Xref: utzoo comp.sys.amiga:34869 comp.sys.amiga.tech:5507
Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ames!eos!phil
From: phil@eos.UUCP (Phil Stone)
Newsgroups: comp.sys.amiga,comp.sys.amiga.tech
Subject: Re: Lattice C 5.02
Message-ID: <3859@eos.UUCP>
Date: 5 Jun 89 16:40:52 GMT
References: <8906041609.AA24115@ucbvax.Berkeley.EDU>
Reply-To: phil@eos.UUCP (Phil Stone)
Followup-To: comp.sys.amiga.tech
Organization: NASA Ames Research Center, Calif.
Lines: 66

In article <8906041609.AA24115@ucbvax.Berkeley.EDU> 11TSTARK@GALLUA.BITNET (Timothy Stark) writes:

		<problems with Lattice 5.0>

>      I have another problems. My program kept to get a visit from GURU.
>I cannot find a bug in my source file. I decided to put debug information
>at starting routines. When it hits GURU, I get last information from
>debug routines. I looked into my source file but I still unable to find
>a bug. It must be a bug in compiler which generate incorrect instructions.
>It may results as illegal instruction, A emulation, or F emulation GURUs
>with task address (.000032D2 -- I am not sure that). What do I do next?
>
>-- Tim Stark

(Note: I'm responding to comp.sys.amiga so Tim will see this answer, but
I think the topic is more appropriate to the .tech group, so follups are
directed there).

Tim, I assume you have CodeProbe with your Lattice 5.0.  You can use
this to single-step through suspected problem areas in your code; often
this will enable you to see where the crash occurs.

However, this is not always enlightening.  Am I crazy, or are there
some significant code-generation bugs in Lattice 5.02?  Here's
a brief code fragment-example:

I have a structure defined as follows:

struct foo
{
	unsigned short shortbar;
	unsigned char bar2;
	unsigned char bar3;
};

In a certain function, the following code occurs:

struct foo *fooptr;
unsigned short temp;

	.
	.
	.
	fooptr->bar2++;
	if( fooptr->shortbar != 0xFFFF )
		fooptr->shortbar = temp;
	fooptr++;
	.
	.
	.


Looking at this area of the code with CPR, I noticed that the generated
assembly code incremented 'fooptr' into the MIDDLE of the next structure
(a simple wordwise increment, rather than the addition of 4 bytes that
is required).

Certain tweaking, like changing the unsigned short field to an 'int'
field, made the problem go away.  But this seems to be a strange problem
which was not generated from the same source using Lattice 3.01 (my
previous version).  What gives?  Do y'all need more detail on this?
Also, I haven't tried the Lattice on-line support; is this indicated?

Again, notice that followups have been directed to comp.sys.amiga.tech.

		Phil Stone	 (phil@eos.arc.nasa.gov | ames!eos!phil)