diff --git a/llvm/lib/Transforms/Utils/BuildLibCalls.cpp b/llvm/lib/Transforms/Utils/BuildLibCalls.cpp
--- a/llvm/lib/Transforms/Utils/BuildLibCalls.cpp
+++ b/llvm/lib/Transforms/Utils/BuildLibCalls.cpp
@@ -255,6 +255,14 @@
   return true;
 }
 
+static bool setAllocKind(Function &F, AllocFnKind K) {
+  if (F.hasFnAttribute(Attribute::AllocKind))
+    return false;
+  F.addFnAttr(
+      Attribute::get(F.getContext(), Attribute::AllocKind, uint64_t(K)));
+  return true;
+}
+
 bool llvm::inferLibFuncAttributes(Module *M, StringRef Name,
                                   const TargetLibraryInfo &TLI) {
   Function *F = M->getFunction(Name);
@@ -457,6 +465,7 @@
     Changed |= setAllocFamily(F, "malloc");
     LLVM_FALLTHROUGH;
   case LibFunc_vec_malloc:
+    Changed |= setAllocKind(F, AllocFnKind::New | AllocFnKind::Uninitialized);
     Changed |= setAllocFamily(F, "vec_malloc");
     Changed |= setAllocSize(F, 0, None);
     Changed |= setOnlyAccessesInaccessibleMemory(F);
@@ -522,6 +531,8 @@
     return Changed;
   case LibFunc_memalign:
     Changed |= setAllocFamily(F, "malloc");
+    Changed |= setAllocKind(F, AllocFnKind::New | AllocFnKind::Aligned |
+                                   AllocFnKind::Uninitialized);
     Changed |= setAllocSize(F, 1, None);
     Changed |= setAlignedAllocParam(F, 0);
     Changed |= setOnlyAccessesInaccessibleMemory(F);
@@ -547,6 +558,7 @@
     Changed |= setAllocFamily(F, "malloc");
     LLVM_FALLTHROUGH;
   case LibFunc_vec_realloc:
+    Changed |= setAllocKind(F, AllocFnKind::Resize);
     Changed |= setAllocFamily(F, "vec_malloc");
     Changed |= setAllocatedPointerParam(F, 0);
     Changed |= setAllocSize(F, 1, None);
@@ -625,6 +637,7 @@
     Changed |= setAllocFamily(F, "malloc");
     LLVM_FALLTHROUGH;
   case LibFunc_vec_calloc:
+    Changed |= setAllocKind(F, AllocFnKind::New | AllocFnKind::Zeroed);
     Changed |= setAllocFamily(F, "vec_malloc");
     Changed |= setAllocSize(F, 0, 1);
     Changed |= setOnlyAccessesInaccessibleMemory(F);
@@ -687,6 +700,7 @@
     Changed |= setAllocFamily(F, "malloc");
     LLVM_FALLTHROUGH;
   case LibFunc_vec_free:
+    Changed |= setAllocKind(F, AllocFnKind::Free);
     Changed |= setAllocFamily(F, "vec_malloc");
     Changed |= setAllocatedPointerParam(F, 0);
     Changed |= setOnlyAccessesInaccessibleMemOrArgMem(F);
diff --git a/llvm/test/Transforms/Attributor/lowerheap.ll b/llvm/test/Transforms/Attributor/lowerheap.ll
--- a/llvm/test/Transforms/Attributor/lowerheap.ll
+++ b/llvm/test/Transforms/Attributor/lowerheap.ll
@@ -67,9 +67,9 @@
 ; IS________OPM: attributes #[[ATTR1]] = { nounwind }
 ;.
 ; IS________NPM: attributes #[[ATTR0:[0-9]+]] = { mustprogress nounwind willreturn }
-; IS________NPM: attributes #[[ATTR1:[0-9]+]] = { inaccessiblememonly mustprogress nofree nounwind willreturn allocsize(0) "alloc-family"="malloc" }
-; IS________NPM: attributes #[[ATTR2:[0-9]+]] = { inaccessiblememonly mustprogress nofree nounwind willreturn allocsize(0,1) "alloc-family"="malloc" }
-; IS________NPM: attributes #[[ATTR3:[0-9]+]] = { inaccessiblemem_or_argmemonly mustprogress nounwind willreturn "alloc-family"="malloc" }
+; IS________NPM: attributes #[[ATTR1:[0-9]+]] = { inaccessiblememonly mustprogress nofree nounwind willreturn allockind("new,uninitialized") allocsize(0) "alloc-family"="malloc" }
+; IS________NPM: attributes #[[ATTR2:[0-9]+]] = { inaccessiblememonly mustprogress nofree nounwind willreturn allockind("new,zeroed") allocsize(0,1) "alloc-family"="malloc" }
+; IS________NPM: attributes #[[ATTR3:[0-9]+]] = { inaccessiblemem_or_argmemonly mustprogress nounwind willreturn allockind("free") "alloc-family"="malloc" }
 ; IS________NPM: attributes #[[ATTR4]] = { nounwind willreturn }
 ; IS________NPM: attributes #[[ATTR5:[0-9]+]] = { argmemonly nofree nounwind willreturn writeonly }
 ;.
diff --git a/llvm/test/Transforms/InferFunctionAttrs/annotate.ll b/llvm/test/Transforms/InferFunctionAttrs/annotate.ll
--- a/llvm/test/Transforms/InferFunctionAttrs/annotate.ll
+++ b/llvm/test/Transforms/InferFunctionAttrs/annotate.ll
@@ -220,7 +220,7 @@
 ; CHECK: declare x86_fp80 @acosl(x86_fp80) [[NOFREE_NOUNWIND_WILLRETURN_WRITEONLY]]
 declare x86_fp80 @acosl(x86_fp80)
 
