[ARM]Fix an assertion failure in A15SDOptimizer about DPair reg class by treating DPair as QPR.

llvm-svn: 204304

1 files changed, 9 insertions, 3 deletions

diff --git a/llvm/lib/Target/ARM/A15SDOptimizer.cpp b/llvm/lib/Target/ARM/A15SDOptimizer.cpp
index 8edf00a..37bf903 100644
--- a/llvm/lib/Target/ARM/A15SDOptimizer.cpp
+++ b/llvm/lib/Target/ARM/A15SDOptimizer.cpp
@@ -416,7 +416,8 @@ SmallVector<unsigned, 8> A15SDOptimizer::getReadDPRs(MachineInstr *MI) {
     if (!MO.isReg() || !MO.isUse())
       continue;
     if (!usesRegClass(MO, &ARM::DPRRegClass) &&
-        !usesRegClass(MO, &ARM::QPRRegClass))
+        !usesRegClass(MO, &ARM::QPRRegClass) &&
+        !usesRegClass(MO, &ARM::DPairRegClass)) // Treat DPair as QPR
       continue;
 
     Defs.push_back(MO.getReg());
@@ -536,7 +537,10 @@ A15SDOptimizer::optimizeAllLanesPattern(MachineInstr *MI, unsigned Reg) {
   InsertPt++;
   unsigned Out;
 
-  if (MRI->getRegClass(Reg)->hasSuperClassEq(&ARM::QPRRegClass)) {
+  // DPair has the same length as QPR and also has two DPRs as subreg.
+  // Treat DPair as QPR.
+  if (MRI->getRegClass(Reg)->hasSuperClassEq(&ARM::QPRRegClass) ||
+      MRI->getRegClass(Reg)->hasSuperClassEq(&ARM::DPairRegClass)) {
     unsigned DSub0 = createExtractSubreg(MBB, InsertPt, DL, Reg,
                                          ARM::dsub_0, &ARM::DPRRegClass);
     unsigned DSub1 = createExtractSubreg(MBB, InsertPt, DL, Reg,
@@ -569,7 +573,9 @@ A15SDOptimizer::optimizeAllLanesPattern(MachineInstr *MI, unsigned Reg) {
       default: llvm_unreachable("Unknown preferred lane!");
     }
 
-    bool UsesQPR = usesRegClass(MI->getOperand(0), &ARM::QPRRegClass);
+    // Treat DPair as QPR
+    bool UsesQPR = usesRegClass(MI->getOperand(0), &ARM::QPRRegClass) ||
+                   usesRegClass(MI->getOperand(0), &ARM::DPairRegClass);
 
     Out = createImplicitDef(MBB, InsertPt, DL);
     Out = createInsertSubreg(MBB, InsertPt, DL, Out, PrefLane, Reg);