RE: [Patch] OPT: Update heuristics for loop-invariant for address arithmetic.
-Original Message- From: Richard Sandiford [mailto:rdsandif...@googlemail.com] Sent: Friday, April 24, 2015 12:40 AM To: Ajit Kumar Agarwal Cc: vmaka...@redhat.com; GCC Patches; Vinod Kathail; Shail Aditya Gupta; Vidhumouli Hunsigida; Nagaraju Mekala Subject: Re: [Patch] OPT: Update heuristics for loop-invariant for address arithmetic. Very delayed answer, sorry... Ajit Kumar Agarwal ajit.kumar.agar...@xilinx.com writes: Hello All: The changes are made in the patch to update the heuristics for loop invariant for address arithemetic at RTL Level. The heuristics are updated with the consideration of single def and use for register pressure calculation instead Of ignoring it and also to update the estimated register pressure cost along with the check of actual uses with Address uses. With the above change, gains are seen in the Geomean for Mibench/EEMBC benchmarks for microblaze target. No Regression is seen in deja GNU regressions tests for microblaze. Since thispatch is basically removing code, were you able to analyse why that code was having a detrimental effect? I assume it benefited some target ??originally. This patch modified the estimated register pressure cost for non ira based register pressure(flag_ira_loop_pressure is not set). Following changes were made in the estimated register pressure cost. size_cost = (estimate_reg_pressure_cost (new_regs[0] + regs_needed[0], regs_used, speed, call_p) - estimate_reg_pressure_cost (new_regs[0], regs_used, speed, call_p)); is changed to size_cost = estimate_reg_pressure_cost (regs_needed[0], regs_used, speed, call_p); This looks reasonable change for the estimated_reg_pressure_cost calculation. The other changes I have made, For the single use for the given Def the current code does not include such invariants in the register pressure calculation which I have enabled including the single use for the Given def for the register pressure calculation. Though the comment in the code says that there won't be a new register for single use after moving, But moving such invariants outside the loop will affect the register pressures as the spans of the live range after moving out of loops differs from The original loop. Since the Live range spans varies such cases should surely affect the registers pressure. The above explanation looks reasonable and the code that does not include such invariants into register pressure is removed in the patch. I don't any see background or the patches in the past that explicit made the above check as part of any performance improvement or bug fix. Thanks Regards Ajit Thanks, Richard
Re: [Patch] OPT: Update heuristics for loop-invariant for address arithmetic.
On 03/23/2015 10:35 AM, Ajit Kumar Agarwal wrote: Hello All: Did you get a chance to look at the below patch. Thanks Regards Ajit -Original Message- From: gcc-patches-ow...@gcc.gnu.org [mailto:gcc-patches-ow...@gcc.gnu.org] On Behalf Of Ajit Kumar Agarwal Sent: Wednesday, March 04, 2015 3:57 PM To: vmaka...@redhat.com; GCC Patches Cc: Vinod Kathail; Shail Aditya Gupta; Vidhumouli Hunsigida; Nagaraju Mekala Subject: [Patch] OPT: Update heuristics for loop-invariant for address arithmetic. Hello All: The changes are made in the patch to update the heuristics for loop invariant for address arithemetic at RTL Level. The heuristics are updated with the consideration of single def and use for register pressure calculation instead Of ignoring it and also to update the estimated register pressure cost along with the check of actual uses with Address uses. With the above change, gains are seen in the Geomean for Mibench/EEMBC benchmarks for microblaze target. No Regression is seen in deja GNU regressions tests for microblaze. Please let us know your feedback. commit 039b95028c93f99fc1da7fa255f9b5fff4e17223 Author: Ajit Kumar Agarwal ajitkum@xhdspdgnu.(none) Date: Wed Mar 4 15:46:45 2015 +0530 [Patch] OPT: Update heuristics for loop-invariant for address arithmetic. The changes are made in the patch to update the heuristics for loop invariant for address arithmetic. The heuristics is changed to incorporate the single def and use in the register pressure calculation in order to move the invariant out of loop. The heuristics are further changed to not to use the check for addr uses with actual uses. Also changes are done in the heuristics of estimated register pressure cost. ChangeLog: 2015-03-04 Ajit Agarwal ajit...@xilinx.com * loop-invariant.c (gain_for_invariant): update the heuristics for estimate_reg_pressure_cost. (get_inv_cost): Remove the check for addr uses with actual uses. Add the single def and use in the register pressure for invariants. This work should probably be coordinated with the Intel folks who are looking to change if/when LICM for address expressions. See the thread: [PATCH, PR target/65103, 2/3] Propagate address constants into loops for i386 jeff
Re: [Patch] OPT: Update heuristics for loop-invariant for address arithmetic.
Very delayed answer, sorry... Ajit Kumar Agarwal ajit.kumar.agar...@xilinx.com writes: Hello All: The changes are made in the patch to update the heuristics for loop invariant for address arithemetic at RTL Level. The heuristics are updated with the consideration of single def and use for register pressure calculation instead Of ignoring it and also to update the estimated register pressure cost along with the check of actual uses with Address uses. With the above change, gains are seen in the Geomean for Mibench/EEMBC benchmarks for microblaze target. No Regression is seen in deja GNU regressions tests for microblaze. Since thispatch is basically removing code, were you able to analyse why that code was having a detrimental effect? I assume it benefited some target originally. Thanks, Richard
Re: [Patch] OPT: Update heuristics for loop-invariant for address arithmetic.
