Readable conditional logic without unnecessary execution?

Question

I'm trying to make the below code both readable and performant. I want to avoid any unnecessary call to getFlagB() while also not repeating anything. Below I have written two methods, each which satisfies exactly one of these criteria.

Assume getFlagB() cannot be altered in any way. Is there a way to meet both these requirements simultaneously in C, without creating additional flags?

// Method 1 - doesn't repeat code blocks but calls getFlagB even when it may not need to
void foo(int flagA)
{
    int flagB;
    getFlagB(&flagB);

    if(flagA & flagB)
    {
        // Code block 0
    }
    else
    {
        // Code block 1
    }
}

// Method 2 - doesn't no extra call to getFlagB, but repeats code block 1
void foo(int flagA)
{
    int flagB;

    if(flagA)
    {
        getFlagB(&flagB);
        if(flagB)
        {
            // Code block 0
        }
        else
        {
            // Code block 1
        }
    }
    else
    {
        // Code block 1
    }
}

Answer 1

You can do this:

void foo(int flagA)
{
    int flagB;

    if(flagA)
    {
        getFlagB(&flagB);
        if(flagB)
        {
            // Code block 0
            return ;
        }
    }
  // code block 1
}

Answer 2

Wrap getFlagB() in another method, then let the compiler sort it out for you.

int myGetFlagB() { int b; getFlagB(&b); return b; }

void foo(int flagA)
{
    /* note: assume you mean && and not &, otherwise there is no way
     * to short circuit - you always need to call getFlagB for a
     * bitwise AND.
     */
    if(flagA && myGetFlagB())
    {
        // Code block 0
    }
    else
    {
        // Code block 1
    }
}