Index: cfe/trunk/include/clang/Basic/BuiltinsX86.def
===================================================================
--- cfe/trunk/include/clang/Basic/BuiltinsX86.def
+++ cfe/trunk/include/clang/Basic/BuiltinsX86.def
@@ -1814,6 +1814,9 @@
 TARGET_BUILTIN(__builtin_ia32_monitorx, "vv*UiUi", "", "mwaitx")
 TARGET_BUILTIN(__builtin_ia32_mwaitx, "vUiUiUi", "", "mwaitx")
 
+// CLZERO
+TARGET_BUILTIN(__builtin_ia32_clzero, "vv*", "", "clzero")
+
 // MSVC
 TARGET_HEADER_BUILTIN(_BitScanForward, "UcULi*ULi", "nh", "intrin.h", ALL_MS_LANGUAGES, "")
 TARGET_HEADER_BUILTIN(_BitScanReverse, "UcULi*ULi", "nh", "intrin.h", ALL_MS_LANGUAGES, "")
Index: cfe/trunk/include/clang/Driver/Options.td
===================================================================
--- cfe/trunk/include/clang/Driver/Options.td
+++ cfe/trunk/include/clang/Driver/Options.td
@@ -1714,6 +1714,7 @@
 def mno_xsavec : Flag<["-"], "mno-xsavec">, Group<m_x86_Features_Group>;
 def mno_xsaves : Flag<["-"], "mno-xsaves">, Group<m_x86_Features_Group>;
 def mno_mwaitx : Flag<["-"], "mno-mwaitx">, Group<m_x86_Features_Group>;
+def mno_clzero : Flag<["-"], "mno-clzero">, Group<m_x86_Features_Group>;
 def mno_pku : Flag<["-"], "mno-pku">, Group<m_x86_Features_Group>;
 def mno_clflushopt : Flag<["-"], "mno-clflushopt">, Group<m_x86_Features_Group>;
 def mno_clwb : Flag<["-"], "mno-clwb">, Group<m_x86_Features_Group>;
@@ -1913,6 +1914,7 @@
 def mxsavec : Flag<["-"], "mxsavec">, Group<m_x86_Features_Group>;
 def mxsaves : Flag<["-"], "mxsaves">, Group<m_x86_Features_Group>;
 def mmwaitx : Flag<["-"], "mmwaitx">, Group<m_x86_Features_Group>;
+def mclzero : Flag<["-"], "mclzero">, Group<m_x86_Features_Group>;
 def mclflushopt : Flag<["-"], "mclflushopt">, Group<m_x86_Features_Group>;
 def mclwb : Flag<["-"], "mclwb">, Group<m_x86_Features_Group>;
 def mmovbe : Flag<["-"], "mmovbe">, Group<m_x86_Features_Group>;
Index: cfe/trunk/lib/Basic/Targets.cpp
===================================================================
--- cfe/trunk/lib/Basic/Targets.cpp
+++ cfe/trunk/lib/Basic/Targets.cpp
@@ -2489,6 +2489,7 @@
   bool HasXSAVEC = false;
   bool HasXSAVES = false;
   bool HasMWAITX = false;
+  bool HasCLZERO = false;
   bool HasPKU = false;
   bool HasCLFLUSHOPT = false;
   bool HasCLWB = false;
@@ -3201,6 +3202,7 @@
     setFeatureEnabledImpl(Features, "bmi", true);
     setFeatureEnabledImpl(Features, "bmi2", true);
     setFeatureEnabledImpl(Features, "clflushopt", true);
+    setFeatureEnabledImpl(Features, "clzero", true);
     setFeatureEnabledImpl(Features, "cx16", true);
     setFeatureEnabledImpl(Features, "f16c", true);
     setFeatureEnabledImpl(Features, "fma", true);
@@ -3560,6 +3562,8 @@
       HasCLWB = true;
     } else if (Feature == "+prefetchwt1") {
       HasPREFETCHWT1 = true;
+    } else if (Feature == "+clzero") {
+      HasCLZERO = true;
     }
 
     X86SSEEnum Level = llvm::StringSwitch<X86SSEEnum>(Feature)
@@ -3887,6 +3891,8 @@
     Builder.defineMacro("__SGX__");
   if (HasPREFETCHWT1)
     Builder.defineMacro("__PREFETCHWT1__");
+  if (HasCLZERO)
+    Builder.defineMacro("__CLZERO__");
 
