mspgcc win32 build 2002-12-17 from www.mikrocontroller.net fail to
compile working code with -O2 flag.
Here a example from the TCPIP source.
memcpy(&TxFrame2[ETH_SA_OFS], &MyMAC, 6);
1c0c: 3f 40 6d 11 mov #4461, r15 ;#0x116d
1c10: b2 4f 06 02 mov @r15+, &0x0206 ;
1c14: b2 4f 08 02 mov @r15+, &0x0208 ;
1c18: b2 4f 0a 02 mov @r15+, &0x020a ;
memcpy(&TxFrame2[ARP_SENDER_HA_OFS], &MyMAC, 6); // !HERE! 1c38: b2
4f 16 02 mov @r15+, &0x0216 ;
1c3c: b2 4f 18 02 mov @r15+, &0x0218 ;
1c40: b2 4f 1a 02 mov @r15+, &0x021a ;
R15 should be reset to 0x116d in the second call of memcpy. I don't
know if it's a bug in memcpy where the pointer on &MyMAC need some
special keyword like "volatile" or it's a bug un the optimization.
memcpy(&TxFrame2[ETH_SA_OFS], &MyMAC, 6);
1c0c: 3f 40 6d 11 mov #4461, r15 ;#0x116d
1c10: b2 4f 06 02 mov @r15+, &0x0206 ;
1c14: b2 4f 08 02 mov @r15+, &0x0208 ;
1c18: b2 4f 0a 02 mov @r15+, &0x020a ;
*(unsigned int *)&TxFrame2[ETH_TYPE_OFS] = SWAPB(FRAME_ARP);
1c1c: b2 40 08 06 0c 02 mov #1544, &0x020c ;#0x0608
// ARP
*(unsigned int *)&TxFrame2[ARP_HARDW_OFS] = SWAPB(HARDW_ETH10);
1c22: b2 40 00 01 0e 02 mov #256, &0x020e ;#0x0100
*(unsigned int *)&TxFrame2[ARP_PROT_OFS] = SWAPB(FRAME_IP);
1c28: b2 42 10 02 mov #8, &0x0210 ;subst r2 with
As==11
*(unsigned int *)&TxFrame2[ARP_HLEN_PLEN_OFS] = SWAPB(IP_HLEN_PLEN);
1c2c: b2 40 06 04 12 02 mov #1030, &0x0212 ;#0x0406
*(unsigned int *)&TxFrame2[ARP_OPCODE_OFS] = SWAPB(OP_ARP_REQUEST);
1c32: b2 40 00 01 14 02 mov #256, &0x0214 ;#0x0100
memcpy(&TxFrame2[ARP_SENDER_HA_OFS], &MyMAC, 6); // !HERE! 1c38: b2
4f 16 02 mov @r15+, &0x0216 ;
1c3c: b2 4f 18 02 mov @r15+, &0x0218 ;
1c40: b2 4f 1a 02 mov @r15+, &0x021a ;
--
Dominic Pageau
