[SLP] Added more missed optimiazation remarks

[miloserd]

Summary

Added more remarks to SLP pass, in particular "missed" optimization remarks.
Also proposed several tests for new functionality.

For reference you may look at: https://reviews.llvm.org/rL302811

[fhahn]

Thanks for working on this! I left a few comments.

lib/Transforms/Vectorize/SLPVectorizer.cpp

62

This is only used by the remark as far as I can see. I think it would be simpler to just to the cast when constructing the remark.

63

The code in the if branch does not use Inst, so could we keep if (!Inst || Inst->getOpcode() != Opcode0) ?

64

What would a better error message look like? We emit it if the the opcodes do not match. Would it make sense to add the opcodes to the message?

68

I think we should be consistent with the messages. At the beginning you use something like Cannot SLP vectorize list

test/Transforms/SLPVectorizer/X86/remark_horcost.ll

2

Please consider using the YAML format when in the test, like in rL302811

[miloserd]

Fixed code style, reworked tests to check YAML output

[miloserd]

lib/Transforms/Vectorize/SLPVectorizer.cpp

63

It should only emit this remark if Inst is not null. And now it uses Inst anyway

64

Rework it to emit instructions, I think it's better now

[anemet]

Please use the new closure API to emit remarks.

[miloserd]

Reworked with closure API

[anemet]

I will look at the rest of the patch in more detail later unless Florian beats me to it. Thanks for tackling this!

lib/Transforms/Vectorize/SLPVectorizer.cpp

4646–4649

Put these are under the closure so that we only compute them if the remark is on.

[anemet]

Also by any chance, did you run this on some real code base? Some of these may trigger quite a bit and I want to make sure they are not on the top of the list. You can use opt-viewer/opt-stats.py to get a sense how frequently your remark is generated.

[miloserd]

In D38367#915259, @anemet wrote:

Also by any chance, did you run this on some real code base? Some of these may trigger quite a bit and I want to make sure they are not on the top of the list. You can use opt-viewer/opt-stats.py to get a sense how frequently your remark is generated.

Yep, I did, it did not produced much noise on our applications.
I've just compiled ~100 random files from LLVM, opt-stats.py says only slp-vectorizer/InequableTypes is in top 10 remarks with 3% of all remarks (that is ~2000 out of 68000). I suppose it's okay.

[anemet]

In D38367#915446, @miloserd wrote:

In D38367#915259, @anemet wrote:

Also by any chance, did you run this on some real code base? Some of these may trigger quite a bit and I want to make sure they are not on the top of the list. You can use opt-viewer/opt-stats.py to get a sense how frequently your remark is generated.

Yep, I did, it did not produced much noise on our applications.
I've just compiled ~100 random files from LLVM, opt-stats.py says only slp-vectorizer/InequableTypes is in top 10 remarks with 3% of all remarks (that is ~2000 out of 68000). I suppose it's okay.

Excellent, thanks!

[miloserd]

Moved the code of one remark under the closure

[miloserd]

ping

[anemet]

This looks great with some minor nits (go ahead and commit after fixing them). Thanks for your work! And sorry about the delay.

lib/Transforms/Vectorize/SLPVectorizer.cpp

5491

Remove this whitespace-only change.

5505

We should probably print the threshold here too

5513–5520

Ouch, thanks for fixing this.

[miloserd]

Fixed minor issues

[miloserd]

Thanks for your time, anemet. I've just fixed these issues you told.
Can you please commit this patch? I haven't got r+w access.

[anemet]

In D38367#924968, @miloserd wrote:

Thanks for your time, anemet. I've just fixed these issues you told.
Can you please commit this patch? I haven't got r+w access.

Sure, will do after lunch.

[anemet]

In D38367#924980, @anemet wrote:

In D38367#924968, @miloserd wrote:

Thanks for your time, anemet. I've just fixed these issues you told.
Can you please commit this patch? I haven't got r+w access.

Sure, will do after lunch.

