1 files changed, 84 insertions, 0 deletions
diff --git a/lib/Analysis/MemoryLocation.cpp b/lib/Analysis/MemoryLocation.cpp
index f87a017b9211..e4491261e055 100644
--- a/lib/Analysis/MemoryLocation.cpp
+++ b/lib/Analysis/MemoryLocation.cpp
@@ -8,6 +8,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/Analysis/MemoryLocation.h"
+#include "llvm/Analysis/TargetLibraryInfo.h"
 #include "llvm/IR/BasicBlock.h"
 #include "llvm/IR/DataLayout.h"
 #include "llvm/IR/Instructions.h"
@@ -88,3 +89,86 @@ MemoryLocation MemoryLocation::getForDest(const MemIntrinsic *MTI) {
 
   return MemoryLocation(MTI->getRawDest(), Size, AATags);
 }
+
+// FIXME: This code is duplicated with BasicAliasAnalysis and should be hoisted
+// to some common utility location.
+static bool isMemsetPattern16(const Function *MS,
+                              const TargetLibraryInfo &TLI) {
+  if (TLI.has(LibFunc::memset_pattern16) &&
+      MS->getName() == "memset_pattern16") {
+    FunctionType *MemsetType = MS->getFunctionType();
+    if (!MemsetType->isVarArg() && MemsetType->getNumParams() == 3 &&
+        isa<PointerType>(MemsetType->getParamType(0)) &&
+        isa<PointerType>(MemsetType->getParamType(1)) &&
+        isa<IntegerType>(MemsetType->getParamType(2)))
+      return true;
+  }
+
+  return false;
+}
+
+MemoryLocation MemoryLocation::getForArgument(ImmutableCallSite CS,
+                                              unsigned ArgIdx,
+                                              const TargetLibraryInfo &TLI) {
+  AAMDNodes AATags;
+  CS->getAAMetadata(AATags);
+  const Value *Arg = CS.getArgument(ArgIdx);
+
+  // We may be able to produce an exact size for known intrinsics.
+  if (const IntrinsicInst *II = dyn_cast<IntrinsicInst>(CS.getInstruction())) {
+    const DataLayout &DL = II->getModule()->getDataLayout();
+
+    switch (II->getIntrinsicID()) {
+    default:
+      break;
+    case Intrinsic::memset:
+    case Intrinsic::memcpy:
+    case Intrinsic::memmove:
+      assert((ArgIdx == 0 || ArgIdx == 1) &&
+             "Invalid argument index for memory intrinsic");
+      if (ConstantInt *LenCI = dyn_cast<ConstantInt>(II->getArgOperand(2)))
+        return MemoryLocation(Arg, LenCI->getZExtValue(), AATags);
+      break;
+
+    case Intrinsic::lifetime_start:
+    case Intrinsic::lifetime_end:
+    case Intrinsic::invariant_start:
+      assert(ArgIdx == 1 && "Invalid argument index");
+      return MemoryLocation(
+          Arg, cast<ConstantInt>(II->getArgOperand(0))->getZExtValue(), AATags);
+
+    case Intrinsic::invariant_end:
+      assert(ArgIdx == 2 && "Invalid argument index");
+      return MemoryLocation(
+          Arg, cast<ConstantInt>(II->getArgOperand(1))->getZExtValue(), AATags);
+
+    case Intrinsic::arm_neon_vld1:
+      assert(ArgIdx == 0 && "Invalid argument index");
+      // LLVM's vld1 and vst1 intrinsics currently only support a single
+      // vector register.
+      return MemoryLocation(Arg, DL.getTypeStoreSize(II->getType()), AATags);
+
+    case Intrinsic::arm_neon_vst1:
+      assert(ArgIdx == 0 && "Invalid argument index");
+      return MemoryLocation(
+          Arg, DL.getTypeStoreSize(II->getArgOperand(1)->getType()), AATags);
+    }
+  }
+
+  // We can bound the aliasing properties of memset_pattern16 just as we can
+  // for memcpy/memset.  This is particularly important because the
+  // LoopIdiomRecognizer likes to turn loops into calls to memset_pattern16
+  // whenever possible.
+  if (CS.getCalledFunction() &&
+      isMemsetPattern16(CS.getCalledFunction(), TLI)) {
+    assert((ArgIdx == 0 || ArgIdx == 1) &&
+           "Invalid argument index for memset_pattern16");
+    if (ArgIdx == 1)
+      return MemoryLocation(Arg, 16, AATags);
+    if (const ConstantInt *LenCI = dyn_cast<ConstantInt>(CS.getArgument(2)))
+      return MemoryLocation(Arg, LenCI->getZExtValue(), AATags);
+  }
+  // FIXME: Handle memset_pattern4 and memset_pattern8 also.
+
+  return MemoryLocation(CS.getArgument(ArgIdx), UnknownSize, AATags);
+}