3 files changed, 15 insertions, 2 deletions
diff --git a/llvm/lib/Transforms/IPO/ArgumentPromotion.cpp b/llvm/lib/Transforms/IPO/ArgumentPromotion.cpp
index d3a7b0e76fe..461c4e12cbd 100644
--- a/llvm/lib/Transforms/IPO/ArgumentPromotion.cpp
+++ b/llvm/lib/Transforms/IPO/ArgumentPromotion.cpp
@@ -817,6 +817,12 @@ promoteArguments(Function *F, function_ref<AAResults &(Function &F)> AARGetter,
                  unsigned MaxElements,
                  Optional<function_ref<void(CallSite OldCS, CallSite NewCS)>>
                      ReplaceCallSite) {
+  // Don't perform argument promotion for naked functions; otherwise we can end
+  // up removing parameters that are seemingly 'not used' as they are referred
+  // to in the assembly.
+  if(F->hasFnAttribute(Attribute::Naked))
+    return nullptr;
+
   // Make sure that it is local to this module.
   if (!F->hasLocalLinkage())
     return nullptr;
diff --git a/llvm/lib/Transforms/IPO/FunctionAttrs.cpp b/llvm/lib/Transforms/IPO/FunctionAttrs.cpp
index 5352e32479b..353daece48e 100644
--- a/llvm/lib/Transforms/IPO/FunctionAttrs.cpp
+++ b/llvm/lib/Transforms/IPO/FunctionAttrs.cpp
@@ -1136,7 +1136,8 @@ PreservedAnalyses PostOrderFunctionAttrsPass::run(LazyCallGraph::SCC &C,
   bool HasUnknownCall = false;
   for (LazyCallGraph::Node &N : C) {
     Function &F = N.getFunction();
-    if (F.hasFnAttribute(Attribute::OptimizeNone)) {
+    if (F.hasFnAttribute(Attribute::OptimizeNone) ||
+        F.hasFnAttribute(Attribute::Naked)) {
       // Treat any function we're trying not to optimize as if it were an
       // indirect call and omit it from the node set used below.
       HasUnknownCall = true;
@@ -1221,7 +1222,8 @@ static bool runImpl(CallGraphSCC &SCC, AARGetterT AARGetter) {
   bool ExternalNode = false;
   for (CallGraphNode *I : SCC) {
     Function *F = I->getFunction();
-    if (!F || F->hasFnAttribute(Attribute::OptimizeNone)) {
+    if (!F || F->hasFnAttribute(Attribute::OptimizeNone) ||
+        F->hasFnAttribute(Attribute::Naked)) {
       // External node or function we're trying not to optimize - we both avoid
       // transform them and avoid leveraging information they provide.
       ExternalNode = true;
diff --git a/llvm/lib/Transforms/IPO/GlobalOpt.cpp b/llvm/lib/Transforms/IPO/GlobalOpt.cpp
index 9dfb61d3d73..274ecf0a099 100644
--- a/llvm/lib/Transforms/IPO/GlobalOpt.cpp
+++ b/llvm/lib/Transforms/IPO/GlobalOpt.cpp
@@ -2221,6 +2221,11 @@ OptimizeFunctions(Module &M, TargetLibraryInfo *TLI,
   for (Module::iterator FI = M.begin(), E = M.end(); FI != E; ) {
     Function *F = &*FI++;
 
+    // Don't perform global opt pass on naked functions; we don't want fast
+    // calling conventions for naked functions.
+    if (F->hasFnAttribute(Attribute::Naked))
+      continue;
+
     // Functions without names cannot be referenced outside this module.
     if (!F->hasName() && !F->isDeclaration() && !F->hasLocalLinkage())
       F->setLinkage(GlobalValue::InternalLinkage);