This does not apply cleanly for me. There are 4 rejects in SLPVectorizer.cpp. Can you please rebase the patch?

[miloserd]

Rebased

[anemet]

In D38367#925182, @anemet wrote:

In D38367#924980, @anemet wrote:

In D38367#924968, @miloserd wrote:

Thanks for your time, anemet. I've just fixed these issues you told.
Can you please commit this patch? I haven't got r+w access.

Sure, will do after lunch.

This does not apply cleanly for me. There are 4 rejects in SLPVectorizer.cpp. Can you please rebase the patch?

It was actually the Windows line breaks that confused arcanist. Just testing now before commit.

[anemet]

I get two failures, can you please take a look?

LLVM :: Transforms/SLPVectorizer/AArch64/getelementptr.ll
LLVM :: Transforms/SLPVectorizer/AArch64/horizontal.ll

[miloserd]

Fixed tests

[miloserd]

Sorry, I forgot to test it with all of the backends. Now changed failing tests as they did not support many remarks at once.
Though I haven't checked all the tests yet since I am still waiting for the local build to finish.

[miloserd]

Just finished testing, seems OK with latest submitted version

lib/Transforms/Vectorize/SLPVectorizer.cpp

 #include "llvm/IR/DataLayout.h"
 #include "llvm/IR/DebugLoc.h"
 #include "llvm/IR/DerivedTypes.h"
 #include "llvm/IR/Dominators.h"
 #include "llvm/IR/Function.h"
 #include "llvm/IR/IRBuilder.h"
 #include "llvm/IR/InstrTypes.h"
 #include "llvm/IR/Instruction.h"
 #include "llvm/IR/Instructions.h"
 #include "llvm/IR/IntrinsicInst.h"
 #include "llvm/IR/Intrinsics.h"
 #include "llvm/IR/Module.h"
 #include "llvm/IR/NoFolder.h"
 #include "llvm/IR/Operator.h"
 #include "llvm/IR/PassManager.h"
 #include "llvm/IR/PatternMatch.h"
 #include "llvm/IR/Type.h"
 #include "llvm/IR/Use.h"
 #include "llvm/IR/User.h"
 #include "llvm/IR/Value.h"
 #include "llvm/IR/ValueHandle.h"
 #include "llvm/IR/Verifier.h"
 #include "llvm/Pass.h"
bool SLPVectorizerPass::tryToVectorizeList(ArrayRef<Value *> VL, BoUpSLP &R,
   if (!I0)
     return false;
 
   unsigned Opcode0 = I0->getOpcode();
 
   unsigned Sz = R.getVectorElementSize(I0);
   unsigned MinVF = std::max(2U, R.getMinVecRegSize() / Sz);
   unsigned MaxVF = std::max<unsigned>(PowerOf2Floor(VL.size()), MinVF);
-  if (MaxVF < 2)
+  if (MaxVF < 2) {
+     R.getORE()->emit([&]() {
+         return OptimizationRemarkMissed(
+                    SV_NAME, "SmallVF", I0)
+                << "Cannot SLP vectorize list: vectorization factor "
+                << "less than 2 is not supported";
+     });
      return false;
+  }
 
   for (Value *V : VL) {
     Type *Ty = V->getType();
-    if (!isValidElementType(Ty))
+    if (!isValidElementType(Ty)) {
+      // NOTE: the following will give user internal llvm type name, which may not be useful
+      R.getORE()->emit([&]() {
+          std::string type_str;
+          llvm::raw_string_ostream rso(type_str);
+          Ty->print(rso);
+          return OptimizationRemarkMissed(
+                     SV_NAME, "UnsupportedType", I0)
+                 << "Cannot SLP vectorize list: type "
+                 << rso.str() + " is unsupported by vectorizer";
+      });
       return false;
+    }
     Instruction *Inst = dyn_cast<Instruction>(V);
-    if (!Inst || Inst->getOpcode() != Opcode0)
+
+    if (!Inst)
+        return false;
+    if (Inst->getOpcode() != Opcode0) {
+      R.getORE()->emit([&]() {
+          return OptimizationRemarkMissed(
+                     SV_NAME, "InequableTypes", I0)
+                 << "Cannot SLP vectorize list: not all of the "
+                 << "parts of scalar instructions are of the same type: "
+                 << ore::NV("Instruction1Opcode", I0) << " and "
+                 << ore::NV("Instruction2Opcode", Inst);
+      });
       return false;
     }
+  }
 
