[SimplifyLibCalls][NFC] Clean up LibCallSimplifier from 'memset + malloc into calloc' transformation

[yurai007]

Summary

FoldMallocMemset can be safely removed because since https://reviews.llvm.org/D103009
such transformation is already performed in DSE.

[yurai007]

TODO: rebase when D103009 is delivered.

[yurai007]

Rebased to D103009.

[nikic]

llvm/test/Transforms/DeadStoreElimination/noop-stores.ll

350

Better include this in the other change.

llvm/test/Transforms/InstCombine/memset-1.ll

32

You can leave the tests here and add a comment that this pattern is now handled by DSE in a more general way.

[yurai007]

Rebased and addressed comments.

[yurai007]

@nikic: Kindly ping, all comments were addressed.

[yurai007]

Ping^2

[nikic]

LG

[gAlfonso-bit]

Can we cherry pick this to release-13.0/12 too since it also has the change that made the removed code in this patch obsolete in the first place?

[yurai007]

Rebased.

llvm/include/llvm/Transforms/Utils/SimplifyLibCalls.h

private:
   void eraseFromParent(Instruction *I);
 
   /// Replace an instruction with a value and erase it from its parent.
   void substituteInParent(Instruction *I, Value *With) {
     replaceAllUsesWith(I, With);
     eraseFromParent(I);
   }
 
-  Value *foldMallocMemset(CallInst *Memset, IRBuilderBase &B);
-
 public:
   LibCallSimplifier(
       const DataLayout &DL, const TargetLibraryInfo *TLI,
       OptimizationRemarkEmitter &ORE,
       BlockFrequencyInfo *BFI, ProfileSummaryInfo *PSI,
       function_ref<void(Instruction *, Value *)> Replacer =
           &replaceAllUsesWithDefault,
       function_ref<void(Instruction *)> Eraser = &eraseFromParentDefault);

llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp

Value *LibCallSimplifier::optimizeMemMove(CallInst *CI, IRBuilderBase &B) {
   CallInst *NewCI = B.CreateMemMove(CI->getArgOperand(0), Align(1),
                                     CI->getArgOperand(1), Align(1), Size);
   NewCI->setAttributes(CI->getAttributes());
   NewCI->removeAttributes(AttributeList::ReturnIndex,
                           AttributeFuncs::typeIncompatible(NewCI->getType()));
   return CI->getArgOperand(0);
 }
 
-/// Fold memset[_chk](malloc(n), 0, n) --> calloc(1, n).
-Value *LibCallSimplifier::foldMallocMemset(CallInst *Memset, IRBuilderBase &B) {
-  // This has to be a memset of zeros (bzero).
-  auto *FillValue = dyn_cast<ConstantInt>(Memset->getArgOperand(1));
-  if (!FillValue || FillValue->getZExtValue() != 0)
-    return nullptr;
-
-  // TODO: We should handle the case where the malloc has more than one use.
-  // This is necessary to optimize common patterns such as when the result of
-  // the malloc is checked against null or when a memset intrinsic is used in
-  // place of a memset library call.
-  auto *Malloc = dyn_cast<CallInst>(Memset->getArgOperand(0));
-  if (!Malloc || !Malloc->hasOneUse())
-    return nullptr;
-
-  // Is the inner call really malloc()?
-  Function *InnerCallee = Malloc->getCalledFunction();
-  if (!InnerCallee)
-    return nullptr;
-
-  LibFunc Func;
-  if (!TLI->getLibFunc(*InnerCallee, Func) || !TLI->has(Func) ||
-      Func != LibFunc_malloc)
-    return nullptr;
-
-  // The memset must cover the same number of bytes that are malloc'd.
-  if (Memset->getArgOperand(2) != Malloc->getArgOperand(0))
-    return nullptr;
-
-  // Replace the malloc with a calloc. We need the data layout to know what the
-  // actual size of a 'size_t' parameter is.
-  B.SetInsertPoint(Malloc->getParent(), ++Malloc->getIterator());
-  const DataLayout &DL = Malloc->getModule()->getDataLayout();
-  IntegerType *SizeType = DL.getIntPtrType(B.GetInsertBlock()->getContext());
-  if (Value *Calloc = emitCalloc(ConstantInt::get(SizeType, 1),
-                                 Malloc->getArgOperand(0),
-                                 Malloc->getAttributes(), B, *TLI)) {
-    substituteInParent(Malloc, Calloc);
-    return Calloc;
-  }
-
-  return nullptr;
-}
-
 Value *LibCallSimplifier::optimizeMemSet(CallInst *CI, IRBuilderBase &B) {
   Value *Size = CI->getArgOperand(2);
   annotateNonNullAndDereferenceable(CI, 0, Size, DL);
   if (isa<IntrinsicInst>(CI))
     return nullptr;
 
