On 11/7/18 3:27 PM, Jan Hubicka wrote: >> On 11/5/18 10:51 AM, Jan Hubicka wrote: >>>> @honza: PING >>>> >>>> On 10/3/18 12:53 PM, Martin Liška wrote: >>>>> On 10/3/18 11:04 AM, Jan Hubicka wrote: >>>>>>> >>>>>>> That was promised to be done by Honza Hubička. He's very skilled in IPA optimizations and he's aware >>>>>>> of optimizations that cause troubles for live-patching. >>>>>> >>>>>> :) I am not sure how skilful I am, but here is what I arrived to. >>>>> >>>>> Heh! Thanks for the analysis. >>>>> >>>>>> >>>>>> We have transformations that are modeled as clonning, which are >>>>>> - inlining (can't be disabled completely because of always inline, but -fno-inline >>>>>> does most of stuff) >>>>>> - cloning (disabled via -fno-ipa-cp) >>>>>> - ipa-sra (-fno-ipa-sra) >>>>>> - splitting (-fno-partial-inlining) >>>>>> These should play well with Martin's tracking code >>>>> >>>>> I hope so! >>>>> >>>>>> >>>>>> We propagate info about side effects of function: >>>>>> - function attribute discovery (pure, const, nothrow, malloc) >>>>>> Some of this can be disabled by -fno-ipa-pure-const, but not all >>>>>> of it. >>>>> >>>>> Would it be possible to add option for the remaining ones? >>> >>> Sure, I can prepare patch unless you beat me :) >> >> Are you sure there's a call to 'analyze_function' where the analysis is done >> when one sets -fno-ipa-pure-const? > > In set_nothrow_function_flags. Probably would be good to grep for > places where node->set_XXXX_flag is used. Ok, so for nothrow there are 2 extra passes (GIMPLE and RTL "nothrow" pass) that set it. But, If I'm correct we should not case in case of C language, right? - set_malloc_flag - only called from pass_local_pure_const pass - set_pure_flag a) call from set_const_flag_1 - should be fine as it's from set_const context b) from pass_ipa_pure_const:: c) from tree-profile.c: node->set_pure_flag (false, false); - which is fine - set_const_flag - likewise to set_pure_const (except set_const_flag_1) >> 2018-11-07 Martin Liska <mliska@xxxxxxx> >> >> * common.opt: Add -fipa-stack-alignment flag. >> * doc/invoke.texi: Document it. >> * final.c (rest_of_clean_state): Guard stack >> shrinking with flag. >> >> gcc/testsuite/ChangeLog: >> >> 2018-11-07 Martin Liska <mliska@xxxxxxx> >> >> * gcc.target/i386/ipa-stack-alignment.c: New test. >> From 8691490a142228021ed65313a72d176d06966829 Mon Sep 17 00:00:00 2001 >> From: marxin <mliska@xxxxxxx> >> Date: Wed, 7 Nov 2018 13:31:41 +0100 >> Subject: [PATCH 1/2] Come up with -fipa-reference-addressable flag. >> >> gcc/ChangeLog: >> >> 2018-11-07 Martin Liska <mliska@xxxxxxx> >> >> * cgraph.h (ipa_discover_readonly_nonaddressable_vars): Rename >> to ... >> (ipa_discover_nonaddressable_vars): ... this. >> * common.opt: Come up with new flag -fipa-reference-addressable. >> * doc/invoke.texi: Document it. >> * ipa-reference.c (propagate): Call the renamed fn. >> * ipa-visibility.c (whole_program_function_and_variable_visibility): >> Likewise. >> * ipa.c (ipa_discover_readonly_nonaddressable_vars): Renamed to >> ... >> (ipa_discover_nonaddressable_vars): ... this. Discove >> non-addressable variables only with the newly added flag. >> * opts.c: Enable the newly added flag with -O1 and higher >> optimization level. > > Hmm, the write-only and readonly flags are not handled in here? You mean the ChangeLog is not mentioning that ipa_discover_nonaddressable_vars does read-only and write-only discovery? Martin > > Honza >
