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Re: changing "configure" to default to "gcc -g -O2 -fwrapv ..."
From: |
Richard Kenner |
Subject: |
Re: changing "configure" to default to "gcc -g -O2 -fwrapv ..." |
Date: |
Sun, 31 Dec 2006 13:18:35 EST |
> Funny you should say that, because the Ada front-end likes to do this
> transformation, rather than leaving it to the back-end. For example:
>
> turns into
>
> if ((unsigned int) ((integer) x - 10) <= 10)
The front end isn't doing this: the routine "fold" in fold-const.c is.
True, it's being *called* by the front-end, but it's very definitely
common code.
See -gnatdg if you want to know what transformations the Ada front end
if making.
> The C front-end performs this transformation too.
See above. ;-)
> I'm not claiming that the back-end optimizers would actually do
> something sensible if the front-end didn't transform this code
I consider the optimizer that does this part of the middle-end (which
is really what you mean, not "back end").
- Re: changing "configure" to default to "gcc -g -O2 -fwrapv ...", (continued)
- Re: changing "configure" to default to "gcc -g -O2 -fwrapv ...", Gerald Pfeifer, 2006/12/31
- Re: changing "configure" to default to "gcc -g -O2 -fwrapv ...", Robert Dewar, 2006/12/31
- Re: changing "configure" to default to "gcc -g -O2 -fwrapv ...", Gabriel Dos Reis, 2006/12/31
- Re: changing "configure" to default to "gcc -g -O2 -fwrapv ...", Richard Kenner, 2006/12/31
- Re: changing "configure" to default to "gcc -g -O2 -fwrapv ...", Vincent Lefevre, 2006/12/31
- Re: changing "configure" to default to "gcc -g -O2 -fwrapv ...", Duncan Sands, 2006/12/31
- Re: changing "configure" to default to "gcc -g -O2 -fwrapv ...",
Richard Kenner <=
- Re: changing "configure" to default to "gcc -g -O2 -fwrapv ...", Robert Dewar, 2006/12/31
- Re: changing "configure" to default to "gcc -g -O2 -fwrapv ...", Vincent Lefevre, 2006/12/31
- Re: changing "configure" to default to "gcc -g -O2 -fwrapv ...", Robert Dewar, 2006/12/31
- Re: changing "configure" to default to "gcc -g -O2 -fwrapv ...", Vincent Lefevre, 2006/12/31
- Re: changing "configure" to default to "gcc -g -O2 -fwrapv ...", Richard Kenner, 2006/12/31
- Re: changing "configure" to default to "gcc -g -O2 -fwrapv ...", Michael Veksler, 2006/12/31
- Re: changing "configure" to default to "gcc -g -O2 -fwrapv ...", Richard Kenner, 2006/12/31
- Re: changing "configure" to default to "gcc -g -O2 -fwrapv ...", Michael Veksler, 2006/12/31
- Re: changing "configure" to default to "gcc -g -O2 -fwrapv ...", Ian Lance Taylor, 2006/12/31
- Re: changing "configure" to default to "gcc -g -O2 -fwrapv ...", Gabriel Dos Reis, 2006/12/31