-  if (auto *Calloc = foldMallocMemset(CI, B))
-    return Calloc;
-
   // memset(p, v, n) -> llvm.memset(align 1 p, v, n)
   Value *Val = B.CreateIntCast(CI->getArgOperand(1), B.getInt8Ty(), false);
   CallInst *NewCI = B.CreateMemSet(CI->getArgOperand(0), Val, Size, Align(1));
   NewCI->setAttributes(CI->getAttributes());
   NewCI->removeAttributes(AttributeList::ReturnIndex,
                           AttributeFuncs::typeIncompatible(NewCI->getType()));
   return CI->getArgOperand(0);
 }
if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(CI)) {
     case Intrinsic::exp2:
       return optimizeExp2(CI, Builder);
     case Intrinsic::log:
     case Intrinsic::log2:
     case Intrinsic::log10:
       return optimizeLog(CI, Builder);
     case Intrinsic::sqrt:
       return optimizeSqrt(CI, Builder);
-    // TODO: Use foldMallocMemset() with memset intrinsic.
     case Intrinsic::memset:
       return optimizeMemSet(CI, Builder);
     case Intrinsic::memcpy:
       return optimizeMemCpy(CI, Builder);
     case Intrinsic::memmove:
       return optimizeMemMove(CI, Builder);
     default:
       return nullptr;
NewCI->removeAttributes(AttributeList::ReturnIndex,
                             AttributeFuncs::typeIncompatible(NewCI->getType()));
     return CI->getArgOperand(0);
   }
   return nullptr;
 }
 
 Value *FortifiedLibCallSimplifier::optimizeMemSetChk(CallInst *CI,
                                                      IRBuilderBase &B) {
-  // TODO: Try foldMallocMemset() here.
-
   if (isFortifiedCallFoldable(CI, 3, 2)) {
     Value *Val = B.CreateIntCast(CI->getArgOperand(1), B.getInt8Ty(), false);
     CallInst *NewCI = B.CreateMemSet(CI->getArgOperand(0), Val,
                                      CI->getArgOperand(2), Align(1));
     NewCI->setAttributes(CI->getAttributes());
     NewCI->removeAttributes(AttributeList::ReturnIndex,
                             AttributeFuncs::typeIncompatible(NewCI->getType()));
     return CI->getArgOperand(0);

llvm/test/Transforms/DeadStoreElimination/noop-stores.ll

entry:
   store i32 0, i32* %y, align 4
   store i32 %lv, i32* %x, align 4
   ret void
 }
 
 declare noalias i8* @malloc(i64)
 declare void @clobber_memory(float*)
 
-; based on pr25892_lite
 define i8* @zero_memset_after_malloc(i64 %size) {
 ; CHECK-LABEL: @zero_memset_after_malloc(
 ; CHECK-NEXT:    [[CALL:%.*]] = call i8* @calloc(i64 1, i64 [[SIZE:%.*]])
 ; CHECK-NEXT:    ret i8* [[CALL]]
 ;
   %call = call i8* @malloc(i64 %size) inaccessiblememonly
   call void @llvm.memset.p0i8.i64(i8* %call, i8 0, i64 %size, i1 false)
   ret i8* %call
 }
 
