[PATCH 2/5] include: Add ShiftRight128 and __shiftright128 support.

[Jacek Caban]

From: Jacek Caban

Based on patch by Rémi Bernon.
---
 include/msvcrt/intrin.h | 1 +
 include/winnt.h         | 9 +++++++++
 2 files changed, 10 insertions(+)

diff --git a/include/msvcrt/intrin.h b/include/msvcrt/intrin.h
index 35762483313..b20fb1b56d0 100644
--- a/include/msvcrt/intrin.h
+++ b/include/msvcrt/intrin.h
@@ -99,6 +99,7 @@ unsigned char _BitScanForward64(unsigned long*,unsigned __int64);
 #endif

#if defined(_MSC_VER) && defined(__x86_64__)
+unsigned __int64 __shiftright128(unsigned __int64, unsigned __int64, unsigned char);
 unsigned __int64 _umul128(unsigned __int64, unsigned __int64, unsigned __int64*);
 #endif

diff --git a/include/winnt.h b/include/winnt.h
index 223db81576f..722d2c3a542 100644
--- a/include/winnt.h
+++ b/include/winnt.h
@@ -7438,17 +7438,26 @@ static FORCEINLINE void YieldProcessor(void)

#if defined(__x86_64__)
 # if defined(__arm64ec__)
+#  define __shiftright128 ShiftRight128
 #  define _umul128 UnsignedMultiply128
 # else
+#  define ShiftRight128 __shiftright128
 #  define UnsignedMultiply128 _umul128
 #  if defined(_MSC_VER)
+DWORD64 __shiftright128(DWORD64,DWORD64,BYTE);
 DWORD64 _umul128(DWORD64,DWORD64,DWORD64*);
+#   pragma intrinsic(__shiftright128)
 #   pragma intrinsic(_umul128)
 #  endif
 # endif
 #endif

#if (defined(__x86_64__) && !defined(_MSC_VER)) || defined(__aarch64__) || defined(__arm64ec__)
+static FORCEINLINE DWORD64 ShiftRight128( DWORD64 lo, DWORD64 hi, BYTE shift )
+{
+    return ((unsigned __int128)hi << 64 | lo) >> shift;
+}
+
 static FORCEINLINE DWORD64 UnsignedMultiply128( DWORD64 a, DWORD64 b, DWORD64 *hi )
 {
     unsigned __int128 v = (unsigned __int128)a * b;