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Re: Proposal for path splitting for reduction in register pressure for Loops.
- From: Richard Biener <richard dot guenther at gmail dot com>
- To: Ajit Kumar Agarwal <ajit dot kumar dot agarwal at xilinx dot com>,"vmakarov at redhat dot com" <vmakarov at redhat dot com>,Jeff Law <law at redhat dot com>,"gcc at gcc dot gnu dot org" <gcc at gcc dot gnu dot org>
- Cc: Vinod Kathail <vinodk at xilinx dot com>,Shail Aditya Gupta <shailadi at xilinx dot com>,Vidhumouli Hunsigida <vidhum at xilinx dot com>,Nagaraju Mekala <nmekala at xilinx dot com>
- Date: Sun, 08 Mar 2015 16:35:29 +0100
- Subject: Re: Proposal for path splitting for reduction in register pressure for Loops.
- Authentication-results: sourceware.org; auth=none
- References: <BN1AFFO11OLC004D84D26C6A4468398AD3DAE1A0 at BN1AFFO11OLC004 dot protection dot gbl>
On March 8, 2015 3:39:08 PM CET, Ajit Kumar Agarwal <firstname.lastname@example.org> wrote:
>The path splitting that replicates the code for better Data flow
>Analysis available. One of the properties
>of path splitting removes the joining nodes for the forked path like
>IF-THEN-ELSE and the Loops.
>The removal of joining nodes makes the path splitted into two
>The increase in register Pressures for the loops are the performance
>bottleneck and sometimes
>lead to spill code in loops.
>The removal of joining nodes like loops and IF-THEN-ELSE makes the
>target independent optimization like
>CSE and Partial redundancy Elimination effective. Along with ease of
>these optimization the path splitting
>reduces the registers because Of the Liveness wont intersect because of
>independent splitted path. The
>ease of less intersection of liveness Reduces the register pressure for
>the Loops, thus better register
>allocation and less spilling code for Loops.
>The heuristics used in IRA code for register pressure will have better
>impact on the splitted path and thus
Are you talking about loop unswitching?
>Thanks & Regards