-; based on pr25892_lite
 define i8* @zero_memset_after_malloc_with_intermediate_clobbering(i64 %size) {
 ; CHECK-LABEL: @zero_memset_after_malloc_with_intermediate_clobbering(
 ; CHECK-NEXT:    [[CALL:%.*]] = call i8* @malloc(i64 [[SIZE:%.*]])
 ; CHECK-NEXT:    [[BC:%.*]] = bitcast i8* [[CALL]] to float*
 ; CHECK-NEXT:    call void @clobber_memory(float* [[BC]])
 ; CHECK-NEXT:    call void @llvm.memset.p0i8.i64(i8* [[CALL]], i8 0, i64 [[SIZE]], i1 false)
 ; CHECK-NEXT:    ret i8* [[CALL]]
 ;
   %call = call i8* @malloc(i64 %size) inaccessiblememonly
   %bc = bitcast i8* %call to float*
   call void @clobber_memory(float* %bc)
   call void @llvm.memset.p0i8.i64(i8* %call, i8 0, i64 %size, i1 false)
   ret i8* %call
 }
 
+; This should not create a calloc and should not crash the compiler.
+define i8* @notmalloc_memset(i64 %size, i8*(i64)* %notmalloc) {
+; CHECK-LABEL: @notmalloc_memset(
+; CHECK-NEXT:    [[CALL1:%.*]] = call i8* [[NOTMALLOC:%.*]](i64 [[SIZE:%.*]])
+; CHECK-NEXT:    call void @llvm.memset.p0i8.i64(i8* [[CALL1]], i8 0, i64 [[SIZE]], i1 false)
+; CHECK-NEXT:    ret i8* [[CALL1]]
+;
+  %call1 = call i8* %notmalloc(i64 %size)
+  call void @llvm.memset.p0i8.i64(i8* %call1, i8 0, i64 %size, i1 false)
+  ret i8* %call1
+}
+
 ; PR50143
 define i8* @store_zero_after_calloc_inaccessiblememonly() {
 ; CHECK-LABEL: @store_zero_after_calloc_inaccessiblememonly(
 ; CHECK-NEXT:    [[CALL:%.*]] = tail call i8* @calloc(i64 1, i64 10) #[[ATTR6:[0-9]+]]
 ; CHECK-NEXT:    store i8 0, i8* [[CALL]], align 1
 ; CHECK-NEXT:    ret i8* [[CALL]]
 ;
   %call = tail call i8* @calloc(i64 1, i64 10)  inaccessiblememonly

llvm/test/Transforms/InstCombine/memset-1.ll

-; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --check-globals
 ; Test that the memset library call simplifier works correctly.
 ;
 ; RUN: opt < %s -instcombine -S | FileCheck %s
 
 target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128"
 
 declare i8* @memset(i8*, i32, i32)
 declare void @llvm.memset.p0i8.i32(i8* nocapture writeonly, i8, i32, i32, i1)
 declare noalias i8* @malloc(i32) #1
 
 ; Check memset(mem1, val, size) -> llvm.memset(mem1, val, size, 1).
 
 define i8* @test_simplify1(i8* %mem, i32 %val, i32 %size) {
 ; CHECK-LABEL: @test_simplify1(
 ; CHECK-NEXT:    [[TMP1:%.*]] = trunc i32 [[VAL:%.*]] to i8
 ; CHECK-NEXT:    call void @llvm.memset.p0i8.i32(i8* align 1 [[MEM:%.*]], i8 [[TMP1]], i32 [[SIZE:%.*]], i1 false)
 ; CHECK-NEXT:    ret i8* [[MEM]]
 ;
   %ret = call i8* @memset(i8* %mem, i32 %val, i32 %size)
   ret i8* %ret
 }
 
