[IA] Remove recursive [de]interleaving support

Now that the loop vectorizer emits just a single llvm.vector.[de]interleaveN intrinsic, we can remove the need to recognise recursively [de]interleaved intrinsics.

No in-tree target currently has instructions to emit an interleaved access with a factor > 8, and I'm not aware of any other passes that will emit recursive interleave patterns, so this code is effectively dead.

Some tests have been converted from the recursive form to a single intrinsic, and some others were deleted that are no longer needed, e.g. to do with the recursive tree.

This closes off the work started in llvm#139893.

Author: lukel97

llvm/lib/CodeGen/InterleavedAccessPass.cpp

@@ -629,173 +629,12 @@ static unsigned getIntrinsicFactor(const IntrinsicInst *II) {
   }
 }
 
-// For an (de)interleave tree like this:
-//
-//   A   C B   D
-//   |___| |___|
-//     |_____|
-//        |
-//     A B C D
-//
-//  We will get ABCD at the end while the leaf operands/results
-//  are ACBD, which are also what we initially collected in
-//  getVectorInterleaveFactor / getVectorDeinterleaveFactor. But TLI
-//  hooks (e.g. lowerDeinterleaveIntrinsicToLoad) expect ABCD, so we need
-//  to reorder them by interleaving these values.
-static void interleaveLeafValues(MutableArrayRef<Value *> SubLeaves) {
-  unsigned NumLeaves = SubLeaves.size();
-  assert(isPowerOf2_32(NumLeaves) && NumLeaves > 1);
-  if (NumLeaves == 2)
-    return;
-
-  const unsigned HalfLeaves = NumLeaves / 2;
-  // Visit the sub-trees.
-  interleaveLeafValues(SubLeaves.take_front(HalfLeaves));
-  interleaveLeafValues(SubLeaves.drop_front(HalfLeaves));
-
-  SmallVector<Value *, 8> Buffer;
-  //    a0 a1 a2 a3 b0 b1 b2 b3
-  // -> a0 b0 a1 b1 a2 b2 a3 b3
-  for (unsigned i = 0U; i < NumLeaves; ++i)
-    Buffer.push_back(SubLeaves[i / 2 + (i % 2 ? HalfLeaves : 0)]);
-
-  llvm::copy(Buffer, SubLeaves.begin());
-}
-
-static bool
-getVectorInterleaveFactor(IntrinsicInst *II, SmallVectorImpl<Value *> &Operands,
-                          SmallVectorImpl<Instruction *> &DeadInsts) {
-  assert(isInterleaveIntrinsic(II->getIntrinsicID()));
-
-  // Visit with BFS
-  SmallVector<IntrinsicInst *, 8> Queue;
-  Queue.push_back(II);
-  while (!Queue.empty()) {
-    IntrinsicInst *Current = Queue.front();
-    Queue.erase(Queue.begin());
-
-    // All the intermediate intrinsics will be deleted.
-    DeadInsts.push_back(Current);
-
-    for (unsigned I = 0; I < getIntrinsicFactor(Current); ++I) {
-      Value *Op = Current->getOperand(I);
-      if (auto *OpII = dyn_cast<IntrinsicInst>(Op))
-        if (OpII->getIntrinsicID() == Intrinsic::vector_interleave2) {
-          Queue.push_back(OpII);
-          continue;
-        }
-
-      // If this is not a perfectly balanced tree, the leaf
-      // result types would be different.
-      if (!Operands.empty() && Op->getType() != Operands.back()->getType())
-        return false;
-
-      Operands.push_back(Op);
-    }
-  }
-
-  const unsigned Factor = Operands.size();
-  // Currently we only recognize factors 2...8 and other powers of 2.
-  // FIXME: should we assert here instead?
-  if (Factor <= 1 ||
-      (!isPowerOf2_32(Factor) && Factor != getIntrinsicFactor(II)))
-    return false;
-
-  // Recursively interleaved factors need to have their values reordered
-  // TODO: Remove once the loop vectorizer no longer recursively interleaves
-  // factors 4 + 8
-  if (isPowerOf2_32(Factor) && getIntrinsicFactor(II) == 2)
-    interleaveLeafValues(Operands);
-  return true;
-}
-
-static bool
-getVectorDeinterleaveFactor(IntrinsicInst *II,