-; CHECK: declare noalias noundef i8* @aligned_alloc(i64 allocalign noundef, i64 noundef) [[INACCESSIBLEMEMONLY_NOFREE_NOUNWIND_WILLRETURN_ALLOCSIZE1_FAMILY_MALLOC:#[0-9]+]]
+; CHECK: declare noalias noundef i8* @aligned_alloc(i64 allocalign noundef, i64 noundef) [[INACCESSIBLEMEMONLY_NOFREE_NOUNWIND_WILLRETURN_ALLOCKIND18_ALLOCSIZE1_FAMILY_MALLOC:#[0-9]+]]
 declare i8* @aligned_alloc(i64, i64)
 
 ; CHECK: declare double @asin(double) [[NOFREE_NOUNWIND_WILLRETURN_WRITEONLY]]
@@ -290,7 +290,7 @@
 ; CHECK: declare void @bzero(i8* nocapture writeonly, i64)  [[ARGMEMONLY_NOFREE_NOUNWIND_WILLRETURN]]
 declare void @bzero(i8*, i64)
 
-; CHECK: declare noalias noundef i8* @calloc(i64 noundef, i64 noundef) [[INACCESSIBLEMEMONLY_MUSTPROGRESS_NOFREE_NOUNWIND_WILLRETURN_ALLOCSIZE01_FAMILY_MALLOC:#[0-9]+]]
+; CHECK: declare noalias noundef i8* @calloc(i64 noundef, i64 noundef) [[INACCESSIBLEMEMONLY_MUSTPROGRESS_NOFREE_NOUNWIND_WILLRETURN_ALLOCKIND34_ALLOCSIZE01_FAMILY_MALLOC:#[0-9]+]]
 declare i8* @calloc(i64, i64)
 
 ; CHECK: declare double @cbrt(double) [[NOFREE_NOUNWIND_WILLRETURN_WRITEONLY]]
@@ -490,7 +490,7 @@
 ; CHECK: declare noundef i64 @fread(i8* nocapture noundef, i64 noundef, i64 noundef, %opaque* nocapture noundef) [[NOFREE_NOUNWIND]]
 declare i64 @fread(i8*, i64, i64, %opaque*)
 
-; CHECK: declare void @free(i8* allocptr nocapture noundef) [[INACCESSIBLEMEMORARGMEMONLY_NOUNWIND_WILLRETURN_FAMILY_MALLOC:#[0-9]+]]
+; CHECK: declare void @free(i8* allocptr nocapture noundef) [[INACCESSIBLEMEMORARGMEMONLY_NOUNWIND_WILLRETURN_ALLOCKIND8_FAMILY_MALLOC:#[0-9]+]]
 declare void @free(i8*)
 
 ; CHECK: declare double @frexp(double, i32* nocapture) [[NOFREE_NOUNWIND_WILLRETURN:#[0-9]+]]
@@ -656,7 +656,7 @@
 ; CHECK-LINUX: declare noundef i32 @lstat64(i8* nocapture noundef readonly, %opaque* nocapture noundef) [[NOFREE_NOUNWIND]]
 declare i32 @lstat64(i8*, %opaque*)
 
