Hello maintainers,
I am using msp430-gcc and friends, and I have found some possible
bugs. My computer is setup according to:
cat /etc/slackware-version
Slackware 9.0.0
uname -a
Linux gaston 2.4.20 #2 Mon Mar 17 22:02:15 PST 2003 i686 unknown
I have included some source-code in this message, which begins at
"Listing 1", and also some assembly output which begins at
"Listing 2". The following files have been downloaded and installed:
msp430-gcc-3.2.2.20030214.tar.bz2
msp430-libc-1.0.20030207.tar.bz2
The commandline used to compile the program in listing 1 was:
msp430-gcc -O -S -fpeephole -fpeephole2 -mmcu=msp430x147 bugsdemo.c -o
bugsdemo.s
The reason that I activated the flag -fpeephole2, was that I was not
satisfied with the optimization when using the datatype long int. The
flag made the optimizer remove a few redundant instructions, but also,
as we will see, a few necessary instructions as well.
Now to the details:
1. Sourcecode line 63 and line 74 generates an invalid opcode, "jne
&0x0000", as can be seen in lines 44 and 61 in the assembly
listing. The workaround was to rewrite the macros DISABLE_TX_INTR
and ENABLE_TX_INTR to generate function calls. This is not a very
efficient way of coding however.
2. Sourcecode line 137 generates an invalid opcode, "jl &0x001D", as
can be seen in line 151 in the assembly listing. The workaround was
to rewrite the macro DATA_DIR_OUT to generate a function call. The
phenomenom seems to be related the one above.
3. Lines 237 to 244 have an #if/#else/#endif macro. If the first case
is compiled, the value of grid[0] will not be correct when the call
to pr_txchar( grid[0] ) in line 239 is made. A "mov @r11, r15"
between lines 266 and 267 would save the day. The second case of
the macro always compile correctly. During the writing of this
message I found that the problem disappeared when I omitted the
flag -fpeephole2 on the commandline. The commndline now was:
msp430-gcc -O -S -fpeephole -mmcu=msp430x147 bugsdemo.c -o bugsdemo.s
I do not know if -O automatically sets -fpeephole, is there any way of
checking this ?
NOTE that the line-numbers above refers to line-numbers in the source,
not to line-numbers in this text.
The code in the example below is copied from different files in
production code.
With Best Regards, Tommy Andersson
tommy.anders...@geodynamik.com
--- Listing 1 begins here ---------------------------------------
#include <io.h>
#include <signal.h>
#define ENABLE_TX_INTR SFR_CMD(bis.b,IE1,UTXIE0)
#define DISABLE_TX_INTR SFR_CMD(bic.b,IE1,UTXIE0)
#define U0_BUFSIZE 10
#define PRC_PRINTER 2
// Push flags and disable interrupts
inline static void pushf_disable( void )
{
asm volatile ( "push r2 \n\t" : : );
dint();
asm volatile ( "nop \n\t" : : ); // dint() is delayed 1 clock !
}
// Pop the flags, possibly enabling interrupts
inline static void popf( void )
{
asm volatile ( "pop r2 \n\t" : : );
}
typedef unsigned char BYTE;
/*** Global control variables: ***/
extern volatile unsigned char curr_pid;
/*----------------------------------------------------------------------
Local variables
----------------------------------------------------------------------*/
static volatile BYTE tx0_buffer[U0_BUFSIZE];
static volatile BYTE *tx0_head = tx0_buffer;
static volatile BYTE *tx0_tail = tx0_buffer;
static volatile BYTE tx0_stop;
static volatile BYTE tx0_pending;
static volatile BYTE suspended, wait_data_flag;
/*----------------------------------------------------------------------
Transmit a character through the serial interface. Returns -1 on a
failure, otherwise 0 is returned.
----------------------------------------------------------------------*/
int pr_txchar( char ch )
{
BYTE *ptr;
retry:
DISABLE_TX_INTR;
if ( !tx0_pending ) { // NO pending transmissions
U0TXBUF = ch;
tx0_pending = 1;
}
else {
ptr = tx0_head;
if (++ptr >= tx0_buffer+U0_BUFSIZE)
ptr = tx0_buffer;
if (ptr == tx0_tail) { // Buffer is FULL !
ENABLE_TX_INTR;
if ( curr_pid == PRC_PRINTER ) {
pushf_disable();
suspended = 1; // This flag MUST BE SET before suspending the proc !
proc_suspend( PRC_PRINTER ); // Suspend printer process
popf();
goto retry;
}
else
return -1; // Otherwise, return error.
