The store to the whole of each volatile object was picked apart
like there had been an individual assignment to each of the
fields. Reads were added as part of that; see PR for details.
The reads from volatile memory were a clear bug; individual
stores questionable. A separate patch clarifies the docs.
gcc:
2020-07-09 Richard Biener <rguenther@suse.de>
PR middle-end/94600
* expr.c (expand_constructor): Make a temporary also if we're
storing to volatile memory.
gcc/testsuite:
2020-07-09 Hans-Peter Nilsson <hp@axis.com>
PR middle-end/94600
* gcc.dg/pr94600-1.c, gcc.dg/pr94600-2.c, gcc.dg/pr94600-3.c,
gcc.dg/pr94600-4.c, gcc.dg/pr94600-5.c, gcc.dg/pr94600-6.c,
gcc.dg/pr94600-7.c, gcc.dg/pr94600-8.c: New tests.
(cherry picked from commit a4aca1edaf37d43b2b7e9111825837a7a317b1b0)
