diff --git a/llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp b/llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp
--- a/llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp
+++ b/llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp
@@ -673,7 +673,12 @@
         LI->getParent() == SI->getParent()) {
 
       auto *T = LI->getType();
-      if (T->isAggregateType()) {
+      // Don't introduce calls to memcpy/memmove intrinsics out of thin air if
+      // the corresponding libcalls are not available.
+      // TODO: We should really distinguish between libcall availability and
+      // our ability to introduce intrinsics.
+      if (T->isAggregateType() && TLI->has(LibFunc_memcpy) &&
+          TLI->has(LibFunc_memmove)) {
         MemoryLocation LoadLoc = MemoryLocation::get(LI);
 
         // We use alias analysis to check if an instruction may store to
@@ -796,6 +801,13 @@
     }
   }
 
+  // The following code creates memset intrinsics out of thin air. Don't do
+  // this if the corresponding libfunc is not available.
+  // TODO: We should really distinguish between libcall availability and
+  // our ability to introduce intrinsics.
+  if (!TLI->has(LibFunc_memset))
+    return false;
+
   // There are two cases that are interesting for this code to handle: memcpy
   // and memset.  Right now we only handle memset.
 
@@ -1548,9 +1560,6 @@
 /// Transforms memmove calls to memcpy calls when the src/dst are guaranteed
 /// not to alias.
 bool MemCpyOptPass::processMemMove(MemMoveInst *M) {
-  if (!TLI->has(LibFunc_memmove))
-    return false;
-
   // See if the pointers alias.
   if (!AA->isNoAlias(MemoryLocation::getForDest(M),
                      MemoryLocation::getForSource(M)))
@@ -1754,11 +1763,6 @@
   MSSA = MSSA_;
   MemorySSAUpdater MSSAU_(MSSA_);
   MSSAU = MSSA_ ? &MSSAU_ : nullptr;
-  // If we don't have at least memset and memcpy, there is little point of doing
-  // anything here.  These are required by a freestanding implementation, so if
-  // even they are disabled, there is no point in trying hard.
-  if (!TLI->has(LibFunc_memset) || !TLI->has(LibFunc_memcpy))
-    return false;
 
   while (true) {
     if (!iterateOnFunction(F))
diff --git a/llvm/test/Transforms/MemCpyOpt/no-libcalls.ll b/llvm/test/Transforms/MemCpyOpt/no-libcalls.ll
new file mode 100644
--- /dev/null
+++ b/llvm/test/Transforms/MemCpyOpt/no-libcalls.ll
@@ -0,0 +1,63 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt -S -memcpyopt < %s | FileCheck %s --check-prefixes=CHECK,LIBCALLS
+; RUN: opt -S -memcpyopt -mtriple=amdgcn-- < %s | FileCheck %s --check-prefixes=CHECK,NO-LIBCALLS
+
+; REQUIRES: amdgpu-registered-target
+
+define void @dont_create_memset(ptr %p) {
+; LIBCALLS-LABEL: @dont_create_memset(
+; LIBCALLS-NEXT:    [[P1:%.*]] = getelementptr i32, ptr [[P:%.*]], i64 1
+; LIBCALLS-NEXT:    [[P2:%.*]] = getelementptr i32, ptr [[P]], i64 2
+; LIBCALLS-NEXT:    [[P3:%.*]] = getelementptr i32, ptr [[P]], i64 3
+; LIBCALLS-NEXT:    call void @llvm.memset.p0.i64(ptr align 4 [[P]], i8 0, i64 16, i1 false)
+; LIBCALLS-NEXT:    ret void
+;
+; NO-LIBCALLS-LABEL: @dont_create_memset(
+; NO-LIBCALLS-NEXT:    store i32 0, ptr [[P:%.*]], align 4
+; NO-LIBCALLS-NEXT:    [[P1:%.*]] = getelementptr i32, ptr [[P]], i64 1
+; NO-LIBCALLS-NEXT:    store i32 0, ptr [[P1]], align 4
+; NO-LIBCALLS-NEXT:    [[P2:%.*]] = getelementptr i32, ptr [[P]], i64 2
+; NO-LIBCALLS-NEXT:    store i32 0, ptr [[P2]], align 4
+; NO-LIBCALLS-NEXT:    [[P3:%.*]] = getelementptr i32, ptr [[P]], i64 3
+; NO-LIBCALLS-NEXT:    store i32 0, ptr [[P3]], align 4
+; NO-LIBCALLS-NEXT:    ret void
+;
+  store i32 0, ptr %p
+  %p1 = getelementptr i32, ptr %p, i64 1
+  store i32 0, ptr %p1
+  %p2 = getelementptr i32, ptr %p, i64 2
+  store i32 0, ptr %p2
+  %p3 = getelementptr i32, ptr %p, i64 3
+  store i32 0, ptr %p3
+  ret void
+}
+
+%ty = type { i64 }
+
+define void @dont_create_memcpy(ptr %p1, ptr %p2) {
+; LIBCALLS-LABEL: @dont_create_memcpy(
+; LIBCALLS-NEXT:    call void @llvm.memmove.p0.p0.i64(ptr align 4 [[P2:%.*]], ptr align 4 [[P1:%.*]], i64 8, i1 false)
+; LIBCALLS-NEXT:    ret void
+;
+; NO-LIBCALLS-LABEL: @dont_create_memcpy(
+; NO-LIBCALLS-NEXT:    [[V:%.*]] = load [[TY:%.*]], ptr [[P1:%.*]], align 4
+; NO-LIBCALLS-NEXT:    store [[TY]] [[V]], ptr [[P2:%.*]], align 4
+; NO-LIBCALLS-NEXT:    ret void
+;
+  %v = load %ty, ptr %p1
+  store %ty %v, ptr %p2
+  ret void
+}
+
+define void @forward_memcpy(ptr noalias %p1, ptr noalias %p2, ptr noalias %p3) {
+; CHECK-LABEL: @forward_memcpy(
+; CHECK-NEXT:    call void @llvm.memcpy.p0.p0.i64(ptr [[P2:%.*]], ptr [[P1:%.*]], i64 16, i1 false)
+; CHECK-NEXT:    call void @llvm.memcpy.p0.p0.i64(ptr [[P3:%.*]], ptr [[P1]], i64 16, i1 false)
+; CHECK-NEXT:    ret void
+;
+  call void @llvm.memcpy.p0.p0.i64(ptr %p2, ptr %p1, i64 16, i1 false)
+  call void @llvm.memcpy.p0.p0.i64(ptr %p3, ptr %p2, i64 16, i1 false)
+  ret void
+}
+
+declare void @llvm.memcpy.p0.p0.i64(ptr, ptr, i64, i1)