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Re: [avr-libc-dev] Strange asm output
From: |
Nicolas Schodet |
Subject: |
Re: [avr-libc-dev] Strange asm output |
Date: |
Thu, 11 Nov 2004 00:43:35 +0100 |
User-agent: |
Mutt/1.5.6+20040722i |
* Dmitry K. <address@hidden> [041110 23:50]:
> > I have a little piece of code which produce a very strange code:
> > I can not understand why gcc do not just test the 23th bit.
> I have try:
> [...]
I change my original code, so I writed a new one:
/* toto.c */
#include <inttypes.h>
int32_t
toto (int32_t a)
{
if (a & (1L << 23))
return 1;
else
return 0;
}
Command line:
avr-gcc -g -Wall -O2 -mmcu=atmega128 -MMD -S -o toto.s toto.c
Gcc version:
avr-gcc (GCC) 3.4.1
Result:
.global toto
.type toto, @function
toto:
.stabn 68,0,6,.LM1-toto
.LM1:
/* prologue: frame size=0 */
/* prologue end (size=0) */
movw r26,r24
movw r24,r22
.stabn 68,0,7,.LM2-toto
.LM2:
ldi r18,23
1: lsr r27
ror r26
ror r25
ror r24
dec r18
brne 1b
andi r24,lo8(1)
andi r25,hi8(1)
or r24,r25
breq .L2
.stabn 68,0,8,.LM3-toto
.LM3:
ldi r22,lo8(1)
ldi r23,hi8(1)
ldi r24,hlo8(1)
ldi r25,hhi8(1)
ret
.L2:
.stabn 68,0,10,.LM4-toto
.LM4:
ldi r22,lo8(0)
ldi r23,hi8(0)
ldi r24,hlo8(0)
ldi r25,hhi8(0)
.stabn 68,0,11,.LM5-toto
.LM5:
ret
/* epilogue: frame size=0 */
ret
/* epilogue end (size=1) */
/* function toto size 24 (23) */
.size toto, .-toto
Tell me if you need more informations.
/Nicolas
- [avr-libc-dev] Strange asm output, Nicolas Schodet, 2004/11/09
- Re: [avr-libc-dev] Strange asm output, Dmitry K., 2004/11/10
- Re: [avr-libc-dev] Strange asm output,
Nicolas Schodet <=
- Re: [avr-libc-dev] Strange asm output, Dmitry K., 2004/11/10
- Re: [avr-libc-dev] Strange asm output, Paul Schlie, 2004/11/10
- Re: [avr-libc-dev] Strange asm output, Paul Schlie, 2004/11/11
- Re: [avr-libc-dev] Strange asm output, Nicolas Schodet, 2004/11/11
- Re: [avr-libc-dev] Strange asm output, Paul Schlie, 2004/11/11
- [avr-libc-dev] soliciting feedback/thoughts on potential value of a few gcc 4.0 tweaks., Paul Schlie, 2004/11/19
- Re: [avr-libc-dev] soliciting feedback/thoughts on potential value of a few gcc 4.0 tweaks., Theodore A. Roth, 2004/11/19
- Re: [avr-libc-dev] soliciting feedback/thoughts on potential value of a few gcc 4.0 tweaks., Paul Schlie, 2004/11/20
- Re: [avr-libc-dev] soliciting feedback/thoughts on potential value of a few gcc 4.0 tweaks., Bob Paddock, 2004/11/19
- Re: [avr-libc-dev] soliciting feedback/thoughts on potential value of a few gcc 4.0 tweaks., Paul Schlie, 2004/11/20