-                            SmallVectorImpl<Value *> &Results,
-                            SmallVectorImpl<Instruction *> &DeadInsts) {
-  assert(isDeinterleaveIntrinsic(II->getIntrinsicID()));
-  using namespace PatternMatch;
-  if (!II->hasNUses(getIntrinsicFactor(II)))
-    return false;
-
-  // Visit with BFS
-  SmallVector<IntrinsicInst *, 8> Queue;
-  Queue.push_back(II);
-  while (!Queue.empty()) {
-    IntrinsicInst *Current = Queue.front();
-    Queue.erase(Queue.begin());
-    assert(Current->hasNUses(getIntrinsicFactor(Current)));
-
-    // All the intermediate intrinsics will be deleted from the bottom-up.
-    DeadInsts.insert(DeadInsts.begin(), Current);
-
-    SmallVector<ExtractValueInst *> EVs(getIntrinsicFactor(Current), nullptr);
-    for (User *Usr : Current->users()) {
-      if (!isa<ExtractValueInst>(Usr))
-        return 0;
-
-      auto *EV = cast<ExtractValueInst>(Usr);
-      // Intermediate ExtractValue instructions will also be deleted.
-      DeadInsts.insert(DeadInsts.begin(), EV);
-      ArrayRef<unsigned> Indices = EV->getIndices();
-      if (Indices.size() != 1)
-        return false;
-
-      if (!EVs[Indices[0]])
-        EVs[Indices[0]] = EV;
-      else
-        return false;
-    }
-
-    // We have legal indices. At this point we're either going
-    // to continue the traversal or push the leaf values into Results.
-    for (ExtractValueInst *EV : EVs) {
-      // Continue the traversal. We're playing safe here and matching only the
-      // expression consisting of a perfectly balanced binary tree in which all
-      // intermediate values are only used once.
-      if (EV->hasOneUse() &&
-          match(EV->user_back(),
-                m_Intrinsic<Intrinsic::vector_deinterleave2>()) &&
-          EV->user_back()->hasNUses(2)) {
-        auto *EVUsr = cast<IntrinsicInst>(EV->user_back());
-        Queue.push_back(EVUsr);
-        continue;
-      }
-
-      // If this is not a perfectly balanced tree, the leaf
-      // result types would be different.
-      if (!Results.empty() && EV->getType() != Results.back()->getType())
-        return false;
-
-      // Save the leaf value.
-      Results.push_back(EV);
-    }
-  }
-
-  const unsigned Factor = Results.size();
-  // Currently we only recognize factors of 2...8 and other powers of 2.
-  // FIXME: should we assert here instead?
-  if (Factor <= 1 ||
-      (!isPowerOf2_32(Factor) && Factor != getIntrinsicFactor(II)))
-    return 0;
-
-  // Recursively interleaved factors need to have their values reordered
-  // TODO: Remove once the loop vectorizer no longer recursively interleaves
-  // factors 4 + 8
-  if (isPowerOf2_32(Factor) && getIntrinsicFactor(II) == 2)
-    interleaveLeafValues(Results);
-  return true;
-}
-
 static Value *getMask(Value *WideMask, unsigned Factor,
                       ElementCount LeafValueEC) {
   if (auto *IMI = dyn_cast<IntrinsicInst>(WideMask)) {
-    SmallVector<Value *, 8> Operands;
-    SmallVector<Instruction *, 8> DeadInsts;
-    if (getVectorInterleaveFactor(IMI, Operands, DeadInsts)) {
-      assert(!Operands.empty());
-      if (Operands.size() == Factor && llvm::all_equal(Operands))
-        return Operands[0];
+    if (isInterleaveIntrinsic(IMI->getIntrinsicID()) &&
+        getIntrinsicFactor(IMI) == Factor && llvm::all_equal(IMI->args())) {
+      return IMI->getArgOperand(0);
     }
   }
 
@@ -830,13 +669,19 @@ bool InterleavedAccessImpl::lowerDeinterleaveIntrinsic(
   if (!LoadedVal->hasOneUse() || !isa<LoadInst, VPIntrinsic>(LoadedVal))
     return false;
 
