--- b/include/clang/Basic/TargetInfo.h
+++ a/include/clang/Basic/TargetInfo.h
@@ -612,8 +612,8 @@
   }
 
   /// Return the largest alignment for which a suitably-sized allocation with
+  /// '::operator new(size_t)' is guaranteed to produce a correctly-aligned
+  /// pointer.
-  /// '::operator new(size_t)' or 'malloc' is guaranteed to produce a
-  /// correctly-aligned pointer.
   unsigned getNewAlign() const {
     return NewAlign ? NewAlign : std::max(LongDoubleAlign, LongLongAlign);
   }
--- b/lib/CodeGen/CGCall.cpp
+++ a/lib/CodeGen/CGCall.cpp
@@ -2048,24 +2048,6 @@
       // allows it to work on indirect virtual function calls.
       if (AttrOnCallSite && TargetDecl->hasAttr<NoMergeAttr>())
         FuncAttrs.addAttribute(llvm::Attribute::NoMerge);
-
-      // Add known guaranteed alignment for allocation functions.
-      if (unsigned BuiltinID = Fn->getBuiltinID()) {
-        switch (BuiltinID) {
-        case Builtin::BIaligned_alloc:
-        case Builtin::BIcalloc:
-        case Builtin::BImalloc:
-        case Builtin::BImemalign:
-        case Builtin::BIrealloc:
-        case Builtin::BIstrdup:
-        case Builtin::BIstrndup:
-          RetAttrs.addAlignmentAttr(Context.getTargetInfo().getNewAlign() /
-                                    Context.getTargetInfo().getCharWidth());
-          break;
-        default:
-          break;
-        }
-      }
     }
 
     // 'const', 'pure' and 'noalias' attributed functions are also nounwind.
--- b/test/CodeGen/alloc-fns-alignment.c
+++ /dev/null
@@ -1,35 +0,0 @@
-// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -emit-llvm < %s | FileCheck %s --check-prefix=ALIGN16
-// RUN: %clang_cc1 -triple x86_64-windows-msvc      -emit-llvm < %s | FileCheck %s --check-prefix=ALIGN16
-// RUN: %clang_cc1 -triple i386-apple-darwin        -emit-llvm < %s | FileCheck %s --check-prefix=ALIGN16
-// RUN: %clang_cc1 -triple i386-unknown-linux-gnu   -emit-llvm < %s | FileCheck %s --check-prefix=ALIGN8
-// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -fno-builtin-malloc  -emit-llvm < %s  | FileCheck %s --check-prefix=NOBUILTIN-MALLOC
-// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -fno-builtin-calloc  -emit-llvm < %s  | FileCheck %s --check-prefix=NOBUILTIN-CALLOC
-// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -fno-builtin-realloc -emit-llvm < %s  | FileCheck %s --check-prefix=NOBUILTIN-REALLOC
-
-typedef __SIZE_TYPE__ size_t;
-
-void *malloc(size_t);
-void *calloc(size_t, size_t);
-void *realloc(void *, size_t);
-
-void *malloc_test(size_t n) {
-  return malloc(n);
-}
-
-void *calloc_test(size_t n) {
-  return calloc(1, n);
-}
-
-void *raalloc_test(void *p, size_t n) {
-  return realloc(p, n);
-}
-
-// ALIGN16: align 16 i8* @malloc
-// ALIGN16: align 16 i8* @calloc
-// ALIGN16: align 16 i8* @realloc
-// ALIGN8: align 8 i8* @malloc
-// ALIGN8: align 8 i8* @calloc
-// ALIGN8: align 8 i8* @realloc
-// NOBUILTIN-MALLOC: declare i8* @malloc
-// NOBUILTIN-CALLOC: declare i8* @calloc
-// NOBUILTIN-REALLOC: declare i8* @realloc