-define i8* @pr25892_lite(i32 %size) #0 {
-; CHECK-LABEL: @pr25892_lite(
-; CHECK-NEXT:    [[CALLOC:%.*]] = call i8* @calloc(i32 1, i32 [[SIZE:%.*]])
-; CHECK-NEXT:    ret i8* [[CALLOC]]
-;
-  %call1 = call i8* @malloc(i32 %size) #1
-  %call2 = call i8* @memset(i8* %call1, i32 0, i32 %size) #1
-  ret i8* %call2
-}
-
 ; FIXME: A memset intrinsic should be handled similarly to a memset() libcall.
 
 define i8* @malloc_and_memset_intrinsic(i32 %n) #0 {
 ; CHECK-LABEL: @malloc_and_memset_intrinsic(
 ; CHECK-NEXT:    [[CALL:%.*]] = call i8* @malloc(i32 [[N:%.*]])
 ; CHECK-NEXT:    call void @llvm.memset.p0i8.i32(i8* align 1 [[CALL]], i8 0, i32 [[N]], i1 false)
 ; CHECK-NEXT:    ret i8* [[CALL]]
 ;
   %call = call i8* @malloc(i32 %n)
   call void @llvm.memset.p0i8.i32(i8* %call, i8 0, i32 %n, i32 1, i1 false)
   ret i8* %call
 }
 
-; This should not create a calloc and should not crash the compiler.
-
-define i8* @notmalloc_memset(i32 %size, i8*(i32)* %notmalloc) {
-; CHECK-LABEL: @notmalloc_memset(
-; CHECK-NEXT:    [[CALL1:%.*]] = call i8* [[NOTMALLOC:%.*]](i32 [[SIZE:%.*]]) [[ATTR0:#.*]]
-; CHECK-NEXT:    call void @llvm.memset.p0i8.i32(i8* align 1 [[CALL1]], i8 0, i32 [[SIZE]], i1 false) [[ATTR0]]
-; CHECK-NEXT:    ret i8* [[CALL1]]
-;
-  %call1 = call i8* %notmalloc(i32 %size) #1
-  %call2 = call i8* @memset(i8* %call1, i32 0, i32 %size) #1
-  ret i8* %call2
-}
-
 ; FIXME: memset(malloc(x), 0, x) -> calloc(1, x)
 ; This doesn't fire currently because the malloc has more than one use.
 
 define float* @pr25892(i32 %size) #0 {
 ; CHECK-LABEL: @pr25892(
 ; CHECK-NEXT:  entry:
-; CHECK-NEXT:    [[CALL:%.*]] = tail call i8* @malloc(i32 [[SIZE:%.*]]) [[ATTR0]]
+; CHECK-NEXT:    [[CALL:%.*]] = tail call i8* @malloc(i32 [[SIZE:%.*]]) #[[ATTR0:[0-9]+]]
 ; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i8* [[CALL]], null
 ; CHECK-NEXT:    br i1 [[CMP]], label [[CLEANUP:%.*]], label [[IF_END:%.*]]
 ; CHECK:       if.end:
 ; CHECK-NEXT:    [[BC:%.*]] = bitcast i8* [[CALL]] to float*
-; CHECK-NEXT:    call void @llvm.memset.p0i8.i32(i8* nonnull align 1 [[CALL]], i8 0, i32 [[SIZE]], i1 false) [[ATTR0]]
+; CHECK-NEXT:    call void @llvm.memset.p0i8.i32(i8* nonnull align 1 [[CALL]], i8 0, i32 [[SIZE]], i1 false) #[[ATTR0]]
 ; CHECK-NEXT:    br label [[CLEANUP]]
 ; CHECK:       cleanup:
 ; CHECK-NEXT:    [[RETVAL_0:%.*]] = phi float* [ [[BC]], [[IF_END]] ], [ null, [[ENTRY:%.*]] ]
 ; CHECK-NEXT:    ret float* [[RETVAL_0]]
 ;
 entry:
   %call = tail call i8* @malloc(i32 %size) #1
   %cmp = icmp eq i8* %call, null
   br i1 %cmp, label %cleanup, label %if.end
 if.end:
   %bc = bitcast i8* %call to float*
   %call2 = tail call i8* @memset(i8* nonnull %call, i32 0, i32 %size) #1
   br label %cleanup
 cleanup:
   %retval.0 = phi float* [ %bc, %if.end ], [ null, %entry ]
   ret float* %retval.0
 }
 