-  SmallVector<Value *, 8> DeinterleaveValues;
-  SmallVector<Instruction *, 8> DeinterleaveDeadInsts;
-  if (!getVectorDeinterleaveFactor(DI, DeinterleaveValues,
-                                   DeinterleaveDeadInsts))
+  const unsigned Factor = getIntrinsicFactor(DI);
+  if (!DI->hasNUses(Factor))
     return false;
-
-  const unsigned Factor = DeinterleaveValues.size();
+  SmallVector<Value *, 8> DeinterleaveValues(Factor);
+  for (auto *User : DI->users()) {
+    auto *Extract = dyn_cast<ExtractValueInst>(User);
+    if (!Extract || Extract->getNumIndices() != 1)
+      return false;
+    unsigned Idx = Extract->getIndices()[0];
+    if (DeinterleaveValues[Idx])
+      return false;
+    DeinterleaveValues[Idx] = Extract;
+  }
 
   if (auto *VPLoad = dyn_cast<VPIntrinsic>(LoadedVal)) {
     if (VPLoad->getIntrinsicID() != Intrinsic::vp_load)
@@ -869,7 +714,9 @@ bool InterleavedAccessImpl::lowerDeinterleaveIntrinsic(
       return false;
   }
 
-  DeadInsts.insert_range(DeinterleaveDeadInsts);
+  for (Value *V : DeinterleaveValues)
+    DeadInsts.insert(cast<Instruction>(V));
+  DeadInsts.insert(DI);
   // We now have a target-specific load, so delete the old one.
   DeadInsts.insert(cast<Instruction>(LoadedVal));
   return true;
@@ -883,12 +730,8 @@ bool InterleavedAccessImpl::lowerInterleaveIntrinsic(
   if (!isa<StoreInst, VPIntrinsic>(StoredBy))
     return false;
 
-  SmallVector<Value *, 8> InterleaveValues;
-  SmallVector<Instruction *, 8> InterleaveDeadInsts;
-  if (!getVectorInterleaveFactor(II, InterleaveValues, InterleaveDeadInsts))
-    return false;
-
-  const unsigned Factor = InterleaveValues.size();
+  SmallVector<Value *, 8> InterleaveValues(II->args());
+  const unsigned Factor = getIntrinsicFactor(II);
 
   if (auto *VPStore = dyn_cast<VPIntrinsic>(StoredBy)) {
     if (VPStore->getIntrinsicID() != Intrinsic::vp_store)
@@ -922,7 +765,7 @@ bool InterleavedAccessImpl::lowerInterleaveIntrinsic(
 
   // We now have a target-specific store, so delete the old one.
   DeadInsts.insert(cast<Instruction>(StoredBy));
-  DeadInsts.insert_range(InterleaveDeadInsts);
+  DeadInsts.insert(II);
   return true;
 }
 

llvm/test/CodeGen/RISCV/rvv/fixed-vectors-deinterleave-load.ll

@@ -293,31 +293,6 @@ define { <8 x i8>, <8 x i8>, <8 x i8>, <8 x i8> } @vector_deinterleave_load_fact
   ret { <8 x i8>, <8 x i8>, <8 x i8>, <8 x i8> } %res3
 }
 
