Note, this problem only happens with -thumb and -O2 (eg. nothing, -O, -O1 and -
O3 work fine).
Here's the original snippet of code:
int
mmcsd_read(void * dst, void * src, unsigned int len)
{
int return_val = NETI_OK;
int i = 0;
cyg_mutex_lock(&mmcsd.mutex);
if(!mmcsd.card_initialized) {
cyg_mutex_unlock(&mmcsd.mutex);
NETI_DEBUG_PRINT_CONT("mmcsd_read(buf, 0x%x, %d) returnign error\n",
(unsigned int) src, len);
return NETI_MMCSD_CARD_UNINITIALIZED;
}
MMCSD_REG_SET_BIT(MMCSD_INT_MASK, MMCSD_INT_MASK_AUTO_CARD_DETECT);
disconnect_card_detect_pullup();
if(!len) {
cyg_mutex_unlock(&mmcsd.mutex);
NETI_DEBUG_PRINT_CONT("mmcsd_read(buf, 0x%x, %d) returning len = 0\n",
(unsigned int) src, len);
return NETI_OK;
}
if((((unsigned int)src)/MMCSD_BLOCK_LENGTH + len/MMCSD_BLOCK_LENGTH) >
mmcsd.device_size) {
cyg_mutex_unlock(&mmcsd.mutex);
NETI_DEBUG_PRINT_CONT("mmcsd_read(buf, 0x%x, %d) returnign error\n",
(unsigned int) src, len);
return NETI_MMCSD_INVALID_CARD_ADDRESS;
}
if(len % MMCSD_BLOCK_LENGTH) {
cyg_mutex_unlock(&mmcsd.mutex);
NETI_DEBUG_PRINT_CONT("mmcsd_read(buf, 0x%x, %d) returnign error\n",
(unsigned int) src, len);
return NETI_MMCSD_INVALID_CARD_ADDRESS;
}
if(((unsigned int)src) % MMCSD_BLOCK_LENGTH) {
cyg_mutex_unlock(&mmcsd.mutex);
NETI_DEBUG_PRINT_CONT("mmcsd_read(buf, 0x%x, %d) returnign error\n",
(unsigned int) src, len);
return NETI_MMCSD_INVALID_CARD_ADDRESS;
}
if((return_val = mmcsd_dma_read_blks(dst, (unsigned int) src,
len/MMCSD_BLOCK_LENGTH)) != NETI_OK) {
cyg_mutex_unlock(&mmcsd.mutex);
NETI_DEBUG_PRINT_CONT("mmcsd_read(buf, 0x%x, %d) returnign error\n",
(unsigned int) src, len);
return return_val;
}
connect_card_detect_pullup();
MMCSD_REG_CLEAR_BIT(MMCSD_INT_MASK,
MMCSD_INT_MASK_AUTO_CARD_DETECT);
cyg_mutex_unlock(&mmcsd.mutex);
return return_val;
}
Here's the output from;
arm-elf-gcc -S -Wall -Wa,--gstabs -g -O2 -mcpu=arm920t ... -o mmcsd.s -c mmcsd.c
mmcsd_read:
.LFB59:
.loc 1 1953 0
push {r4, r5, r6, r7, lr}
.LCFI33:
mov r7, fp
mov r6, sl
mov r5, r9
mov r4, r8
push {r4, r5, r6, r7}
.LCFI34:
.loc 1 1957 0
ldr r4, .L623
.loc 1 1953 0
mov fp, r0
.loc 1 1957 0
mov r0, r4
.loc 1 1953 0
mov r7, r2
mov r6, r1
.loc 1 1957 0
bl cyg_mutex_lock
.loc 1 1960 0
mov r2, #116
neg r2, r2
add r2, r2, r4
ldr r3, [r2, #112]
mov r8, r2
cmp r3, #0
bne .LCB2871
b .L615 @long jump
.LCB2871:
.LBB133:
.loc 1 1972 0
ldr r3, .L623+4
.LBE133:
mov r1, #64
ldr r2, [r3]
orr r2, r2, r1
str r2, [r3]
.loc 1 1975 0
bl disconnect_card_detect_pullup
.loc 1 1977 0
cmp r7, #0
beq .L616
.loc 1 1984 0
lsr r3, r7, #9
mov r5, r8
mov sl, r3
lsr r2, r6, #9
ldr r3, [r5, #68]
add r2, r2, sl
cmp r2, r3
bls .LCB2893
b .L611 @long jump
.LCB2893:
.loc 1 1992 0
ldr r3, .L623+8
tst r7, r3
beq .LCB2898
b .L611 @long jump
.LCB2898:
.loc 1 2000 0
tst r6, r3
beq .LCB2902
b .L611 @long jump
.LCB2902:
.LBB134:
.LBB135:
.loc 1 1376 0
ldr r3, [r5, #92]
cmp r3, #0
bne .L583
mov r4, #23
.L610:
.LBE135:
.LBE134:
.loc 1 2010 0
ldr r0, .L623
bl cyg_mutex_unlock
.loc 1 2012 0
ldr r0, .L623+12
mov r1, r6
mov r2, r7
bl printf
.loc 1 2014 0
mov r0, r4
.L573:
.loc 1 2040 0
@ sp needed for prologue
pop {r3, r4, r5, r6}
mov r8, r3
mov r9, r4
mov sl, r5
mov fp, r6
pop {r4, r5, r6, r7}
pop {r1}
bx r1
.L616:
.loc 1 1978 0
mov r0, r4
bl cyg_mutex_unlock
.loc 1 1980 0
ldr r0, .L623+16
mov r1, r6
mov r2, #0
bl printf
.loc 1 2039 0
mov r0, #0
b .L573
.L583:
.LBB136:
.LBB137:
.loc 1 1379 0
mov r0, #128
lsl r0, r0, #2
mov r1, sl
bl mmcsd_setup_transfer
cmp r0, #0
mov r9, r0
beq .L617
.L602:
.loc 1 1503 0
mov r4, r9
.LBE137:
.LBE136:
.loc 1 1371 0
cmp r4, #0
bne .L610
.loc 1 2031 0
bl connect_card_detect_pullup
.LBB138:
.loc 1 2032 0
ldr r3, .L623+4
.LBE138:
mov r1, #64
ldr r2, [r3]
.loc 1 2035 0
ldr r0, .L623
.loc 1 2032 0
bic r2, r2, r1
str r2, [r3]
.loc 1 2035 0
bl cyg_mutex_unlock
.loc 1 2039 0
mov r0, #0
b .L573
.L617:
.LBB139:
.LBB140:
.loc 1 1383 0
mov r1, #1
ldr r0, [r5, #56]
bl dma_channel_set_operation
.loc 1 1386 0
ldr r1, .L623+20
mov r2, #0
ldr r0, [r5, #56]
bl dma_channel_set_source_addr
.loc 1 1389 0
mov r1, fp
mov r2, #1
ldr r0, [r5, #56]
bl dma_channel_set_dest_addr
.loc 1 1392 0
mov r2, sl
ldr r0, [r5, #56]
lsl r1, r2, #9
bl dma_channel_set_count_reg
.loc 1 1394 0
ldr r3, [r5, #84]
cmp r3, #0
bne .L618
.loc 1 1421 0
mov r2, r8
ldr r0, [r2, #56]
mov r1, #16
bl dma_channel_set_burst_length
.loc 1 1424 0
mov r3, sl
cmp r3, #1
beq .L619
.loc 1 1436 0
lsl r2, r6, #16
mov r0, #18
lsr r1, r6, #16
lsr r2, r2, #16
mov r3, #9
bl mmcsd_send_cmd_wait_resp
cmp r0, #0
mov r9, r0
bne .L602
.L591:
.loc 1 1451 0
ldr r2, .L623+4
mov r3, #2
neg r3, r3
str r3, [r2]
.loc 1 1458 0
bl dma_cache_sync
.loc 1 1462 0
ldr r4, .L623+24
ldr r1, .L623+28
