[PATCH, libgfortran] proposed fix for SPEC CPU2017 621.wrf_s failures

[Jerry DeLisle]

On 06/25/2017 05:50 PM, Jim Wilson wrote:
> As mentioned in bug 81195, I see openmp related failures due to a lack
> of locking of the newunit_stack and newunit_tos variables.  The code
> locks when pushing onto the stack, but does not lock when popping from
> the stack.  This can cause multiple threads to pop the same structure,
> which then eventually leads to an error.
> 
> This patch was tested with an aarch64 bootstrap and make check.  There
> were no regressions.  It was also tested with a SPEC CPU2017 run, and
> solves the 621.wrf_s failure I get without the patch.
> 
> gcc 7 has the same problem.  gcc 6 is OK.
> 
> Jim
> 

OK to commit for trunk and 7. Thanks for spotting this,

Jerry