[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [avr-gcc-list] Extremly confusing behaviour... (Suspectcompiler?, op
|
From: |
Mike Panetta |
|
Subject: |
Re: [avr-gcc-list] Extremly confusing behaviour... (Suspectcompiler?, optimization error?) |
|
Date: |
14 May 2003 14:14:12 -0400 |
Ohh that may be it then... According to the FAQ regs 18-27 are
"Call-Used" registers, so they should be saved before calling a function
if you use them. On second look, it seems that srf08_read does not use
r18 or r19, so I have no clue what the problem is... All this ASM code
is making my vision go blurry :P
For refrence the code is (again, sorry I recompiled) pasted below.
I have recompiled it since so here is a new listing of the do {} while;
loop:
do
1d0: 0f 90 pop r0
1d2: 0f 90 pop r0
{
delay = 1000;
1d4: 88 ee ldi r24, 0xE8 ; 232
1d6: 93 e0 ldi r25, 0x03 ; 3
1d8: a0 e0 ldi r26, 0x00 ; 0
1da: b0 e0 ldi r27, 0x00 ; 0
1dc: 89 83 std Y+1, r24 ; 0x01
1de: 9a 83 std Y+2, r25 ; 0x02
1e0: ab 83 std Y+3, r26 ; 0x03
1e2: bc 83 std Y+4, r27 ; 0x04
while (delay--);
1e4: 89 81 ldd r24, Y+1 ; 0x01
1e6: 9a 81 ldd r25, Y+2 ; 0x02
1e8: ab 81 ldd r26, Y+3 ; 0x03
1ea: bc 81 ldd r27, Y+4 ; 0x04
1ec: 01 97 sbiw r24, 0x01 ; 1
1ee: a1 09 sbc r26, r1
1f0: b1 09 sbc r27, r1
1f2: 89 83 std Y+1, r24 ; 0x01
1f4: 9a 83 std Y+2, r25 ; 0x02
1f6: ab 83 std Y+3, r26 ; 0x03
1f8: bc 83 std Y+4, r27 ; 0x04
1fa: 89 81 ldd r24, Y+1 ; 0x01
1fc: 9a 81 ldd r25, Y+2 ; 0x02
1fe: ab 81 ldd r26, Y+3 ; 0x03
200: bc 81 ldd r27, Y+4 ; 0x04
202: 8f 5f subi r24, 0xFF ; 255
204: 9f 4f sbci r25, 0xFF ; 255
206: af 4f sbci r26, 0xFF ; 255
208: bf 4f sbci r27, 0xFF ; 255
20a: 61 f7 brne .-40 ; 0x1e4
PORTA |= _BV (PA1);
20c: d9 9a sbi 0x1b, 1 ; 27
retval = srf08_read(1, 0, pingdata, 2);
20e: 35 e0 ldi r19, 0x05 ; 5
210: c3 2e mov r12, r19
212: d1 2c mov r13, r1
214: cc 0e add r12, r28
216: dd 1e adc r13, r29
218: 02 e0 ldi r16, 0x02 ; 2
21a: 10 e0 ldi r17, 0x00 ; 0
21c: 20 e0 ldi r18, 0x00 ; 0
21e: 30 e0 ldi r19, 0x00 ; 0
220: a6 01 movw r20, r12
222: 60 e0 ldi r22, 0x00 ; 0
224: 81 e0 ldi r24, 0x01 ; 1
226: 0e 94 56 04 call 0x8ac
PORTA &= ~(_BV(PA1));
22a: d9 98 cbi 0x1b, 1 ; 27
PORTB = retval;
22c: 68 bb out 0x18, r22 ; 24
} while (retval != 2);
22e: 60 17 cp r22, r16
230: 71 07 cpc r23, r17
232: 82 07 cpc r24, r18
234: 93 07 cpc r25, r19
236: 71 f6 brne .-100 ; 0x1d4
Here is the listing from srf08_read:
000008ac <srf08_read>:
int32_t
srf08_read(uint8_t address, uint8_t reg, uint8_t *data, int32_t len)
{
8ac: 6f 92 push r6
8ae: 7f 92 push r7
8b0: 8f 92 push r8
8b2: 9f 92 push r9
8b4: af 92 push r10
8b6: bf 92 push r11
8b8: df 92 push r13
8ba: ef 92 push r14
8bc: ff 92 push r15
8be: 0f 93 push r16
8c0: 1f 93 push r17
8c2: cf 93 push r28
8c4: df 93 push r29
8c6: cd b7 in r28, 0x3d ; 61
8c8: de b7 in r29, 0x3e ; 62
8ca: 21 97 sbiw r28, 0x01 ; 1
8cc: 0f b6 in r0, 0x3f ; 63
8ce: f8 94 cli