 ; If there's a calloc transform, the store must also be eliminated.
 
 define i8* @buffer_is_modified_then_memset(i32 %size) {
 ; CHECK-LABEL: @buffer_is_modified_then_memset(
-; CHECK-NEXT:    [[PTR:%.*]] = tail call i8* @malloc(i32 [[SIZE:%.*]]) [[ATTR0]]
+; CHECK-NEXT:    [[PTR:%.*]] = tail call i8* @malloc(i32 [[SIZE:%.*]]) #[[ATTR0]]
 ; CHECK-NEXT:    store i8 1, i8* [[PTR]], align 1
-; CHECK-NEXT:    call void @llvm.memset.p0i8.i32(i8* nonnull align 1 [[PTR]], i8 0, i32 [[SIZE]], i1 false) [[ATTR0]]
+; CHECK-NEXT:    call void @llvm.memset.p0i8.i32(i8* nonnull align 1 [[PTR]], i8 0, i32 [[SIZE]], i1 false) #[[ATTR0]]
 ; CHECK-NEXT:    ret i8* [[PTR]]
 ;
   %ptr = tail call i8* @malloc(i32 %size) #1
   store i8 1, i8* %ptr           ;; fdata[0] = 1;
   %memset = tail call i8* @memset(i8* nonnull %ptr, i32 0, i32 %size) #1
   ret i8* %memset
 }
 
 define i8* @memset_size_select(i1 %b, i8* %ptr) {
 ; CHECK-LABEL: @memset_size_select(
 ; CHECK-NEXT:    [[SIZE:%.*]] = select i1 [[B:%.*]], i32 10, i32 50
-; CHECK-NEXT:    call void @llvm.memset.p0i8.i32(i8* noundef nonnull align 1 dereferenceable(10) [[PTR:%.*]], i8 0, i32 [[SIZE]], i1 false) [[ATTR0]]
+; CHECK-NEXT:    call void @llvm.memset.p0i8.i32(i8* noundef nonnull align 1 dereferenceable(10) [[PTR:%.*]], i8 0, i32 [[SIZE]], i1 false) #[[ATTR0]]
 ; CHECK-NEXT:    ret i8* [[PTR]]
 ;
   %size = select i1 %b, i32 10, i32 50
   %memset = tail call i8* @memset(i8* nonnull %ptr, i32 0, i32 %size) #1
   ret i8* %memset
 }
 
 
 define i8* @memset_size_select2(i1 %b, i8* %ptr) {
 ; CHECK-LABEL: @memset_size_select2(
 ; CHECK-NEXT:    [[SIZE:%.*]] = select i1 [[B:%.*]], i32 10, i32 50
-; CHECK-NEXT:    call void @llvm.memset.p0i8.i32(i8* noundef nonnull align 1 dereferenceable(80) [[PTR:%.*]], i8 0, i32 [[SIZE]], i1 false) [[ATTR0]]
+; CHECK-NEXT:    call void @llvm.memset.p0i8.i32(i8* noundef nonnull align 1 dereferenceable(80) [[PTR:%.*]], i8 0, i32 [[SIZE]], i1 false) #[[ATTR0]]
 ; CHECK-NEXT:    ret i8* [[PTR]]
 ;
   %size = select i1 %b, i32 10, i32 50
   %memset = tail call i8* @memset(i8* nonnull dereferenceable(80) %ptr, i32 0, i32 %size) #1
   ret i8* %memset
 }
 