-; CHECK: declare noalias noundef i8* @malloc(i64 noundef) [[INACCESSIBLEMEMONLY_NOFREE_NOUNWIND_WILLRETURN_ALLOCSIZE0_FAMILY_MALLOC:#[0-9]+]]
+; CHECK: declare noalias noundef i8* @malloc(i64 noundef) [[INACCESSIBLEMEMONLY_NOFREE_NOUNWIND_WILLRETURN_ALLOCKIND18_ALLOCSIZE0_FAMILY_MALLOC:#[0-9]+]]
 declare i8* @malloc(i64)
 
 ; CHECK-LINUX: declare noalias noundef i8* @memalign(i64 allocalign, i64) [[INACCESSIBLEMEMONLY_NOFREE_NOUNWIND_WILLRETURN:#[0-9]+]]
@@ -779,10 +779,10 @@
 ; CHECK: declare noundef i64 @readlink(i8* nocapture noundef readonly, i8* nocapture noundef, i64 noundef) [[NOFREE_NOUNWIND]]
 declare i64 @readlink(i8*, i8*, i64)
 
-; CHECK: declare noalias noundef i8* @realloc(i8* allocptr nocapture, i64 noundef) [[INACCESSIBLEMEMORARGMEMONLY_NOUNWIND_WILLRETURN_ALLOCSIZE_FAMILY_MALLOC:#[0-9]+]]
+; CHECK: declare noalias noundef i8* @realloc(i8* allocptr nocapture, i64 noundef) [[INACCESSIBLEMEMORARGMEMONLY_NOUNWIND_WILLRETURN_ALLOCKIND4_ALLOCSIZE1_FAMILY_MALLOC:#[0-9]+]]
 declare i8* @realloc(i8*, i64)
 
-; CHECK: declare noalias noundef i8* @reallocf(i8* allocptr nocapture, i64 noundef) [[INACCESSIBLEMEMORARGMEMONLY_NOUNWIND_WILLRETURN_ALLOCSIZE_FAMILY_MALLOC]]
+; CHECK: declare noalias noundef i8* @reallocf(i8* allocptr nocapture, i64 noundef) [[INACCESSIBLEMEMORARGMEMONLY_NOUNWIND_WILLRETURN_ALLOCKIND4_ALLOCSIZE1_FAMILY_MALLOC]]
 declare i8* @reallocf(i8*, i64)
 
 ; CHECK: declare noundef i8* @realpath(i8* nocapture noundef readonly, i8* noundef) [[NOFREE_NOUNWIND]]
@@ -1031,7 +1031,7 @@
 ; CHECK: declare noundef i32 @utimes(i8* nocapture noundef readonly, %opaque* nocapture noundef readonly) [[NOFREE_NOUNWIND]]
 declare i32 @utimes(i8*, %opaque*)
 
-; CHECK: declare noalias noundef i8* @valloc(i64 noundef) [[INACCESSIBLEMEMONLY_NOFREE_NOUNWIND_WILLRETURN_ALLOCSIZE0_FAMILY_MALLOC]]
+; CHECK: declare noalias noundef i8* @valloc(i64 noundef) [[INACCESSIBLEMEMONLY_NOFREE_NOUNWIND_WILLRETURN_ALLOCKIND18_ALLOCSIZE0_FAMILY_MALLOC]]
 declare i8* @valloc(i64)
 
