[Top][All Lists]

[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 01:47:11 -0400
User-agent: Thunderbird (Windows/20070221)

Ian Lance Taylor wrote:

The new option -fstrict-overflow tells gcc that it can assume the
strict signed overflow semantics prescribed by the language standard.
This option is enabled by default at -O2 and higher.  Using
-fno-strict-overflow will tell gcc that it can not assume that signed
overflow is undefined behaviour.  The general effect of using this
option will be that signed overflow will become implementation
defined.  This will disable a number of generally harmless
optimizations, but will not have the same effect as -fwrapv.

Can you share the implementation definition (implementation defined
generally means that the implementation must define what it does).
This seems awfully vague.

reply via email to

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