[clang] [Arm64EC] Fix compilation of arm_acle.h (PR #91281)

[via cfe-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-backend-x86

Author: Eli Friedman (efriedma-quic)

<details>
<summary>Changes</summary>



---
Full diff: https://github.com/llvm/llvm-project/pull/91281.diff


2 Files Affected:

- (modified) clang/lib/Headers/arm_acle.h (+1-1) 
- (modified) clang/test/Headers/arm-acle-header.c (+1) 


``````````diff
diff --git a/clang/lib/Headers/arm_acle.h b/clang/lib/Headers/arm_acle.h
index 6e557eda1dddca..5785954c9171ab 100644
--- a/clang/lib/Headers/arm_acle.h
+++ b/clang/lib/Headers/arm_acle.h
@@ -109,7 +109,7 @@ __swp(uint32_t __x, volatile uint32_t *__p) {
 #endif
 
 /* 7.7 NOP */
-#if !defined(_MSC_VER) || !defined(__aarch64__)
+#if !defined(_MSC_VER) || (!defined(__aarch64__) && !defined(__arm64ec__))
 static __inline__ void __attribute__((__always_inline__, __nodebug__)) __nop(void) {
   __builtin_arm_nop();
 }
diff --git a/clang/test/Headers/arm-acle-header.c b/clang/test/Headers/arm-acle-header.c
index f04c7e1f0f35f7..fea8472183c871 100644
--- a/clang/test/Headers/arm-acle-header.c
+++ b/clang/test/Headers/arm-acle-header.c
@@ -7,6 +7,7 @@
 // RUN: %clang_cc1 -x c++ -triple thumbv7-windows -target-cpu cortex-a15 -fsyntax-only -ffreestanding -fms-extensions -fms-compatibility -fms-compatibility-version=19.11 %s
 // RUN: %clang_cc1 -x c++ -triple aarch64-windows -target-cpu cortex-a53 -fsyntax-only -ffreestanding -fms-extensions -fms-compatibility -fms-compatibility-version=19.11 %s
 // RUN: %clang_cc1 -x c++ -triple arm64-apple-ios -target-cpu apple-a7 -fsyntax-only -ffreestanding -fms-extensions %s
+// RUN: %clang_cc1 -x c++ -triple arm64ec-windows -target-cpu cortex-a53 -fsyntax-only -ffreestanding -fms-extensions -fms-compatibility -fms-compatibility-version=19.11 %s
 // expected-no-diagnostics
 
 #include <arm_acle.h>

``````````

</details>


https://github.com/llvm/llvm-project/pull/91281