Need some clarification about optimization flags, what "exactly" does -O1 do?

[Diego Novillo]

On Fri, Nov 28, 2008 at 05:58, Andrew Haley <aph@redhat.com> wrote:

> That's interesting.  tree-dce is Dead Code Elimination on trees, where
> gcc removes code that can't possibly be reached.

Strictly speaking, DCE removes code that can't possibly affect the
output of the program.  Unreachable code is removed by the CFG cleanup
helper.  Apologies for nitpicking, but this distinction is handled in
two different spots in the compiler, so it may affect what files/dumps
you need to look at.


Diego.