[sdcc-devel] [ sdcc-Bugs-2435941 ] Compiler crash w/ large model: Internal error (gen.c:441)

[SourceForge.net <no...@so...>]

Bugs item #2435941, was opened at 2008-12-16 15:33
Message generated for change (Tracker Item Submitted) made by Item Submitter
You can respond by visiting: 
https://sourceforge.net/tracker/?func=detail&atid=100599&aid=2435941&group_id=599

Please note that this message will contain a full copy of the comment thread,
including the initial issue submission, for this request,
not just the latest update.
Category: None
Group: None
Status: Open
Resolution: None
Priority: 5
Private: No
Submitted By: Colin D Bennett (cbennett)
Assigned to: Nobody/Anonymous (nobody)
Summary: Compiler crash w/ large model: Internal error (gen.c:441)

Initial Comment:
I have encountered an internal compiler error when compiling
a particular bit of code for the 8051 (mcs51) using the large memory
model and a re-entrant function.

If the small memory model is used or if the function is made
non-reentrant, then it compiles successfully (although the generated
code is incorrect! I will post separately about the code generation
error).

However, this particular re-entrant function has no local variables,
parameters, or return value.  I think that SDCC is, however, creating a
temporary stack variable for the value of the "(now - updated)"
expression, and perhaps it is confused since SDCC thought it was not
going to require storage for any local variables.


Compiler Error
==============

$ ~/bin/sdcc/bin/sdcc -mmcs51 -c --model-small bad.c
$ ~/bin/sdcc/bin/sdcc -mmcs51 -c --model-large bad.c
bad.c:16: error 9: FATAL Compiler Internal Error in file 'gen.c' line
number '441' : getFreePtr should never reach here
Contact Author with source code


SDCC version
============

I am using SDCC svn revision 5287, though I also tested rev 5252, which
also exhibits the same error.
$ ~/bin/sdcc/bin/sdcc --version SDCC : mcs51 2.8.4 #5287 (Dec 16 2008)
(UNIX)


Source Code (bad.c)
===================
------------------------------------------------------------
#include <stdint.h>

uint32_t sleep_timer_get(void);

int32_t remaining;
uint32_t updated;
uint32_t now;

static void do_test(void) __reentrant
{
  while (1)
    {
      now = sleep_timer_get();

      remaining -= (now - updated) & 0xFF;
      updated = now;
    }
}
------------------------------------------------------------


Regards,
Colin


----------------------------------------------------------------------

You can respond by visiting: 
https://sourceforge.net/tracker/?func=detail&atid=100599&aid=2435941&group_id=599