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Re: Authoritative answer wanted: "-g -O1" vs. "-O1"
- From: Ian Lance Taylor <iant at google dot com>
- To: David Brown <david at westcontrol dot com>
- Cc: Gene Smith <gds at chartertn dot net>, gcc-help at gcc dot gnu dot org
- Date: Tue, 18 Jun 2013 09:32:24 -0700
- Subject: Re: Authoritative answer wanted: "-g -O1" vs. "-O1"
- References: <kpoqoj$ebj$1 at ger dot gmane dot org> <CAKOQZ8zJ9Rn3xOS1=Co+Rzrjbrpt7=8u=TCR+4Qiz-ZVbuzKBA at mail dot gmail dot com> <51C07046 dot 3090005 at westcontrol dot com>
On Tue, Jun 18, 2013 at 7:35 AM, David Brown <david@westcontrol.com> wrote:
>
> I did not think that was the case. As I understood it, "-g" /may/ cause
> to the code to improve debugging. I can't say that I have ever noticed
> any code changes, but I've always assumed it is possible especially with
> more advanced optimisations.
>
> I certainly don't see anything in the documentation that suggests "-g"
> cannot change the code - only that "-g -O" will generate optimised and
> debugable code (though possibly with confusing debugging).
That turns out not to be the case. It always been a strict rule with
GCC that -g does not affect code generation.
What the OP is describing is a serious bug.
Ian