}
*tx0_head = ch; // Save next printer character.
tx0_head = ptr;
}
ENABLE_TX_INTR;
return 0;
}
#define CLOCK_LOW SFR_CMD( bic, P4OUT, 1<<0 )
#define CLOCK_HIGH SFR_CMD( bis, P4OUT, 1<<0 )
#define DATA_LOW SFR_CMD( bic, P4OUT, 1<<1 )
#define DATA_HIGH SFR_CMD( bis, P4OUT, 1<<1 )
#define DATA_DIR_IN SFR_CMD( bic, P4DIR, 1<<1 )
#define DATA_DIR_OUT SFR_CMD( bis, P4DIR, 1<<1 )
#define DATA_IN (P4IN&(1<<1))
/*----------------------------------------------------------------------
Read one byte of data from the RTC.
The argument 'bytecount' shall be assigned the number of to be read at
this 'session', and is used to control the acknowledge bit.
----------------------------------------------------------------------*/
static unsigned char rtc_read( signed char bytecount )
{
unsigned char bitcount, data_read;
static signed char count;
if (bytecount)
count = bytecount-1;
else
--count;
DATA_DIR_IN; // DATA goes high (hi-z)
for (bitcount = 0; bitcount < 8; bitcount++ ) {
CLOCK_HIGH;
delay_us( 4 );
data_read <<= 1;
if ( DATA_IN )
data_read |= (1<<0);
else
data_read &= ~(1<<0);
CLOCK_LOW;
delay_us( 4 );
}
DATA_LOW;
if ( count > 0 )
DATA_DIR_OUT; // DATA goes low -> Acknowledge */
delay_us( 2 );
CLOCK_HIGH;
delay_us( 4 );
CLOCK_LOW;
delay_us( 2 );
DATA_DIR_IN;
return data_read;
}
#define LF 10
#define FF 12
#define CR 13
#define ESC 27
#define WIDTH_CHAR 12
#define WIDTH_PRINTROW 400
#define MAXWIDTH_PRINTROW
(WIDTH_PRINTROW>WIDTH_LOGO?WIDTH_PRINTROW:WIDTH_LOGO)
#define LOGO_HORZ_TAB ((480-300)/2)
#define HDR_HORZ_TAB 49
#define DATA_HORZ_TAB 49
#define FOOT_HORZ_TAB 49
#define HEIGHT_TEXTLINE 12
#define HEIGHT_PRINTROW 8
#define HEIGHT_FOOTER (12*HEIGHT_TEXTLINE)
#define HEIGHT_A4 ((int)(VERT_DPI*297/25.4))
#define HORZ_GRIDLINE_SPACE 30
#define COARSE_VERT_GRIDLINE_SPACE 67
#define FINE_VERT_GRIDLINE_SPACE 100
#define CURVE_WIDTH 3
#define PC_BEGIN_LOGO {pr_txchar(ESC);pr_txchar('L');\
pr_txchar((WIDTH_LOGO+LOGO_HORZ_TAB)&0xff);\
pr_txchar((WIDTH_LOGO+LOGO_HORZ_TAB)>>8);}
#define PC_BEGIN_HDRTAB {pr_txchar(ESC);pr_txchar('L');\
pr_txchar(LOGO_HORZ_TAB&0xff);\
pr_txchar(LOGO_HORZ_TAB>>8);}
#define PC_BEGIN_GRAPHIC {pr_txchar(ESC);pr_txchar('L');\
pr_txchar((WIDTH_PRINTROW)&0xff);\
pr_txchar((WIDTH_PRINTROW)>>8);}
#define PC_BEGIN_GRA_RMV {pr_txchar(ESC);pr_txchar('L');\
pr_txchar((WIDTH_PRINTROW+5)&0xff);\
pr_txchar((WIDTH_PRINTROW+5)>>8);}
#define PC_SET_LINESPACING(x) {pr_txchar(ESC);pr_txchar('A');pr_txchar(x);}
#define PC_SET_GRLINESPACING {pr_txchar(ESC);pr_txchar('A');pr_txchar(8);}
#define PC_SET_TXTLINESPACING {pr_txchar(ESC);pr_txchar('A');pr_txchar(12);}
#define PC_SELECT_CHARSET(x) {pr_txchar(ESC);pr_txchar('R');pr_txchar(x);\
pr_txchar(ESC);pr_txchar('t');pr_txchar(x);}
#define PC_CRLF {pr_txchar(CR);pr_txchar(LF);}
#define PC_PIXELTAB(x) {int q;pr_txchar(ESC);pr_txchar('L');\
pr_txchar((x)&0xff);pr_txchar((x)>>8);\
for(q=(x);q;q--)pr_txchar(0);}
#define PC_FEED pr_txchar(FF)
#define PC_SET_CONDENSED pr_txchar(0x0f)
#define PC_SET_NORMAL pr_txchar(0x12)
static int timeaxis;
unsigned char *make_grid_and_frame( int horz_pos, int vert_pos );
unsigned char create_data_curve( int pos );
int print_data( void )
{
int printbyte;
unsigned char vline8, *grid;