8d0: de bf out 0x3e, r29 ; 62
8d2: 0f be out 0x3f, r0 ; 63
8d4: cd bf out 0x3d, r28 ; 61
8d6: d8 2e mov r13, r24
8d8: 69 83 std Y+1, r22 ; 0x01
8da: 3a 01 movw r6, r20
8dc: 48 01 movw r8, r16
8de: 59 01 movw r10, r18
int32_t retval;
if (address == 0)
8e0: 88 23 and r24, r24
8e2: 09 f4 brne .+2 ; 0x8e6
8e4: a8 c0 rjmp .+336 ; 0xa36
return -1;
if (address > 0 && address < 17)
8e6: 81 50 subi r24, 0x01 ; 1
8e8: 80 31 cpi r24, 0x10 ; 16
8ea: 18 f4 brcc .+6 ; 0x8f2
{
address = (address - 1) * 2 + 0xe0;
8ec: dd 0c add r13, r13
8ee: 8e ed ldi r24, 0xDE ; 222
8f0: d8 0e add r13, r24
}
rearb:
retval = i2c_start();
8f2: 0e 94 61 02 call 0x4c2
8f6: e8 2e mov r14, r24
8f8: ff 24 eor r15, r15
8fa: e7 fc sbrc r14, 7
8fc: f0 94 com r15
8fe: 0f 2d mov r16, r15
900: 1f 2d mov r17, r15
switch (retval)
902: 80 e1 ldi r24, 0x10 ; 16
904: e8 16 cp r14, r24
906: f1 04 cpc r15, r1
908: 01 05 cpc r16, r1
90a: 11 05 cpc r17, r1
90c: a1 f0 breq .+40 ; 0x936
90e: 81 e1 ldi r24, 0x11 ; 17
910: e8 16 cp r14, r24
912: f1 04 cpc r15, r1
914: 01 05 cpc r16, r1
916: 11 05 cpc r17, r1
918: 3c f4 brge .+14 ; 0x928
91a: 88 e0 ldi r24, 0x08 ; 8
91c: e8 16 cp r14, r24
91e: f1 04 cpc r15, r1
920: 01 05 cpc r16, r1
922: 11 05 cpc r17, r1
924: 41 f0 breq .+16 ; 0x936
926: 87 c0 rjmp .+270 ; 0xa36
928: 88 e3 ldi r24, 0x38 ; 56
92a: e8 16 cp r14, r24
92c: f1 04 cpc r15, r1
92e: 01 05 cpc r16, r1
930: 11 05 cpc r17, r1
932: f9 f2 breq .-66 ; 0x8f2
{
case TW_REP_START:
case TW_START:
break;
case TW_MT_ARB_LOST:
//printf("a");
goto rearb;
934: 80 c0 rjmp .+256 ; 0xa36
default:
//printf("A");
return -1;
}
retval = i2c_sla_w(address);
936: 8d 2d mov r24, r13
938: 0e 94 6d 02 call 0x4da
93c: e8 2e mov r14, r24
93e: ff 24 eor r15, r15
940: e7 fc sbrc r14, 7
942: f0 94 com r15
944: 0f 2d mov r16, r15
946: 1f 2d mov r17, r15
switch (retval)
948: 80 e2 ldi r24, 0x20 ; 32
94a: e8 16 cp r14, r24
94c: f1 04 cpc r15, r1
94e: 01 05 cpc r16, r1
950: 11 05 cpc r17, r1
952: 09 f4 brne .+2 ; 0x956
954: 6e c0 rjmp .+220 ; 0xa32
956: 81 e2 ldi r24, 0x21 ; 33
958: e8 16 cp r14, r24
95a: f1 04 cpc r15, r1
95c: 01 05 cpc r16, r1
95e: 11 05 cpc r17, r1
960: 0c f0 brlt .+2 ; 0x964
962: 51 c0 rjmp .+162 ; 0xa06
964: 88 e1 ldi r24, 0x18 ; 24
966: e8 16 cp r14, r24
968: f1 04 cpc r15, r1
96a: 01 05 cpc r16, r1
96c: 11 05 cpc r17, r1
96e: 09 f0 breq .+2 ; 0x972
970: 60 c0 rjmp .+192 ; 0xa32
{
case TW_MT_SLA_ACK:
break;
case TW_MT_SLA_NACK:
//printf("B");
goto quit;
case TW_MT_ARB_LOST:
//printf("b");
goto rearb;
default:
//printf("B");
//printf("0x%x\n", retval);
goto quit;
}
retval = i2c_write_bytes(®, 1);
972: 41 e0 ldi r20, 0x01 ; 1
974: 50 e0 ldi r21, 0x00 ; 0
976: 60 e0 ldi r22, 0x00 ; 0
978: 70 e0 ldi r23, 0x00 ; 0
97a: ce 01 movw r24, r28
97c: 01 96 adiw r24, 0x01 ; 1
97e: 0e 94 cf 02 call 0x59e
982: 7b 01 movw r14, r22
984: 8c 01 movw r16, r24
if (retval != 1) // Something happened...
