ARM: Add NOP intrinsic mapping in arm_acle.h

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@212950 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Headers/arm_acle.h

@@ -33,8 +33,9 @@
 #if defined(__cplusplus)
 extern "C" {
 #endif
-
-/* 8.4 - Hints */
+ 
+/* 8 SYNCHRONIZATION, BARRIER AND HINT INTRINSICS */
+/* 8.4 Hints */
 
 #if !defined(_MSC_VER)
 static __inline__ void __attribute__((always_inline, nodebug)) __wfi(void) {
@@ -58,6 +59,11 @@ static __inline__ void __attribute__((always_inline, nodebug)) __yield(void) {
 }
 #endif
 
+/* 8.7 NOP */
+static __inline__ void __attribute__((always_inline, nodebug)) __nop(void) {
+  __builtin_arm_nop();
+}
+
 /* 9 DATA-PROCESSING INTRINSICS */
 /* 9.2 Miscellaneous data-processing intrinsics */
 static __inline__ uint32_t __attribute__((always_inline, nodebug))

test/CodeGen/arm_acle.c

@@ -40,6 +40,14 @@ void test_sevl(void) {
   __sevl();
 }
 
+/* 8.7 NOP */
+// ARM-LABEL: test_nop
+// AArch32: call void @llvm.arm.hint(i32 0)
+// AArch64: call void @llvm.aarch64.hint(i32 0)
+void test_nop(void) {
+  __nop();
+}
+
 /* 9 DATA-PROCESSING INTRINSICS */
 /* 9.2 Miscellaneous data-processing intrinsics */
 // ARM-LABEL: test_rev