autoconf-patches
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: changing "configure" to default to "gcc -g -O2 -fwrapv ..."


From: Robert Dewar
Subject: Re: changing "configure" to default to "gcc -g -O2 -fwrapv ..."
Date: Sat, 24 Mar 2007 20:30:26 -0400
User-agent: Thunderbird 1.5.0.10 (Windows/20070221)

Ian Lance Taylor wrote:

I believe there is a comprehensible distinction between "compiler will
not assume that signed overflow is undefined behaviour" and "compiler
will cause all arithmetic to wrap around."

In any case, I have no plans to continue working on this.  I described
my work in considerable detail as I did it and the patches have gone
through multiple rounds of review.  I would be happy to see your
concrete proposal.

First, I would get some real figures on performance comparing

-fstrict-overflow
-fno-strict-overflow
-fwrapv

It is really hard to estimate the value of the second dubious
(dubious because ill-defined, it seems to try to create a state
of undefined definedness) switch compared to the other two
possibilities.

Ian





reply via email to

[Prev in Thread] Current Thread [Next in Thread]