__emul, __emulu
Visual Studio 2005
Microsoft Specific
Performs multiplications that overflow what a 32-bit integer can hold.
__int64 __emul( int a, int b ); unsigned __int64 __emulu( unsigned int a, unsigned int b );
Parameters
- [in] a
-
The first integer operand of the multiplication.
- [in] b
-
The second integer operand of the multiplication.
// emul.cpp
// compile with: /EHsc
// processor: x86, x64
#include <iostream>
#include <intrin.h>
using namespace std;
#pragma intrinsic(__emul)
#pragma intrinsic(__emulu)
int main()
{
int a = -268435456;
int b = 2;
__int64 result = __emul(a, b);
cout << a << " * " << b << " = " << result << endl;
unsigned int ua = 0xFFFFFFFF; // Dec value: 4294967295
unsigned int ub = 0xF000000; // Dec value: 251658240
unsigned __int64 uresult = __emulu(ua, ub);
cout << ua << " * " << ub << " = " << uresult << endl;
}