986: 81 e0 ldi r24, 0x01 ; 1
988: e8 16 cp r14, r24
98a: f1 04 cpc r15, r1
98c: 01 05 cpc r16, r1
98e: 11 05 cpc r17, r1
990: 59 f0 breq .+22 ; 0x9a8
{
if (retval == -2) // lost arb
992: 8e ef ldi r24, 0xFE ; 254
994: e8 16 cp r14, r24
996: 8f ef ldi r24, 0xFF ; 255
998: f8 06 cpc r15, r24
99a: 8f ef ldi r24, 0xFF ; 255
99c: 08 07 cpc r16, r24
99e: 8f ef ldi r24, 0xFF ; 255
9a0: 18 07 cpc r17, r24
9a2: 09 f0 breq .+2 ; 0x9a6
9a4: 46 c0 rjmp .+140 ; 0xa32
{
//printf("c");
goto rearb;
9a6: a5 cf rjmp .-182 ; 0x8f2
}
else
{
//printf("C");
//printf("%d\n", retval);
goto quit;
}
}
retval = i2c_start();
9a8: 0e 94 61 02 call 0x4c2
9ac: e8 2e mov r14, r24
9ae: ff 24 eor r15, r15
9b0: e7 fc sbrc r14, 7
9b2: f0 94 com r15
9b4: 0f 2d mov r16, r15
9b6: 1f 2d mov r17, r15
switch (retval)
9b8: 80 e1 ldi r24, 0x10 ; 16
9ba: e8 16 cp r14, r24
9bc: f1 04 cpc r15, r1
9be: 01 05 cpc r16, r1
9c0: 11 05 cpc r17, r1
9c2: 61 f0 breq .+24 ; 0x9dc
9c4: 81 e1 ldi r24, 0x11 ; 17
9c6: e8 16 cp r14, r24
9c8: f1 04 cpc r15, r1
9ca: 01 05 cpc r16, r1
9cc: 11 05 cpc r17, r1
9ce: dc f4 brge .+54 ; 0xa06
9d0: 88 e0 ldi r24, 0x08 ; 8
9d2: e8 16 cp r14, r24
9d4: f1 04 cpc r15, r1
9d6: 01 05 cpc r16, r1
9d8: 11 05 cpc r17, r1
9da: 59 f5 brne .+86 ; 0xa32
{
case TW_REP_START:
case TW_START:
break;
case TW_MT_ARB_LOST:
goto rearb;
default:
goto quit;
}
retval = i2c_sla_r(address);
9dc: 8d 2d mov r24, r13
9de: 0e 94 79 02 call 0x4f2
9e2: e8 2e mov r14, r24
9e4: ff 24 eor r15, r15
9e6: e7 fc sbrc r14, 7
9e8: f0 94 com r15
9ea: 0f 2d mov r16, r15
9ec: 1f 2d mov r17, r15
switch (retval)
9ee: 80 e4 ldi r24, 0x40 ; 64
9f0: e8 16 cp r14, r24
9f2: f1 04 cpc r15, r1
9f4: 01 05 cpc r16, r1
9f6: 11 05 cpc r17, r1
9f8: 71 f0 breq .+28 ; 0xa16
9fa: 81 e4 ldi r24, 0x41 ; 65
9fc: e8 16 cp r14, r24
9fe: f1 04 cpc r15, r1
a00: 01 05 cpc r16, r1
a02: 11 05 cpc r17, r1
a04: b4 f4 brge .+44 ; 0xa32
a06: 88 e3 ldi r24, 0x38 ; 56
a08: e8 16 cp r14, r24
a0a: f1 04 cpc r15, r1
a0c: 01 05 cpc r16, r1
a0e: 11 05 cpc r17, r1
a10: 09 f4 brne .+2 ; 0xa14
a12: 6f cf rjmp .-290 ; 0x8f2
a14: 0e c0 rjmp .+28 ; 0xa32
{
case TW_MR_SLA_ACK:
break;
case TW_MR_SLA_NACK:
goto quit;
case TW_MR_ARB_LOST:
goto rearb;
default:
goto quit;
}
retval = i2c_read_bytes(data, len);
a16: b5 01 movw r22, r10
a18: a4 01 movw r20, r8
a1a: c3 01 movw r24, r6
a1c: 0e 94 8f 02 call 0x51e
a20: 7b 01 movw r14, r22
a22: 8c 01 movw r16, r24
if (retval < 0)
a24: 99 23 and r25, r25
a26: 2c f0 brlt .+10 ; 0xa32
goto quit;
i2c_stop();
a28: 0e 94 86 02 call 0x50c
//printf(__FUNCTION__"() Return OK. (Returns %d)\n", retval);
return retval;
a2c: c8 01 movw r24, r16
a2e: b7 01 movw r22, r14
a30: 06 c0 rjmp .+12 ; 0xa3e
quit:
i2c_stop();
a32: 0e 94 86 02 call 0x50c
//printf(__FUNCTION__"() Return ERROR.\n");
return -1;
a36: 6f ef ldi r22, 0xFF ; 255
a38: 7f ef ldi r23, 0xFF ; 255
a3a: 8f ef ldi r24, 0xFF ; 255
a3c: 9f ef ldi r25, 0xFF ; 255
}
a3e: 21 96 adiw r28, 0x01 ; 1
