https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58372
--- Comment #27 from David Grayson <davidegrayson at gmail dot com> --- Thanks to everyone who is working on this. I can confirm that the patch in comment #20 by Uroš Bizjak applies cleanly to GCC 7.3.0, and I successfully used the resulting toolchain targeting i686-w64-mingw32 to build Qt and several Qt GUI examples, all of which run correctly. Just in case it helps you find more bugs: I noticed there are several other places in the code (of gcc-8-20181019) where ctrl->preferred_stack_boundary gets updated without any obvious update of ctrl->stack_alignment_needed: gcc/explow.c:1247 in get_dynamic_stack_size gcc/explow.c:1595 in get_dynamic_stack_base gcc/calls.c:3811 in expand_call gcc/config/i386/i386.c:12593 in ix86_update_stack_boundary