-; TODO: Remove once recursive deinterleaving support is removed
-define { <8 x i8>, <8 x i8>, <8 x i8>, <8 x i8> } @vector_deinterleave_load_factor4_recursive(ptr %p) {
-; CHECK-LABEL: vector_deinterleave_load_factor4_recursive:
-; CHECK:       # %bb.0:
-; CHECK-NEXT:    vsetivli zero, 8, e8, mf2, ta, ma
-; CHECK-NEXT:    vlseg4e8.v v8, (a0)
-; CHECK-NEXT:    ret
-  %vec = load <32 x i8>, ptr %p
-  %d0 = call {<16 x i8>, <16 x i8>} @llvm.vector.deinterleave2.v32i8(<32 x i8> %vec)
-  %d0.0 = extractvalue { <16 x i8>, <16 x i8> } %d0, 0
-  %d0.1 = extractvalue { <16 x i8>, <16 x i8> } %d0, 1
-  %d1 = call {<8 x i8>, <8 x i8>} @llvm.vector.deinterleave2.v16i8(<16 x i8> %d0.0)
-  %t0 = extractvalue { <8 x i8>, <8 x i8> } %d1, 0
-  %t2 = extractvalue { <8 x i8>, <8 x i8> } %d1, 1
-  %d2 = call {<8 x i8>, <8 x i8>} @llvm.vector.deinterleave2.v16i8(<16 x i8> %d0.1)
-  %t1 = extractvalue { <8 x i8>, <8 x i8> } %d2, 0
-  %t3 = extractvalue { <8 x i8>, <8 x i8> } %d2, 1
-
-  %res0 = insertvalue { <8 x i8>, <8 x i8>, <8 x i8>, <8 x i8> } undef, <8 x i8> %t0, 0
-  %res1 = insertvalue { <8 x i8>, <8 x i8>, <8 x i8>, <8 x i8> } %res0, <8 x i8> %t1, 1
-  %res2 = insertvalue { <8 x i8>, <8 x i8>, <8 x i8>, <8 x i8> } %res1, <8 x i8> %t2, 2
-  %res3 = insertvalue { <8 x i8>, <8 x i8>, <8 x i8>, <8 x i8> } %res2, <8 x i8> %t3, 3
-  ret { <8 x i8>, <8 x i8>, <8 x i8>, <8 x i8> } %res3
-}
-
 define { <8 x i8>, <8 x i8>, <8 x i8>, <8 x i8>, <8 x i8> } @vector_deinterleave_load_factor5(ptr %p) {
 ; CHECK-LABEL: vector_deinterleave_load_factor5:
 ; CHECK:       # %bb.0:
@@ -414,45 +389,3 @@ define { <8 x i8>, <8 x i8>, <8 x i8>, <8 x i8>, <8 x i8>, <8 x i8>, <8 x i8>, <
   %res7 = insertvalue { <8 x i8>, <8 x i8>, <8 x i8>, <8 x i8>, <8 x i8>, <8 x i8>, <8 x i8>, <8 x i8> } %res6, <8 x i8> %t6, 7
   ret { <8 x i8>, <8 x i8>, <8 x i8>, <8 x i8>, <8 x i8>, <8 x i8>, <8 x i8>, <8 x i8> } %res7
 }
-
-; TODO: Remove once recursive deinterleaving support is removed
-define {<2 x i32>, <2 x i32>, <2 x i32>, <2 x i32>, <2 x i32>, <2 x i32>, <2 x i32>, <2 x i32>} @vector_deinterleave_load_factor8_recursive(ptr %ptr) {
-; CHECK-LABEL: vector_deinterleave_load_factor8_recursive:
-; CHECK:       # %bb.0:
-; CHECK-NEXT:    vsetivli zero, 2, e32, mf2, ta, ma
-; CHECK-NEXT:    vlseg8e32.v v8, (a0)
-; CHECK-NEXT:    ret
-  %vec = load <16 x i32>, ptr %ptr
-  %d0 = call { <8 x i32>, <8 x i32> } @llvm.vector.deinterleave2.v16i32(<16 x i32> %vec)
-  %d0.0 = extractvalue { <8 x i32>, <8 x i32> } %d0, 0
