[Bug target/72827] [7 Regression] gnat bootstrap broken on powerpc64le-linux-gnu

[wschmidt at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=72827

--- Comment #12 from Bill Schmidt <wschmidt at gcc dot gnu.org> ---
(In reply to Eric Botcazou from comment #10)
> > So the double-word load before the call to SS_Release should be from a
> Mark_Id object obtained from a preceding call to SS_Mark.  It indeed looks
> like the double-word store to this Mark_Id object has been optimized away,
> possibly because of the strange back-and-forth adjustment to the FP.  Does
> passing CFLAGS="-O2 -fno-dse" for the gnattools make a difference?

Yes, it does!  The tools appear to be building normally with this option. 
Without it the build of gnattools fails almost immediately.

I'll work on getting some dumps to see what is happening in DSE.