Implement __umulh with __int128 arithmetic
Use the same approach as _umul128, but just return the high half.
llvm-svn: 223316
diff --git a/clang/lib/Headers/Intrin.h b/clang/lib/Headers/Intrin.h
index 8cd4a0d..84bc430 100644
--- a/clang/lib/Headers/Intrin.h
+++ b/clang/lib/Headers/Intrin.h
@@ -330,7 +330,6 @@
unsigned char _Shift);
static __inline__
void __stosq(unsigned __int64 *, unsigned __int64, size_t);
-unsigned __int64 __umulh(unsigned __int64, unsigned __int64);
unsigned char __vmx_on(unsigned __int64 *);
unsigned char __vmx_vmclear(unsigned __int64 *);
unsigned char __vmx_vmlaunch(void);
@@ -429,6 +428,12 @@
*_HighProduct = _FullProduct >> 64;
return _FullProduct;
}
+static __inline__ unsigned __int64 __attribute__((__always_inline__, __nodebug__))
+__umulh(unsigned __int64 _Multiplier, unsigned __int64 _Multiplicand) {
+ unsigned __int128 _FullProduct =
+ (unsigned __int128)_Multiplier * (unsigned __int128)_Multiplicand;
+ return _FullProduct >> 64;
+}
void __cdecl _xrstor64(void const *, unsigned __int64);
void __cdecl _xsave64(void *, unsigned __int64);
void __cdecl _xsaveopt64(void *, unsigned __int64);