On 2015-03-23 12:35 PM, Ajit Kumar Agarwal wrote: Hello All: Did you get a chance to look at the below patch. Thanks Regards Ajit -Original Message- From: gcc-patches-ow...@gcc.gnu.org [mailto:gcc-patches-ow...@gcc.gnu.org] On Behalf Of Ajit Kumar Agarwal Sent: Wednesday, March 04, 2015 3:57 PM To: vmaka...@redhat.com; GCC Patches Cc: Vinod Kathail; Shail Aditya Gupta; Vidhumouli Hunsigida; Nagaraju Mekala Subject: [Patch] OPT: Update heuristics for loop-invariant for address arithmetic. Hello All: The changes are made in the patch to update the heuristics for loop invariant for address arithemetic at RTL Level. The heuristics are updated with the consideration of single def and use for register pressure calculation instead Of ignoring it and also to update the estimated register pressure cost along with the check of actual uses with Address uses. With the above change, gains are seen in the Geomean for Mibench/EEMBC benchmarks for microblaze target. No Regression is seen in deja GNU regressions tests for microblaze. Sorry, I am not a maintainer/reviewer of loop invariant motion pass. I had no power to approve this, especially when you change mostly code for ! flag_ira_loop_pressure. I only should say that microblaze is not a primary target. You should demonstrate improvement on a primary target, x86/x86-64 the best. SPEC2000 or SPEC2006 would be a good benchmark for this.
RE: [Patch] OPT: Update heuristics for loop-invariant for address arithmetic.
Hello All: Did you get a chance to look at the below patch. Thanks Regards Ajit -Original Message- From: gcc-patches-ow...@gcc.gnu.org [mailto:gcc-patches-ow...@gcc.gnu.org] On Behalf Of Ajit Kumar Agarwal Sent: Wednesday, March 04, 2015 3:57 PM To: vmaka...@redhat.com; GCC Patches Cc: Vinod Kathail; Shail Aditya Gupta; Vidhumouli Hunsigida; Nagaraju Mekala Subject: [Patch] OPT: Update heuristics for loop-invariant for address arithmetic. Hello All: The changes are made in the patch to update the heuristics for loop invariant for address arithemetic at RTL Level. The heuristics are updated with the consideration of single def and use for register pressure calculation instead Of ignoring it and also to update the estimated register pressure cost along with the check of actual uses with Address uses. With the above change, gains are seen in the Geomean for Mibench/EEMBC benchmarks for microblaze target. No Regression is seen in deja GNU regressions tests for microblaze. Please let us know your feedback. commit 039b95028c93f99fc1da7fa255f9b5fff4e17223 Author: Ajit Kumar Agarwal ajitkum@xhdspdgnu.(none) Date: Wed Mar 4 15:46:45 2015 +0530 [Patch] OPT: Update heuristics for loop-invariant for address arithmetic. The changes are made in the patch to update the heuristics for loop invariant for address arithmetic. The heuristics is changed to incorporate the single def and use in the register pressure calculation in order to move the invariant out of loop. The heuristics are further changed to not to use the check for addr uses with actual uses. Also changes are done in the heuristics of estimated register pressure cost. ChangeLog: 2015-03-04 Ajit Agarwal ajit...@xilinx.com * loop-invariant.c (gain_for_invariant): update the heuristics for estimate_reg_pressure_cost. (get_inv_cost): Remove the check for addr uses with actual uses. Add the single def and use in the register pressure for invariants. Signed-off-by:Ajit Agarwal ajit...@xilinx.com Thanks Regards Ajit
[Patch] OPT: Update heuristics for loop-invariant for address arithmetic.
Hello All: The changes are made in the patch to update the heuristics for loop invariant for address arithemetic at RTL Level. The heuristics are updated with the consideration of single def and use for register pressure calculation instead Of ignoring it and also to update the estimated register pressure cost along with the check of actual uses with Address uses. With the above change, gains are seen in the Geomean for Mibench/EEMBC benchmarks for microblaze target. No Regression is seen in deja GNU regressions tests for microblaze. Please let us know your feedback. commit 039b95028c93f99fc1da7fa255f9b5fff4e17223 Author: Ajit Kumar Agarwal ajitkum@xhdspdgnu.(none) Date: Wed Mar 4 15:46:45 2015 +0530 [Patch] OPT: Update heuristics for loop-invariant for address arithmetic. The changes are made in the patch to update the heuristics for loop invariant for address arithmetic. The heuristics is changed to incorporate the single def and use in the register pressure calculation in order to move the invariant out of loop. The heuristics are further changed to not to use the check for addr uses with actual uses. Also changes are done in the heuristics of estimated register pressure cost. ChangeLog: 2015-03-04 Ajit Agarwal ajit...@xilinx.com * loop-invariant.c (gain_for_invariant): update the heuristics for estimate_reg_pressure_cost. (get_inv_cost): Remove the check for addr uses with actual uses. Add the single def and use in the register pressure for invariants. Signed-off-by:Ajit Agarwal ajit...@xilinx.com Thanks Regards Ajit 0001-Patch-OPT-Update-heuristics-for-loop-invariant-for-a.patch Description: 0001-Patch-OPT-Update-heuristics-for-loop-invariant-for-a.patch
