Extend the IL for selecting TLS models (PR9788)
This allows the user/front-end to specify a model that is better
than what LLVM would choose by default. For example, a variable
might be declared as
@x = thread_local(initialexec) global i32 42
if it will not be used in a shared library that is dlopen'ed.
If the specified model isn't supported by the target, or if LLVM can
make a better choice, a different model may be used.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159077 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Bitcode/Writer/BitcodeWriter.cpp b/lib/Bitcode/Writer/BitcodeWriter.cpp
index 333d82a..5b1725f 100644
--- a/lib/Bitcode/Writer/BitcodeWriter.cpp
+++ b/lib/Bitcode/Writer/BitcodeWriter.cpp
@@ -379,6 +379,17 @@
llvm_unreachable("Invalid visibility");
}
+static unsigned getEncodedThreadLocalMode(const GlobalVariable *GV) {
+ switch (GV->getThreadLocalMode()) {
+ case GlobalVariable::NotThreadLocal: return 0;
+ case GlobalVariable::GeneralDynamicTLSModel: return 1;
+ case GlobalVariable::LocalDynamicTLSModel: return 2;
+ case GlobalVariable::InitialExecTLSModel: return 3;
+ case GlobalVariable::LocalExecTLSModel: return 4;
+ }
+ llvm_unreachable("Invalid TLS model");
+}
+
// Emit top-level description of module, including target triple, inline asm,
// descriptors for global variables, and function prototype info.
static void WriteModuleInfo(const Module *M, const ValueEnumerator &VE,
@@ -487,7 +498,7 @@
GV->getVisibility() != GlobalValue::DefaultVisibility ||
GV->hasUnnamedAddr()) {
Vals.push_back(getEncodedVisibility(GV));
- Vals.push_back(GV->isThreadLocal());
+ Vals.push_back(getEncodedThreadLocalMode(GV));
Vals.push_back(GV->hasUnnamedAddr());
} else {
AbbrevToUse = SimpleGVarAbbrev;