Hi Fintan,
Could you give us a clue what you think is wrong?
Fintan McAndrew wrote:
Hello there,
I'm having a problem with the the msp430-gcc compiler when i use the
optimisation flag -02.
The problem relates to a section of code in my serial RX ISR. I have
included the incorrect code listing below and as you can see @ f278 there is
no actual code for the "serialHdrPtr" address assignment. When i take out
the -O2 flag everything build correctly. Is this a bug with the mp430-gcc ?
as this definitly should not be happening. All ideas and help welcome as i
would like to turn on opitimisation prioir to first field code release.
/*listing for the UART0 RX ISR routine */
if (transmitting == 0)
f268: c2 93 93 02 cmp.b #0, &0x0293 ;r3 As==00
f26c: 10 20 jnz $+34 ;abs 0xf28e
OK so far
transmitting = 1;
f26e: d2 43 93 02 mov.b #1, &0x0293 ;r3 As==01
still OK
serialBuffPtr = (unsigned char *)&serialBuff[0];
f272: b2 40 0a 02 mov #522, &0x0200 ;#0x020a
f276: 00 02
still OK
serialDataCnt = 0;
f278: c2 43 08 02 mov.b #0, &0x0208 ;r3 As==00
still OK
serialHdrPtr = (unsigned char *)&serialHdrBuff[0];
serialHdrCnt =0;
U0TXBUF = *serialHdrPtr++;
f27c: d2 42 04 02 mov.b &0x0204,&0x0077 ;0x0204
f280: 77 00
f282: b2 40 05 02 mov #517, &0x0202 ;#0x0205
f286: 02 02
serialHdrCnt++;
f288: d2 43 90 02 mov.b #1, &0x0290 ;r3 As==01
f28c: 35 3c jmp $+108 ;abs 0xf2f8
Now things have got rearranged. The "=0" and "++" for serialHdrPt rhave
been merged into "=1". The assignment to the port looks OK. serialHdrPtr
has been assigned one beyond the start of the buffer, so the "++" has
been eliminated.
}
Am I missing something, or did you?
Regards,
Steve
