https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78972
Thomas Koenig <tkoenig at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Target Milestone|--- |7.0
--- Comment #6 from Thomas Koenig <tkoenig at gcc dot gnu.org> ---
(In reply to Andrew Pinski from comment #5)
> What happens if you add -fschedule-insns?
-fschedule-insns makes the stack use slightly higher. With current trunk:
ig25@linux-fd1f:~/Krempel/SMID> gcc -O1 -S example.c && grep subq example.s
subq $2416, %rsp
ig25@linux-fd1f:~/Krempel/SMID> gcc -O1 -fschedule-insns -S example.c && grep
subq example.s
subq $2432, %rsp
By comparison, gcc 4.8 uses _far_ less stack:
ig25@linux-fd1f:~/Krempel/SMID> /usr/bin/gcc -O1 -S example.c && grep subq
example.s
subq $272, %rsp
ig25@linux-fd1f:~/Krempel/SMID> /usr/bin/gcc -O1 -fschedule-insns -S example.c
&& grep subq example.s
subq $416, %rsp
-O2 and -O3 do not help either.
