From patchwork Mon Jun 30 12:04:36 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: =?utf-8?q?Martin_Li=C5=A1ka?= X-Patchwork-Id: 365566 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from sourceware.org (server1.sourceware.org [209.132.180.131]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id CBC671400EE for ; Mon, 30 Jun 2014 22:05:22 +1000 (EST) DomainKey-Signature: a=rsa-sha1; c=nofws; d=gcc.gnu.org; h=list-id :list-unsubscribe:list-archive:list-post:list-help:sender :message-id:date:from:mime-version:to:subject:references :in-reply-to:content-type; q=dns; s=default; b=Yb7S2nFgQi/KRO1E+ cJnAqdozIzQ3pgixiPLZjq873NFd0liEz4wFj7XmdkqDwv8EmzPKBbb0n1fZK7gt Qrbb3rLCo1PHgapybMexOEDnKn5l1qM8U3wUHuyBq4j66FiuRgn0rdXJhNEgOyNV 5SvEXhrn0MX4taPjy2AnFhnv7c= DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=gcc.gnu.org; h=list-id :list-unsubscribe:list-archive:list-post:list-help:sender :message-id:date:from:mime-version:to:subject:references :in-reply-to:content-type; s=default; bh=dIOePPV3W8eYMsdGM0+a9ue CHAc=; b=b6PPnCE7f+X2+hGmTS3fs3n5V+Ga9wxstAnZzmZSfzEbpcPsqDm7dCa g60XLOBD/YrEKYUWneoBU88okiVGFtX4HYipz8GFMk4zkpzvrknNaOgKL7565BRb Z+YfkWMQ/WTSEe8n+AgJwHrSRMgY371nxHbe6PdOhyRIxQkZQDI4= Received: (qmail 31936 invoked by alias); 30 Jun 2014 12:05:09 -0000 Mailing-List: contact gcc-patches-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Archive: List-Post: List-Help: Sender: gcc-patches-owner@gcc.gnu.org Delivered-To: mailing list gcc-patches@gcc.gnu.org Received: (qmail 31899 invoked by uid 89); 30 Jun 2014 12:05:06 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-0.1 required=5.0 tests=AWL, BAYES_05 autolearn=ham version=3.3.2 X-HELO: mx2.suse.de Received: from cantor2.suse.de (HELO mx2.suse.de) (195.135.220.15) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (CAMELLIA256-SHA encrypted) ESMTPS; Mon, 30 Jun 2014 12:04:40 +0000 Received: from relay1.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id B9153ABEB for ; Mon, 30 Jun 2014 12:04:36 +0000 (UTC) Message-ID: <53B15254.2040003@suse.cz> Date: Mon, 30 Jun 2014 14:04:36 +0200 From: =?windows-1252?Q?Martin_Li=9Aka?= User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.5.0 MIME-Version: 1.0 To: gcc-patches@gcc.gnu.org Subject: Re: [PATCH 3/5] IPA ICF pass References: <53A9E021.8000400@redhat.com> <20140626184614.GB29056@kam.mff.cuni.cz> In-Reply-To: <20140626184614.GB29056@kam.mff.cuni.cz> X-IsSubscribed: yes On 06/26/2014 08:46 PM, Jan Hubicka wrote: > Jeff, > thanks for review! I did some passes over the patch before it got to the ML, I am > happy to have independent opinion. >>> +@item -fipa-icf >>> +@opindex fipa-icf >>> +Perform Identical Code Folding for functions and read-only variables. >>> +Behavior is similar to Gold Linker ICF optimization. Symbols proved >>> +as semantically equivalent are redirected to corresponding symbol. The pass >>> +sensitively decides for usage of alias, thunk or local redirection. >>> +This flag is enabled by default at @option{-O2}. >> So you've added this at -O2, what is the general compile-time >> impact? Would it make more sense to instead have it be part of -O3, >> particularly since ICF is rarely going to improve performance (sans >> icache issues). > I think code size optimization not sacrifying any (or too much of) performance are > generally very welcome at -O2. Compared to LLVM and Microsoft compilers we are > on code bloat side at -O2. > > http://hubicka.blogspot.ca/2014/04/linktime-optimization-in-gcc-2-firefox.html > has some numbers for -O2 GGC/LLVM. > > I believe this is result of tunning for relatively small benchamrks (SPECS) and > I hope we could revisit -O2 for code size considerations for 4.10 somewhat. If > tuned well, ICF has no reason to be expnesive wrt compile time. So lets shoot > for that. The considerable donwside of enabling ICF IMO should be only > disturbing effect on debug info. >>> + return true; >>> +} >> Isn't this really checking for equivalence? "do correspond" seems >> awkward here. > The function turns the names equivalent on first invocation for a given name > and later checks that this tentative equivalence holds. > > Not sure what is best name for it (originaly it was verify that did not sound > right to me either) >>> + >>> +/* Verification function for edges E1 and E2. */ >>> + >>> +bool >>> +func_checker::compare_edge (edge e1, edge e2) >>> +{ >>> + if (e1->flags != e2->flags) >>> + return false; >> Presumably there's no flags we can safely ignore. So absolute >> equality seems reasonable here. > Yep >>> +/* Compare two types if are same aliases in case of strict aliasing >>> + is enabled. */ >>> +bool >>> +sem_item::compare_for_aliasing (tree t1, tree t2) >>> +{ >>> + if (flag_strict_aliasing) >>> + { >>> + alias_set_type s1 = get_deref_alias_set (TREE_TYPE (t1)); >>> + alias_set_type s2 = get_deref_alias_set (TREE_TYPE (t2)); >>> + >>> + return s1 == s2; >>> + } >>> + >>> + return true; >>> +} >> Is returning TRUE really the conservatively correct thing to do in >> the absence of aliasing information? Isn't that case really "I >> don't know" in which case the proper return value is FALSE? > I think with -fno-strict-aliasing the set should be 0 (Richi?) and thus we can > compare for equality. We probably can be on agressive side and let 0 alias > set prevail the non-0. But that can be done incrementally. > > We also need to match type inheritance equality for polymorphic types. I will > add function for that into ipa-devirt. Hi, I would welcome help with type comparison function sensitive to type inheritance. > >>> +/* References independent hash function. */ >>> + >>> +hashval_t >>> +sem_function::get_hash (void) >>> +{ >>> + if(!hash) >>> + { >>> + hash = 177454; /* Random number for function type. */ >>> + >>> + hash = iterative_hash_object (arg_count, hash); >>> + hash = iterative_hash_object (bb_count, hash); >>> + hash = iterative_hash_object (edge_count, hash); >>> + hash = iterative_hash_object (cfg_checksum, hash); >> Does CFG_CHECKSUM encompass the bb/edge counts? > It is one used by profiling code to match profiles, so it should. >>> + SE_EXIT_FALSE(); >>> + >>> + if (!equals_wpa (item)) >>> + return false; >>> + >>> + /* Checking function arguments. */ >>> + tree decl1 = DECL_ATTRIBUTES (decl); >>> + tree decl2 = DECL_ATTRIBUTES (compared_func->decl); >> So are there any attributes we can safely ignore? Probably not. >> However, we ought to handle the case where the attributes appear in >> different orders. > There are few, like we can ignore "weak" or "visibility" attribute because we do > produce alias with proper visibility anyway. My plan is to start removing those > attributes from declarations once they are turned into suitable representation > in symbol table (or for attributes like const/noreturn/pure where we have explicit > decl flags). This will make our life bit easier later, too. > > We probably then can whitelist some attributes, but I would deal with this later. >>> +/* Returns cgraph_node. */ >>> + >>> +struct cgraph_node * >>> +sem_function::get_node (void) >>> +{ >>> + return cgraph (node); >>> +} >>> + >>> +/* Initialize semantic item by info reachable during LTO WPA phase. */ >>> + >>> +void >>> +sem_function::init_wpa (void) >>> +{ >>> + parse_tree_args (); >>> +} >> inline? Worth or not worth the headache? > We ought to autoinline simple wrappers even at -Os (for size) > (I am not agains explicit inline keywords here tough) >> >>> + >>> +bool >>> +sem_function::compare_bb (sem_bb_t *bb1, sem_bb_t *bb2, tree func1, tree func2) >> So this routine walks down the gimple statements and compares them >> for equality. Would it make sense to have the equality testing in >> gimple? That way if someone adds a new gimple code the places they >> need to check/update are at least somewhat more localized? > There are few places that does equality testing (tailmerge) AFAIK. They are