ldr r0, [r4, #56]
bl dma_channel_set_control_register
.loc 1 1474 0
mov r0, r4
add r0, r0, #60
bl cyg_semaphore_wait
.loc 1 1479 0
bl dma_cache_sync
.loc 1 1484 0
mov r0, r4
add r0, r0, #48
bl cyg_semaphore_wait
.loc 1 1489 0
ldr r3, .L623+32
ldr r1, [r3]
mov r3, #47
tst r1, r3
bne .L600
lsl r2, r1, #20
bmi .L599
.L600:
.loc 1 1491 0
ldr r3, .L623+36
ldr r3, [r3]
cmp r3, #0
bne .L620
mov r4, #24
b .L610
.L615:
.LBE140:
.LBE139:
.loc 1 1961 0
mov r0, r4
bl cyg_mutex_unlock
.loc 1 1962 0
ldr r0, .L623+12
mov r1, r6
mov r2, r7
bl printf
.loc 1 1963 0
mov r0, #27
b .L573
.L618:
.LBB141:
.LBB142:
.loc 1 1396 0
ldr r0, [r5, #56]
mov r1, #0
bl dma_channel_set_burst_length
.loc 1 1398 0
mov r3, sl
cmp r3, #1
beq .L621
.loc 1 1409 0
lsl r2, r6, #16
mov r0, #18
.L613:
ldr r3, .L623+40
lsr r1, r6, #16
lsr r2, r2, #16
.L614:
.loc 1 1426 0
bl mmcsd_send_cmd_wait_resp
cmp r0, #0
mov r9, r0
beq .L591
b .L602
.L620:
.loc 1 1491 0
ldr r0, .L623+44
bl printf
mov r4, #24
b .L610
.L611:
.LBE142:
.LBE141:
.loc 1 2001 0
mov r0, r4
bl cyg_mutex_unlock
.loc 1 2003 0
ldr r0, .L623+12
mov r1, r6
mov r2, r7
bl printf
.loc 1 2005 0
mov r0, #26
b .L573
.L621:
.LBB143:
.LBB144:
.loc 1 1399 0
lsl r2, r6, #16
mov r0, #17
b .L613
.L619:
.loc 1 1426 0
lsl r2, r6, #16
mov r0, #17
lsr r1, r6, #16
lsr r2, r2, #16
mov r3, #9
b .L614
.L599:
.loc 1 1496 0
mov r3, sl
cmp r3, #1
bhi .LCB3173
b .L602 @long jump
.LCB3173:
.loc 1 1497 0
mov r0, #12
mov r1, #0
mov r2, #0
mov r3, #1
bl mmcsd_send_cmd_wait_resp
cmp r0, #0
mov r9, r0
beq .LCB3181
b .L622 @long jump
.LCB3181:
b .L602
.L624:
.align 2
.L623:
.word mmcsd+116
.word -1610530780
.word 511
.word .LC105
.word .LC107
.word 2179128
.word mmcsd
.word 2089
.word mmcsd_status_reg
.word neti_debug
.word 521
.word .LC101
.LBE144:
.LBE143:
.LFE59:
.size mmcsd_read, .-mmcsd_read
.section .text.mmcsd_erase,"ax",%progbits
.align 2
.global mmcsd_erase
.code 16
.thumb_func
.type mmcsd_erase, %function
--
Summary: Bad assembly output in Thumb mode with -O2
Product: gcc
Version: 3.4.4
Status: UNCONFIRMED
Severity: normal
Priority: P2
Component: c
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: czimman at bloomberg dot com
CC: gcc-bugs at gcc dot gnu dot org
GCC host triplet: i386-unknown-linux
GCC target triplet: arm-elf-gcc
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23980