   bool Changed = false;
+  bool CandidateFound = false;
+  int MinCost = SLPCostThreshold;
 
   // Keep track of values that were deleted by vectorizing in the loop below.
   SmallVector<WeakTrackingVH, 8> TrackValues(VL.begin(), VL.end());
 
   unsigned NextInst = 0, MaxInst = VL.size();
   for (unsigned VF = MaxVF; NextInst + 1 < MaxInst && VF >= MinVF;
        VF /= 2) {
     // No actual vectorization should happen, if number of parts is the same as
for (unsigned I = NextInst; I < MaxInst; ++I) {
         Value *ReorderedOps[] = {Ops[1], Ops[0]};
         R.buildTree(ReorderedOps, None);
       }
       if (R.isTreeTinyAndNotFullyVectorizable())
         continue;
 
       R.computeMinimumValueSizes();
       int Cost = R.getTreeCost();
+      CandidateFound = true;
+      MinCost = std::min(MinCost, Cost);
 
       if (Cost < -SLPCostThreshold) {
         DEBUG(dbgs() << "SLP: Vectorizing list at cost:" << Cost << ".\n");
         R.getORE()->emit(OptimizationRemark(SV_NAME, "VectorizedList",
                                                     cast<Instruction>(Ops[0]))
                                  << "SLP vectorized with cost " << ore::NV("Cost", Cost)
                                  << " and with tree size "
                                  << ore::NV("TreeSize", R.getTreeSize()));
 
         Value *VectorizedRoot = R.vectorizeTree();
 
         // Reconstruct the build vector by extracting the vectorized root. This
         // way we handle the case where some elements of the vector are
         // undefined.
         //  (return (inserelt <4 xi32> (insertelt undef (opd0) 0) (opd1) 2))
         if (!BuildVectorSlice.empty()) {
for (unsigned I = NextInst; I < MaxInst; ++I) {
         // Move to the next bundle.
         I += VF - 1;
         NextInst = I + 1;
         Changed = true;
       }
     }
   }
 
+  if (!Changed && CandidateFound) {
+    R.getORE()->emit([&]() {
+        return OptimizationRemarkMissed(
+                   SV_NAME, "NotBeneficial",  I0)
+               << "List vectorization was possible but not beneficial with cost "
+               << ore::NV("Cost", MinCost) << " >= "
+               << ore::NV("Treshold", -SLPCostThreshold);
+    });
+  } else if (!Changed) {
+    R.getORE()->emit([&]() {
+        return OptimizationRemarkMissed(
+                   SV_NAME, "NotPossible", I0)
+               << "Cannot SLP vectorize list: vectorization was impossible"
+               << " with available vectorization factors";
+    });
+  }
   return Changed;
 }
 
 bool SLPVectorizerPass::tryToVectorize(Instruction *I, BoUpSLP &R) {
   if (!I)
     return false;
 
   if (!isa<BinaryOperator>(I) && !isa<CmpInst>(I))
for (auto &V : ReductionOps)
       IgnoreList.append(V.begin(), V.end());
     while (i < NumReducedVals - ReduxWidth + 1 && ReduxWidth > 2) {
       auto VL = makeArrayRef(&ReducedVals[i], ReduxWidth);
       V.buildTree(VL, ExternallyUsedValues, IgnoreList);
       if (V.shouldReorder()) {
         SmallVector<Value *, 8> Reversed(VL.rbegin(), VL.rend());
         V.buildTree(Reversed, ExternallyUsedValues, IgnoreList);
       }
       if (V.isTreeTinyAndNotFullyVectorizable())
         break;
 
