SSE_FLAGS "-msse" PARENT_SCOPE)
+    else()
+      message(FATAL_ERROR "Can not figure out how to turn on sse instructions for i386")
+    endif()
+  endif()
+  set(${TO_VAR} "${HAVE_TARGET_SSE}" PARENT_SCOPE)
+endFunction()
diff --git a/util/CMakeLists.txt b/util/CMakeLists.txt
@@ -16,6 +16,7 @@ if (HAVE_COHERENT_DMA)
   set(C_FILES ${C_FILES}
     mmio.c
     )
+  set_source_files_properties(mmio.c PROPERTIES COMPILE_FLAGS "${SSE_FLAGS}")
 endif()
 
 add_library(rdma_util STATIC ${C_FILES})
-Original file line number
+Diff line change
@@ Expand Up / @@ -16,6 +16,7 @@ if (HAVE_COHERENT_DMA) @@
       set(C_FILES ${C_FILES}
         mmio.c
         )
+      set_source_files_properties(mmio.c PROPERTIES COMPILE_FLAGS "${SSE_FLAGS}")
     endif()
     add_library(rdma_util STATIC ${C_FILES})
@@ Expand Down @@