-  %d0.1 = extractvalue { <8 x i32>, <8 x i32> } %d0, 1
-  %d1 = call { <4 x i32>, <4 x i32> } @llvm.vector.deinterleave2.v8i32(<8 x i32> %d0.0)
-  %d1.0 = extractvalue { <4 x i32>, <4 x i32> } %d1, 0
-  %d1.1 = extractvalue { <4 x i32>, <4 x i32> } %d1, 1
-  %d2 = call { <4 x i32>, <4 x i32> } @llvm.vector.deinterleave2.v8i32(<8 x i32> %d0.1)
-  %d2.0 = extractvalue { <4 x i32>, <4 x i32> } %d2, 0
-  %d2.1 = extractvalue { <4 x i32>, <4 x i32> } %d2, 1
-
-  %d3 = call { <2 x i32>, <2 x i32> } @llvm.vector.deinterleave2.v4i32(<4 x i32> %d1.0)
-  %t0 = extractvalue { <2 x i32>, <2 x i32> } %d3, 0
-  %t4 = extractvalue { <2 x i32>, <2 x i32> } %d3, 1
-  %d4 = call { <2 x i32>, <2 x i32> } @llvm.vector.deinterleave2.v4i32(<4 x i32> %d1.1)
-  %t2 = extractvalue { <2 x i32>, <2 x i32> } %d4, 0
-  %t6 = extractvalue { <2 x i32>, <2 x i32> } %d4, 1
-  %d5 = call { <2 x i32>, <2 x i32> } @llvm.vector.deinterleave2.v4i32(<4 x i32> %d2.0)
-  %t1 = extractvalue { <2 x i32>, <2 x i32> } %d5, 0
-  %t5 = extractvalue { <2 x i32>, <2 x i32> } %d5, 1
-  %d6 = call { <2 x i32>, <2 x i32> } @llvm.vector.deinterleave2.v4i32(<4 x i32> %d2.1)
-  %t3 = extractvalue { <2 x i32>, <2 x i32> } %d6, 0
-  %t7 = extractvalue { <2 x i32>, <2 x i32> } %d6, 1
-
-  %res0 = insertvalue { <2 x i32>, <2 x i32>, <2 x i32>, <2 x i32>, <2 x i32>, <2 x i32>, <2 x i32>, <2 x i32> } undef, <2 x i32> %t0, 0
-  %res1 = insertvalue { <2 x i32>, <2 x i32>, <2 x i32>, <2 x i32>, <2 x i32>, <2 x i32>, <2 x i32>, <2 x i32> } %res0, <2 x i32> %t1, 1
-  %res2 = insertvalue { <2 x i32>, <2 x i32>, <2 x i32>, <2 x i32>, <2 x i32>, <2 x i32>, <2 x i32>, <2 x i32> } %res1, <2 x i32> %t2, 2
-  %res3 = insertvalue { <2 x i32>, <2 x i32>, <2 x i32>, <2 x i32>, <2 x i32>, <2 x i32>, <2 x i32>, <2 x i32> } %res2, <2 x i32> %t3, 3
-  %res4 = insertvalue { <2 x i32>, <2 x i32>, <2 x i32>, <2 x i32>, <2 x i32>, <2 x i32>, <2 x i32>, <2 x i32> } %res3, <2 x i32> %t4, 4
-  %res5 = insertvalue { <2 x i32>, <2 x i32>, <2 x i32>, <2 x i32>, <2 x i32>, <2 x i32>, <2 x i32>, <2 x i32> } %res4, <2 x i32> %t5, 5
-  %res6 = insertvalue { <2 x i32>, <2 x i32>, <2 x i32>, <2 x i32>, <2 x i32>, <2 x i32>, <2 x i32>, <2 x i32> } %res5, <2 x i32> %t6, 6
-  %res7 = insertvalue { <2 x i32>, <2 x i32>, <2 x i32>, <2 x i32>, <2 x i32>, <2 x i32>, <2 x i32>, <2 x i32> } %res6, <2 x i32> %t7, 7
-  ret { <2 x i32>, <2 x i32>, <2 x i32>, <2 x i32>, <2 x i32>, <2 x i32>, <2 x i32>, <2 x i32> } %res7
-}

