I use gcc on large project with the optimization options below.
gcc never finishes on some larger modules.
Options are rather large compared with default values, this is because
previously while experimenting I saw performance improvements when I kept
increasing them (using gcc-3.4.3). And speed is of exceptional importance on my
project.
Now I try gcc-4.0.1 with the same options. Compile times of 90% of the modules
~2-5 times longer but on some of them it never finishes (at least not within 3
days).
It's good if compile times are long. But it's not clear if I should keep waiting
in order to gain some more speed or gcc just looped.
Gcc should produce some (maybe activated by option) messages:
* progress indicator: around how long it can take, are there any improvements
made
* when it finishes did it give up or other improvements are possible if options
were more aggressive
I am eager to wait days if it gives few percents improvements. But when no
messages are coming it's just an uncertainty.
used options:
-O5 -finline-limit=5000 -funit-at-a-time --param max-inline-insns-single=5000
--param max-inline-insns-auto=1200 --param large-function-insns=30000 --param
large-function-growth=2000 --param inline-unit-growth=10000 -funroll-loops
-fpeel-loops -funswitch-loops
--
Summary: gcc-4.0.1 never finishes with aggressive optimization
options
Product: gcc
Version: 4.0.1
Status: UNCONFIRMED
Severity: normal
Priority: P2
Component: rtl-optimization
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: yuri at tsoft dot com
CC: gcc-bugs at gcc dot gnu dot org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24132
