[ARM] Predicate UMAAL selection on hasDSP.

UMAAL is a DSP instruction and it is not available on thumbv7m
(Cortex-M3) and thumbv6m (Cortex-M0+1) targets. Also fix wrong
CHECK prefix in longMAC.ll test.

Patch by Vadzim Dambrouski.

Differential Revision: https://reviews.llvm.org/D25890

llvm-svn: 285278
diff --git a/llvm/lib/Target/ARM/ARMISelDAGToDAG.cpp b/llvm/lib/Target/ARM/ARMISelDAGToDAG.cpp
index d818030..89dcffc 100644
--- a/llvm/lib/Target/ARM/ARMISelDAGToDAG.cpp
+++ b/llvm/lib/Target/ARM/ARMISelDAGToDAG.cpp
@@ -2992,7 +2992,8 @@
   case ARMISD::UMLAL:{
     // UMAAL is similar to UMLAL but it adds two 32-bit values to the
     // 64-bit multiplication result.
-    if (Subtarget->hasV6Ops() && N->getOperand(2).getOpcode() == ARMISD::ADDC &&
+    if (Subtarget->hasV6Ops() && Subtarget->hasDSP() &&
+        N->getOperand(2).getOpcode() == ARMISD::ADDC &&
         N->getOperand(3).getOpcode() == ARMISD::ADDE) {
 
       SDValue Addc = N->getOperand(2);