llvm/test/CodeGen/RISCV/rvv/fixed-vectors-interleave-store.ll

@@ -203,20 +203,6 @@ define void @vector_interleave_store_factor4(<4 x i32> %a, <4 x i32> %b, <4 x i3
   ret void
 }
 
-; TODO: Remove once recursive interleaving support is removed
-define void @vector_interleave_store_factor4_recursive(<4 x i32> %a, <4 x i32> %b, <4 x i32> %c, <4 x i32> %d, ptr %p) {
-; CHECK-LABEL: vector_interleave_store_factor4_recursive:
-; CHECK:       # %bb.0:
-; CHECK-NEXT:    vsetivli zero, 4, e32, m1, ta, ma
-; CHECK-NEXT:    vsseg4e32.v v8, (a0)
-; CHECK-NEXT:    ret
-  %v0 = call <8 x i32> @llvm.vector.interleave2.v8i32(<4 x i32> %a, <4 x i32> %c)
-  %v1 = call <8 x i32> @llvm.vector.interleave2.v8i32(<4 x i32> %b, <4 x i32> %d)
-  %v2 = call <16 x i32> @llvm.vector.interleave2.v16i32(<8 x i32> %v0, <8 x i32> %v1)
-  store <16 x i32> %v2, ptr %p
-  ret void
-}
-
 define void @vector_interleave_store_factor5(<4 x i32> %a, <4 x i32> %b, <4 x i32> %c, <4 x i32> %d, <4 x i32> %e, ptr %p) {
 ; CHECK-LABEL: vector_interleave_store_factor5:
 ; CHECK:       # %bb.0:
@@ -260,23 +246,3 @@ define void @vector_interleave_store_factor8(<4 x i32> %a, <4 x i32> %b, <4 x i3
   store <32 x i32> %v, ptr %p
   ret void
 }
-
-; TODO: Remove once recursive interleaving support is removed
-define void @vector_interleave_store_factor8_recursive(<4 x i32> %a, <4 x i32> %b, <4 x i32> %c, <4 x i32> %d, <4 x i32> %e, <4 x i32> %f, <4 x i32> %g, <4 x i32> %h, ptr %p) {
-; CHECK-LABEL: vector_interleave_store_factor8_recursive:
-; CHECK:       # %bb.0:
-; CHECK-NEXT:    vsetivli zero, 4, e32, m1, ta, ma
-; CHECK-NEXT:    vsseg8e32.v v8, (a0)
-; CHECK-NEXT:    ret
-  %v0 = call <8 x i32> @llvm.vector.interleave2.v8i32(<4 x i32> %a, <4 x i32> %e)
-  %v1 = call <8 x i32> @llvm.vector.interleave2.v8i32(<4 x i32> %c, <4 x i32> %g)
-  %v2 = call <16 x i32> @llvm.vector.interleave2.v16i32(<8 x i32> %v0, <8 x i32> %v1)
-
-  %v3 = call <8 x i32> @llvm.vector.interleave2.v8i32(<4 x i32> %b, <4 x i32> %f)
-  %v4 = call <8 x i32> @llvm.vector.interleave2.v8i32(<4 x i32> %d, <4 x i32> %h)
-  %v5 = call <16 x i32> @llvm.vector.interleave2.v16i32(<8 x i32> %v3, <8 x i32> %v4)
-
-  %v6 = call <32 x i32> @llvm.vector.interleave2.v32i32(<16 x i32> %v2, <16 x i32> %v5)
-  store <32 x i32> %v6, ptr %p
-  ret void
-}

llvm/test/CodeGen/RISCV/rvv/fixed-vectors-interleaved-access.ll

@@ -302,15 +302,11 @@ define {<2 x i32>, <2 x i32>, <2 x i32>, <2 x i32>} @vpload_factor4_intrinsics(p
 ; CHECK-NEXT:    vlseg4e32.v v8, (a0)
 ; CHECK-NEXT:    ret
   %wide.masked.load = call <8 x i32> @llvm.vp.load.v8i32.p0(ptr %ptr, <8 x i1> splat (i1 true), i32 8)
-  %d0 = call { <4 x i32>, <4 x i32> } @llvm.vector.deinterleave2.v8i32(<8 x i32> %wide.masked.load)
-  %d0.0 = extractvalue { <4 x i32>, <4 x i32> } %d0, 0
-  %d0.1 = extractvalue { <4 x i32>, <4 x i32> } %d0, 1
-  %d1 = call { <2 x i32>, <2 x i32> } @llvm.vector.deinterleave2.v4i32(<4 x i32> %d0.0)
-  %t0 = extractvalue { <2 x i32>, <2 x i32> } %d1, 0
-  %t2 = extractvalue { <2 x i32>, <2 x i32> } %d1, 1
-  %d2 = call { <2 x i32>, <2 x i32> } @llvm.vector.deinterleave2.v4i32(<4 x i32> %d0.1)
-  %t1 = extractvalue { <2 x i32>, <2 x i32> } %d2, 0
-  %t3 = extractvalue { <2 x i32>, <2 x i32> } %d2, 1
+  %d = call { <2 x i32>, <2 x i32>, <2 x i32>, <2 x i32> } @llvm.vector.deinterleave4.v8i32(<8 x i32> %wide.masked.load)
+  %t0 = extractvalue { <2 x i32>, <2 x i32>, <2 x i32>, <2 x i32> } %d, 0
+  %t1 = extractvalue { <2 x i32>, <2 x i32>, <2 x i32>, <2 x i32> } %d, 1
+  %t2 = extractvalue { <2 x i32>, <2 x i32>, <2 x i32>, <2 x i32> } %d, 2
+  %t3 = extractvalue { <2 x i32>, <2 x i32>, <2 x i32>, <2 x i32> } %d, 3
 
   %res0 = insertvalue { <2 x i32>, <2 x i32>, <2 x i32>, <2 x i32> } poison, <2 x i32> %t0, 0
   %res1 = insertvalue { <2 x i32>, <2 x i32>, <2 x i32>, <2 x i32> } %res0, <2 x i32> %t1, 1