diff --git a/lib/CodeGen/RegisterCoalescer.cpp b/lib/CodeGen/RegisterCoalescer.cpp
index 11ba9ac2bd1..6770c82af3b 100644
--- a/lib/CodeGen/RegisterCoalescer.cpp
+++ b/lib/CodeGen/RegisterCoalescer.cpp
@@ -278,15 +278,6 @@ bool CoalescerPair::setRegisters(const MachineInstr *MI) {
                                          SrcIdx, DstIdx);
       if (!NewRC)
         return false;
-
-      // We cannot handle the case where both Src and Dst would be a
-      // sub-register. Yet.
-      if (SrcIdx && DstIdx) {
-        DEBUG(dbgs() << "\tCannot handle " << NewRC->getName()
-                     << " with subregs " << TRI.getSubRegIndexName(SrcIdx)
-                     << " and " << TRI.getSubRegIndexName(DstIdx) << '\n');
-        return false;
-      }
     } else if (DstSub) {
       // SrcReg will be merged with a sub-register of DstReg.
       SrcIdx = DstSub;
diff --git a/test/CodeGen/ARM/coalesce-subregs.ll b/test/CodeGen/ARM/coalesce-subregs.ll
new file mode 100644
index 00000000000..fb0f4c67c92
--- /dev/null
+++ b/test/CodeGen/ARM/coalesce-subregs.ll
@@ -0,0 +1,68 @@
+; RUN: llc < %s -mcpu=cortex-a9 | FileCheck %s
+target datalayout = "e-p:32:32:32-i1:8:32-i8:8:32-i16:16:32-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:32:64-v128:32:128-a0:0:32-n32-S32"
+target triple = "thumbv7-apple-ios0.0.0"
+
+; CHECK: f
+; The vld2 and vst2 are not aligned wrt each other, the second Q loaded is the
+; first one stored.
+; The coalescer must find a super-register larger than QQ to eliminate the copy
+; setting up the vst2 data.
+; CHECK: vld2
+; CHECK-NOT: vorr
+; CHECK-NOT: vmov
+; CHECK: vst2
+define void @f(float* %p, i32 %c) nounwind ssp {
+entry:
+  %0 = bitcast float* %p to i8*
+  %vld2 = tail call { <4 x float>, <4 x float> } @llvm.arm.neon.vld2.v4f32(i8* %0, i32 4)
+  %vld221 = extractvalue { <4 x float>, <4 x float> } %vld2, 1
+  %add.ptr = getelementptr inbounds float* %p, i32 8
+  %1 = bitcast float* %add.ptr to i8*
+  tail call void @llvm.arm.neon.vst2.v4f32(i8* %1, <4 x float> %vld221, <4 x float> undef, i32 4)
+  ret void
+}
+
+; CHECK: f1
+; FIXME: This function still has copies.
+define void @f1(float* %p, i32 %c) nounwind ssp {
+entry:
+  %0 = bitcast float* %p to i8*
+  %vld2 = tail call { <4 x float>, <4 x float> } @llvm.arm.neon.vld2.v4f32(i8* %0, i32 4)
+  %vld221 = extractvalue { <4 x float>, <4 x float> } %vld2, 1
+  %add.ptr = getelementptr inbounds float* %p, i32 8
+  %1 = bitcast float* %add.ptr to i8*
+  %vld22 = tail call { <4 x float>, <4 x float> } @llvm.arm.neon.vld2.v4f32(i8* %1, i32 4)
+  %vld2215 = extractvalue { <4 x float>, <4 x float> } %vld22, 0
+  tail call void @llvm.arm.neon.vst2.v4f32(i8* %1, <4 x float> %vld221, <4 x float> %vld2215, i32 4)
+  ret void
+}
+
+; CHECK: f2
+; FIXME: This function still has copies.
+define void @f2(float* %p, i32 %c) nounwind ssp {
+entry:
+  %0 = bitcast float* %p to i8*
+  %vld2 = tail call { <4 x float>, <4 x float> } @llvm.arm.neon.vld2.v4f32(i8* %0, i32 4)
+  %vld224 = extractvalue { <4 x float>, <4 x float> } %vld2, 1
+  br label %do.body
+
+do.body:                                          ; preds = %do.body, %entry
+  %qq0.0.1.0 = phi <4 x float> [ %vld224, %entry ], [ %vld2216, %do.body ]
+  %c.addr.0 = phi i32 [ %c, %entry ], [ %dec, %do.body ]
+  %p.addr.0 = phi float* [ %p, %entry ], [ %add.ptr, %do.body ]
+  %add.ptr = getelementptr inbounds float* %p.addr.0, i32 8
+  %1 = bitcast float* %add.ptr to i8*
+  %vld22 = tail call { <4 x float>, <4 x float> } @llvm.arm.neon.vld2.v4f32(i8* %1, i32 4)
+  %vld2215 = extractvalue { <4 x float>, <4 x float> } %vld22, 0
+  %vld2216 = extractvalue { <4 x float>, <4 x float> } %vld22, 1
+  tail call void @llvm.arm.neon.vst2.v4f32(i8* %1, <4 x float> %qq0.0.1.0, <4 x float> %vld2215, i32 4)
+  %dec = add nsw i32 %c.addr.0, -1
+  %tobool = icmp eq i32 %dec, 0
+  br i1 %tobool, label %do.end, label %do.body
+
+do.end:                                           ; preds = %do.body
+  ret void
+}
+
+declare { <4 x float>, <4 x float> } @llvm.arm.neon.vld2.v4f32(i8*, i32) nounwind readonly
+declare void @llvm.arm.neon.vst2.v4f32(i8*, <4 x float>, <4 x float>, i32) nounwind