all somewhat > different - I think we can export this equality machinery with reosnable API and try to turn > those to use it, but it may be good incremental project IMO. I definitely agree with aforementioned approach. The pass has few places where we can approve it to catch more-complex semantically equivalent functions and variables. These corner cases can improve the pass, but I would expect just small gain. Majority of observations was added to this new version of the pass. I moved GIMPLE related comparison machinery to a separate file (ipa-icf-gimple.c). I hope it is acceptable for better pass understanding. Further enhancement would require introduction of a new API and as Honza said that could be good incremental project. Thank you, Martin gcc/ChangeLog 2014-06-13 Martin Liska Jan Hubicka * Makefile.in: New pass object file added. * common.opt: New -fipa-icf flag introduced. * doc/invoke.texi: Documentation enhanced for the pass. * lto-section-in.c: New LTO section for a summary created by IPA-ICF. * lto-streamer.h: New section name introduced. * opts.c: Optimization is added to -O2. * passes.def: New pass added. * timevar.def: New time var for IPA-ICF. * tree-pass.h: Pass construction function. * ipa-icf.h: New pass header file added. * ipa-icf.c: New pass source file added. * ipa-icf-gimple.c: Likewise. >> >>> + >>> + for (i = 0; i < size1; ++i) >>> + { >>> + t1 = gimple_phi_arg (phi1, i)->def; >>> + t2 = gimple_phi_arg (phi2, i)->def; >>> + >>> + if (!compare_operand (t1, t2, func1, func2)) >>> + SE_EXIT_FALSE (); >>> + >>> + e1 = gimple_phi_arg_edge (phi1, i); >>> + e2 = gimple_phi_arg_edge (phi2, i); >>> + >>> + if (!checker.compare_edge (e1, e2)) >>> + SE_EXIT_FALSE (); >>> + } >> I don't think we guarantee any particular order on the PHI args. >> ISTM you'd want to sort them or something so as not to reject a >> possible duplicate simply because of ordering issues. >> >> Related, I'm not sure bb indexes are even guaranteed to have any >> stable ordering. So ISTM you'd want to do something like a DFS walk >> to set a index for each block, then sort the PHI arguments based on >> DFS index to get a stable, consistent check here. > Yep, there are no resonable orders on it. If function starts same in source code they ought > to end up same here. Plan was to first match for exact equality and then play with > smarter tricks here. >> I'm starting to gloss over things.... It feels like we've got too >> much stuff in this one file. Breaking things out would help (like >> for example the hashing/equality bits). I'd like to see things >> broken out a bit and reposted for further reviewing. > Yep, the pass has grown up to be rather long. The gimple equality testing is the > main body of work, so perhaps doing this in separate file is good idea. > > Honza >> Jeff diff --git a/gcc/Makefile.in b/gcc/Makefile.in index 3d15eff..915038d 100644 --- a/gcc/Makefile.in +++ b/gcc/Makefile.in @@ -1276,6 +1276,8 @@ OBJS = \ ipa-profile.o \ ipa-prop.o \ ipa-pure-const.o \ + ipa-icf.o \ + ipa-icf-gimple.o \ ipa-reference.o \ ipa-ref.o \ ipa-utils.o \ diff --git a/gcc/common.opt b/gcc/common.opt index d515dca..253d9ea 100644 --- a/gcc/common.opt +++ b/gcc/common.opt @@ -1409,6 +1409,18 @@ fipa-pure-const Common Report Var(flag_ipa_pure_const) Init(0) Optimization Discover pure and const functions +fipa-icf +Common Report Var(flag_ipa_icf) Optimization +Perform Identical Code Folding for functions and read-only variables + +fipa-icf-functions +Common Report Var(flag_ipa_icf_functions) Optimization +Perform Identical Code Folding for functions + +fipa-icf-variables +Common Report Var(flag_ipa_icf_variables) Optimization +Perform Identical Code Folding for variables + fipa-reference Common Report Var(flag_ipa_reference) Init(0) Optimization Discover readonly and non addressable static variables diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi index 4df5f81..3f38c60 100644 --- a/gcc/doc/invoke.texi +++ b/gcc/doc/invoke.texi @@ -377,7 +377,7 @@ Objective-C and Objective-C++ Dialects}. -fif-conversion2 -findirect-inlining @gol -finline-functions -finline-functions-called-once -finline-limit=@var{n} @gol -finline-small-functions -fipa-cp -fipa-cp-clone @gol --fipa-pta -fipa-profile -fipa-pure-const -fipa-reference @gol +-fipa-pta -fipa-profile -fipa-pure-const -fipa-reference -fipa-icf @gol -fira-algorithm=@var{algorithm} @gol -fira-region=@var{region} -fira-hoist-pressure @gol -fira-loop-pressure -fno-ira-share-save-slots @gol @@ -6956,6 +6956,7 @@ also turns on the following optimization flags: -finline-small-functions @gol -findirect-inlining @gol -fipa-sra @gol +-fipa-icf @gol -fisolate-erroneous-paths-dereference @gol -foptimize-sibling-calls @gol -fpartial-inlining @gol @@ -7887,6 +7888,26 @@ it may significantly increase code size (see @option{--param ipcp-unit-growth=@var{value}}). This flag is enabled by default at @option{-O3}. +@item -fipa-icf +@opindex fipa-icf +Perform Identical Code Folding for functions and read-only variables. +Behavior is similar to Gold Linker ICF optimization. Symbols proved +as semantically equivalent are redirected to corresponding symbol. The pass +sensitively decides for usage of alias, thunk or local redirection. +This flag is enabled by default at @option{-O2}. + +The following options are enabled: @code{-fipa-icf-functions}, @code{-fipa-icf-variables}. + +@item -fipa-icf-functions +@opindex fipa-icf-functions +Perform Identical Code Folding for just for functions. +This flag is enabled by @option{fipa-icf}. + +@item -fipa-icf-variables +@opindex fipa-icf-variables +Perform Identical Code Folding for just for read-only variables. +This flag is enabled by @option{fipa-icf}. + @item -fisolate-erroneous-paths-dereference Detect paths which trigger erroneous or undefined behaviour due to dereferencing a NULL pointer. Isolate those paths from the main control diff --git a/gcc/ipa-icf-gimple.c b/gcc/ipa-icf-gimple.c new file mode 100644 index 0000000..01c723c --- /dev/null +++ b/gcc/ipa-icf-gimple.c @@ -0,0 +1,384 @@ +/* Interprocedural Identical Code Folding pass + Copyright (C) 2014 Free Software Foundation, Inc. + + Contributed by Jan Hubicka and Martin Liska + +This file is part of GCC. + +GCC is free software; you can redistribute it and/or modify it under +the terms of the GNU General Public License as published by the Free +Software Foundation; either version 3, or (at your option) any later +version. + +GCC is distributed in the hope that it will be useful, but WITHOUT ANY +WARRANTY; without even the implied warranty of MERCHANTABILITY or +FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License +for more details. + +You should have received a copy of the GNU General Public License +along with GCC; see the file COPYING3. If not see +. */ + +#include "config.h" +#include "system.h" +#include "coretypes.h" +#include "tree.h" +#include "basic-block.h" +#include "tree-ssa-alias.h" +#include "internal-fn.h" +#include "gimple-expr.h" +#include "is-a.h" +#include "gimple.h" +#include "expr.h" +#include "gimple-iterator.h" +#include "gimple-ssa.h" +#include "tree-cfg.h" +#include "stringpool.h" +#include "tree-dfa.h" +#include "tree-pass.h" +#include "gimple-pretty-print.h" +#include "cfgloop.h" +#include "except.h" +#include "data-streamer.h" +#include "ipa-utils.h" +#include "ipa-icf.h" + +namespace ipa_icf { + +/* Basic block equivalence comparison function that returns true if + basic blocks BB1 and BB2 (from functions FUNC1 and FUNC2) correspond. */ + +bool +sem_function::compare_bb (sem_bb_t *bb1, sem_bb_t *bb2, tree func1, tree func2) +{ + unsigned i; + gimple_stmt_iterator gsi1, gsi2; + gimple s1, s2; + + if (bb1->nondbg_stmt_count != bb2->nondbg_stmt_count + || bb1->edge_count != bb2->edge_count) + SE_EXIT_FALSE (); + + gsi1 = gsi_start_bb (bb1->bb); + gsi2 = gsi_start_bb (bb2->bb); + + for (i = 0; i < bb1->nondbg_stmt_count; i++) + { + if (is_gimple_debug (gsi_stmt (gsi1))) + gsi_next_nondebug (&gsi1); + + if (is_gimple_debug (gsi_stmt (gsi2))) + gsi_next_nondebug (&gsi2); + + s1 = gsi_stmt (gsi1); + s2 = gsi_stmt (gsi2); + + if (gimple_code (s1) != gimple_code (s2)) + SE_EXIT_FALSE_WITH_MSG ("gimple codes are different"); + + switch (gimple_code (s1)) + { + case GIMPLE_CALL: + if (!compare_gimple_call (s1, s2, func1, func2)) + SE_DIFF_STATEMENT (s1, s2, "GIMPLE_CALL"); + break; + case GIMPLE_ASSIGN: + if (!compare_gimple_assign (s1, s2, func1, func2)) + SE_DIFF_STATEMENT (s1, s2, "GIMPLE_ASSIGN"); + break; + case GIMPLE_COND: + if (!compare_gimple_cond (s1, s2, func1, func2)) + SE_DIFF_STATEMENT (s1, s2, "GIMPLE_COND"); + break; + case GIMPLE_SWITCH: + if (!compare_gimple_switch (s1, s2, func1, func2)) + SE_DIFF_STATEMENT (s1, s2, "GIMPLE_SWITCH"); + break; + case GIMPLE_DEBUG: + case GIMPLE_EH_DISPATCH: + break; + case GIMPLE_RESX: + if (!compare_gimple_resx (s1, s2)) + SE_DIFF_STATEMENT (s1, s2, "GIMPLE_RESX"); + break; + case GIMPLE_LABEL: + if (!compare_gimple_label (s1, s2, func1, func2)) + SE_DIFF_STATEMENT (s1, s2, "GIMPLE_LABEL"); + break; + case GIMPLE_RETURN: + if (!compare_gimple_return (s1, s2, func1, func2)) + SE_DIFF_STATEMENT (s1, s2, "GIMPLE_RETURN"); + break; + case GIMPLE_GOTO: + if (!compare_gimple_goto (s1, s2, func1, func2)) + SE_DIFF_STATEMENT (s1, s2, "GIMPLE_GOTO"); + break; + case GIMPLE_ASM: + if (!compare_gimple_asm (s1, s2)) + SE_DIFF_STATEMENT (s1, s2, "GIMPLE_ASM"); + break; + case GIMPLE_PREDICT: + case GIMPLE_NOP: + return true; + default: + SE_EXIT_FALSE_WITH_MSG ("Unknown GIMPLE code reached") + } + + gsi_next (&gsi1); + gsi_next (&gsi2); + } + + return true; +} + + +/* Verifies for given GIMPLEs S1 and S2 (from function FUNC1, resp. FUNC2) that + call statements are semantically equivalent. */ + +bool +sem_function::compare_gimple_call (gimple s1, gimple s2, tree func1, tree func2) +{ + unsigned i; + tree t1, t2; + + if (gimple_call_num_args (s1) != gimple_call_num_args (s2)) + return false; + + t1 = gimple_call_fndecl (s1); + t2 = gimple_call_fndecl (s2); + + /* Function pointer variables are not supported yet. */ + if (t1 == NULL || t2 == NULL) + { + if (!compare_operand (t1, t2, func1, func2)) + SE_EXIT_FALSE(); + } + else if (!compare_function_decl (t1, t2)) + return false; + + /* Checking of argument. */ + for (i = 0; i < gimple_call_num_args (s1); ++i) + { + t1 = gimple_call_arg (s1, i); + t2 = gimple_call_arg (s2, i); + + if (!compare_operand (t1, t2, func1, func2)) + return false; + } + + /* Return value checking. */ + t1 = gimple_get_lhs (s1); + t2 = gimple_get_lhs (s2); + + return compare_operand (t1, t2, func1, func2); +} + +/* Verifies for given GIMPLEs S1 and S2 (from function FUNC1, resp. FUNC2) that + assignment statements are semantically equivalent. */ + +bool +sem_function::compare_gimple_assign (gimple s1, gimple s2, tree func1, + tree func2) +{ + tree arg1, arg2; + enum tree_code code1, code2; + unsigned i; + + code1 = gimple_expr_code (s1); + code2 = gimple_expr_code (s2); + + if (code1 != code2) + return false; + + code1 = gimple_assign_rhs_code (s1); + code2 = gimple_assign_rhs_code (s2); + + if (code1 != code2) + return false; + + for (i = 0; i < gimple_num_ops (s1); i++) + { + arg1 = gimple_op (s1, i); + arg2 = gimple_op (s2, i); + + if (!compare_operand (arg1, arg2, func1, func2)) + return false; + } + + return true; +} + +/* Verifies for given GIMPLEs S1 and S2 (from function FUNC1, resp. FUNC2) that + condition statements are semantically equivalent. */ + +bool +sem_function::compare_gimple_cond (gimple s1, gimple s2, tree func1, tree func2) +{ + tree t1, t2; + enum tree_code code1, code2; + + code1 = gimple_expr_code (s1); + code2 = gimple_expr_code (s2); + + if (code1 != code2) + return false; + + t1 = gimple_cond_lhs (s1); + t2 = gimple_cond_lhs (s2); + + if (!compare_operand (t1, t2, func1, func2)) + return false; + + t1 = gimple_cond_rhs (s1); + t2 = gimple_cond_rhs (s2); + + return compare_operand (t1, t2, func1, func2); +} + +/* Verifies that tree labels T1 and T2 correspond in FUNC1 and FUNC2. */ + +bool +sem_function::compare_tree_ssa_label (tree t1, tree t2, tree func1, tree func2) +{ + return compare_operand (t1, t2, func1, func2); +} + +/* Verifies for given GIMPLEs S1 and S2 (from function FUNC1, resp. FUNC2) that + label statements are semantically equivalent. */ + +bool +sem_function::compare_gimple_label (gimple g1, gimple g2, tree func1, + tree func2) +{ + tree t1 = gimple_label_label (g1); + tree t2 = gimple_label_label (g2); + + return compare_tree_ssa_label (t1, t2, func1, func2); +} + +/* Verifies for given GIMPLEs S1 and S2 (from function FUNC1, resp. FUNC2) that + switch statements are semantically equivalent. */ + +bool +sem_function::compare_gimple_switch (gimple g1, gimple g2, tree func1, + tree func2) +{ + unsigned lsize1, lsize2, i; + tree t1, t2, low1, low2, high1, high2; + + lsize1 = gimple_switch_num_labels (g1); + lsize2 = gimple_switch_num_labels (g2); + + if (lsize1 != lsize2) + return false; + + t1 = gimple_switch_index (g1); + t2 = gimple_switch_index (g2); + + if (TREE_CODE (t1) != SSA_NAME || TREE_CODE(t2) != SSA_NAME) + return false; + + if (!compare_operand (t1, t2, func1, func2)) + return false; + + for (i = 0; i < lsize1; i++) + { + low1 = CASE_LOW (gimple_switch_label (g1, i)); + low2 = CASE_LOW (gimple_switch_label (g2, i)); + + if ((low1 != NULL) != (low2 != NULL) + || (low1 && low2 && TREE_INT_CST_LOW (low1) != TREE_INT_CST_LOW (low2))) + return false; + + high1 = CASE_HIGH (gimple_switch_label (g1, i)); + high2 = CASE_HIGH (gimple_switch_label (g2, i)); + + if ((high1 != NULL) != (high2 != NULL) + || (high1 && high2 + && TREE_INT_CST_LOW (high1) != TREE_INT_CST_LOW (high2))) + return false; + } + + return true; +} + +/* Verifies for given GIMPLEs S1 and S2 (from function FUNC1, resp. FUNC2) that + return statements are semantically equivalent. */ + +bool +sem_function::compare_gimple_return (gimple g1, gimple g2, tree func1, + tree func2) +{ + tree t1, t2; + + t1 = gimple_return_retval (g1); + t2 = gimple_return_retval (g2); + + /* Void return type. */ + if (t1 == NULL && t2 == NULL) + return true; + else + return compare_operand (t1, t2, func1, func2); +} + +/* Verifies for given GIMPLEs S1 and S2 (from function FUNC1, resp. FUNC2) that + goto statements are semantically equivalent. */ + +bool +sem_function::compare_gimple_goto (gimple g1, gimple g2, tree func1, tree func2) +{ + tree dest1, dest2; + + dest1 = gimple_goto_dest (g1); + dest2 = gimple_goto_dest (g2); + + if (TREE_CODE (dest1) != TREE_CODE (dest2) || TREE_CODE (dest1) != SSA_NAME) + return false; + + return compare_operand (dest1, dest2, func1, func2); +} + +/* Verifies for given GIMPLEs S1 and S2 (from function FUNC1, resp. FUNC2) that + resx statements are semantically equivalent. */ + +bool +sem_function::compare_gimple_resx (gimple g1, gimple g2) +{ + return gimple_resx_region (g1) == gimple_resx_region (g2); +} + +/* Verifies for given GIMPLEs S1 and S2 that ASM statements are equivalent. + For the beginning, the pass only supports equality for + '__asm__ __volatile__ ("", "", "", "memory")'. */ + +bool +sem_function::compare_gimple_asm (gimple g1, gimple g2) +{ + if (gimple_asm_volatile_p (g1) != gimple_asm_volatile_p (g2)) + return false; + + if (gimple_asm_ninputs (g1) || gimple_asm_ninputs (g2)) + return false; + + if (gimple_asm_noutputs (g1) || gimple_asm_noutputs (g2)) + return false; + + if (gimple_asm_nlabels (g1) || gimple_asm_nlabels (g2)) + return false; + + if (gimple_asm_nclobbers (g1) != gimple_asm_nclobbers (g2)) + return false; + + for (unsigned i = 0; i < gimple_asm_nclobbers (g1); i++) + { + tree clobber1 = TREE_VALUE (gimple_asm_clobber_op (g1, i)); + tree clobber2 = TREE_VALUE (gimple_asm_clobber_op (g2, i)); + + if (!operand_equal_p (clobber1, clobber2, OEP_ONLY_CONST)) + return false; + } + + return