Re: print gcc optimization log

[Ian Lance Taylor <iant@xxxxxxxxxx>]

On Wed, Aug 15, 2012 at 8:58 PM, Xin Tong <xerox.time.tech@xxxxxxxxx> wrote:
> I sometimes run into issues where i want to figure out why gcc is
> performing a specific optimization and what the optimization affects
> the tree. is there any documents on how to print gcc optimizations and
> code generation logs ?

Unfortunately GCC has very little in the way of logs intended for end
users.  About all I know is the -ftree-vectorizer-verbose information,
which gives useful feedback about the vectorization optimizations.

You can a lot of information by  using -fdump-tree-all-details
-fdump-rtl-all-details, but it's difficult to interpret without the
source code and a working knowledge of GCC internals.

Ian