[clang] [clang] Add arm64_neon.h wrapper (PR #196014)

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llvmorg-github-actions[bot] wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang

Author: GkvJwa

<details>
<summary>Changes</summary>

Add an MSVC-compatible <arm64_neon.h> resource header that forwards to
Clang's generated <arm_neon.h>. This lets ARM64 Windows code using the
MSVC header name lower NEON intrinsics through Clang builtins instead of
eaving external neon_* calls such as neon_ld1m4_q32

Fix #<!-- -->195683

---
Full diff: https://github.com/llvm/llvm-project/pull/196014.diff


4 Files Affected:

- (modified) clang/lib/Headers/CMakeLists.txt (+1) 
- (added) clang/lib/Headers/arm64_neon.h (+15) 
- (modified) clang/lib/Headers/module.modulemap (+6) 
- (added) clang/test/CodeGen/arm64-neon-header.c (+13) 


``````````diff
diff --git a/clang/lib/Headers/CMakeLists.txt b/clang/lib/Headers/CMakeLists.txt
index d60ae2b5961e0..ce34f8b9410a7 100644
--- a/clang/lib/Headers/CMakeLists.txt
+++ b/clang/lib/Headers/CMakeLists.txt
@@ -55,6 +55,7 @@ set(arm_only_files
   )
 
 set(aarch64_only_files
+  arm64_neon.h
   arm64intr.h
   arm_neon_sve_bridge.h
   )
diff --git a/clang/lib/Headers/arm64_neon.h b/clang/lib/Headers/arm64_neon.h
new file mode 100644
index 0000000000000..380e88d545621
--- /dev/null
+++ b/clang/lib/Headers/arm64_neon.h
@@ -0,0 +1,15 @@
+/*===---- arm64_neon.h - ARM64 NEON intrinsics -----------------------------===
+ *
+ * Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+ * See https://llvm.org/LICENSE.txt for license information.
+ * SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+ *
+ *===-----------------------------------------------------------------------===
+ */
+
+#ifndef __ARM64_NEON_H
+#define __ARM64_NEON_H
+
+#include <arm_neon.h>
+
+#endif /* __ARM64_NEON_H */
diff --git a/clang/lib/Headers/module.modulemap b/clang/lib/Headers/module.modulemap
index 3fcaa55f1110e..c8f96df1672c1 100644
--- a/clang/lib/Headers/module.modulemap
+++ b/clang/lib/Headers/module.modulemap
@@ -50,6 +50,12 @@ module _Builtin_intrinsics [system] [extern_c] {
 
     header "arm64intr.h"
     export *
+
+    explicit module neon {
+      requires neon
+      header "arm64_neon.h"
+      export *
+    }
   }
 
   explicit module intel {
diff --git a/clang/test/CodeGen/arm64-neon-header.c b/clang/test/CodeGen/arm64-neon-header.c
new file mode 100644
index 0000000000000..f0aea4093caad
--- /dev/null
+++ b/clang/test/CodeGen/arm64-neon-header.c
@@ -0,0 +1,13 @@
+// RUN: %clang_cc1 -triple arm64-pc-windows-msvc -fms-compatibility \
+// RUN:     -emit-llvm -o - %s | FileCheck %s
+
+#include <arm64_neon.h>
+
+// CHECK-LABEL: define{{.*}} @test_vld1q_s32_x4(
+// CHECK-NOT: neon_ld1m4_q32
+// CHECK: call { <4 x i32>, <4 x i32>, <4 x i32>, <4 x i32> } @llvm.aarch64.neon.ld1x4.v4i32.p0(ptr {{.*}})
+// CHECK-NOT: neon_ld1m4_q32
+// CHECK: ret
+int32x4x4_t test_vld1q_s32_x4(int32_t const *a) {
+  return vld1q_s32_x4(a);
+}

``````````

</details>


https://github.com/llvm/llvm-project/pull/196014