true; +} + +} // ipa_icf namespace diff --git a/gcc/ipa-icf.c b/gcc/ipa-icf.c new file mode 100644 index 0000000..8a13dca --- /dev/null +++ b/gcc/ipa-icf.c @@ -0,0 +1,2762 @@ +/* Interprocedural Identical Code Folding pass + Copyright (C) 2014 Free Software Foundation, Inc. + + Contributed by Jan Hubicka and Martin Liska + +This file is part of GCC. + +GCC is free software; you can redistribute it and/or modify it under +the terms of the GNU General Public License as published by the Free +Software Foundation; either version 3, or (at your option) any later +version. + +GCC is distributed in the hope that it will be useful, but WITHOUT ANY +WARRANTY; without even the implied warranty of MERCHANTABILITY or +FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License +for more details. + +You should have received a copy of the GNU General Public License +along with GCC; see the file COPYING3. If not see +. */ + +/* Interprocedural Identical Code Folding for functions and + read-only variables. + + The goal of this transformation is to discover functions and read-only + variables which do have exactly the same semantics. + + In case of functions, + we could either create a virtual clone or do a simple function wrapper + that will call equivalent function. If the function is just locally visible, + all function calls can be redirected. For read-only variables, we create + aliases if possible. + + Optimization pass arranges as follows: + 1) All functions and read-only variables are visited and internal + data structure, either sem_function or sem_variables is created. + 2) For every symbol from the previous step, VAR_DECL and FUNCTION_DECL are + saved and matched to corresponding sem_items. + 3) These declaration are ignored for equality check and are solved + by Value Numbering algorithm published by Alpert, Zadeck in 1992. + 4) We compute hash value for each symbol. + 5) Congruence classes are created based on hash value. If hash value are + equal, equals function is called and symbols are deeply compared. + We must prove that all SSA names, declarations and other items + correspond. + 6) Value Numbering is executed for these classes. At the end of the process + all symbol members in remaining classes can be merged. + 7) Merge operation creates alias in case of read-only variables. For + callgraph node, we must decide if we can redirect local calls, + create an alias or a thunk. + +*/ + +#include "config.h" +#include "system.h" +#include "coretypes.h" +#include "tree.h" +#include "basic-block.h" +#include "tree-ssa-alias.h" +#include "internal-fn.h" +#include "gimple-expr.h" +#include "is-a.h" +#include "gimple.h" +#include "expr.h" +#include "gimple-iterator.h" +#include "gimple-ssa.h" +#include "tree-cfg.h" +#include "tree-phinodes.h" +#include "stringpool.h" +#include "tree-ssanames.h" +#include "tree-dfa.h" +#include "tree-pass.h" +#include "gimple-pretty-print.h" +#include "ipa-inline.h" +#include "cfgloop.h" +#include "except.h" +#include "hash-table.h" +#include "coverage.h" +#include "pointer-set.h" +#include "attribs.h" +#include "print-tree.h" +#include "lto-streamer.h" +#include "data-streamer.h" +#include "ipa-utils.h" +#include "ipa-icf.h" + +namespace ipa_icf { + +/* Itializes internal structures according to given number of + source and target SSA names. The number of source names is SSA_SOURCE, + respectively SSA_TARGET. */ + +func_checker::func_checker (unsigned ssa_source, unsigned ssa_target) +{ + m_source_ssa_names.create (ssa_source); + m_target_ssa_names.create (ssa_target); + + for (unsigned int i = 0; i < ssa_source; i++) + m_source_ssa_names.safe_push (-1); + + for (unsigned int i = 0; i < ssa_target; i++) + m_target_ssa_names.safe_push (-1); + + m_edge_map = new hash_map (); + m_decl_map = new hash_map (); +} + +/* Memory release routine. */ + +func_checker::~func_checker () +{ + delete m_edge_map; + delete m_decl_map; + m_source_ssa_names.release(); + m_target_ssa_names.release(); +} + +/* Verifies that trees T1 and T2 are equivalent from perspective of ICF. */ + +bool +func_checker::compare_ssa_name (tree t1, tree t2) +{ + unsigned i1 = SSA_NAME_VERSION (t1); + unsigned i2 = SSA_NAME_VERSION (t2); + + if (m_source_ssa_names[i1] == -1) + m_source_ssa_names[i1] = i2; + else if (m_source_ssa_names[i1] != (int) i2) + return false; + + if(m_target_ssa_names[i2] == -1) + m_target_ssa_names[i2] = i1; + else if (m_target_ssa_names[i2] != (int) i1) + return false; + + return true; +} + +/* Verification function for edges E1 and E2. */ + +bool +func_checker::compare_edge (edge e1, edge e2) +{ + if (e1->flags != e2->flags) + return false; + + bool existed_p; + + edge &slot = m_edge_map->get_or_insert (e1, &existed_p); + if (existed_p) + { + SE_EXIT_DEBUG (slot == e2); + } + else + slot = e2; + + return true; +} + +/* Verification function for declaration trees T1 and T2 that + come from functions FUNC1 and FUNC2. */ + +bool +func_checker::compare_decl (tree t1, tree t2, tree func1, tree func2) +{ + if (!auto_var_in_fn_p (t1, func1) || !auto_var_in_fn_p (t2, func2)) + SE_EXIT_DEBUG (t1 == t2); + + if (!types_compatible_p (TREE_TYPE (t1), TREE_TYPE (t2))) + SE_EXIT_FALSE (); + + bool existed_p; + + tree &slot = m_decl_map->get_or_insert (t1, &existed_p); + if (existed_p) + { + SE_EXIT_DEBUG (slot == t2); + } + else + slot = t2; + + return true; +} + +/* Constructor for key value pair, where _ITEM is key and _INDEX is a target. */ + +sem_usage_pair::sem_usage_pair (sem_item *_item, unsigned int _index): + item (_item), index (_index) +{ +} + +/* Semantic item constructor for a node of _TYPE, where STACK is used + for bitmap memory allocation. */ + +sem_item::sem_item (enum sem_item_type _type, + bitmap_obstack *stack): type(_type), hash(0) +{ + setup (stack); +} + +/* Semantic item constructor for a node of _TYPE, where STACK is used + for bitmap memory allocation. The item is based on symtab node _NODE + with computed _HASH. */ + +sem_item::sem_item (enum sem_item_type _type, struct symtab_node *_node, + hashval_t _hash, bitmap_obstack *stack): type(_type), + node (_node), hash (_hash) +{ + decl = node->decl; + setup (stack); +} + +/* Initialize internal data structures. Bitmap STACK is used for + bitmap memory allocation process. */ + +void +sem_item::setup (bitmap_obstack *stack) +{ + gcc_checking_assert (node); + + refs.create (0); + tree_refs.create (0); + usages.create (0); + tree_refs_set = pointer_set_create (); + usage_index_bitmap = BITMAP_ALLOC (stack); +} + +sem_item::~sem_item () +{ + if (tree_refs_set) + pointer_set_destroy (tree_refs_set); + + for (unsigned i = 0; i < usages.length (); i++) + delete usages[i]; + + refs.release (); + tree_refs.release (); + usages.release (); + + BITMAP_FREE (usage_index_bitmap); +} + +/* Dump function for debugging purpose. */ + +DEBUG_FUNCTION void +sem_item::dump (void) +{ + if (dump_file) + { + fprintf (dump_file, "[%s] %s (%u) (tree:%p)\n", type == FUNC ? "func" : "var", + name(), node->order, (void *) node->decl); + fprintf (dump_file, " hash: %u\n", get_hash ()); + fprintf (dump_file, " references: "); + + for (unsigned i = 0; i < refs.length (); i++) + fprintf (dump_file, "%s%s ", refs[i]->name (), + i < refs.length() - 1 ? "," : ""); + + fprintf (dump_file, "\n"); + } +} + +/* If strict aliasing is enabled, function compares if given types are + in the same alias set. */ +bool +sem_item::compare_for_aliasing (tree t1, tree t2) +{ + if (flag_strict_aliasing) + { + alias_set_type s1 = get_deref_alias_set (TREE_TYPE (t1)); + alias_set_type s2 = get_deref_alias_set (TREE_TYPE (t2)); + + return s1 == s2; + } + + return true; +} + +/* Semantic function constructor that uses STACK as bitmap memory stack. */ + +sem_function::sem_function (bitmap_obstack *stack): sem_item (FUNC, stack), + m_checker (NULL), m_compared_func (NULL) +{ + arg_types.create (0); + bb_sizes.create (0); + bb_sorted.create (0); +} + +/* Constructor based on callgraph node _NODE with computed hash _HASH. + Bitmap STACK is used for memory allocation. */ +sem_function::sem_function (cgraph_node *node, hashval_t hash, + bitmap_obstack *stack): + sem_item (FUNC, node, hash, stack), + m_checker (NULL), m_compared_func (NULL) +{ + arg_types.create (0); + bb_sizes.create (0); + bb_sorted.create (0); +} + +sem_function::~sem_function () +{ + for (unsigned i = 0; i < bb_sorted.length (); i++) + free (bb_sorted[i]); + + arg_types.release (); + bb_sizes.release (); + bb_sorted.release (); +} + +/* Calculates hash value based on a BASIC_BLOCK. */ + +hashval_t +sem_function::get_bb_hash (const sem_bb_t *basic_block) +{ + hashval_t hash = basic_block->nondbg_stmt_count; + hash = iterative_hash_object (basic_block->edge_count, hash); + + return hash; +} + +/* References independent hash function. */ + +hashval_t +sem_function::get_hash (void) +{ + if(!hash) + { + hash = 177454; /* Random number for function type. */ + + hash = iterative_hash_object (arg_count, hash); + hash = iterative_hash_object (cfg_checksum, hash); + hash = iterative_hash_object (gcode_hash, hash); + + for (unsigned i = 0; i < bb_sorted.length (); i++) + hash = iterative_hash_object (hash, get_bb_hash (bb_sorted[i])); + + for (unsigned i = 0; i < bb_sizes.length (); i++) + hash = iterative_hash_object (bb_sizes[i], hash); + } + + return hash; +} + +/* Fast equality function based on knowledge known in WPA. */ + +bool +sem_function::equals_wpa (sem_item *item) +{ + gcc_assert (item->type == FUNC); + + m_compared_func = static_cast (item); + + if (arg_types.length () != m_compared_func->arg_types.length ()) + SE_EXIT_FALSE_WITH_MSG ("different number of arguments"); + + /* Checking types of arguments. */ + for (unsigned i = 0; i < arg_types.length (); i++) + { + /* This guard is here for function pointer with attributes (pr59927.c). */ + if (!arg_types[i] || !m_compared_func->arg_types[i]) + SE_EXIT_FALSE_WITH_MSG ("NULL arg type"); + + if (!types_compatible_p (arg_types[i], m_compared_func->arg_types[i])) + SE_EXIT_FALSE_WITH_MSG("argument type is different"); + } + + /* Result type checking. */ + if (!types_compatible_p (result_type, m_compared_func->result_type)) + SE_EXIT_FALSE_WITH_MSG("result types are different"); + + return true; +} + +/* Returns true if the item equals to ITEM given as argument. */ + +bool +sem_function::equals (sem_item *item) +{ + gcc_assert (item->type == FUNC); + bool eq = equals_private (item); + + if (m_checker != NULL) + { + delete m_checker; + m_checker = NULL; + } + + if (dump_file && (dump_flags & TDF_DETAILS)) + fprintf (dump_file, + "Equals called for:%s:%s (%u:%u) (%s:%s) with result: %s\n\n", + name(), item->name (), node->order, item->node->order, asm_name (), + item->asm_name (), eq ? "true" : "false"); + + return eq; +} + +/* Processes function equality comparison. */ + +bool +sem_function::equals_private (sem_item *item) +{ + if (item->type != FUNC) + return false; + + basic_block bb1, bb2; + edge e1, e2; + edge_iterator ei1, ei2; + int *bb_dict = NULL; + bool result = true; + tree arg1, arg2; + + m_compared_func = static_cast (item); + + gcc_assert (decl != item->decl); + + if (bb_sorted.length () != m_compared_func->bb_sorted.length () + || edge_count != m_compared_func->edge_count + || cfg_checksum != m_compared_func->cfg_checksum) + SE_EXIT_FALSE(); + + if (!equals_wpa (item)) + return false; + + /* Checking function arguments. */ + tree decl1 = DECL_ATTRIBUTES (decl); + tree decl2 = DECL_ATTRIBUTES (m_compared_func->decl); + + while (decl1) + { + if (decl2 == NULL) + SE_EXIT_FALSE(); + + if (get_attribute_name (decl1) != get_attribute_name (decl2)) + SE_EXIT_FALSE(); + + tree attr_value1 = TREE_VALUE (decl1); + tree attr_value2 = TREE_VALUE (decl2); + + if (attr_value1 && attr_value2) + { + bool ret = compare_operand (TREE_VALUE (attr_value1), + TREE_VALUE (attr_value2), decl, + m_compared_func->decl); + if (!ret) + SE_EXIT_FALSE_WITH_MSG ("attribute values are different") + } + else if (!attr_value1 && !attr_value2) + {} + else + SE_EXIT_FALSE (); + + decl1 = TREE_CHAIN (decl1); + decl2 = TREE_CHAIN (decl2); + } + + if (decl1 != decl2) + SE_EXIT_FALSE(); + + m_checker = new func_checker (ssa_names_size, m_compared_func->ssa_names_size); + + for (arg1 = DECL_ARGUMENTS (decl), + arg2 = DECL_ARGUMENTS (m_compared_func->decl); + arg1; arg1 = DECL_CHAIN (arg1), arg2 = DECL_CHAIN (arg2)) + m_checker->compare_decl (arg1, arg2, decl, m_compared_func->decl); + + /* Exception handling regions comparison. */ + if (!compare_eh_region (region_tree, m_compared_func->region_tree, decl, + m_compared_func->decl)) + SE_EXIT_FALSE(); + + /* Checking all basic blocks. */ + for (unsigned i = 0; i < bb_sorted.length (); ++i) + if(!compare_bb (bb_sorted[i], m_compared_func->bb_sorted[i], decl, + m_compared_func->decl)) + SE_EXIT_FALSE(); + + SE_DUMP_MESSAGE ("All BBs are equal\n"); + + /* Basic block edges check. */ + for (unsigned i = 0; i < bb_sorted.length (); ++i) + { + bb_dict = XNEWVEC (int, bb_sorted.length () + 2); + memset (bb_dict, -1, (bb_sorted.length () + 2) * sizeof (int)); + + bb1 = bb_sorted[i]->bb; + bb2 = m_compared_func->bb_sorted[i]->bb; + + ei2 = ei_start (bb2->preds); + + for (ei1 = ei_start (bb1->preds); ei_cond (ei1, &e1); ei_next (&ei1)) + { + ei_cond (ei2, &e2); + + if (e1->flags != e2->flags) + SE_EXIT_FALSE_WITH_MSG("flags comparison returns false"); + + if (!bb_dict_test (bb_dict, e1->src->index, e2->src->index)) + SE_EXIT_FALSE_WITH_MSG("edge comparison returns false"); + + if (!bb_dict_test (bb_dict, e1->dest->index, e2->dest->index)) + SE_EXIT_FALSE_WITH_MSG("BB comparison returns false"); + + if (!m_checker->compare_edge (e1, e2)) + SE_EXIT_FALSE_WITH_MSG("edge comparison returns false"); + + ei_next (&ei2); + } + } + + /* Basic block PHI nodes comparison. */ + for (unsigned i = 0; i < bb_sorted.length (); i++) + if (!compare_phi_node (bb_sorted[i]->bb, m_compared_func->bb_sorted[i]->bb, + decl, m_compared_func->decl)) + SE_EXIT_FALSE_WITH_MSG ("PHI node comparison returns false"); + + return result; +} + +/* Initializes references to another sem_item for tree T. */ + +void +sem_function::init_refs_for_tree (tree t) +{ + switch (TREE_CODE (t)) + { + case VAR_DECL: + case FUNCTION_DECL: + tree_refs.safe_push (t); + break; + case MEM_REF: + case ADDR_EXPR: + case OBJ_TYPE_REF: + init_refs_for_tree (TREE_OPERAND (t, 0)); + break; + case FIELD_DECL: + init_refs_for_tree (DECL_FCONTEXT (t)); + break; + default: + break; + } +} + +/* Initializes references to another sem_item for gimple STMT of type assign. */ + +void +sem_function::init_refs_for_assign (gimple stmt) +{ + if (gimple_num_ops (stmt) != 2) + return; + + tree rhs = gimple_op (stmt, 1); + + init_refs_for_tree (rhs); +} + +/* Initializes references to other semantic functions/variables. */ + +void +sem_function::init_refs (void) +{ + for (unsigned i = 0; i < bb_sorted.length (); i++) + { + basic_block bb = bb_sorted[i]->bb; + + for (gimple_stmt_iterator gsi = gsi_start_bb (bb); !gsi_end_p (gsi); + gsi_next (&gsi)) + { + gimple stmt = gsi_stmt (gsi); + hashval_t code = (hashval_t) gimple_code (stmt); + + switch (code) + { + case GIMPLE_CALL: + { + tree funcdecl = gimple_call_fndecl (stmt); + + /* Function pointer variables are not supported yet. */ + if (funcdecl) + tree_refs.safe_push (funcdecl); + + break; + } + case GIMPLE_ASSIGN: + init_refs_for_assign (stmt); + break; + default: + break; + } + } + } +} + +/* Merges instance with an ALIAS_ITEM, where alias, thunk or redirection can + be applied. */ +bool +sem_function::merge (sem_item *alias_item) +{ + gcc_assert (alias_item->type == FUNC); + + sem_function *alias_func = static_cast (alias_item); + + struct cgraph_node *original = get_node (); + struct cgraph_node *local_original = original; + struct cgraph_node *alias = alias_func->get_node (); + bool original_address_matters; + bool alias_address_matters; + + bool create_thunk = false; + bool create_alias = false; + bool redirect_callers = false; + bool original_discardable = false; + + /* Do not attempt to mix functions from different user sections; + we do not know what user intends with those. */ + if (((DECL_SECTION_NAME (original->decl) && !original->implicit_section) + || (DECL_SECTION_NAME (alias->decl) && !alias->implicit_section)) + && DECL_SECTION_NAME (original->decl) != DECL_SECTION_NAME (alias->decl)) + { + if (dump_file) + fprintf (dump_file, + "Not unifying; original and alias are in different sections.