How could I change boost release variant to use cxxflags=-O2?

Question

On my machine cxxflags for variant=release is -O3 by default.
I need to change it to -O2. Please advise how to proceed.

I am fine with defining a new variant as well, if someone could advise me on that.

try bjam release -n -a to know for sure if it is -O3 or -O2 now — usta, Sep 03 '10 at 14:20
Thanks usta. Used "bjam release -n -a" . shows "g++" -ftemplate-depth-128 -O3 -finline-functions -Wno-inline -Wall -DNDEBUG — Humble Debugger, Sep 03 '10 at 14:26

score 5 · Accepted Answer · answered Sep 04 '10 at 09:05

5

Just use:

<variant>release:<cxxflags>-O2

as requirements on top-level project. Options specified with cxxflags are passed to gcc after all the other options, so -O3 will be overridden.

answered Sep 04 '10 at 09:05

Vladimir Prus

score 1 · Answer 2 · answered Sep 03 '10 at 15:34

1

I think your best bet is to create a new variant, like this:

    variant o2release : <cxxflags>-O2 <debug-symbols>off <inlining>full <runtime-debugging>off define=NDEBUG

answered Sep 03 '10 at 15:34

usta

Thanks. I had access to the feature.jam file and I was able to change O3 to O2 for optimization in gcc. That worked as well. – Humble Debugger Sep 03 '10 at 17:19
Yep, that's also an option when local modification is OK for you :) – usta Sep 03 '10 at 17:42

2 Answers2