CodeWarrior for MCUのトピックRe: Embedded Assembly code compiled wrong?

Embedded Assembly code compiled wrong?

UtopiaTim — Sat, 01 Mar 2008 05:01:44 GMT

Hi Folks,

I have embedded some assembly code in my C for the JM60

using CW 6.1.

What you see on the left is the source, and on the right

is the actual code that was generated in the 'assembly'

window.

How come the branch to location at 7900 isn't correct?

The code at 7900 should have the branch location as 78F4.

Thanks,

Tim

Key_temp = 0x00

Second_current = 0x01

Bottle_loop:
asm{
lda   Key_temp                   78F4 LDA 0x00B0
  cmp   #$00                       78F7 CMP #0x00
  bne   check_keys                 78F9  BNE *+14    ;abs = 0x7907

  lda   Second_current             78FB LDA 0x0150

cmp #$3b 78FE CMP #0x3B
bne Bottle_loop 7900 BNE *+2 ;abs = 0x7902 <-- WRONG

location, should

be 78F4

  jsr   update_clock               7902 JSR 0x79B6
  bra   Bottle_loop                7905  BRA *+2     ;abs = 0x7907

check_keys:
    }

Re: Embedded Assembly code compiled wrong?

CrasyCat — Sat, 01 Mar 2008 15:15:03 GMT

Hello

I would recommend you to submit a service request for that.

Click here to submit a service request.

Make sure to attach a reproducible project and installed product information to the service request.
To generate the required information:
- Start CodeWarrior
- Open the project
- Select "Help" -> "Pack and Go" and follow instructions on the screen.

Attach the generated .zip file to the SR.

CrasyCat

Re: Embedded Assembly code compiled wrong?

bigmac — Mon, 03 Mar 2008 22:28:32 GMT

Hello,

I suspect the problem may be because the label Bottle_loop has been defined at a location outside the assembly block.

When I attempted to compile the code, using an earlier version of CW, I received the error "Label not set", and the compile failed. Once the label was positioned within the block, the intended result was obtained.

Regards,

Mac

Re: Embedded Assembly code compiled wrong?

UtopiaTim — Mon, 03 Mar 2008 22:40:50 GMT

Thanks Mac,

I didn't get any warning or error messages, but I'll give it a try.

Again,

Thanks!

TIm

Re: Embedded Assembly code compiled wrong?

CompilerGuru — Tue, 04 Mar 2008 14:00:50 GMT

I think Bigmag did notice the issue, well I did not see it.
Is Bottle_loop not defined in a asm section?
Basically labels outside of asm sections are plain C labels to be used with the C goto statement. Labels inside of asm sections are HLI labels, and the two namespaces are distinct, they do not mix.

Daniel

Re: Embedded Assembly code compiled wrong?

bigmac — Thu, 06 Mar 2008 13:51:28 GMT

Hello,

CompilerGuru wrote:
I think Bigmag did notice the issue, well I did not see it.
Is Bottle_loop not defined in a asm section?
Basically labels outside of asm sections are plain C labels to be used with the C goto statement. Labels inside of asm sections are HLI labels, and the two namespaces are distinct, they do not mix.

Daniel

To clarify my findings, I needed to alter the label position as follows, to avoid the compile error. This seems to tally with Daniel's post.

asm {
Bottle_loop:

   lda   Key_temp
    cmp   #$00
    bne   check_keys

    lda   Second_current

cmp #$3b
bne Bottle_loop

    jsr   update_clock
    bra   Bottle_loop
check_keys:
    }

The main issue seems to be why the original code correctly generated an error with CW5.0, but did not with CW6.1. The erroneous result was to ignore the branch, and skip to the next instruction, for both instances within the original code.

Regards,

Mac

Re: Embedded Assembly code compiled wrong?

CompilerGuru — Fri, 07 Mar 2008 13:01:26 GMT

Is there another global symbol (function, variable) named Bottle_loop?
That would explain the generated code.