On Thu, 26 Nov 2020, Jakub Jelinek via Gcc-patches wrote:
For signed integers with undefined overflow we already optimize x * y / y
into x, but for signed integers with -fwrapv or unsigned integers we don't.
The following patch allows optimizing that into just x if value ranges
prove that x * y
On 11/26/20 3:52 AM, Jakub Jelinek wrote:
Hi!
For signed integers with undefined overflow we already optimize x * y / y
into x, but for signed integers with -fwrapv or unsigned integers we don't.
The following patch allows optimizing that into just x if value ranges
prove that x * y will never o
On Thu, 26 Nov 2020, Jakub Jelinek wrote:
> On Thu, Nov 26, 2020 at 09:24:30AM +, Richard Biener wrote:
> > > For signed integers with undefined overflow we already optimize x * y / y
> > > into x, but for signed integers with -fwrapv or unsigned integers we
> > > don't.
> > > The following p
On Thu, Nov 26, 2020 at 09:24:30AM +, Richard Biener wrote:
> > For signed integers with undefined overflow we already optimize x * y / y
> > into x, but for signed integers with -fwrapv or unsigned integers we don't.
> > The following patch allows optimizing that into just x if value ranges
>
On Thu, 26 Nov 2020, Jakub Jelinek wrote:
> Hi!
>
> For signed integers with undefined overflow we already optimize x * y / y
> into x, but for signed integers with -fwrapv or unsigned integers we don't.
> The following patch allows optimizing that into just x if value ranges
> prove that x * y w
Hi!
For signed integers with undefined overflow we already optimize x * y / y
into x, but for signed integers with -fwrapv or unsigned integers we don't.
The following patch allows optimizing that into just x if value ranges
prove that x * y will never overflow.
It uses the global SSA_NAME_RANGE_I
