[PATCH] CFE Knob for: Add a thread-model knob for lowering atomics on baremetal & single threaded systems

[David Majnemer]

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Comment at: lib/CodeGen/BackendUtil.cpp:422-429
@@ -421,1 +421,10 @@
 
+  if (CodeGenOpts.ThreadModel == "posix")
+    Options.ThreadModel = llvm::ThreadModel::POSIX;
+  else if (CodeGenOpts.ThreadModel == "single")
+    Options.ThreadModel = llvm::ThreadModel::Single;
+  else {
+    assert(false && "Invalid Thread model!");
+    Options.ThreadModel = llvm::ThreadModel::POSIX;
+  }
+
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You may want to consider using LLVM's [[ http://llvm.org/docs/doxygen/html/classllvm_1_1StringSwitch.html#details | StringSwitch ]] here.

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Comment at: lib/CodeGen/BackendUtil.cpp:427
@@ +426,3 @@
+  else {
+    assert(false && "Invalid Thread model!");
+    Options.ThreadModel = llvm::ThreadModel::POSIX;
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This assertion doesn't look too useful.

http://reviews.llvm.org/D4985