 define i8* @memset_size_select3(i1 %b, i8* %ptr) {
 ; CHECK-LABEL: @memset_size_select3(
 ; CHECK-NEXT:    [[SIZE:%.*]] = select i1 [[B:%.*]], i32 10, i32 50
 ; CHECK-NEXT:    call void @llvm.memset.p0i8.i32(i8* noundef nonnull align 1 dereferenceable(40) [[PTR:%.*]], i8 0, i32 [[SIZE]], i1 false)
 ; CHECK-NEXT:    ret i8* [[PTR]]
 ;
   %size = select i1 %b, i32 10, i32 50
   %memset = tail call i8* @memset(i8* dereferenceable_or_null(40) %ptr, i32 0, i32 %size)
   ret i8* %memset
 }
 
 define i8* @memset_size_select4(i1 %b, i8* %ptr) {
 ; CHECK-LABEL: @memset_size_select4(
 ; CHECK-NEXT:    [[SIZE:%.*]] = select i1 [[B:%.*]], i32 10, i32 50
-; CHECK-NEXT:    call void @llvm.memset.p0i8.i32(i8* noundef nonnull align 1 dereferenceable(40) [[PTR:%.*]], i8 0, i32 [[SIZE]], i1 false) [[ATTR0]]
+; CHECK-NEXT:    call void @llvm.memset.p0i8.i32(i8* noundef nonnull align 1 dereferenceable(40) [[PTR:%.*]], i8 0, i32 [[SIZE]], i1 false) #[[ATTR0]]
 ; CHECK-NEXT:    ret i8* [[PTR]]
 ;
   %size = select i1 %b, i32 10, i32 50
   %memset = tail call i8* @memset(i8* nonnull dereferenceable_or_null(40) %ptr, i32 0, i32 %size) #1
   ret i8* %memset
 }
 
 define i8* @memset_size_ashr(i1 %b, i8* %ptr, i32 %v) {
 ; CHECK-LABEL: @memset_size_ashr(
 ; CHECK-NEXT:    [[SIZE:%.*]] = ashr i32 -2, [[V:%.*]]
-; CHECK-NEXT:    call void @llvm.memset.p0i8.i32(i8* noundef nonnull align 1 [[PTR:%.*]], i8 0, i32 [[SIZE]], i1 false) [[ATTR0]]
+; CHECK-NEXT:    call void @llvm.memset.p0i8.i32(i8* noundef nonnull align 1 [[PTR:%.*]], i8 0, i32 [[SIZE]], i1 false) #[[ATTR0]]
 ; CHECK-NEXT:    ret i8* [[PTR]]
 ;
   %size = ashr i32 -2, %v
   %memset = tail call i8* @memset(i8* nonnull %ptr, i32 0, i32 %size) #1
   ret i8* %memset
 }
 
 define i8* @memset_attrs1(i1 %b, i8* %ptr, i32 %size) {
 ; CHECK-LABEL: @memset_attrs1(
-; CHECK-NEXT:    call void @llvm.memset.p0i8.i32(i8* align 1 dereferenceable_or_null(40) [[PTR:%.*]], i8 0, i32 [[SIZE:%.*]], i1 false) [[ATTR0]]
+; CHECK-NEXT:    call void @llvm.memset.p0i8.i32(i8* align 1 dereferenceable_or_null(40) [[PTR:%.*]], i8 0, i32 [[SIZE:%.*]], i1 false) #[[ATTR0]]
 ; CHECK-NEXT:    ret i8* [[PTR]]
 ;
   %memset = tail call i8* @memset(i8* dereferenceable_or_null(40) %ptr, i32 0, i32 %size) #1
   ret i8* %memset
 }
 
