[avr-gcc-list] First steps with avr-gcc

[David Bourgeois]

Hello,

I'm pretty new at avr-gcc and the GNU suite. I'm using WinAVR integrated  
with AVR Studio 4.12 (RC1).

Here's the simple function I'm using and the asm code generated (I should  
better do a macro out of it).

uint8_t getSwitches(void)
{
    return (PINB & SW_MK);
}

@00000074: getSwitches
24:       {
+00000074:   B183        IN      R24,0x03         In from I/O location
+00000075:   2799        CLR     R25              Clear Register
26:       }
+00000076:   718D        ANDI    R24,0x1D         Logical AND with  
immediate
+00000077:   7090        ANDI    R25,0x00         Logical AND with  
immediate
+00000078:   9508        RET

avr-gcc  -mmcu=atmega88 -Wall -gdwarf-2          -DF_CPU=8000000  -O2   
-funsigned-char  -funsigned-bitfields  -fpack-struct  -fshort-enums   
-Wp,-M,-MP,-MT,main.o,-MF,dep/main.o.d  -c   ../main.c -o main.o

My questions:
- The C code is not complete in the list file. Usually, the next line  
after a '{' is missing. Is there something wrong on my side or should it  
simply be like this?
- the function uses 2 registers (16 bits) while it should only use 8 bits.  
Is there something wrong on the make settings I used (generated by AVR  
Studio btw) or something else?
- I'm surely lacking some knowledge here, should I first start reading the  
make manual, the gcc one or simply improve my C knowledge?

Thanks,

David