[IA] Fix crash when dealing with deinterleave(interleave)

Having a sequence of `deinterleave2(interleave2)` causes a crash due to
recent change that expects `getMaskOperand` to only work with load or
store intrinsics.
The change relaxes this and moves `llvm_unreachables` into lowering of
interleaved loads or stores

Author: npanchen

llvm/lib/CodeGen/InterleavedAccessPass.cpp

@@ -256,7 +256,7 @@ static bool isReInterleaveMask(ShuffleVectorInst *SVI, unsigned &Factor,
 static Value *getMaskOperand(IntrinsicInst *II) {
   switch (II->getIntrinsicID()) {
   default:
-    llvm_unreachable("Unexpected intrinsic");
+    return nullptr;
   case Intrinsic::vp_load:
     return II->getOperand(1);
   case Intrinsic::masked_load:
@@ -382,8 +382,11 @@ bool InterleavedAccessImpl::lowerInterleavedLoad(
   if (LI) {
     LLVM_DEBUG(dbgs() << "IA: Found an interleaved load: " << *Load << "\n");
   } else {
+    Value *MaskOperand = getMaskOperand(II);
+    if (!MaskOperand)
+      llvm_unreachable("unsupported intrinsic");
     // Check mask operand. Handle both all-true/false and interleaved mask.
-    Mask = getMask(getMaskOperand(II), Factor, VecTy);
+    Mask = getMask(MaskOperand, Factor, VecTy);
     if (!Mask)
       return false;
 
@@ -534,10 +537,12 @@ bool InterleavedAccessImpl::lowerInterleavedStore(
   if (SI) {
     LLVM_DEBUG(dbgs() << "IA: Found an interleaved store: " << *Store << "\n");
   } else {
+    Value *MaskOperand = getMaskOperand(II);
+    if (!MaskOperand)
+      llvm_unreachable("unsupported intrinsic");
     // Check mask operand. Handle both all-true/false and interleaved mask.
     unsigned LaneMaskLen = NumStoredElements / Factor;
-    Mask = getMask(getMaskOperand(II), Factor,
-                   ElementCount::getFixed(LaneMaskLen));
+    Mask = getMask(MaskOperand, Factor, ElementCount::getFixed(LaneMaskLen));
     if (!Mask)
       return false;
 
@@ -634,9 +639,12 @@ bool InterleavedAccessImpl::lowerDeinterleaveIntrinsic(
                       << " and factor = " << Factor << "\n");
   } else {
     assert(II);
+    Value *MaskOperand = getMaskOperand(II);
+    if (!MaskOperand)
+      return false;
 
     // Check mask operand. Handle both all-true/false and interleaved mask.
-    Mask = getMask(getMaskOperand(II), Factor, getDeinterleavedVectorType(DI));
+    Mask = getMask(MaskOperand, Factor, getDeinterleavedVectorType(DI));
     if (!Mask)
       return false;
 
@@ -673,8 +681,11 @@ bool InterleavedAccessImpl::lowerInterleaveIntrinsic(
 
   Value *Mask = nullptr;
   if (II) {
+    Value *MaskOperand = getMaskOperand(II);
+    if (!MaskOperand)
+      return false;
     // Check mask operand. Handle both all-true/false and interleaved mask.
-    Mask = getMask(getMaskOperand(II), Factor,
+    Mask = getMask(MaskOperand, Factor,
                    cast<VectorType>(InterleaveValues[0]->getType()));
     if (!Mask)
       return false;

llvm/test/CodeGen/X86/x86-interleaved-access.ll

@@ -1897,3 +1897,15 @@ define <2 x i64> @PR37616(ptr %a0) nounwind {
   %shuffle = shufflevector <16 x i64> %load, <16 x i64> undef, <2 x i32> <i32 2, i32 6>
   ret <2 x i64> %shuffle
 }
+
+define { <8 x float>, <8 x float> } @interleave_deinterleave2() {
+; AVX-LABEL: interleave_deinterleave2:
+; AVX:       # %bb.0: # %.entry
+; AVX-NEXT:    vxorps %xmm0, %xmm0, %xmm0
+; AVX-NEXT:    vxorps %xmm1, %xmm1, %xmm1
+; AVX-NEXT:    retq
+.entry:
+  %0 = call <16 x float> @llvm.vector.interleave2.v16f32(<8 x float> zeroinitializer, <8 x float> zeroinitializer)
+  %1 = call { <8 x float>, <8 x float> } @llvm.vector.deinterleave2.v16f32(<16 x float> %0)
+  ret { <8 x float>, <8 x float> } %1
+}