   // Each case falls through to the previous one here.
   switch (SSELevel) {
@@ -3973,6 +3979,7 @@
       .Case("bmi2", HasBMI2)
       .Case("clflushopt", HasCLFLUSHOPT)
       .Case("clwb", HasCLWB)
+      .Case("clzero", HasCLZERO)
       .Case("cx16", HasCX16)
       .Case("f16c", HasF16C)
       .Case("fma", HasFMA)
Index: cfe/trunk/lib/Headers/CMakeLists.txt
===================================================================
--- cfe/trunk/lib/Headers/CMakeLists.txt
+++ cfe/trunk/lib/Headers/CMakeLists.txt
@@ -28,6 +28,7 @@
   __clang_cuda_intrinsics.h
   __clang_cuda_math_forward_declares.h
   __clang_cuda_runtime_wrapper.h
+  clzerointrin.h
   cpuid.h
   clflushoptintrin.h
   emmintrin.h
Index: cfe/trunk/lib/Headers/clzerointrin.h
===================================================================
--- cfe/trunk/lib/Headers/clzerointrin.h
+++ cfe/trunk/lib/Headers/clzerointrin.h
@@ -0,0 +1,50 @@
+/*===----------------------- clzerointrin.h - CLZERO ----------------------===
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ *===-----------------------------------------------------------------------===
+ */
+#ifndef __X86INTRIN_H
+#error "Never use <clzerointrin.h> directly; include <x86intrin.h> instead."
+#endif
+
+#ifndef _CLZEROINTRIN_H
+#define _CLZEROINTRIN_H
+
+/* Define the default attributes for the functions in this file. */
+#define __DEFAULT_FN_ATTRS \
+  __attribute__((__always_inline__, __nodebug__,  __target__("clzero")))
+
+/// \brief Loads the cache line address and zero's out the cacheline
+///
+/// \headerfile <clzerointrin.h>
+///
+/// This intrinsic corresponds to the <c> CLZERO </c> instruction.
+///
+/// \param __line
+///    A pointer to a cacheline which needs to be zeroed out.
+static __inline__ void __DEFAULT_FN_ATTRS
+_mm_clzero (void * __line)
+{
+  __builtin_ia32_clzero ((void *)__line);
+}
+
+#undef __DEFAULT_FN_ATTRS 
+
+#endif /* _CLZEROINTRIN_H */
Index: cfe/trunk/lib/Headers/module.modulemap
===================================================================
--- cfe/trunk/lib/Headers/module.modulemap
+++ cfe/trunk/lib/Headers/module.modulemap
@@ -61,6 +61,7 @@
     textual header "xopintrin.h"
     textual header "fma4intrin.h"
     textual header "mwaitxintrin.h"
+    textual header "clzerointrin.h"
 
     explicit module mm_malloc {
       requires !freestanding
Index: cfe/trunk/lib/Headers/x86intrin.h
===================================================================
--- cfe/trunk/lib/Headers/x86intrin.h
+++ cfe/trunk/lib/Headers/x86intrin.h
@@ -80,6 +80,10 @@
 #include <mwaitxintrin.h>
 #endif
 
+#if !defined(_MSC_VER) || __has_feature(modules) || defined(__CLZERO__)
+#include <clzerointrin.h>
+#endif
+
 /* FIXME: LWP */
 
 #endif /* __X86INTRIN_H */
Index: cfe/trunk/test/CodeGen/builtin-clflushopt.c
===================================================================
--- cfe/trunk/test/CodeGen/builtin-clflushopt.c
+++ cfe/trunk/test/CodeGen/builtin-clflushopt.c
@@ -3,7 +3,7 @@
 
