[X86] Add the movbe instruction intrinsics from icc.

These intrinsics exist in icc. They can be found on the Intel Intrinsics Guide website.

All the backend support is in place to pattern match a load+bswap or a bswap+store pattern to the MOVBE instructions. So we just need to get the frontend to emit the correct IR. The pointer arguments in icc are declared as void so I had to jump through a packed struct to forcing a specific alignment on the load/store. Same trick we use in the unaligned vector load/store intrinsics

Differential Revision: https://reviews.llvm.org/D52586

llvm-svn: 343343

1 files changed, 59 insertions, 0 deletions

diff --git a/clang/lib/Headers/immintrin.h b/clang/lib/Headers/immintrin.h
index e7bfbf964d5..7d0722ec765 100644
--- a/clang/lib/Headers/immintrin.h
+++ b/clang/lib/Headers/immintrin.h
@@ -306,6 +306,65 @@ _writegsbase_u64(unsigned long long __V)
 #endif
 #endif /* __FSGSBASE__ */
 
+#if !defined(_MSC_VER) || __has_feature(modules) || defined(__MOVBE__)
+
+/* The structs used below are to force the load/store to be unaligned. This
+ * is accomplished with the __packed__ attribute. The __may_alias__ prevents
+ * tbaa metadata from being generated based on the struct and the type of the
+ * field inside of it.
+ */
+
+static __inline__ short __attribute__((__always_inline__, __nodebug__, __target__("movbe")))
+_loadbe_i16(void const * __P) {
+  struct __loadu_i16 {
+    short __v;
+  } __attribute__((__packed__, __may_alias__));
+  return __builtin_bswap16(((struct __loadu_i16*)__P)->__v);
+}
+
+static __inline__ void __attribute__((__always_inline__, __nodebug__, __target__("movbe")))
+_storebe_i16(void * __P, short __D) {
+  struct __storeu_i16 {
+    short __v;
+  } __attribute__((__packed__, __may_alias__));
+  ((struct __storeu_i16*)__P)->__v = __builtin_bswap16(__D);
+}
+
+static __inline__ int __attribute__((__always_inline__, __nodebug__, __target__("movbe")))
+_loadbe_i32(void const * __P) {
+  struct __loadu_i32 {
+    int __v;
+  } __attribute__((__packed__, __may_alias__));
+  return __builtin_bswap32(((struct __loadu_i32*)__P)->__v);
+}
+
+static __inline__ void __attribute__((__always_inline__, __nodebug__, __target__("movbe")))
+_storebe_i32(void * __P, int __D) {
+  struct __storeu_i32 {
+    int __v;
+  } __attribute__((__packed__, __may_alias__));
+  ((struct __storeu_i32*)__P)->__v = __builtin_bswap32(__D);
+}
+
+#ifdef __x86_64__
+static __inline__ long long __attribute__((__always_inline__, __nodebug__, __target__("movbe")))
+_loadbe_i64(void const * __P) {
+  struct __loadu_i64 {
+    long long __v;
+  } __attribute__((__packed__, __may_alias__));
+  return __builtin_bswap64(((struct __loadu_i64*)__P)->__v);
+}
+
+static __inline__ void __attribute__((__always_inline__, __nodebug__, __target__("movbe")))
+_storebe_i64(void * __P, long long __D) {
+  struct __storeu_i64 {
+    long long __v;
+  } __attribute__((__packed__, __may_alias__));
+  ((struct __storeu_i64*)__P)->__v = __builtin_bswap64(__D);
+}
+#endif
+#endif /* __MOVBE */
+
 #if !defined(_MSC_VER) || __has_feature(modules) || defined(__RTM__)
 #include <rtmintrin.h>
 #include <xtestintrin.h>