x86 MUL Instruction from VS 2008/2010

Question

Will modern (2008/2010) incantations of Visual Studio or Visual C++ Express produce x86 MUL instructions (unsigned multiply) in the compiled code? I cannot seem to find or

Answer 1

According to http://gmplib.org/~tege/x86-timing.pdf, the IMUL instruction has a lower latency and higher throughput (if I'm reading the table correctly). Perhaps VS is simply using the faster instruction (that's assuming that IMUL and MUL always produce the same output).

I don't have Visual Studio handy, so I tried to get something else with GCC. I also always get some variation of IMUL.

This:

unsigned int func(unsigned int a, unsigned int b)
{ 
    return a * b;
}

Assembles to this (with -O2):

_func:
LFB2:
        pushq   %rbp
LCFI0:
        movq    %rsp, %rbp
LCFI1:
        movl    %esi, %eax
        imull   %edi, %eax
        movzbl  %al, %eax
        leave
        ret