https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109780
--- Comment #35 from Uroš Bizjak <ubizjak at gmail dot com> --- (In reply to Uroš Bizjak from comment #34) > The problematic code is expanded from: > > ;; Generating RTL for gimple basic block 5 > > ;; __builtin_memset (&k, 0, 40); > > (insn 21 20 22 (parallel [ > (set (reg:DI 107) > (plus:DI (reg/f:DI 93 virtual-stack-vars) > (const_int -48 [0xffffffffffffffd0]))) > (clobber (reg:CC 17 flags)) > ]) "pr109780.c":11:12 -1 > (nil)) It is not a good idea to CSE address that refers to virtual stack vars to a temporary. This defeats stack/frame pointer detection, mentioned in Comment #33, and consequently fails to increase stack alignment.
