[ms] Add __shiftleft128 / __shiftright128 intrinsics

Carefully match the pattern matched by ISel so that this produces shld / shrd
(unless Subtarget->isSHLDSlow() is true).

Thanks to Craig Topper for providing the LLVM IR pattern that gets successfully
matched.

Fixes PR37755.

llvm-svn: 337619

diff --git a/clang/lib/Headers/intrin.h b/clang/lib/Headers/intrin.h
index edb947e..9191421 100644 (file)
--- a/clang/lib/Headers/intrin.h
+++ b/clang/lib/Headers/intrin.h
@@ -863,6 +863,20 @@ __nop(void) {
   __asm__ volatile ("nop");
 }
 #endif
+#if defined(__x86_64__)
+static __inline__ unsigned __int64 __DEFAULT_FN_ATTRS
+__shiftleft128(unsigned __int64 __l, unsigned __int64 __h, unsigned char __d) {
+  unsigned __int128 __val = ((unsigned __int128)__h << 64) | __l;
+  unsigned __int128 __res = __val << (__d & 63);
+  return (unsigned __int64)(__res >> 64);
+}
+static __inline__ unsigned __int64 __DEFAULT_FN_ATTRS
+__shiftright128(unsigned __int64 __l, unsigned __int64 __h, unsigned char __d) {
+  unsigned __int128 __val = ((unsigned __int128)__h << 64) | __l;
+  unsigned __int128 __res = __val >> (__d & 63);
+  return (unsigned __int64)__res;
+}
+#endif
 
 /*----------------------------------------------------------------------------*\
 |* Privileged intrinsics

diff --git a/clang/test/Headers/ms-intrin.cpp b/clang/test/Headers/ms-intrin.cpp
index b0fef9c..d8a4d38 100644 (file)
--- a/clang/test/Headers/ms-intrin.cpp
+++ b/clang/test/Headers/ms-intrin.cpp
@@ -42,6 +42,8 @@ void f() {
   __stosw(0, 0, 0);
 
 #ifdef _M_X64
+  __shiftleft128(1, 2, 3);
+  __shiftright128(1, 2, 3);
   __movsq(0, 0, 0);
   __stosq(0, 0, 0);
 #endif