1 files changed, 35 insertions, 19 deletions

diff --git a/lib/Transforms/IPO/ArgumentPromotion.cpp b/lib/Transforms/IPO/ArgumentPromotion.cpp
index b25cbcad3b9d..f2c2b55b1c5b 100644
--- a/lib/Transforms/IPO/ArgumentPromotion.cpp
+++ b/lib/Transforms/IPO/ArgumentPromotion.cpp
@@ -220,8 +220,8 @@ doPromotion(Function *F, SmallPtrSetImpl<Argument *> &ArgsToPromote,
   NF->setSubprogram(F->getSubprogram());
   F->setSubprogram(nullptr);
 
-  DEBUG(dbgs() << "ARG PROMOTION:  Promoting to:" << *NF << "\n"
-               << "From: " << *F);
+  LLVM_DEBUG(dbgs() << "ARG PROMOTION:  Promoting to:" << *NF << "\n"
+                    << "From: " << *F);
 
   // Recompute the parameter attributes list based on the new arguments for
   // the function.
@@ -426,8 +426,8 @@ doPromotion(Function *F, SmallPtrSetImpl<Argument *> &ArgsToPromote,
         I2->setName(I->getName() + ".val");
         LI->replaceAllUsesWith(&*I2);
         LI->eraseFromParent();
-        DEBUG(dbgs() << "*** Promoted load of argument '" << I->getName()
-                     << "' in function '" << F->getName() << "'\n");
+        LLVM_DEBUG(dbgs() << "*** Promoted load of argument '" << I->getName()
+                          << "' in function '" << F->getName() << "'\n");
       } else {
         GetElementPtrInst *GEP = cast<GetElementPtrInst>(I->user_back());
         IndicesVector Operands;
@@ -453,8 +453,8 @@ doPromotion(Function *F, SmallPtrSetImpl<Argument *> &ArgsToPromote,
         NewName += ".val";
         TheArg->setName(NewName);
 
-        DEBUG(dbgs() << "*** Promoted agg argument '" << TheArg->getName()
-                     << "' of function '" << NF->getName() << "'\n");
+        LLVM_DEBUG(dbgs() << "*** Promoted agg argument '" << TheArg->getName()
+                          << "' of function '" << NF->getName() << "'\n");
 
         // All of the uses must be load instructions.  Replace them all with
         // the argument specified by ArgNo.
@@ -688,11 +688,11 @@ static bool isSafeToPromoteArgument(Argument *Arg, bool isByValOrInAlloca,
     // to do.
     if (ToPromote.find(Operands) == ToPromote.end()) {
       if (MaxElements > 0 && ToPromote.size() == MaxElements) {
-        DEBUG(dbgs() << "argpromotion not promoting argument '"
-                     << Arg->getName()
-                     << "' because it would require adding more "
-                     << "than " << MaxElements
-                     << " arguments to the function.\n");
+        LLVM_DEBUG(dbgs() << "argpromotion not promoting argument '"
+                          << Arg->getName()
+                          << "' because it would require adding more "
+                          << "than " << MaxElements
+                          << " arguments to the function.\n");
         // We limit aggregate promotion to only promoting up to a fixed number
         // of elements of the aggregate.
         return false;
@@ -738,7 +738,7 @@ static bool isSafeToPromoteArgument(Argument *Arg, bool isByValOrInAlloca,
   return true;
 }
 
-/// \brief Checks if a type could have padding bytes.
+/// Checks if a type could have padding bytes.
 static bool isDenselyPacked(Type *type, const DataLayout &DL) {
   // There is no size information, so be conservative.
   if (!type->isSized())
@@ -772,7 +772,7 @@ static bool isDenselyPacked(Type *type, const DataLayout &DL) {
   return true;
 }
 
-/// \brief Checks if the padding bytes of an argument could be accessed.
+/// Checks if the padding bytes of an argument could be accessed.
 static bool canPaddingBeAccessed(Argument *arg) {
   assert(arg->hasByValAttr());
 
@@ -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;
@@ -847,10 +853,20 @@ promoteArguments(Function *F, function_ref<AAResults &(Function &F)> AARGetter,
     if (CS.getInstruction() == nullptr || !CS.isCallee(&U))
       return nullptr;
 
+    // Can't change signature of musttail callee
+    if (CS.isMustTailCall())
+      return nullptr;
+
     if (CS.getInstruction()->getParent()->getParent() == F)
       isSelfRecursive = true;
   }
 
+  // Can't change signature of musttail caller
+  // FIXME: Support promoting whole chain of musttail functions
+  for (BasicBlock &BB : *F)
+    if (BB.getTerminatingMustTailCall())
+      return nullptr;
+
   const DataLayout &DL = F->getParent()->getDataLayout();
 
   AAResults &AAR = AARGetter(*F);
@@ -885,11 +901,11 @@ promoteArguments(Function *F, function_ref<AAResults &(Function &F)> AARGetter,
     if (isSafeToPromote) {
       if (StructType *STy = dyn_cast<StructType>(AgTy)) {
         if (MaxElements > 0 && STy->getNumElements() > MaxElements) {
-          DEBUG(dbgs() << "argpromotion disable promoting argument '"
-                       << PtrArg->getName()
-                       << "' because it would require adding more"
-                       << " than " << MaxElements
-                       << " arguments to the function.\n");
+          LLVM_DEBUG(dbgs() << "argpromotion disable promoting argument '"
+                            << PtrArg->getName()
+                            << "' because it would require adding more"
+                            << " than " << MaxElements
+                            << " arguments to the function.\n");
           continue;
         }
 
@@ -963,7 +979,7 @@ PreservedAnalyses ArgumentPromotionPass::run(LazyCallGraph::SCC &C,
         return FAM.getResult<AAManager>(F);
       };
 
-      Function *NewF = promoteArguments(&OldF, AARGetter, 3u, None);
+      Function *NewF = promoteArguments(&OldF, AARGetter, MaxElements, None);
       if (!NewF)
         continue;
       LocalChange = true;