 #include <immintrin.h>
 void test_mm_clflushopt(char * __m) {
-  //CHECK-LABLE: @test_mm_clflushopt
+  //CHECK-LABEL: @test_mm_clflushopt
   //CHECK: @llvm.x86.clflushopt
   _mm_clflushopt(__m);
 }
Index: cfe/trunk/test/CodeGen/builtin-clzero.c
===================================================================
--- cfe/trunk/test/CodeGen/builtin-clzero.c
+++ cfe/trunk/test/CodeGen/builtin-clzero.c
@@ -0,0 +1,9 @@
+// RUN: %clang_cc1 %s -triple=x86_64-apple-darwin -target-feature +clzero  -emit-llvm -o - -Wall -Werror | FileCheck %s
+#define __MM_MALLOC_H
+
+#include <x86intrin.h>
+void test_mm_clzero(void * __m) {
+  //CHECK-LABEL: @test_mm_clzero
+  //CHECK: @llvm.x86.clflushopt
+  _mm_clzero(__m);
+}
Index: cfe/trunk/test/CodeGen/builtins-x86.c
===================================================================
--- cfe/trunk/test/CodeGen/builtins-x86.c
+++ cfe/trunk/test/CodeGen/builtins-x86.c
@@ -1,5 +1,5 @@
-// RUN: %clang_cc1 -DUSE_64 -triple x86_64-unknown-unknown -target-feature +fxsr -target-feature +avx -target-feature +xsaveopt -target-feature +xsaves -target-feature +xsavec -target-feature +mwaitx -emit-llvm -o %t %s
-// RUN: %clang_cc1 -DUSE_ALL -triple x86_64-unknown-unknown -target-feature +fxsr -target-feature +avx -target-feature +xsaveopt -target-feature +xsaves -target-feature +xsavec -target-feature +mwaitx -fsyntax-only -o %t %s
+// RUN: %clang_cc1 -DUSE_64 -triple x86_64-unknown-unknown -target-feature +fxsr -target-feature +avx -target-feature +xsaveopt -target-feature +xsaves -target-feature +xsavec -target-feature +mwaitx -target-feature +clzero -emit-llvm -o %t %s
+// RUN: %clang_cc1 -DUSE_ALL -triple x86_64-unknown-unknown -target-feature +fxsr -target-feature +avx -target-feature +xsaveopt -target-feature +xsaves -target-feature +xsavec -target-feature +mwaitx -target-feature +clzero -fsyntax-only -o %t %s
 
 #ifdef USE_ALL
 #define USE_3DNOW
@@ -285,6 +285,7 @@
 
   (void) __builtin_ia32_monitorx(tmp_vp, tmp_Ui, tmp_Ui);
   (void) __builtin_ia32_mwaitx(tmp_Ui, tmp_Ui, tmp_Ui);
+  (void) __builtin_ia32_clzero(tmp_vp);
 
   tmp_V4f = __builtin_ia32_cvtpi2ps(tmp_V4f, tmp_V2i);
   tmp_V2i = __builtin_ia32_cvtps2pi(tmp_V4f);
Index: cfe/trunk/test/Driver/x86-target-features.c
===================================================================
--- cfe/trunk/test/Driver/x86-target-features.c
+++ cfe/trunk/test/Driver/x86-target-features.c
@@ -79,3 +79,8 @@
 // RUN: %clang -target i386-unknown-linux-gnu -march=i386 -mno-prefetchwt1 %s -### -o %t.o 2>&1 | FileCheck -check-prefix=NO-PREFETCHWT1 %s
 // PREFETCHWT1: "-target-feature" "+prefetchwt1"
 // NO-PREFETCHWT1: "-target-feature" "-prefetchwt1"
+
+// RUN: %clang -target i386-unknown-linux-gnu -march=i386 -mclzero %s -### -o %t.o 2>&1 | FileCheck -check-prefix=CLZERO %s
+// RUN: %clang -target i386-unknown-linux-gnu -march=i386 -mno-clzero %s -### -o %t.o 2>&1 | FileCheck -check-prefix=NO-CLZERO %s
+// CLZERO: "-target-feature" "+clzero"
+// NO-CLZERO: "-target-feature" "-clzero"
Index: cfe/trunk/test/Preprocessor/predefined-arch-macros.c
===================================================================
--- cfe/trunk/test/Preprocessor/predefined-arch-macros.c
+++ cfe/trunk/test/Preprocessor/predefined-arch-macros.c
@@ -1883,6 +1883,7 @@
 // CHECK_ZNVER1_M32: #define __BMI2__ 1
 // CHECK_ZNVER1_M32: #define __BMI__ 1
 // CHECK_ZNVER1_M32: #define __CLFLUSHOPT__ 1
+// CHECK_ZNVER1_M32: #define __CLZERO__ 1
 // CHECK_ZNVER1_M32: #define __F16C__ 1
 // CHECK_ZNVER1_M32: #define __FMA__ 1
 // CHECK_ZNVER1_M32: #define __FSGSBASE__ 1
@@ -1924,6 +1925,7 @@
 // CHECK_ZNVER1_M64: #define __BMI2__ 1
 // CHECK_ZNVER1_M64: #define __BMI__ 1
 // CHECK_ZNVER1_M64: #define __CLFLUSHOPT__ 1
+// CHECK_ZNVER1_M64: #define __CLZERO__ 1
 // CHECK_ZNVER1_M64: #define __F16C__ 1
 // CHECK_ZNVER1_M64: #define __FMA__ 1
 // CHECK_ZNVER1_M64: #define __FSGSBASE__ 1