> On Feb 17, 2016, at 3:01 PM, Howard Bussey <[email protected]> wrote:
> 
> Googling “Process PTE …” shows this occurred before:
> 
> http://mailman.trailing-edge.com/pipermail/simh/2010-May/010760.html
> 
> The suggestion was to try turning off optimization when compiling simh…

In that case, gcc is the compiler.  In the case Michael mentioned, it's LLVM.  
So the conclusion is that it's a SimH bug, non-compliant code that gets caught 
by modern optimizing compilers.

Turning on GCC warnings may help; a lot of issues of this kind are reported as 
warnings if you build with -Wall.  I don't see anything interesting when I try 
that on OSX, but that's LLVM.  When I try it on Linux, I get a bunch of 
possible uninitialized variables -- those are sometimes false warnings but 
worth looking at.  More interesting is a bunch of "does break strict-aliasing 
rules".  Those indicate incorrect (not ANSI compliant) code that you used to be 
able to get away with, but can't any longer when optimization is enabled.  The 
correct way to handle those errors is to fix the code, not to disable the 
warning or the optimization (as is done by some other software teams).

More info can be found here: 
https://homes.cs.washington.edu/~akcheung/papers/apsys12.pdf -- a very good 
article that all C programmers should read.

        paul


_______________________________________________
Simh mailing list
[email protected]
http://mailman.trailing-edge.com/mailman/listinfo/simh

Reply via email to