Date: Sat, 2 May 92 21:23:16 CDT
From: csaba AT vuse DOT vanderbilt DOT edu (Csaba A. Biegl)
To: kuku AT acds DOT physik DOT rwth-aachen DOT de
Subject: Re:  gcc 2.1 code generation bug?
Cc: djgpp%sun DOT soe DOT clarkson DOT edu AT RELAY DOT CS DOT NET
Status: O

> you were mentioning that gcc2.1 was producing incorrect code in one case.
> I a bit anxious about it (using it any further). In what area was this
> behaviour?
>
> --Chris

I did not track it down yet. It is related to the mouse cursor drawing 
in my graphics library ("cbgrx100.zip"). In 16 color EGA/VGA modes I was
allocating the work and save areas for the cursor in offscreen video RAM
for faster bitblt-s. It works perfectly with GCC 1.39 and Turbo C but
produces garbage on the screen when compiled with GCC 2.1. The 2.1
compiled code works fine if the work/save areas are in system RAM. Until I have 
time to track it down I just '#ifdef' the relevant code out when compiled
with the new GCC. (i.e. if 'libgrx.a' is compiled with 2.1 it always 
allocates these areas in system RAM.) See 'cursor.c'.

I will let you know when I figure out what goes wrong.

Csaba Biegl

csaba AT vuse DOT vanderbilt DOT edu