PC_SET_GRLINESPACING;
// Left margin
grid = make_grid_and_frame( 0, timeaxis );
if (grid[1] != 128) {
#if (DATA_HORZ_TAB - 4*WIDTH_CHAR -1) < 0
#error "***** Not enough space for numeric scale at left edge *****"
#else
#if (DATA_HORZ_TAB - 4*WIDTH_CHAR -1) > 0
PC_PIXELTAB(DATA_HORZ_TAB - 4*WIDTH_CHAR -1);
#endif
#endif
pr_txnum_i( (timeaxis+7-grid[1])/3, 3 ); pr_txchar( 's' );
PC_PIXELTAB(1);
}
else
PC_PIXELTAB(DATA_HORZ_TAB);
// Data
PC_BEGIN_GRA_RMV;
for (printbyte = 0; printbyte<WIDTH_PRINTROW; printbyte++ ) {
grid = make_grid_and_frame( printbyte, timeaxis );
#ifndef COMPILER_BUG // This does not work due to a compiler bug
grid[0] |= create_data_curve( printbyte );
pr_txchar( grid[0] );
#else
vline8 = grid[0];
vline8 |= create_data_curve( printbyte );
pr_txchar( vline8 );
#endif
}
pr_txchar( 0 );
pr_txchar( 0 );
vline8 = create_rmv8( printbyte );
pr_txchar( vline8 );
pr_txchar( vline8 );
pr_txchar( vline8 );
PC_CRLF;
timeaxis += 8;
return HEIGHT_PRINTROW;
}
--- Listing 2 begins here ---------------------------------------
.file "bugsdemo.c"
.arch msp430x147
/* Hardware multiplier registers: */
__MPY=0x130
__MPYS=0x132
__MAC=0x134
__MACS=0x136
__OP2=0x138
__RESLO=0x13a
__RESHI=0x13c
__SUMEXT=0x13e
.data
.p2align 1,0
.type tx0_head,@object
.size tx0_head,2
tx0_head:
.short tx0_buffer
.p2align 1,0
.type tx0_tail,@object
.size tx0_tail,2
tx0_tail:
.short tx0_buffer
.text
.p2align 1,0
.global pr_txchar
.type pr_txchar,@function
/***********************
* Function `pr_txchar'
***********************/
pr_txchar:
/* prologue: frame size = 0 */
.L__FrameSize_pr_txchar=0x0
.L__FrameOffset_pr_txchar=0x2
push r11
/* prologue end (size=1) */
mov.b r15, r11
.L2:
/* #APP */
bic.b #llo(-128), &0x0000
/* #NOAPP */
cmp.b #llo(0), &tx0_pending
jne &0x0000
mov.b r11, &0x0077
mov.b #llo(1), &tx0_pending
jmp .L4
.L3:
mov &tx0_head, r14
add #llo(1), r14
cmp #tx0_buffer+10, r14
jlo .L5
mov #tx0_buffer, r14
.L5:
cmp &tx0_tail, r14
jne .L6
/* #APP */
bis.b #llo(-128), &0x0000
/* #NOAPP */
cmp.b #llo(2), &curr_pid
jne &0x0000
/* #APP */
push r2
dint
nop
/* #NOAPP */
mov.b #llo(1), &suspended
mov #llo(2), r15
call #proc_suspend
/* #APP */
pop r2
/* #NOAPP */
jmp .L2
.L7:
mov #llo(-1), r15
jmp .L1
.L6:
mov &tx0_head, r15
mov.b r11, @r15
mov r14, &tx0_head
.L4:
/* #APP */
bis.b #llo(-128), &0x0000
/* #NOAPP */
mov #llo(0), r15
.L1:
/* epilogue: frame size=0 */
pop r11
ret
/* epilogue end (size=2) */
/* function pr_txchar size 64 (61) */
.Lfe1:
.size pr_txchar,.Lfe1-pr_txchar
/********* End of function ******/
.local count.0
.comm count.0,1
.p2align 1,0
.type rtc_read,@function
/***********************
* Function `rtc_read'
***********************/
rtc_read:
/* prologue: frame size = 0 */
.L__FrameSize_rtc_read=0x0
.L__FrameOffset_rtc_read=0x4
push r11
push r10
/* prologue end (size=2) */
cmp.b #llo(0), r15
jeq .L12
add.b #llo(-1), r15
mov.b r15, &count.0
jmp .L13
.L12:
add.b #llo(-1), &count.0
.L13:
/* #APP */
bic #llo(2), &0x001E
/* #NOAPP */
mov.b #llo(0), r10
.L20:
/* #APP */
bis #llo(1), &0x001D
/* #NOAPP */
mov #llo(4), r15
call #delay_us
rla.b r11
bit.b #llo(2),&0x001C
jeq .L18
bis.b #llo(1), r11
jmp .L19
.L18:
bic.b #llo(1),r11
.L19:
/* #APP */
bic #llo(1), &0x001D
