FW: Apparent SH3-DSP and SH4 compiler bugs encountered

["Biessman, Bill" <biessman at electric dot amc dot bell-labs dot com>]

> >
The tail end of this mail I sent to Hitachi and Wind River with regard to
bugs found in the
compilers Wind River distributes with their VxWorks development package.
The bugs
have to do with the optimizer for the SH3 and SH4 compilers.  In both cases
they
cause sign extension bugs that do not occur with the optimizer off, and in
the case of
the SH4-float builds the optimizer actually crashes with a core dump.  The
non-optimized
float version does not crash, though I haven't been able to get my code to
run yet since I
use inlines and these functions do not get included with the optimizer off.

I'm not sure that it is correct to send this to you in addtion to Wind
River, but I figured it
was worth a try.

Thanks

Bill Biessman
William J. Biessman
>biessman@lucent.com
>biessman@electric.amc.bell-labs.com
>biessman@home.com
>732-949-7922

> >Here are three examples of Wind River SH compiler bugs we have
> encountered.
> >They are in a PC Zipped executable format.
> > <<Shbug.exe>> 
> > The first bug, sh3extend, was found in the sh3 compiler that runs on the
> >PC-NT environment.  It has to do with improper conversion of a 16-bit
> >unsigned constant to a register value. The value 0xF000 is converted to
> >0xFFFFF000 when the optimizer is on.
> >
> >The second bug has to do with sign extension with the SH4.  The optimizer
> >seems to drops sign extension instructions some times and moves them to
> the
> >wrong place other times.
> >
> >The third bug, sh4float, has to do with the float implementation and
> seems
> >independent of the optimizer setting.  In this case the compiler crashes
> >with an illegal instruction for the sample C file.
> >
> >The directories have original C files, compilation scripts, and compiler
> >outputs.
> >
> >Please let me know what you find.
> >
> >
> >William J. Biessman
> >biessman@lucent.com
> >biessman@electric.amc.bell-labs.com
> >biessman@home.com
> >732-949-7922
> >
> > <<Shbug.exe>>

Shbug.exe