       V.computeMinimumValueSizes();
 
       // Estimate cost.
       int Cost =
           V.getTreeCost() + getReductionCost(TTI, ReducedVals[i], ReduxWidth);
-      if (Cost >= -SLPCostThreshold)
+      if (Cost >= -SLPCostThreshold) {
+          V.getORE()->emit([&]() {
+              return OptimizationRemarkMissed(
+                         SV_NAME, "HorSLPNotBeneficial", cast<Instruction>(VL[0]))
+                     << "Vectorizing horizontal reduction is possible"
+                     << "but not beneficial with cost "
+                     << ore::NV("Cost", Cost) << " and threshold "
+                     << ore::NV("Threshold", -SLPCostThreshold);
+          });
           break;
+      }
 
       DEBUG(dbgs() << "SLP: Vectorizing horizontal reduction at cost:" << Cost
                    << ". (HorRdx)\n");
-      auto *I0 = cast<Instruction>(VL[0]);
-      V.getORE()->emit(
-          OptimizationRemark(SV_NAME, "VectorizedHorizontalReduction", I0)
+      V.getORE()->emit([&]() {
+          return OptimizationRemark(
+                     SV_NAME, "VectorizedHorizontalReduction", cast<Instruction>(VL[0]))
           << "Vectorized horizontal reduction with cost "
           << ore::NV("Cost", Cost) << " and with tree size "
-          << ore::NV("TreeSize", V.getTreeSize()));
+          << ore::NV("TreeSize", V.getTreeSize());
+      });
 
       // Vectorize a tree.
       DebugLoc Loc = cast<Instruction>(ReducedVals[i])->getDebugLoc();
       Value *VectorizedRoot = V.vectorizeTree(ExternallyUsedValues);
 
       // Emit a reduction.
       Value *ReducedSubTree =
           emitReduction(VectorizedRoot, Builder, ReduxWidth, TTI);
       if (VectorizedTree) {

