Re: [PATCH] Eliminates phi on branch for CMP result

On Mon, 13 May 2019, Segher Boessenkool wrote: > On Sun, May 12, 2019 at 10:07:28PM -0500, Jiufu Guo wrote: > > To elimiate the instructions which moving result of CMP to GPR, I'm > > wondering maybe we could do a combine(or a peephole) after bbro to let > > the condition jump directly using the r

Re: [PATCH] Eliminates phi on branch for CMP result

On Sun, May 12, 2019 at 10:07:28PM -0500, Jiufu Guo wrote: > To elimiate the instructions which moving result of CMP to GPR, I'm > wondering maybe we could do a combine(or a peephole) after bbro to let > the condition jump directly using the result of CMP. It will have to be a peephole. And peeph

Re: [PATCH] Eliminates phi on branch for CMP result

Jeff Law writes: > On 5/8/19 6:20 AM, Richard Biener wrote: >> On Wed, 8 May 2019, Jiufu Guo wrote: >> >> The main thing the transform does is tail-duplicate the PHI block, >> if we'd just do that followup transforms would do the rest. > One might even claim this is really a transformation for c

Re: [PATCH] Eliminates phi on branch for CMP result

On 5/9/19 12:07 AM, Richard Biener wrote: > On Wed, 8 May 2019, Jeff Law wrote: > >> On 5/8/19 6:20 AM, Richard Biener wrote: >>> On Wed, 8 May 2019, Jiufu Guo wrote: >>> Hi, Thanks Richard, Segher, Andrew and all. Segher Boessenkool writes: > Let me try to answe

Re: [PATCH] Eliminates phi on branch for CMP result

On Wed, 8 May 2019, Jeff Law wrote: > On 5/8/19 6:20 AM, Richard Biener wrote: > > On Wed, 8 May 2019, Jiufu Guo wrote: > > > >> Hi, > >> > >> Thanks Richard, Segher, Andrew and all. > >> > >> Segher Boessenkool writes: > >> > >>> Let me try to answer some of this... > >>> > >>> On Tue, May 07,

Re: [PATCH] Eliminates phi on branch for CMP result

Jeff Law writes: > On 5/6/19 8:24 AM, Jiufu Guo wrote: >> Hi, >> >> This patch implements the optimization in PR77820. The optimization >> eliminates phi and phi's basic block, if the phi is used only by >> condition branch, and the phi's incoming value in the result of a >> CMP result. >> >>

Re: [PATCH] Eliminates phi on branch for CMP result

On 5/6/19 8:24 AM, Jiufu Guo wrote: > Hi, > > This patch implements the optimization in PR77820. The optimization > eliminates phi and phi's basic block, if the phi is used only by > condition branch, and the phi's incoming value in the result of a > CMP result. > > This optimization eliminates:

Re: [PATCH] Eliminates phi on branch for CMP result

On 5/8/19 6:20 AM, Richard Biener wrote: > On Wed, 8 May 2019, Jiufu Guo wrote: > >> Hi, >> >> Thanks Richard, Segher, Andrew and all. >> >> Segher Boessenkool writes: >> >>> Let me try to answer some of this... >>> >>> On Tue, May 07, 2019 at 03:31:27PM +0200, Richard Biener wrote: On Mon,

Re: [PATCH] Eliminates phi on branch for CMP result

On Wed, 8 May 2019, Segher Boessenkool wrote: > On Wed, May 08, 2019 at 02:20:19PM +0200, Richard Biener wrote: > > Btw, I wonder if on RTL basic-block reordering (which also does > > some tail duplication) could be a place to do such transform? > > Or is it too late to do the desired cleanups aft

Re: [PATCH] Eliminates phi on branch for CMP result

On Wed, May 08, 2019 at 02:20:19PM +0200, Richard Biener wrote: > Btw, I wonder if on RTL basic-block reordering (which also does > some tail duplication) could be a place to do such transform? > Or is it too late to do the desired cleanups after that? > Possibly since we're after RA. It is *much*

Re: [PATCH] Eliminates phi on branch for CMP result

On Wed, 8 May 2019, Jiufu Guo wrote: > Hi, > > Thanks Richard, Segher, Andrew and all. > > Segher Boessenkool writes: > > > Let me try to answer some of this... > > > > On Tue, May 07, 2019 at 03:31:27PM +0200, Richard Biener wrote: > >> On Mon, 6 May 2019, Jiufu Guo wrote: > >> > This patch i

Re: [PATCH] Eliminates phi on branch for CMP result

On Tue, 7 May 2019, Andrew Pinski wrote: > On Mon, May 6, 2019 at 7:24 AM Jiufu Guo wrote: > > > > Hi, > > > > This patch implements the optimization in PR77820. The optimization > > eliminates phi and phi's basic block, if the phi is used only by > > condition branch, and the phi's incoming val

Re: [PATCH] Eliminates phi on branch for CMP result

Hi, Thanks Richard, Segher, Andrew and all. Segher Boessenkool writes: > Let me try to answer some of this... > > On Tue, May 07, 2019 at 03:31:27PM +0200, Richard Biener wrote: >> On Mon, 6 May 2019, Jiufu Guo wrote: >> > This patch implements the optimization in PR77820. The optimization >>

Re: [PATCH] Eliminates phi on branch for CMP result

On Mon, May 6, 2019 at 7:24 AM Jiufu Guo wrote: > > Hi, > > This patch implements the optimization in PR77820. The optimization > eliminates phi and phi's basic block, if the phi is used only by > condition branch, and the phi's incoming value in the result of a > CMP result. > > This optimizatio

Re: [PATCH] Eliminates phi on branch for CMP result

Let me try to answer some of this... On Tue, May 07, 2019 at 03:31:27PM +0200, Richard Biener wrote: > On Mon, 6 May 2019, Jiufu Guo wrote: > > This patch implements the optimization in PR77820. The optimization > > eliminates phi and phi's basic block, if the phi is used only by > > condition br

Re: [PATCH] Eliminates phi on branch for CMP result

On Mon, 6 May 2019, Jiufu Guo wrote: > Hi, > > This patch implements the optimization in PR77820. The optimization > eliminates phi and phi's basic block, if the phi is used only by > condition branch, and the phi's incoming value in the result of a > CMP result. > > This optimization eliminate