1 files changed, 15 insertions, 0 deletions
diff --git a/lib/IR/InlineAsm.cpp b/lib/IR/InlineAsm.cpp
index 9f2a9fea4b..121fe1528e 100644
--- a/lib/IR/InlineAsm.cpp
+++ b/lib/IR/InlineAsm.cpp
@@ -293,3 +293,18 @@ bool InlineAsm::Verify(FunctionType *Ty, StringRef ConstStr) {
   return true;
 }
 
+// @LOCALMOD-START
+bool InlineAsm::isAsmMemory() const {
+  bool retVoid = getFunctionType()->getReturnType()->isVoidTy();
+  bool noArgs = getFunctionType()->getNumParams() == 0 &&
+      !getFunctionType()->isVarArg();
+  bool isEmptyAsm = AsmString.empty();
+  // Different triples will encode "touch everything" differently, e.g.:
+  //  - le32-unknown-nacl has "~{memory}".
+  //  - x86 "~{memory},~{dirflag},~{fpsr},~{flags}".
+  // The following code therefore only searches for memory.
+  bool touchesMemory = Constraints.find("~{memory}") != std::string::npos;
+
+  return retVoid && noArgs && hasSideEffects() && isEmptyAsm && touchesMemory;
+}
+// @LOCALMOD-END