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authorXerxes Ranby <xerxes@zafena.se>2009-07-17 19:22:41 +0000
committerXerxes Ranby <xerxes@zafena.se>2009-07-17 19:22:41 +0000
commit6215c6227e788c7c13d5d83d469e5b0019a0f1af (patch)
tree661605be3062b23c92bb284d4170f09335b6314b /cmake
parentd8aa9fc06274604eae2b5156045a71857a8f18c4 (diff)
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Implement cmake LLVM_MULTITHREADED gcc atomic builtin checks.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@76221 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'cmake')
-rwxr-xr-xcmake/config-ix.cmake3
-rw-r--r--cmake/modules/CheckAtomic.cmake18
2 files changed, 21 insertions, 0 deletions
diff --git a/cmake/config-ix.cmake b/cmake/config-ix.cmake
index 731071ef85..5833119e26 100755
--- a/cmake/config-ix.cmake
+++ b/cmake/config-ix.cmake
@@ -76,6 +76,9 @@ if( LLVM_USING_GLIBC )
add_llvm_definitions( -D_GNU_SOURCE )
endif()
+# Define LLVM_MULTITHREADED if gcc atomic builtins exists.
+include(CheckAtomic)
+
include(CheckCXXCompilerFlag)
check_cxx_compiler_flag("-fPIC" SUPPORTS_FPIC_FLAG)
diff --git a/cmake/modules/CheckAtomic.cmake b/cmake/modules/CheckAtomic.cmake
new file mode 100644
index 0000000000..27bbaba699
--- /dev/null
+++ b/cmake/modules/CheckAtomic.cmake
@@ -0,0 +1,18 @@
+# atomic builtins are required for threading support.
+
+INCLUDE(CheckCXXSourceCompiles)
+
+CHECK_CXX_SOURCE_COMPILES("
+int main() {
+ volatile unsigned long val = 1;
+ __sync_synchronize();
+ __sync_val_compare_and_swap(&val, 1, 0);
+ __sync_add_and_fetch(&val, 1);
+ __sync_sub_and_fetch(&val, 1);
+ return 0;
+ }
+" LLVM_MULTITHREADED)
+
+if( NOT LLVM_MULTITHREADED )
+ message(STATUS "Warning: LLVM will be built thread-unsafe because atomic builtins are missing")
+endif()