5 files changed, 63 insertions, 0 deletions
diff --git a/clang/lib/Basic/Targets.cpp b/clang/lib/Basic/Targets.cpp
index bbc3d16493d..a288a35137b 100644
--- a/clang/lib/Basic/Targets.cpp
+++ b/clang/lib/Basic/Targets.cpp
@@ -2489,6 +2489,7 @@ class X86TargetInfo : public TargetInfo {
   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 @@ bool X86TargetInfo::initFeatureMap(
     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 @@ bool X86TargetInfo::handleTargetFeatures(std::vector<std::string> &Features,
       HasCLWB = true;
     } else if (Feature == "+prefetchwt1") {
       HasPREFETCHWT1 = true;
+    } else if (Feature == "+clzero") {
+      HasCLZERO = true;
     }
 
     X86SSEEnum Level = llvm::StringSwitch<X86SSEEnum>(Feature)
@@ -3887,6 +3891,8 @@ void X86TargetInfo::getTargetDefines(const LangOptions &Opts,
     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 @@ bool X86TargetInfo::hasFeature(StringRef Feature) const {
       .Case("bmi2", HasBMI2)
       .Case("clflushopt", HasCLFLUSHOPT)
       .Case("clwb", HasCLWB)
+      .Case("clzero", HasCLZERO)
       .Case("cx16", HasCX16)
       .Case("f16c", HasF16C)
       .Case("fma", HasFMA)
diff --git a/clang/lib/Headers/CMakeLists.txt b/clang/lib/Headers/CMakeLists.txt
index efc4dd0971b..35aff4017e9 100644
--- a/clang/lib/Headers/CMakeLists.txt
+++ b/clang/lib/Headers/CMakeLists.txt
@@ -28,6 +28,7 @@ set(files
   __clang_cuda_intrinsics.h
   __clang_cuda_math_forward_declares.h
   __clang_cuda_runtime_wrapper.h
+  clzerointrin.h
   cpuid.h
   clflushoptintrin.h
   emmintrin.h
diff --git a/clang/lib/Headers/clzerointrin.h b/clang/lib/Headers/clzerointrin.h
new file mode 100644
index 00000000000..ed7478ff87e
--- /dev/null
+++ b/clang/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 */
diff --git a/clang/lib/Headers/module.modulemap b/clang/lib/Headers/module.modulemap
index 11ef2f90294..95d26cefa6f 100644
--- a/clang/lib/Headers/module.modulemap
+++ b/clang/lib/Headers/module.modulemap
@@ -61,6 +61,7 @@ module _Builtin_intrinsics [system] [extern_c] {
     textual header "xopintrin.h"
     textual header "fma4intrin.h"
     textual header "mwaitxintrin.h"
+    textual header "clzerointrin.h"
 
     explicit module mm_malloc {
       requires !freestanding
diff --git a/clang/lib/Headers/x86intrin.h b/clang/lib/Headers/x86intrin.h
index 81a404f55d0..2003029cb5a 100644
--- a/clang/lib/Headers/x86intrin.h
+++ b/clang/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 */