Cryptic bug for DMD v2.087.x

[Peter Jacobs]

We have a flow simulation code 
(http://cfcfd.mechmining.uq.edu.au/eilmer/) that fails to build 
optimized with DMD v2.087.0 or v2.087.1.  The cryptic message at 
the end of the attempt to build is:
   tym = x14
   makefile:414: recipe for target 'e4shared' failed
   make: *** [e4shared] Illegal instruction (core dumped)
and the compiler flags are:
   dmd -w -O -release -inline -boundscheck=off -dip1008 ...

The build is successful if we omit the -O flag.

In contrast, we have successful optimized builds for DMD 2.086.1 
and LDC 1.17.0-beta1.

I can provide more details but I was thinking that the "tym = 
x14" might already mean something to someone familiar with the 
insides of DMD.

Best regards,
Peter J.