test/Transforms/SLPVectorizer/X86/remark_horcost.ll

+; RUN: opt -S -mtriple=x86_64-pc-linux-gnu -mcpu=generic -slp-vectorizer -pass-remarks-output=%t < %s | FileCheck %s
+; RUN: FileCheck --input-file=%t --check-prefix=YAML %s
+
+define i32 @foo(i32* %diff) #0 {
+entry:
+  %m2 = alloca [8 x [8 x i32]], align 16
+  %0 = bitcast [8 x [8 x i32]]* %m2 to i8*
+  br label %for.body
+
+for.body:                                         ; preds = %for.body, %entry
+  %indvars.iv = phi i64 [ 0, %entry ], [ %indvars.iv.next, %for.body ]
+  %a.088 = phi i32 [ 0, %entry ], [ %add52, %for.body ]
+  %1 = shl i64 %indvars.iv, 3
+  %arrayidx = getelementptr inbounds i32, i32* %diff, i64 %1
+  %2 = load i32, i32* %arrayidx, align 4
+  %3 = or i64 %1, 4
+  %arrayidx2 = getelementptr inbounds i32, i32* %diff, i64 %3
+  %4 = load i32, i32* %arrayidx2, align 4
+  %add3 = add nsw i32 %4, %2
+  %arrayidx6 = getelementptr inbounds [8 x [8 x i32]], [8 x [8 x i32]]* %m2, i64 0, i64 %indvars.iv, i64 0
+  store i32 %add3, i32* %arrayidx6, align 16
+ 
+  %add10 = add nsw i32 %add3, %a.088
+  %5 = or i64 %1, 1
+  %arrayidx13 = getelementptr inbounds i32, i32* %diff, i64 %5
+  %6 = load i32, i32* %arrayidx13, align 4
+  %7 = or i64 %1, 5
+  %arrayidx16 = getelementptr inbounds i32, i32* %diff, i64 %7
+  %8 = load i32, i32* %arrayidx16, align 4
+  %add17 = add nsw i32 %8, %6
+  %arrayidx20 = getelementptr inbounds [8 x [8 x i32]], [8 x [8 x i32]]* %m2, i64 0, i64 %indvars.iv, i64 1
+  store i32 %add17, i32* %arrayidx20, align 4
+  
+  %add24 = add nsw i32 %add10, %add17
+  %9 = or i64 %1, 2
+  %arrayidx27 = getelementptr inbounds i32, i32* %diff, i64 %9
+  %10 = load i32, i32* %arrayidx27, align 4
+  %11 = or i64 %1, 6
+  %arrayidx30 = getelementptr inbounds i32, i32* %diff, i64 %11
+  %12 = load i32, i32* %arrayidx30, align 4
+  %add31 = add nsw i32 %12, %10
+  %arrayidx34 = getelementptr inbounds [8 x [8 x i32]], [8 x [8 x i32]]* %m2, i64 0, i64 %indvars.iv, i64 2
+  store i32 %add31, i32* %arrayidx34, align 8
+  
+  %add38 = add nsw i32 %add24, %add31
+  %13 = or i64 %1, 3
+  %arrayidx41 = getelementptr inbounds i32, i32* %diff, i64 %13
+  %14 = load i32, i32* %arrayidx41, align 4
+  %15 = or i64 %1, 7
+  %arrayidx44 = getelementptr inbounds i32, i32* %diff, i64 %15
+  %16 = load i32, i32* %arrayidx44, align 4
+  
+  %add45 = add nsw i32 %16, %14
+  %arrayidx48 = getelementptr inbounds [8 x [8 x i32]], [8 x [8 x i32]]* %m2, i64 0, i64 %indvars.iv, i64 3
+  store i32 %add45, i32* %arrayidx48, align 4
+  
+  %add52 = add nsw i32 %add38, %add45
+ ; CHECK: add nsw <{{[0-9]+}} x i32>
+ ; CHECK-NOT: add nsw <{{[0-9]+}} x i32>
+ 
+ ; YAML:      --- !Missed
+ ; YAML-NEXT: Pass:            slp-vectorizer
+ ; YAML-NEXT: Name:            HorSLPNotBeneficial
+ ; YAML-NEXT: Function:        foo
+ ; YAML-NEXT: Args:
+ ; YAML-NEXT:   - String:          Vectorizing horizontal reduction is possible
+ ; YAML-NEXT:   - String:          'but not beneficial with cost ' 
+ ; YAML-NEXT:   - Cost:            '1'
+ ; YAML-NEXT:   - String:          ' and threshold '
+ ; YAML-NEXT:   - Threshold:       '0'
+
+  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
+  %exitcond = icmp eq i64 %indvars.iv.next, 8
+  br i1 %exitcond, label %for.end, label %for.body
+
+for.end:                                          ; preds = %for.body
+  ret i32 %add52
+}