a40: 0f b6 in r0, 0x3f ; 63
a42: f8 94 cli
a44: de bf out 0x3e, r29 ; 62
a46: 0f be out 0x3f, r0 ; 63
a48: cd bf out 0x3d, r28 ; 61
a4a: df 91 pop r29
a4c: cf 91 pop r28
a4e: 1f 91 pop r17
a50: 0f 91 pop r16
a52: ff 90 pop r15
a54: ef 90 pop r14
a56: df 90 pop r13
a58: bf 90 pop r11
a5a: af 90 pop r10
a5c: 9f 90 pop r9
a5e: 8f 90 pop r8
a60: 7f 90 pop r7
a62: 6f 90 pop r6
a64: 08 95 ret
I hope that was not too much text.
Thanks,
Mike
On Wed, 2003-05-14 at 13:29, Larry Barello wrote:
> It looks like the compiler assumes R18 & R19 are preserved across the call.
> Isn't that
> a bug? Gotta look at the assembly for srf08_read() to see what it does with
> those
> registers.
>
- [avr-gcc-list] Extremly confusing behaviour..., Mike Panetta, 2003/05/13
- Re: [avr-gcc-list] Extremly confusing behaviour..., Keith Gudger, 2003/05/13
- Re: [avr-gcc-list] Extremly confusing behaviour... (Suspect compiler?, optimization error?), Mike Panetta, 2003/05/14
- Re: [avr-gcc-list] Extremly confusing behaviour... (Suspect compiler?, optimization error?), Joerg Wunsch, 2003/05/14
- Re: [avr-gcc-list] Extremly confusing behaviour... (Suspect compiler?, optimization error?), Mike Panetta, 2003/05/14
- Re: [avr-gcc-list] Extremly confusing behaviour... (Suspect compiler?, optimization error?), Keith Gudger, 2003/05/14
- Re: [avr-gcc-list] Extremly confusing behaviour... (Suspect compiler?, optimization error?), Mike Panetta, 2003/05/14
- Re: [avr-gcc-list] Extremly confusing behaviour... (Suspectcompiler?, optimization error?), Larry Barello, 2003/05/14
- Re: [avr-gcc-list] Extremly confusing behaviour... (Suspectcompiler?, optimization error?),
Mike Panetta <=
- RE: [avr-gcc-list] Extremely confusing behaviour... (Suspectcompiler?,optimization error?), Ralph Mason, 2003/05/14
- Re: [avr-gcc-list] Extremly confusing behaviour... (Suspect compiler?, optimization error?), Joerg Wunsch, 2003/05/14
- Re: [avr-gcc-list] Extremly confusing behaviour... (more detailed explanation of error, believe me its not a volatile thing), Mike Panetta, 2003/05/14
- Re: [avr-gcc-list] Extremly confusing behaviour... (more detailedexplanation of error, believe me its not a volatile thing), Larry Barello, 2003/05/14
- Re: [avr-gcc-list] Extremly confusing behaviour... (more detailedexplanation of error, believe me its not a volatile thing), Mike Panetta, 2003/05/14
- Re: [avr-gcc-list] Extremly confusing behaviour... (more detailed explanation of error, believe me its not a volatile thing), E. Weddington, 2003/05/14
- Re: [avr-gcc-list] Extremly confusing behaviour... (more detailed explanation of error, believe me its not a volatile thing), Mike Panetta, 2003/05/14
- Re: [avr-gcc-list] Extremly confusing behaviour... (more detailedexplanation of error, believe me its not a volatile thing), David Brown, 2003/05/16
Re: [avr-gcc-list] Extremly confusing behaviour... (Suspect compiler?, optimization error?), E. Weddington, 2003/05/14