CodeWarrior for MCUのトピックcompiler issue

compiler issue

frogman_sr — Wed, 17 May 2006 07:44:45 GMT

I am using the memcpy function with identical parameters in two different locations. However, looking at the assembly code, there is a difference bewteen the two. Here is the output from the list file:

This one works correctly

470:    memcpy((uchar *)&flash_data,(uchar *)&Flash_Data_1,sizeof(flash_data));
0002 95       [2]             TSX
0003 89       [2]             PSHX
0004 8b       [2]             PSHH
0005 450000   [3]             LDHX @Flash_Data_1
0008 89       [2]             PSHX
0009 8b       [2]             PSHH
000a ae07     [2]             LDX   #7
000c 8c       [1]             CLRH
000d cd0000   [6]             JSR   memcpy
0010 a704     [2]             AIS   #4

this one causes the mp to reboot

477:      memcpy((uchar *)&flash_data,(uchar *)&Flash_Data_1,sizeof(flash_data));
002b 95       [2]             TSX
002c 89       [2]             PSHX
002d 8b       [2]             PSHH
002e 450000   [3]             LDHX @Flash_Data_1
0031 89       [2]             PSHX
0032 8b       [2]             PSHH
0033 ae07     [2]             LDX   #7
0035 cd0000   [6]             JSR   memcpy
0038 a704     [2]             AIS   #4

The only difference is the CLRH followign the LDX #7 command. The memcpy function uses the HX register to store the length value of the data you are copying. Because the H register is not being cleared, my length value is garbage.

Is this a known bug? Are there any workarounds?

I am using CodeWarrior IDE version 5.7.0 Build 1932 for target MC9S08GT32. Thanks for any help you can give.

frogman_sr

Re: compiler issue

CompilerGuru — Thu, 18 May 2006 05:00:09 GMT

Can you provide a compilable code snippet to show the wrong code pattern? Together with the options actually used.

Something which could explain it is that for the HC08 (as opposed to a HCS08), the last 16 bit argument is passed in A/X and not in H/X.
So did you compile the second snippet without -CS08?

Also make sure memcpy is NOT implicitely (or incorrectly) defined. Make sure you did include stdio.h before calling it.

Daniel

Re: compiler issue

frogman_sr — Thu, 18 May 2006 23:59:29 GMT

Both snippets were compiled at the same time within the same function, a couple of lines apart. Originally there were to different source addresses, but for comparison, I made them both the same. -CS08 was included in the compiler options.

I did forget to include stdio.h. But adding it appears not to have worked.

After looking over my pragma statements to place my source variables into specific memory locations, I appear to have left the SHORT modifier when I copied over my zeropage definition. After removing SHORT, everything is compiling fine.

Thanks for your help.