 ; CHECK: declare noundef i32 @vfprintf(%opaque* nocapture noundef, i8* nocapture noundef readonly, %opaque* noundef) [[NOFREE_NOUNWIND]]
@@ -1070,18 +1070,18 @@
 ; CHECK-DAG: attributes [[NOFREE_NOUNWIND_WILLRETURN]] = { mustprogress nofree nounwind willreturn }
 ; CHECK-DAG: attributes [[NOFREE_NOUNWIND_WILLRETURN_WRITEONLY]] = { mustprogress nofree nounwind willreturn writeonly }
 ; CHECK-DAG: attributes [[NOFREE_NOUNWIND]] = { nofree nounwind }
-; CHECK-DAG: attributes [[INACCESSIBLEMEMONLY_NOFREE_NOUNWIND_WILLRETURN_ALLOCSIZE1_FAMILY_MALLOC]] = { inaccessiblememonly mustprogress nofree nounwind willreturn allocsize(1) "alloc-family"="malloc" }
+; CHECK-DAG: attributes [[INACCESSIBLEMEMONLY_NOFREE_NOUNWIND_WILLRETURN_ALLOCKIND18_ALLOCSIZE1_FAMILY_MALLOC]] = { inaccessiblememonly mustprogress nofree nounwind willreturn allockind("new,uninitialized") allocsize(1) "alloc-family"="malloc" }
 ; CHECK-DAG: attributes [[NOFREE_NOUNWIND_READONLY_WILLRETURN]] = { mustprogress nofree nounwind readonly willreturn }
 ; CHECK-DAG: attributes [[ARGMEMONLY_NOFREE_NOUNWIND_WILLRETURN]] = { argmemonly mustprogress nofree nounwind willreturn }
-; CHECK-DAG: attributes [[INACCESSIBLEMEMONLY_MUSTPROGRESS_NOFREE_NOUNWIND_WILLRETURN_ALLOCSIZE01_FAMILY_MALLOC]] = { inaccessiblememonly mustprogress nofree nounwind willreturn allocsize(0,1) "alloc-family"="malloc" }
+; CHECK-DAG: attributes [[INACCESSIBLEMEMONLY_MUSTPROGRESS_NOFREE_NOUNWIND_WILLRETURN_ALLOCKIND34_ALLOCSIZE01_FAMILY_MALLOC]] = { inaccessiblememonly mustprogress nofree nounwind willreturn allockind("new,zeroed") allocsize(0,1) "alloc-family"="malloc" }
 ; CHECK-DAG: attributes [[NOFREE_NOUNWIND_READONLY]] = { nofree nounwind readonly }
-; CHECK-DAG: attributes [[INACCESSIBLEMEMORARGMEMONLY_NOUNWIND_WILLRETURN_FAMILY_MALLOC]] = { inaccessiblemem_or_argmemonly mustprogress nounwind willreturn "alloc-family"="malloc" }
+; CHECK-DAG: attributes [[INACCESSIBLEMEMORARGMEMONLY_NOUNWIND_WILLRETURN_ALLOCKIND8_FAMILY_MALLOC]] = { inaccessiblemem_or_argmemonly mustprogress nounwind willreturn allockind("free") "alloc-family"="malloc" }
 ; CHECK-DAG: attributes [[NOFREE_WILLRETURN]] = { mustprogress nofree willreturn }
-; CHECK-DAG: attributes [[INACCESSIBLEMEMONLY_NOFREE_NOUNWIND_WILLRETURN_ALLOCSIZE0_FAMILY_MALLOC]] = { inaccessiblememonly mustprogress nofree nounwind willreturn allocsize(0) "alloc-family"="malloc" }
+; CHECK-DAG: attributes [[INACCESSIBLEMEMONLY_NOFREE_NOUNWIND_WILLRETURN_ALLOCKIND18_ALLOCSIZE0_FAMILY_MALLOC]] = { inaccessiblememonly mustprogress nofree nounwind willreturn allockind("new,uninitialized") allocsize(0) "alloc-family"="malloc" }
 ; CHECK-DAG: attributes [[ARGMEMONLY_NOFREE_NOUNWIND_READONLY_WILLRETURN]] = { argmemonly mustprogress nofree nounwind readonly willreturn }
 ; CHECK-DAG: attributes [[NOFREE]] = { nofree }
 ; CHECK-DAG: attributes [[ARGMEMONLY_NOFREE_NOUNWIND]] = { argmemonly nofree nounwind }
-; CHECK-DAG: attributes [[INACCESSIBLEMEMORARGMEMONLY_NOUNWIND_WILLRETURN_ALLOCSIZE_FAMILY_MALLOC]] = { inaccessiblemem_or_argmemonly mustprogress nounwind willreturn allocsize(1) "alloc-family"="malloc" }
+; CHECK-DAG: attributes [[INACCESSIBLEMEMORARGMEMONLY_NOUNWIND_WILLRETURN_ALLOCKIND4_ALLOCSIZE1_FAMILY_MALLOC]] = { inaccessiblemem_or_argmemonly mustprogress nounwind willreturn allockind("resize") allocsize(1) "alloc-family"="malloc" }
 ; CHECK-DAG: attributes [[INACCESSIBLEMEMORARGONLY_NOFREE_NOUNWIND_WILLRETURN_FAMILY_MALLOC]] = { inaccessiblemem_or_argmemonly mustprogress nofree nounwind willreturn "alloc-family"="malloc" }
 ; CHECK-DAG: attributes [[INACCESSIBLEMEMORARGONLY_NOFREE_NOUNWIND_WILLRETURN_ALLOCSIZE_FAMILY_MALLOC]] = { inaccessiblemem_or_argmemonly mustprogress nofree nounwind willreturn allocsize(1) "alloc-family"="malloc" }