Index: lib/Transforms/Instrumentation/AddressSanitizer.cpp
===================================================================
--- lib/Transforms/Instrumentation/AddressSanitizer.cpp
+++ lib/Transforms/Instrumentation/AddressSanitizer.cpp
@@ -326,9 +326,6 @@
                                  bool IsWrite, size_t AccessSizeIndex,
                                  Value *SizeArgument);
   void instrumentMemIntrinsic(MemIntrinsic *MI);
-  void instrumentMemIntrinsicParam(Instruction *OrigIns, Value *Addr,
-                                   Value *Size, Instruction *InsertBefore,
-                                   bool IsWrite, bool UseCalls);
   Value *memToShadow(Value *Shadow, IRBuilder<> &IRB);
   bool runOnFunction(Function &F) override;
   bool maybeInsertAsanInitAtFunctionEntry(Function &F);
@@ -603,24 +600,6 @@
     return IRB.CreateAdd(Shadow, ConstantInt::get(IntptrTy, Mapping.Offset));
 }
 
-void AddressSanitizer::instrumentMemIntrinsicParam(Instruction *OrigIns,
-                                                   Value *Addr, Value *Size,
-                                                   Instruction *InsertBefore,
-                                                   bool IsWrite,
-                                                   bool UseCalls) {
-  IRBuilder<> IRB(InsertBefore);
-  if (Size->getType() != IntptrTy)
-    Size = IRB.CreateIntCast(Size, IntptrTy, false);
-  // Check the first byte.
-  instrumentAddress(OrigIns, InsertBefore, Addr, 8, IsWrite, Size, false);
-  // Check the last byte.
-  IRB.SetInsertPoint(InsertBefore);
-  Value *SizeMinusOne = IRB.CreateSub(Size, ConstantInt::get(IntptrTy, 1));
-  Value *AddrLong = IRB.CreatePointerCast(Addr, IntptrTy);
-  Value *AddrLast = IRB.CreateAdd(AddrLong, SizeMinusOne);
-  instrumentAddress(OrigIns, InsertBefore, AddrLast, 8, IsWrite, Size, false);
-}
-
 // Instrument memset/memmove/memcpy
 void AddressSanitizer::instrumentMemIntrinsic(MemIntrinsic *MI) {
   IRBuilder<> IRB(MI);
@@ -756,13 +735,20 @@
   // and the last bytes. We call __asan_report_*_n(addr, real_size) to be able
   // to report the actual access size.
   IRBuilder<> IRB(I);
-  Value *LastByte =  IRB.CreateIntToPtr(
-      IRB.CreateAdd(IRB.CreatePointerCast(Addr, IntptrTy),
-                    ConstantInt::get(IntptrTy, TypeSize / 8 - 1)),
-      OrigPtrTy);
   Value *Size = ConstantInt::get(IntptrTy, TypeSize / 8);
-  instrumentAddress(I, I, Addr, 8, IsWrite, Size, false);
-  instrumentAddress(I, I, LastByte, 8, IsWrite, Size, false);
+  Value *AddrLong = IRB.CreatePointerCast(Addr, IntptrTy);
+  if (UseCalls) {
+    CallInst *Check = IRB.CreateCall2(
+        AsanMemoryAccessCallbackSized[IsWrite], AddrLong, Size);
+    Check->setDebugLoc(I->getDebugLoc());
+  } else {
+    Value *LastByte =  IRB.CreateIntToPtr(
+        IRB.CreateAdd(AddrLong,
+                      ConstantInt::get(IntptrTy, TypeSize / 8 - 1)),
+        OrigPtrTy);
+    instrumentAddress(I, I, Addr, 8, IsWrite, Size, false);
+    instrumentAddress(I, I, LastByte, 8, IsWrite, Size, false);
+  }
 }
 
 // Validate the result of Module::getOrInsertFunction called for an interface
Index: test/Instrumentation/AddressSanitizer/instrumentation-with-call-threshold.ll
===================================================================
--- test/Instrumentation/AddressSanitizer/instrumentation-with-call-threshold.ll
+++ test/Instrumentation/AddressSanitizer/instrumentation-with-call-threshold.ll
@@ -10,15 +10,18 @@
 target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64"
 target triple = "x86_64-unknown-linux-gnu"
 
-define void @test_load(i32* %a, i64* %b) sanitize_address {
+define void @test_load(i32* %a, i64* %b, i512* %c) sanitize_address {
 entry:
 ; CHECK-CALL: call void @__asan_load4
 ; CHECK-CALL: call void @__asan_load8
+; CHECK-CALL: call void @__asan_loadN
 ; CHECK-CUSTOM-PREFIX: call void @__foo_load4
 ; CHECK-CUSTOM-PREFIX: call void @__foo_load8
+; CHECK-CUSTOM-PREFIX: call void @__foo_loadN
 ; CHECK-INLINE-NOT: call void @__asan_load
   %tmp1 = load i32* %a
   %tmp2 = load i64* %b
+  %tmp3 = load i512* %c
   ret void
 }