efficient packing

First, I am using 7.5 so it is an old compiler, but that is the way it is.

I have a number of bit variables that I am trying to pack into a byte. they are scattered all across the bit area

volatile bit var1;
volatile bit var2;
volatile bit var3;

char result;

The compiler won't let me do

          result=   (var1 <<1) | (var2 <<2) | (var3 <<4);

the only way I have been able to get this to work is

           result= var1;
           result= ((((result << 1) | var2)<<1) | var3)<<1);

This results in very inefficient code
           mov a,result
           mov  r7,a

           mov   c,v2
           clr  a
           rlc  A
           orl  A,R7;
           add  A,ACC
           mov  a,r7

           mov  c,var3
           rlc  A
           orl  A,R7
           add  A,ACC
           mov  a,r7
etc.
as compared to:

           mov A,result
           mov c,v2
           rlc a
           mov  c,v3
           rlc a

would be much better.  Does anyone know how this might be forced in C, without resorting to assembly?

I'm wondering if because the ACC and PSW are evenly divisible by 8, whether or not you can use
those and explicitly use the _crol_ intrinsic to accomplish this.  I have not had any luck so far.

In this case memory efficiency is more important than speed.