RE: [avr-gcc-list] Using in/out Instructions with ATmega128

[Weddington, Eric]

> -----Original Message-----
> From: 
> address@hidden 
> [mailto:address@hidden
> org] On Behalf Of Thomas D. Dean
> Sent: Monday, May 04, 2009 4:37 PM
> To: address@hidden
> Subject: [avr-gcc-list] Using in/out Instructions with ATmega128
> 
> I have
> # avr-gcc --version
> avr-gcc (GCC) 4.3.2
> Copyright (C) 2008 Free Software Foundation, Inc.
> ...
> 
> I want to use the ATmega128 and in/out instructions for 
> registers below
> 0x40.  
> 
> # avr-gcc   -mmcu=atmega128  -c -o 4x40-lcd.o xxx.c
> # avr-gcc    -mmcu=atmega128  4x40-lcd.o -o xxx.elf  -lc
> # avr-objdump   -d xxx.elf
> ...
> 804:  a2 e3           ldi     r26, 0x32       ; 50
>  806: b0 e0           ldi     r27, 0x00       ; 0
>  808: e2 e3           ldi     r30, 0x32       ; 50
>  80a: f0 e0           ldi     r31, 0x00       ; 0
>  80c: 80 81           ld      r24, Z
>  80e: 8f 70           andi    r24, 0x0F       ; 15
>  810: 80 62           ori     r24, 0x20       ; 32
>  812: 8c 93           st      X, r24
> ...
> 
> This can be done with four instructions, in, andi, ori, and, 
> out.  And,
> 6 fewer clocks.

Where is the source code that corresponds to the above assembly?