test/Transforms/SLPVectorizer/X86/remark_listcost.ll

+; RUN: opt -S -mtriple=x86_64-pc-linux-gnu -mcpu=generic -slp-vectorizer -pass-remarks-output=%t < %s | FileCheck %s
+; RUN: FileCheck --input-file=%t --check-prefix=YAML %s
+
+define void @vsub2_test(i32* %pin1, i32* %pin2, i32* %pout) #0 {
+  br label %1
+
+  %idx.04 = phi i32 [ 0, %0 ], [ %8, %1 ]
+  %po.03 = phi i32* [ %pout, %0 ], [ %7, %1 ]
+  %ptmpi2.02 = phi i32* [ %pin2, %0 ], [ %4, %1 ]
+  %ptmpi1.01 = phi i32* [ %pin1, %0 ], [ %2, %1 ]
+  %2 = getelementptr inbounds i32, i32* %ptmpi1.01, i64 1
+  %3 = load i32, i32* %ptmpi1.01, align 4, !tbaa !1
+  %4 = getelementptr inbounds i32, i32* %ptmpi2.02, i64 1
+  %5 = load i32, i32* %ptmpi2.02, align 4, !tbaa !1
+  %6 = sub nsw i32 %3, %5
+  %7 = getelementptr inbounds i32, i32* %po.03, i64 1
+ ; CHECK-NOT: <{{[0-9]+}} x i32>
+ ; YAML:      Pass:            slp-vectorizer
+ ; YAML-NEXT: Name:            NotBeneficial
+ ; YAML-NEXT: Function:        vsub2_test
+ ; YAML-NEXT: Args:
+ ; YAML-NEXT:   - String:          'List vectorization was possible but not beneficial with cost '
+ ; YAML-NEXT:   - Cost:            '0'
+ ; YAML-NEXT:   - String:          ' >= '
+ ; YAML-NEXT:   - Treshold:        '0'
+  store i32 %6, i32* %po.03, align 4, !tbaa !1
+  %8 = add nuw nsw i32 %idx.04, 1
+  %exitcond = icmp eq i32 %8, 64
+  br i1 %exitcond, label %9, label %1, !llvm.loop !5
+
+  ret void
+}
+
+!llvm.ident = !{!0}
+
+!0 = !{!"clang version 3.8.0-2ubuntu4 (tags/RELEASE_380/final)"}
+!1 = !{!2, !2, i64 0}
+!2 = !{!"int", !3, i64 0}
+!3 = !{!"omnipotent char", !4, i64 0}
+!4 = !{!"Simple C/C++ TBAA"}
+!5 = distinct !{!5, !6, !7}
+!6 = !{!"llvm.loop.vectorize.width", i32 1}
+!7 = !{!"llvm.loop.interleave.count", i32 1}

test/Transforms/SLPVectorizer/X86/remark_not_all_parts.ll

+; RUN: opt -S -mtriple=x86_64-pc-linux-gnu -mcpu=generic -slp-vectorizer -pass-remarks-output=%t < %s | FileCheck %s
+; RUN: FileCheck --input-file=%t --check-prefix=YAML %s
+
+define i32 @foo(i32* nocapture readonly %diff) #0 {
+entry:
+  %m2 = alloca [8 x [8 x i32]], align 16
+  %0 = bitcast [8 x [8 x i32]]* %m2 to i8*
+  br label %for.body
+
+for.body:                                         ; preds = %for.body, %entry
+  %indvars.iv = phi i64 [ 0, %entry ], [ %indvars.iv.next, %for.body ]
+  %a.088 = phi i32 [ 0, %entry ], [ %add24, %for.body ]
+  %1 = shl i64 %indvars.iv, 3
+  %arrayidx = getelementptr inbounds i32, i32* %diff, i64 %1
+  %2 = load i32, i32* %arrayidx, align 4
+  %3 = or i64 %1, 4
+  %arrayidx2 = getelementptr inbounds i32, i32* %diff, i64 %3
+  %4 = load i32, i32* %arrayidx2, align 4
+  %add3 = add nsw i32 %4, %2
+  %arrayidx6 = getelementptr inbounds [8 x [8 x i32]], [8 x [8 x i32]]* %m2, i64 0, i64 %indvars.iv, i64 0
+  store i32 %add3, i32* %arrayidx6, align 16
+  %add10 = add nsw i32 %add3, %a.088
+  %5 = or i64 %1, 1
+  %arrayidx13 = getelementptr inbounds i32, i32* %diff, i64 %5
+  %6 = load i32, i32* %arrayidx13, align 4
+  %7 = or i64 %1, 5
+  %arrayidx16 = getelementptr inbounds i32, i32* %diff, i64 %7
+  %8 = load i32, i32* %arrayidx16, align 4
+  %add17 = add nsw i32 %8, %6
+  %arrayidx20 = getelementptr inbounds [8 x [8 x i32]], [8 x [8 x i32]]* %m2, i64 0, i64 %indvars.iv, i64 1
+  store i32 %add17, i32* %arrayidx20, align 4
+  %add24 = add nsw i32 %add10, %add17
+
+ ; CHECK-NOT: add nsw <{{[0-9]+}} x i32> 
+ ; YAML:      Pass:            slp-vectorizer
+ ; YAML-NEXT: Name:            InequableTypes
+ ; YAML-NEXT: Function:        foo
+ ; YAML-NEXT: Args:
+ ; YAML-NEXT:   - String:          'Cannot SLP vectorize list: not all of the '
+ ; YAML-NEXT:   - String:          'parts of scalar instructions are of the same type: '
+ ; YAML-NEXT:   - Instruction1Opcode: add
+ ; YAML-NEXT:   - String:          ' and '
+ ; YAML-NEXT:   - Instruction2Opcode: phi
+
+ ; YAML:      Pass:            slp-vectorizer
+ ; YAML-NEXT: Name:            NotPossible
+ ; YAML-NEXT: Function:        foo
+ ; YAML-NEXT: Args:
+ ; YAML-NEXT:   - String:          'Cannot SLP vectorize list: vectorization was impossible'
+ ; YAML-NEXT:   - String:          ' with available vectorization factors'
+
+  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
+  %exitcond = icmp eq i64 %indvars.iv.next, 8
+  br i1 %exitcond, label %for.end, label %for.body
+
+for.end:                                          ; preds = %for.body
+  %arraydecay = getelementptr inbounds [8 x [8 x i32]], [8 x [8 x i32]]* %m2, i64 0, i64 0
+  ret i32 %add24
+}
+