 ; be sure to drop nonnull since size is unknown and can be 0
 ; do not change dereferenceable attribute
 define i8* @memset_attrs2(i1 %b, i8* %ptr, i32 %size) {
 ; CHECK-LABEL: @memset_attrs2(
-; CHECK-NEXT:    call void @llvm.memset.p0i8.i32(i8* nonnull align 1 dereferenceable(40) [[PTR:%.*]], i8 0, i32 [[SIZE:%.*]], i1 false) [[ATTR0]]
+; CHECK-NEXT:    call void @llvm.memset.p0i8.i32(i8* nonnull align 1 dereferenceable(40) [[PTR:%.*]], i8 0, i32 [[SIZE:%.*]], i1 false) #[[ATTR0]]
 ; CHECK-NEXT:    ret i8* [[PTR]]
 ;
   %memset = tail call i8* @memset(i8* nonnull dereferenceable(40) %ptr, i32 0, i32 %size) #1
   ret i8* %memset
 }
 
 ; size is unknown, just copy attrs, no changes in attrs
 define i8* @memset_attrs3(i1 %b, i8* %ptr, i32 %size) {
 ; CHECK-LABEL: @memset_attrs3(
-; CHECK-NEXT:    call void @llvm.memset.p0i8.i32(i8* nonnull align 1 dereferenceable_or_null(40) [[PTR:%.*]], i8 0, i32 [[SIZE:%.*]], i1 false) [[ATTR0]]
+; CHECK-NEXT:    call void @llvm.memset.p0i8.i32(i8* nonnull align 1 dereferenceable_or_null(40) [[PTR:%.*]], i8 0, i32 [[SIZE:%.*]], i1 false) #[[ATTR0]]
 ; CHECK-NEXT:    ret i8* [[PTR]]
 ;
   %memset = tail call i8* @memset(i8* nonnull dereferenceable_or_null(40) %ptr, i32 0, i32 %size) #1
   ret i8* %memset
 }
 
 ; be sure to drop nonnull since size is unknown and can be 0
 define i8* @memset_attrs4(i1 %b, i8* %ptr, i32 %size) {
 ; CHECK-LABEL: @memset_attrs4(
-; CHECK-NEXT:    call void @llvm.memset.p0i8.i32(i8* nonnull align 1 [[PTR:%.*]], i8 0, i32 [[SIZE:%.*]], i1 false) [[ATTR0]]
+; CHECK-NEXT:    call void @llvm.memset.p0i8.i32(i8* nonnull align 1 [[PTR:%.*]], i8 0, i32 [[SIZE:%.*]], i1 false) #[[ATTR0]]
 ; CHECK-NEXT:    ret i8* [[PTR]]
 ;
   %memset = tail call i8* @memset(i8* nonnull %ptr, i32 0, i32 %size) #1
   ret i8* %memset
 }
 
 define i8* @test_no_incompatible_attr(i8* %mem, i32 %val, i32 %size) {
 ; CHECK-LABEL: @test_no_incompatible_attr(
 ; CHECK-NEXT:    [[TMP1:%.*]] = trunc i32 [[VAL:%.*]] to i8
 ; CHECK-NEXT:    call void @llvm.memset.p0i8.i32(i8* align 1 [[MEM:%.*]], i8 [[TMP1]], i32 [[SIZE:%.*]], i1 false)
 ; CHECK-NEXT:    ret i8* [[MEM]]
 ;
   %ret = call dereferenceable(1) i8* @memset(i8* %mem, i32 %val, i32 %size)
   ret i8* %ret
 }
 
 attributes #0 = { nounwind ssp uwtable }
 attributes #1 = { nounwind }
 attributes #2 = { nounwind readnone }
 
+;.
+; CHECK: attributes #[[ATTR0]] = { nounwind }
+; CHECK: attributes #[[ATTR1:[0-9]+]] = { nounwind ssp uwtable }
+; CHECK: attributes #[[ATTR2:[0-9]+]] = { argmemonly nofree nounwind willreturn writeonly }
+;.