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Awareness of register pressure on strength reduction of induction variables.
- From: Ajit Kumar Agarwal <ajit dot kumar dot agarwal at xilinx dot com>
- To: Jeff Law <law at redhat dot com>, "vmakarov at redhat dot com" <vmakarov at redhat dot com>, Richard Biener <richard dot guenther at gmail 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: Tue, 1 Sep 2015 17:57:44 +0000
- Subject: Awareness of register pressure on strength reduction of induction variables.
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The Global code motion are the important optimization that have an impact on register spills and Fetch. Thus
The Global code motion takes into account the increase or decrease of register pressure.
Strength Reductions is an important optimization that has an impact on register pressure. The strength reduction
Optimizations doesn't take into account the register pressure and especially the strength reduction for induction
Variables that are inside the Loops. Loops are the bottleneck for the register pressure and any spill inside the loops
Based on strength reduction of induction variables degrades the performance of the Loops.
Thus the strength reductions in general and especially the strength reduction for induction variables should take
Into account the register pressure based on Live range info.
I don't think we do take into account the register pressure for strength reduction optimization in general and especially the
Strength reduction based on induction variables.
Thanks & Regards