[COFF, ARM64] Add __byteswap intrinsics

Reviewers: rnk, efriedma, ssijaric, TomTan, haripul

Reviewed By: efriedma

Subscribers: javed.absar, cfe-commits, kristof.beyls

Differential Revision: https://reviews.llvm.org/D56685

2 files changed, 32 insertions, 6 deletions

diff --git a/clang/lib/Headers/intrin.h b/clang/lib/Headers/intrin.h
index 1a33af7f295..c86f41faeb8 100644
--- a/clang/lib/Headers/intrin.h
+++ b/clang/lib/Headers/intrin.h
@@ -566,6 +566,16 @@ unsigned __int64 __getReg(int);
 long _InterlockedAdd(long volatile *Addend, long Value);
 int _ReadStatusReg(int);
 void _WriteStatusReg(int, int);
+
+static inline unsigned short _byteswap_ushort (unsigned short val) {
+  return __builtin_bswap16(val);
+}
+static inline unsigned long _byteswap_ulong (unsigned long val) {
+  return __builtin_bswap32(val);
+}
+static inline unsigned __int64 _byteswap_uint64 (unsigned __int64 val) {
+  return __builtin_bswap64(val);
+}
 #endif
 
 /*----------------------------------------------------------------------------*\
diff --git a/clang/test/Headers/ms-arm64-intrin.cpp b/clang/test/Headers/ms-arm64-intrin.cpp
index 0b337aa69f7..729ca5e7f2d 100644
--- a/clang/test/Headers/ms-arm64-intrin.cpp
+++ b/clang/test/Headers/ms-arm64-intrin.cpp
@@ -1,13 +1,29 @@
-// RUN: %clang_cc1 -triple arm64-windows \
+// REQUIRES: aarch64-registered-target
+
+// RUN: %clang_cc1 -triple arm64-windows -O1 \
 // RUN: -fms-compatibility -fms-compatibility-version=17.00 \
 // RUN: -ffreestanding -fsyntax-only -Werror \
-// RUN: -isystem %S/Inputs/include %s -S -o - 2>&1 | FileCheck %s
-
-// REQUIRES: aarch64-registered-target
+// RUN: -isystem %S/Inputs/include %s -S -o - -emit-llvm 2>&1 \
+// RUN: | FileCheck %s
 
 #include <intrin.h>
 
-void f() {
-// CHECK: nop
+void check_nop() {
+// CHECK: "nop"
   __nop();
 }
+
+unsigned short check_byteswap_ushort(unsigned short val) {
+// CHECK: call i16 @llvm.bswap.i16(i16 %val)
+  return _byteswap_ushort(val);
+}
+
+unsigned long check_byteswap_ulong(unsigned long val) {
+// CHECK: call i32 @llvm.bswap.i32(i32 %val)
+  return _byteswap_ulong(val);
+}
+
+unsigned __int64 check_byteswap_uint64(unsigned __int64 val) {
+// CHECK: call i64 @llvm.bswap.i64(i64 %val)
+  return _byteswap_uint64(val);
+}