1 files changed, 55 insertions, 0 deletions

diff --git a/llvm/lib/IR/AutoUpgrade.cpp b/llvm/lib/IR/AutoUpgrade.cpp
index 12c354c89b2..c83313fa654 100644
--- a/llvm/lib/IR/AutoUpgrade.cpp
+++ b/llvm/lib/IR/AutoUpgrade.cpp
@@ -144,6 +144,36 @@ static bool UpgradeIntrinsicFunction1(Function *F, Function *&NewFn) {
     }
     break;
   }
+  case 'm': {
+    if (Name.startswith("memcpy.") && F->arg_size() == 5) {
+      F->setName(Name + ".old");
+      // Get the types of dest, src, and len.
+      ArrayRef<Type *> ParamTypes = F->getFunctionType()->params().slice(0, 3);
+      NewFn = Intrinsic::getDeclaration(F->getParent(), Intrinsic::memcpy,
+                                        ParamTypes);
+      return true;
+    }
+    if (Name.startswith("memmove.") && F->arg_size() == 5) {
+      F->setName(Name + ".old");
+      // Get the types of dest, src, and len.
+      ArrayRef<Type *> ParamTypes = F->getFunctionType()->params().slice(0, 3);
+      NewFn = Intrinsic::getDeclaration(F->getParent(), Intrinsic::memmove,
+                                        ParamTypes);
+      return true;
+    }
+    if (Name.startswith("memset.") && F->arg_size() == 5) {
+      F->setName(Name + ".old");
+      // Get the types of dest and len.
+      Type *ParamTypes[2] = {
+        F->getFunctionType()->getParamType(0),
+        F->getFunctionType()->getParamType(2)
+      };
+      NewFn = Intrinsic::getDeclaration(F->getParent(), Intrinsic::memset,
+                                        ParamTypes);
+      return true;
+    }
+    break;
+  }
 
   case 'o':
     // We only need to change the name to match the mangling including the
@@ -727,6 +757,31 @@ void llvm::UpgradeIntrinsicCall(CallInst *CI, Function *NewFn) {
     CI->eraseFromParent();
     return;
 
+  case Intrinsic::memcpy:
+  case Intrinsic::memmove:
+  case Intrinsic::memset: {
+    // Remove alignment argument (3), and add alignment attributes to the
+    // dest/src pointers.
+    Value *Args[4] = {
+      CI->getArgOperand(0),
+      CI->getArgOperand(1),
+      CI->getArgOperand(2),
+      CI->getArgOperand(4)
+    };
+    auto *MemCI = cast<MemIntrinsic>(Builder.CreateCall(NewFn, Args, Name));
+
+    // All mem intrinsics support dest alignment.
+    const ConstantInt *Align = cast<ConstantInt>(CI->getArgOperand(3));
+    MemCI->setDestAlignment(Align->getZExtValue());
+
+    // Memcpy/Memmove also support source alignment.
+    if (auto *MemTransferI = dyn_cast<MemTransferInst>(MemCI))
+      MemTransferI->setSrcAlignment(Align->getZExtValue());
+    CI->replaceAllUsesWith(MemCI);
+    CI->eraseFromParent();
+    return;
+  }
+
   case Intrinsic::objectsize:
     CI->replaceAllUsesWith(Builder.CreateCall(
         NewFn, {CI->getArgOperand(0), CI->getArgOperand(1)}, Name));