If P1 (or whatever port you connected the servos to) is free to use, you can also use a table lookup.
Thus you have no performance penalty within the IRQ for connecting up to 8 servos:)

#include <8052.h>

static unsigned char ms_tenth_countdown;

// dynamically setup table.
// Indexed top down.
// setup glitchlessly!
unsigned char __pdata table_P1_over_time[180 + 1];

void Timer0_ISR (void) interrupt 1 {

    // assuming P1 is only used for servos.
    P1 = table_P1_over_time [ ms_tenth_countdown ];

    TF0 = 0;

    if (!--ms_tenth_countdown)
        ms_tenth_countdown = 180;

}

void main(void){}
 

Now you'd be at:

   0000                     371 _Timer0_ISR:
   0000 C0 E0               380         push    acc
   0002 C0 00               381         push    ar0
   0004 C0 D0               382         push    psw
   0006 75 D0 00            383         mov     psw,#0x00
                            384 ;       servo_lookup.c:13: P1 = table_P1_over_time [ ms_tenth_countdown ];
   0009 E5*00               385         mov     a,_ms_tenth_countdown
   000B 24r00               386         add     a,#_table_P1_over_time
   000D F8                  387         mov     r0,a
   000E E2                  388         movx    a,@r0
   000F F5 90               389         mov     _P1,a
                            390 ;       servo_lookup.c:15: TF0 = 0;
   0011 C2 8D               391         clr     _TF0
                            392 ;       servo_lookup.c:17: if (!--ms_tenth_countdown)
   0013 D5*00 03            393         djnz    _ms_tenth_countdown,00103$
                            394 ;       servo_lookup.c:18: ms_tenth_countdown = 180;
   0016 75*00 B4            395         mov     _ms_tenth_countdown,#0xB4
   0019                     396 00103$:
   0019 D0 D0               397         pop     psw
   001B D0 00               398         pop     ar0
   001D D0 E0               399         pop     acc
   001F 32                  400         reti

 

I doubt that switching compilers would help much in this case. What's worse: coding directly in assembly code won't help much either:^)