[Bug ipa/97816] [11 Regression] ICE in good_cloning_opportunity_p, at ipa-cp.c:3266 since r11-4949-gb86aedb0cc083efe712e530a723f1237051a6b56
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97816 Martin Jambor changed: What|Removed |Added Resolution|--- |FIXED Status|ASSIGNED|RESOLVED --- Comment #7 from Martin Jambor --- Now fixed properly.
[Bug ipa/97816] [11 Regression] ICE in good_cloning_opportunity_p, at ipa-cp.c:3266 since r11-4949-gb86aedb0cc083efe712e530a723f1237051a6b56
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97816 --- Comment #6 from CVS Commits --- The master branch has been updated by Martin Jambor : https://gcc.gnu.org/g:a6a0db7d1bc7ad640bab51769e53f1cb4ad4bb88 commit r11-5811-ga6a0db7d1bc7ad640bab51769e53f1cb4ad4bb88 Author: Martin Jambor Date: Mon Dec 7 09:35:09 2020 +0100 ipa-cp: Avoid unwanted multiple propagations (PR 97816) When looking at the testcase of PR 97816 I realized that the reason why we were hitting overflows in size growth estimates in IPA-CP is not because the chains of how lattices feed values to each other are so long but mainly because we add estimates in callee lattices to caller lattices for each value source, which roughly corresponds to a call graph edge, and therefore if there are multiple calls between two functions passing the same value in a parameter we end up doing it more than once, sometimes actually quite many times. This patch avoids it by using a has_set to remember the source values we have already updated and not increasing their size again. Furhtermore, to improve estimation of times we scale the propagated time benefits with edge frequencies as we accumulate them. This should make any overflows very unlikely but not impossible, so I still included checks for overflows but decided to restructure the code to only need it in the propagate_effects function and modified it so that it does not need to perform the check before each sum. This is because I decided to add local estimates to propagated estimates already in propagate_effects and not at the evaluation time. The function can then do the sums in a wide type and discard them in the unlikely case of an overflow. I also decided to use the opportunity to make propagated effect stats now include stats from other values in the same SCCs. In the dumps I have seen this tended to increase size cost a tiny bit more than the estimated time benefit but both increases were small. Martin gcc/ChangeLog: 2020-11-20 Martin Jambor PR ipa/97816 * ipa-cp.c (safe_add): Removed. (good_cloning_opportunity_p): Remove special handling of INT_MAX. (value_topo_info::propagate_effects): Take care not to propagate from size one value to another through more sources. Scale propagated times with edge frequencies. Include local time and size in propagates ones here. Take care not to overflow size. (decide_about_value): Do not add local and propagated effects when passing them to good_cloning_opportunity_p.
[Bug ipa/97816] [11 Regression] ICE in good_cloning_opportunity_p, at ipa-cp.c:3266 since r11-4949-gb86aedb0cc083efe712e530a723f1237051a6b56
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97816 --- Comment #5 from Martin Jambor --- As noted in the commit message above, the ICE will go away but the underlying issue stays so please keep this opened until I fix it, hopefully no later than next week.
[Bug ipa/97816] [11 Regression] ICE in good_cloning_opportunity_p, at ipa-cp.c:3266 since r11-4949-gb86aedb0cc083efe712e530a723f1237051a6b56
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97816 --- Comment #4 from CVS Commits --- The master branch has been updated by Martin Jambor : https://gcc.gnu.org/g:2e97d6443f0a862ce9b798084499635914e3b8c6 commit r11-5000-g2e97d6443f0a862ce9b798084499635914e3b8c6 Author: Martin Jambor Date: Fri Nov 13 18:30:11 2020 +0100 ipa-cp: One more safe_add (PR 97816) The new behavior of safe_add triggered an ICE because of one use where it had not been used instead of a simple addition. I'll fix it with the following obvious patch so that periodic benchmarkers can continue working because a proper fix (see below) will need a review. The testcase showed me, however, that we can propagate time and cost from one lattice to another more than once even when that was not the intent. I'll address that as a follow-up after I verify it does not affect the IPA-CP heuristics too much or change the corresponding params accordingly. Bootstrapped and tested on x86_64-linux. gcc/ChangeLog: 2020-11-13 Martin Jambor PR ipa/97816 * ipa-cp.c (value_topo_info::propagate_effects): Use safe_add instead of a simple addition.
[Bug ipa/97816] [11 Regression] ICE in good_cloning_opportunity_p, at ipa-cp.c:3266 since r11-4949-gb86aedb0cc083efe712e530a723f1237051a6b56
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97816 Martin Jambor changed: What|Removed |Added Assignee|unassigned at gcc dot gnu.org |jamborm at gcc dot gnu.org Status|NEW |ASSIGNED --- Comment #3 from Martin Jambor --- I see, mine.
[Bug ipa/97816] [11 Regression] ICE in good_cloning_opportunity_p, at ipa-cp.c:3266 since r11-4949-gb86aedb0cc083efe712e530a723f1237051a6b56
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97816 --- Comment #2 from Martin Liška --- size_cost: -2147480169 So it's likely about an integer overflow..
[Bug ipa/97816] [11 Regression] ICE in good_cloning_opportunity_p, at ipa-cp.c:3266 since r11-4949-gb86aedb0cc083efe712e530a723f1237051a6b56
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97816 --- Comment #1 from Martin Liška --- Apparently, without the '-fPIC' option.
[Bug ipa/97816] [11 Regression] ICE in good_cloning_opportunity_p, at ipa-cp.c:3266 since r11-4949-gb86aedb0cc083efe712e530a723f1237051a6b56
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97816 Martin Liška changed: What|Removed |Added Last reconfirmed||2020-11-13 Blocks||26163 Target Milestone|--- |11.0 Status|UNCONFIRMED |NEW Known to work||10.2.0 Ever confirmed|0 |1 Priority|P3 |P1 Known to fail||11.0 Referenced Bugs: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=26163 [Bug 26163] [meta-bug] missed optimization in SPEC (2k17, 2k and 2k6 and 95)