test/Transforms/SLPVectorizer/X86/remark_unsupported.ll

+; RUN: opt -S -mtriple=x86_64-pc-linux-gnu -mcpu=generic -slp-vectorizer -pass-remarks-output=%t < %s | FileCheck %s
+; RUN: FileCheck --input-file=%t --check-prefix=YAML %s
+
+; This type is not supported by SLP
+define void @test(x86_fp80* %i1, x86_fp80* %i2, x86_fp80* %o) {
+
+entry:
+  %i1.0 = load x86_fp80, x86_fp80* %i1, align 16
+  %i1.gep1 = getelementptr x86_fp80, x86_fp80* %i1, i64 1
+  %i1.1 = load x86_fp80, x86_fp80* %i1.gep1, align 16
+  br i1 undef, label %then, label %end
+then:
+  %i2.gep0 = getelementptr inbounds x86_fp80, x86_fp80* %i2, i64 0
+  %i2.0 = load x86_fp80, x86_fp80* %i2.gep0, align 16
+  %i2.gep1 = getelementptr inbounds x86_fp80, x86_fp80* %i2, i64 1
+  %i2.1 = load x86_fp80, x86_fp80* %i2.gep1, align 16
+  br label %end
+end:
+  %phi0 = phi x86_fp80 [ %i1.0, %entry ], [ %i2.0, %then ]
+
+  %phi1 = phi x86_fp80 [ %i1.1, %entry ], [ %i2.1, %then ]
+  store x86_fp80 %phi0, x86_fp80* %o, align 16
+  %o.gep1 = getelementptr inbounds x86_fp80, x86_fp80* %o, i64 1
+  store x86_fp80 %phi1, x86_fp80* %o.gep1, align 16
+ ; CHECK-NOT: <{{[0-9]+}} x x86_fp80>
+ ; YAML:      Pass:            slp-vectorizer
+ ; YAML-NEXT: Name:            UnsupportedType
+ ; YAML-NEXT: Function:        test
+ ; YAML-NEXT: Args:
+ ; YAML-NEXT:   - String:          'Cannot SLP vectorize list: type '
+ ; YAML-NEXT:   - String:          x86_fp80 is unsupported by vectorizer
+
+  ret void
+}