/* #NOAPP */
mov #llo(4), r15
call #delay_us
add.b #llo(1), r10
cmp.b #llo(8), r10
jlo .L20
/* #APP */
bic #llo(2), &0x001D
/* #NOAPP */
cmp.b #llo(1), &count.0
jl &0x001D ; &0x001D
/* #APP */
bis #llo(2), &0x001E
/* #NOAPP */
.L21:
mov #llo(2), r15
call #delay_us
/* #APP */
bis #llo(1), &0x001D
/* #NOAPP */
mov #llo(4), r15
call #delay_us
/* #APP */
bic #llo(1), &0x001D
/* #NOAPP */
mov #llo(2), r15
call #delay_us
/* #APP */
bic #llo(2), &0x001E
/* #NOAPP */
mov.b r11, r15
/* epilogue: frame size=0 */
pop r10
pop r11
ret
/* epilogue end (size=3) */
/* function rtc_read size 61 (56) */
.Lfe2:
.size rtc_read,.Lfe2-rtc_read
/********* End of function ******/
.p2align 1,0
.global print_data
.type print_data,@function
/***********************
* Function `print_data'
***********************/
print_data:
/* prologue: frame size = 0 */
.L__FrameSize_print_data=0x0
.L__FrameOffset_print_data=0x4
push r11
push r10
/* prologue end (size=2) */
mov.b #llo(27), r15
call #pr_txchar
mov.b #llo(65), r15
call #pr_txchar
mov.b #llo(8), r15
call #pr_txchar
mov &timeaxis, r14
mov #llo(0), r15
call #make_grid_and_frame
cmp.b #llo(-128), 1(r15)
jeq .L25
mov.b 1(r15), r15
mov &timeaxis, r14
sub r15, r14
mov r14, r15
add #llo(7), r15
mov r15, r12
mov #llo(3), r10
call #__divmodhi4
mov r12, r15
mov #llo(3), r14
call #pr_txnum_i
mov.b #llo(115), r15
call #pr_txchar
mov.b #llo(27), r15
call #pr_txchar
mov.b #llo(76), r15
call #pr_txchar
mov.b #llo(1), r15
call #pr_txchar
mov.b #llo(0), r15
call #pr_txchar
mov #llo(1), r11
.L30:
mov.b #llo(0), r15
call #pr_txchar
add #llo(-1), r11
jeq .L31
jmp .L30
.L25:
mov.b #llo(27), r15
call #pr_txchar
mov.b #llo(76), r15
call #pr_txchar
mov.b #llo(49), r15
call #pr_txchar
mov.b #llo(0), r15
call #pr_txchar
mov #llo(49), r11
.L36:
mov.b #llo(0), r15
call #pr_txchar
add #llo(-1), r11
jne .L36
.L31:
mov.b #llo(27), r15
call #pr_txchar
mov.b #llo(76), r15
call #pr_txchar
mov.b #llo(-107), r15
call #pr_txchar
mov.b #llo(1), r15
call #pr_txchar
mov #llo(0), r10
.L41:
mov &timeaxis, r14
mov r10, r15
call #make_grid_and_frame
mov r15, r11
mov r10, r15
call #create_data_curve
bis.b r15, @r11
call #pr_txchar
add #llo(1), r10
cmp #llo(400), r10
jl .L41 ; .L41
mov.b #llo(0), r15
call #pr_txchar
mov.b #llo(0), r15
call #pr_txchar
mov r10, r15
call #create_rmv8
mov r15, r11
call #pr_txchar
mov.b r11, r15
call #pr_txchar
mov.b r11, r15
call #pr_txchar
mov.b #llo(13), r15
call #pr_txchar
mov.b #llo(10), r15
call #pr_txchar
add #llo(8), &timeaxis
mov #llo(8), r15
/* epilogue: frame size=0 */
pop r10
pop r11
ret
/* epilogue end (size=3) */
/* function print_data size 153 (148) */
.Lfe3:
.size print_data,.Lfe3-print_data
/********* End of function ******/
.local tx0_buffer
.comm tx0_buffer,10,2
.local tx0_stop
.comm tx0_stop,1
.local tx0_pending
.comm tx0_pending,1
.local suspended
.comm suspended,1
.local wait_data_flag
.comm wait_data_flag,1
.local timeaxis
.comm timeaxis,2,2
/*********************************************************************
* File bugsdemo.c: code size: 278 words (0x116)
* incl. words in prologues: 5, epilogues: 8
*********************************************************************/
--- End Of File ---------------------------------------