\n\n"); + return false; + } + + /* See if original is in a section that can be discarded if the main + symbol is not used. */ + if (DECL_EXTERNAL (original->decl)) + original_discardable = true; + if (original->resolution == LDPR_PREEMPTED_REG + || original->resolution == LDPR_PREEMPTED_IR) + original_discardable = true; + if (symtab_can_be_discarded (original)) + original_discardable = true; + + /* See if original and/or alias address can be compared for equality. */ + original_address_matters + = (!DECL_VIRTUAL_P (original->decl) + && (original->externally_visible + || address_taken_from_non_vtable_p (original))); + alias_address_matters + = (!DECL_VIRTUAL_P (alias->decl) + && (alias->externally_visible + || address_taken_from_non_vtable_p (alias))); + + /* If alias and original can be compared for address equality, we need + to create a thunk. Also we can not create extra aliases into discardable + section (or we risk link failures when section is discarded). */ + if ((original_address_matters + && alias_address_matters) + || original_discardable) + { + create_thunk = !stdarg_p (TREE_TYPE (alias->decl)); + create_alias = false; + /* When both alias and original are not overwritable, we can save + the extra thunk wrapper for direct calls. */ + redirect_callers + = (!original_discardable + && cgraph_function_body_availability (alias) > AVAIL_OVERWRITABLE + && cgraph_function_body_availability (original) > AVAIL_OVERWRITABLE); + } + else + { + create_alias = true; + create_thunk = false; + redirect_callers = false; + } + + if (create_alias && DECL_COMDAT_GROUP (alias->decl)) + { + create_alias = false; + create_thunk = true; + } + + /* We want thunk to always jump to the local function body + unless the body is comdat and may be optimized out. */ + if ((create_thunk || redirect_callers) + && (!original_discardable + || (DECL_COMDAT_GROUP (original->decl) + && (DECL_COMDAT_GROUP (original->decl) + == DECL_COMDAT_GROUP (alias->decl))))) + local_original + = cgraph (symtab_nonoverwritable_alias (original)); + + if (redirect_callers) + { + /* If alias is non-overwritable then + all direct calls are safe to be redirected to the original. */ + bool redirected = false; + while (alias->callers) + { + struct cgraph_edge *e = alias->callers; + cgraph_redirect_edge_callee (e, local_original); + push_cfun (DECL_STRUCT_FUNCTION (e->caller->decl)); + + if (e->call_stmt) + cgraph_redirect_edge_call_stmt_to_callee (e); + + pop_cfun (); + redirected = true; + } + + /* The alias function is removed if symbol address + does not matter. */ + if (!alias_address_matters) + cgraph_remove_node (alias); + + if (dump_file && redirected) + fprintf (dump_file, "Callgraph local calls have been redirected.\n\n"); + } + /* If the condtion above is not met, we are lucky and can turn the + function into real alias. */ + else if (create_alias) + { + /* Remove the function's body. */ + ipa_merge_profiles (original, alias); + cgraph_release_function_body (alias); + cgraph_reset_node (alias); + + /* Create the alias. */ + cgraph_create_function_alias (alias_func->decl, decl); + symtab_resolve_alias (alias, original); + + if (dump_file) + fprintf (dump_file, "Callgraph alias has been created.\n\n"); + } + else if (create_thunk) + { + if (DECL_COMDAT_GROUP (alias->decl)) + { + if (dump_file) + fprintf (dump_file, "Callgraph thunk cannot be created because of COMDAT\n"); + + return 0; + } + + ipa_merge_profiles (local_original, alias); + cgraph_make_wrapper (alias, local_original); + + if (dump_file) + fprintf (dump_file, "Callgraph thunk has been created.\n\n"); + } + else if (dump_file) + fprintf (dump_file, "Callgraph merge operation cannot be performed.\n\n"); + + return true; +} + +/* Semantic item initialization function. */ + +void +sem_function::init (void) +{ + if (in_lto_p) + cgraph_get_body (get_node ()); + + tree fndecl = node->decl; + struct function *func = DECL_STRUCT_FUNCTION (fndecl); + + gcc_assert (func); + gcc_assert (SSANAMES (func)); + + ssa_names_size = SSANAMES (func)->length (); + node = node; + + decl = fndecl; + region_tree = func->eh->region_tree; + + /* iterating all function arguments. */ + arg_count = count_formal_params (fndecl); + + edge_count = n_edges_for_fn (func); + cfg_checksum = coverage_compute_cfg_checksum (func); + + gcode_hash = 0; + + basic_block bb; + FOR_EACH_BB_FN (bb, func) + { + unsigned nondbg_stmt_count = 0; + + edge e; + for (edge_iterator ei = ei_start (bb->preds); ei_cond (ei, &e); ei_next (&ei)) + cfg_checksum = iterative_hash_host_wide_int (e->flags, + cfg_checksum); + + for (gimple_stmt_iterator gsi = gsi_start_bb (bb); !gsi_end_p (gsi); + gsi_next (&gsi)) + { + gimple stmt = gsi_stmt (gsi); + hashval_t code = (hashval_t) gimple_code (stmt); + + /* We ignore all debug statements. */ + if (code != GIMPLE_DEBUG) + { + nondbg_stmt_count++; + gcode_hash = iterative_hash_object (code, gcode_hash); + } + } + + bb_sizes.safe_push (nondbg_stmt_count); + + /* Inserting basic block to hash table. */ + sem_bb_t *sem_bb = XNEW (sem_bb_t); + sem_bb->bb = bb; + sem_bb->nondbg_stmt_count = nondbg_stmt_count; + sem_bb->edge_count = EDGE_COUNT (bb->preds) + EDGE_COUNT (bb->succs); + + bb_sorted.safe_push (sem_bb); + } + + parse_tree_args (); +} + +/* For a given call graph NODE, the function constructs new + semantic function item. */ + +sem_function * +sem_function::parse (struct cgraph_node *node, bitmap_obstack *stack) +{ + tree fndecl = node->decl; + struct function *func = DECL_STRUCT_FUNCTION (fndecl); + + if (!func || !cgraph_function_with_gimple_body_p (node)) + return NULL; + + if (lookup_attribute_by_prefix ("omp ", DECL_ATTRIBUTES (node->decl)) != NULL) + return NULL; + + sem_function *f = new sem_function (node, 0, stack); + + f->init (); + + return f; +} + +/* Parses function arguments and result type. */ + +void +sem_function::parse_tree_args (void) +{ + tree result; + + if (arg_types.exists ()) + arg_types.release (); + + arg_types.create (4); + tree fnargs = DECL_ARGUMENTS (decl); + + for (tree parm = fnargs; parm; parm = DECL_CHAIN (parm)) + arg_types.safe_push (TYPE_CANONICAL (DECL_ARG_TYPE (parm))); + + /* Function result type. */ + result = DECL_RESULT (decl); + result_type = result ? TYPE_CANONICAL (TREE_TYPE (result)) : NULL; + + /* During WPA, we can get arguments by following method. */ + if (!fnargs) + { + tree type = TYPE_ARG_TYPES (TREE_TYPE (decl)); + for (tree parm = type; parm; parm = TREE_CHAIN (parm)) + arg_types.safe_push (TYPE_CANONICAL (TREE_VALUE (parm))); + + result_type = TREE_TYPE (TREE_TYPE (decl)); + } +} + +/* For given basic blocks BB1 and BB2 (from functions FUNC1 and FUNC), + return true if phi nodes are sematically equivalent in these blocks . */ + +bool +sem_function::compare_phi_node (basic_block bb1, basic_block bb2, + tree func1, tree func2) +{ + gimple_stmt_iterator si1, si2; + gimple phi1, phi2; + unsigned size1, size2, i; + tree t1, t2; + edge e1, e2; + + gcc_assert (bb1 != NULL); + gcc_assert (bb2 != NULL); + + si2 = gsi_start_phis (bb2); + for (si1 = gsi_start_phis (bb1); !gsi_end_p (si1); + gsi_next (&si1)) + { + gsi_next_nonvirtual_phi (&si1); + gsi_next_nonvirtual_phi (&si2); + + if (gsi_end_p (si1) && gsi_end_p (si2)) + break; + + if (gsi_end_p (si1) || gsi_end_p (si2)) + SE_EXIT_FALSE (); + + phi1 = gsi_stmt (si1); + phi2 = gsi_stmt (si2); + + size1 = gimple_phi_num_args (phi1); + size2 = gimple_phi_num_args (phi2); + + if (size1 != size2) + SE_EXIT_FALSE (); + + for (i = 0; i < size1; ++i) + { + t1 = gimple_phi_arg (phi1, i)->def; + t2 = gimple_phi_arg (phi2, i)->def; + + if (!compare_operand (t1, t2, func1, func2)) + SE_EXIT_FALSE (); + + e1 = gimple_phi_arg_edge (phi1, i); + e2 = gimple_phi_arg_edge (phi2, i); + + if (!m_checker->compare_edge (e1, e2)) + SE_EXIT_FALSE (); + } + + gsi_next (&si2); + } + + return true; +} + +/* For given basic blocks BB1 and BB2 (from functions FUNC1 and FUNC), + true value is returned if exception handling regions are equivalent + in these blocks. */ + +bool +sem_function::compare_eh_region (eh_region r1, eh_region r2, tree func1, + tree func2) +{ + eh_landing_pad lp1, lp2; + eh_catch c1, c2; + tree t1, t2; + + while (1) + { + if (!r1 && !r2) + return true; + + if (!r1 || !r2) + return false; + + if (r1->index != r2->index || r1->type != r2->type) + return false; + + /* Landing pads comparison */ + lp1 = r1->landing_pads; + lp2 = r2->landing_pads; + + while (lp1 && lp2) + { + if (lp1->index != lp2->index) + return false; + + /* Comparison of post landing pads. */ + if (lp1->post_landing_pad && lp2->post_landing_pad) + { + t1 = lp1->post_landing_pad; + t2 = lp2->post_landing_pad; + + gcc_assert (TREE_CODE (t1) == LABEL_DECL); + gcc_assert (TREE_CODE (t2) == LABEL_DECL); + + if (!compare_tree_ssa_label (t1, t2, func1, func2)) + return false; + } + else if (lp1->post_landing_pad || lp2->post_landing_pad) + return false; + + lp1 = lp1->next_lp; + lp2 = lp2->next_lp; + } + + if (lp1 || lp2) + return false; + + switch (r1->type) + { + case ERT_TRY: + c1 = r1->u.eh_try.first_catch; + c2 = r2->u.eh_try.first_catch; + + while (c1 && c2) + { + /* Catch label checking */ + if (c1->label && c2->label) + { + if (!compare_tree_ssa_label (c1->label, c2->label, + func1, func2)) + return false; + } + else if (c1->label || c2->label) + return false; + + /* Type list checking */ + if (!compare_type_list (c1->type_list, c2->type_list)) + return false; + + c1 = c1->next_catch; + c2 = c2->next_catch; + } + + break; + + case ERT_ALLOWED_EXCEPTIONS: + if (r1->u.allowed.filter != r2->u.allowed.filter) + return false; + + if (!compare_type_list (r1->u.allowed.type_list, + r2->u.allowed.type_list)) + return false; + + break; + case ERT_CLEANUP: + break; + case ERT_MUST_NOT_THROW: + if (r1->u.must_not_throw.failure_decl != r1->u.must_not_throw.failure_decl) + return false; + break; + default: + gcc_unreachable (); + break; + } + + /* If there are sub-regions, process them. */ + if ((!r1->inner && r2->inner) || (!r1->next_peer && r2->next_peer)) + return false; + + if (r1->inner) + { + r1 = r1->inner; + r2 = r2->inner; + } + + /* If there are peers, process them. */ + else if (r1->next_peer) + { + r1 = r1->next_peer; + r2 = r2->next_peer; + } + /* Otherwise, step back up the tree to the next peer. */ + else + { + do + { + r1 = r1->outer; + r2 = r2->outer; + + /* All nodes have been visited. */ + if (!r1 && !r2) + return true; + } + while (r1->next_peer == NULL); + + r1 = r1->next_peer; + r2 = r2->next_peer; + } + } + + return false; +} + +/* Verifies that trees T1 and T2, representing function declarations + are equivalent from perspective of ICF. */ + +bool +sem_function::compare_function_decl (tree t1, tree t2) +{ + if (t1 == t2) + return true; + + bool ret = pointer_set_contains (tree_refs_set, t1) + && pointer_set_contains (m_compared_func->tree_refs_set, t2); + + if (ret) + return true; + + /* If function decl is WEAKREF, we compare targets. */ + struct cgraph_node *f1 = cgraph_get_node (t1); + struct cgraph_node *f2 = cgraph_get_node (t2); + + if(f1 && f2 && f1->weakref && f2->weakref) + ret = f1->alias_target == f2->alias_target; + + return ret; +} + +/* Verifies that trees T1 and T2 do correspond. */ + +bool +sem_function::compare_variable_decl (tree t1, tree t2, tree func1, tree func2) +{ + if (t1 == t2) + return true; + + bool ret = pointer_set_contains (tree_refs_set, t1) + && pointer_set_contains (m_compared_func->tree_refs_set, t2); + + if (ret) + return true; + + ret = m_checker->compare_decl (t1, t2, func1, func2); + + SE_EXIT_DEBUG (ret); +} + + +/* Returns true if tree T can be compared as a handled component. */ + +bool +sem_function::icf_handled_component_p (tree t) +{ + enum tree_code tc = TREE_CODE (t); + + return ((handled_component_p (t)) + || tc == ADDR_EXPR || tc == MEM_REF || tc == REALPART_EXPR + || tc == IMAGPART_EXPR || tc == OBJ_TYPE_REF); +} + +/* Basic blocks dictionary BB_DICT returns true if SOURCE index BB + corresponds to TARGET. */ + +bool +sem_function::bb_dict_test (int* bb_dict, int source, int target) +{ + if (bb_dict[source] == -1) + { + bb_dict[source] = target; + return true; + } + else + return bb_dict[source] == target; +} + +/* If T1 and T2 are SSA names, dictionary comparison is processed. Otherwise, + declaration comparasion is executed. */ + +bool +sem_function::compare_ssa_name (tree t1, tree t2, tree func1, tree func2) +{ + tree b1, b2; + bool ret; + + if (!m_checker->compare_ssa_name (t1, t2)) + SE_EXIT_FALSE (); + + if (SSA_NAME_IS_DEFAULT_DEF (t1)) + { + b1 = SSA_NAME_VAR (t1); + b2 = SSA_NAME_VAR (t2); + + if (b1 == NULL && b2 == NULL) + return true; + + if (b1 == NULL || b2 == NULL || TREE_CODE (b1) != TREE_CODE (b2)) + SE_EXIT_FALSE (); + + switch (TREE_CODE (b1)) + { + case VAR_DECL: + SE_EXIT_DEBUG (compare_variable_decl (t1, t2, func1, func2)); + case PARM_DECL: + case RESULT_DECL: + ret = m_checker->compare_decl (b1, b2, func1, func2); + SE_EXIT_DEBUG (ret); + default: + SE_EXIT_FALSE_WITH_MSG ("Unknown TREE code reached") + } + } + else + return true; +} + +/* Function responsible for comparison of handled components T1 and T2. + If these components, from functions FUNC1 and FUNC2, are equal, true + is returned. */ + +bool +sem_function::compare_operand (tree t1, tree t2, + tree func1, tree func2) +{ + tree base1, base2, x1, x2, y1, y2, z1, z2; + HOST_WIDE_INT offset1, offset2; + bool ret; + + if (!t1 && !t2) + return true; + else if (!t1 || !t2) + return false; + + if (!types_compatible_p (TREE_TYPE (t1), TREE_TYPE (t2))) + SE_EXIT_FALSE_WITH_MSG ("types are not compatible"); + + if (TREE_CODE (t1) == RECORD_TYPE && TREE_CODE (t2) == RECORD_TYPE) + { + tree ctx1 = DECL_CONTEXT (t1); + tree ctx2 = DECL_CONTEXT (t2); + + if (TYPE_BINFO (ctx1) && TYPE_BINFO (ctx2) + && polymorphic_type_binfo_p (TYPE_BINFO (ctx1)) + && polymorphic_type_binfo_p (TYPE_BINFO (ctx2))) + if (!types_same_for_odr (t1, t2)) + SE_EXIT_FALSE_WITH_MSG ("polymorphic types detected"); + } + + base1 = get_addr_base_and_unit_offset (t1, &offset1); + base2 = get_addr_base_and_unit_offset (t2, &offset2); + + if (offset1 != offset2) + SE_EXIT_FALSE_WITH_MSG ("base offsets are different"); + + if (base1 && base2) + { + t1 = base1; + t2 = base2; + } + + if (TREE_CODE (t1) != TREE_CODE (t2)) + SE_EXIT_FALSE_WITH_MSG (""); + + switch (TREE_CODE (t1)) + { + case CONSTRUCTOR: + { + unsigned length1 = vec_safe_length (CONSTRUCTOR_ELTS (t1)); + unsigned length2 = vec_safe_length (CONSTRUCTOR_ELTS (t2)); + + if (length1 != length2) + SE_EXIT_FALSE_WITH_MSG (""); + + for (unsigned i = 0; i < length1; i++) + if (!compare_operand (CONSTRUCTOR_ELT (t1, i)->value, + CONSTRUCTOR_ELT (t2, i)->value, func1, func2)) + SE_EXIT_FALSE_WITH_MSG (""); + + return true; + } + case ARRAY_REF: + case ARRAY_RANGE_REF: + { + x1 = TREE_OPERAND (t1, 0); + x2 = TREE_OPERAND (t2, 0); + y1 = TREE_OPERAND (t1, 1); + y2 = TREE_OPERAND (t2, 1); + + if (!compare_operand (array_ref_low_bound (t1), + array_ref_low_bound (t2), + func1, func2)) + SE_EXIT_FALSE_WITH_MSG (""); + if (!compare_operand (array_ref_element_size (t1), + array_ref_element_size (t2), + func1, func2)) + SE_EXIT_FALSE_WITH_MSG (""); + if (!compare_operand (x1, x2, func1, func2)) + SE_EXIT_FALSE_WITH_MSG (""); + return compare_operand (y1, y2, func1, func2); + } + + case MEM_REF: + { + x1 = TREE_OPERAND (t1, 0); + x2 = TREE_OPERAND (t2, 0); + y1 = TREE_OPERAND (t1, 1); + y2 = TREE_OPERAND (t2, 1); + + /* See if operand is an memory access (the test originate from + gimple_load_p). + + In this case the alias set of the function being replaced must + be subset of the alias set of the other function. At the moment + we seek for equivalency classes, so simply require inclussion in + both directions. */ + + if (!sem_item::compare_for_aliasing (y1, y2)) + SE_EXIT_FALSE_WITH_MSG ("strict aliasing types do not match"); + + if (!compare_operand (x1, x2, func1, func2)) + SE_EXIT_FALSE_WITH_MSG (""); + + /* Type of the offset on MEM_REF does not matter. */ + return wi::to_offset (y1) == wi::to_offset (y2); + } + case COMPONENT_REF: + { + x1 = TREE_OPERAND (t1, 0); + x2 = TREE_OPERAND (t2, 0); + y1 = TREE_OPERAND (t1, 1); + y2 = TREE_OPERAND (t2, 1); + + ret = compare_operand (x1, x2, func1, func2) + && compare_operand (y1, y2, func1, func2); + + SE_EXIT_DEBUG (ret); + } + /* Virtual table call. */ + case OBJ_TYPE_REF: + { + x1 = TREE_OPERAND (t1, 0); + x2 = TREE_OPERAND (t2, 0); + y1 = TREE_OPERAND (t1, 1); + y2 = TREE_OPERAND (t2, 1); + z1 = TREE_OPERAND (t1, 2); + z2 = TREE_OPERAND (t2, 2); + + ret = compare_operand (x1, x2, func1, func2) + && compare_operand (y1, y2, func1, func2) + && compare_operand (z1, z2, func1, func2); + + SE_EXIT_DEBUG (ret); + } + case ADDR_EXPR: + { + x1 = TREE_OPERAND (t1, 0); + x2 = TREE_OPERAND (t2, 0); + + ret = compare_operand (x1, x2, func1, func2); + SE_EXIT_DEBUG (ret); + } + case SSA_NAME: + { + ret = compare_ssa_name (t1, t2, func1, func2); + SE_EXIT_DEBUG (ret); + } + case INTEGER_CST: + { + ret = types_compatible_p (TREE_TYPE (t1), TREE_TYPE (t2)) + && wi::to_offset (t1) == wi::to_offset (t2); + + SE_EXIT_DEBUG (ret); + } + case COMPLEX_CST: + case VECTOR_CST: + case STRING_CST: + case REAL_CST: + { + ret = operand_equal_p (t1, t2, OEP_ONLY_CONST); + SE_EXIT_DEBUG (ret); + } + case FUNCTION_DECL: + { + ret = compare_function_decl (t1, t2); + SE_EXIT_DEBUG (ret); + } + case VAR_DECL: + SE_EXIT_DEBUG (compare_variable_decl (t1, t2, func1, func2)); + case FIELD_DECL: + { + tree fctx1 = DECL_FCONTEXT (t1); + tree fctx2 = DECL_FCONTEXT (t2); + + tree offset1 = DECL_FIELD_OFFSET (t1); + tree offset2 = DECL_FIELD_OFFSET (t1); + + ret = compare_operand (fctx1, fctx2, func1, func2) + && compare_operand (offset1, offset2, func1, func2); + + SE_EXIT_DEBUG (ret); + } + case PARM_DECL: + case LABEL_DECL: + case RESULT_DECL: + case CONST_DECL: + case BIT_FIELD_REF: + { + ret = m_checker->compare_decl (t1, t2, func1, func2); + SE_EXIT_DEBUG (ret); + } + default: + SE_EXIT_FALSE_WITH_MSG ("Unknown TREE code reached") + } +} + +/* Iterates all tree types in T1 and T2 and returns true if all types + are compatible. */ + +bool +sem_function::compare_type_list (tree t1, tree t2) +{ + tree tv1, tv2; + enum tree_code tc1, tc2; + + if (!t1 && !t2) + return true; + + while (t1 != NULL && t2 != NULL) + { + tv1 = TREE_VALUE (t1); + tv2 = TREE_VALUE (t2); + + tc1 = TREE_CODE (tv1); + tc2 = TREE_CODE (tv2); + + if (tc1 == NOP_EXPR && tc2 == NOP_EXPR) + {} + else if (tc1 == NOP_EXPR || tc2 == NOP_EXPR) + return false; + else if (!types_compatible_p (tv1, tv2)) + return false; + + t1 = TREE_CHAIN (t1); + t2 = TREE_CHAIN (t2); + } + + return !(t1 || t2); +} + + +/* Semantic variable constructor that uses STACK as bitmap memory stack. */ + +sem_variable::sem_variable (bitmap_obstack *stack): sem_item (VAR, stack) +{ +} + +/* Constructor based on varpool node _NODE with computed hash _HASH. + Bitmap STACK is used for memory allocation. */ + +sem_variable::sem_variable (varpool_node *node, hashval_t _hash, + bitmap_obstack *stack): sem_item(VAR, + node, _hash, stack) +{ + gcc_checking_assert (node); + gcc_checking_assert (get_node ()); +} + +/* Returns true if the item equals to ITEM given as argument. */ + +bool +sem_variable::equals (sem_item *item) +{ + gcc_assert (item->type == VAR); + + return sem_variable::equals (ctor, static_cast(item)->ctor); +} + +/* Compares trees T1 and T2 for semantic equality. */ + +bool +sem_variable::equals (tree t1, tree t2) +{ + tree_code tc1 = TREE_CODE (t1); + tree_code tc2 = TREE_CODE (t2); + + if (tc1 != tc2) + return false; + + switch (tc1) + { + case CONSTRUCTOR: + { + unsigned len1 = vec_safe_length (CONSTRUCTOR_ELTS (t1)); + unsigned len2 = vec_safe_length (CONSTRUCTOR_ELTS (t2)); + + if (len1 != len2) + return false; + + for (unsigned i = 0; i < len1; i++) + if (!sem_variable::equals (CONSTRUCTOR_ELT (t1, i)->value, + CONSTRUCTOR_ELT (t2, i)->value)) + return false; + + return true; + } + case MEM_REF: + { + tree x1 = TREE_OPERAND (t1, 0); + tree x2 = TREE_OPERAND (t2, 0); + tree y1 = TREE_OPERAND (t1, 1); + tree y2 = TREE_OPERAND (t2, 1); + + if (!sem_item::compare_for_aliasing (y1, y2)) + SE_EXIT_FALSE_WITH_MSG ("strict aliasing types do not match"); + + /* Type of the offset on MEM_REF does not matter. */ + return sem_variable::equals (x1, x2) + && wi::to_offset (y1) == wi::to_offset (y2); + } + case NOP_EXPR: + case ADDR_EXPR: + { + tree op1 = TREE_OPERAND (t1, 0); + tree op2 = TREE_OPERAND (t2, 0); + return sem_variable::equals (op1, op2); + } + case FUNCTION_DECL: + case VAR_DECL: + case FIELD_DECL: + case LABEL_DECL: + return t1 == t2; + case INTEGER_CST: + return types_compatible_p (TREE_TYPE (t1), TREE_TYPE (t2)) + && wi::to_offset (t1) == wi::to_offset (t2); + case STRING_CST: + case REAL_CST: + case COMPLEX_CST: + return operand_equal_p (t1, t2, OEP_ONLY_CONST); + case COMPONENT_REF: + case ARRAY_REF: + case POINTER_PLUS_EXPR: + { + tree x1 = TREE_OPERAND (t1, 0); + tree x2 = TREE_OPERAND (t2, 0); + tree y1 = TREE_OPERAND (t1, 1); + tree y2 = TREE_OPERAND (t2, 1); + + return sem_variable::equals (x1, x2) && sem_variable::equals (y1, y2); + } + case ERROR_MARK: + SE_EXIT_FALSE_WITH_MSG ("ERROR_MARK"); + default: + SE_EXIT_FALSE_WITH_MSG ("Unknown TREE code reached") + } +} + +/* Parser function that visits a varpool NODE. */ + +sem_variable * +sem_variable::parse (struct varpool_node *node, bitmap_obstack *stack) +{ + tree decl = node->decl; + + bool readonly = TYPE_P (decl) ? TYPE_READONLY (decl) : TREE_READONLY (decl); + bool can_handle = readonly && (DECL_VIRTUAL_P (decl) + || !TREE_ADDRESSABLE (decl)); + + if (!can_handle) + return NULL; + + tree ctor = ctor_for_folding (decl); + if (!ctor) + return NULL; + + sem_variable *v = new sem_variable (node, 0, stack); + + v->init (); + + return v; +} + +/* References independent hash function. */ + +hashval_t +sem_variable::get_hash (void) +{ + if (hash) + return hash; + + hashval_t hash = 456346417; + + tree_code tc = TREE_CODE (ctor); + hash = iterative_hash_object (tc, hash); + + if (TREE_CODE (ctor) == CONSTRUCTOR) + { + unsigned length = vec_safe_length (CONSTRUCTOR_ELTS (ctor)); + hash = iterative_hash_object (length, hash); + } + + return hash; +} + +/* Merges instance with an ALIAS_ITEM, where alias, thunk or redirection can + be applied. */ + +bool +sem_variable::merge (sem_item *alias_item) +{ + gcc_assert (alias_item->type == VAR); + + sem_variable *alias_var = static_cast (alias_item); + + struct varpool_node *original = get_node (); + struct varpool_node *alias = alias_var->get_node (); + bool original_discardable = false; + + /* See if original is in a section that can be discarded if the main + symbol is not used. */ + if (DECL_EXTERNAL (original->decl)) + original_discardable = true; + if (original->resolution == LDPR_PREEMPTED_REG + || original->resolution == LDPR_PREEMPTED_IR) + original_discardable = true; + if (symtab_can_be_discarded (original)) + original_discardable = true; + + gcc_assert (!TREE_ASM_WRITTEN (alias->decl)); + + if (original_discardable || DECL_EXTERNAL (alias_var->decl) || + !compare_sections (alias_var)) + { + if (dump_file) + fprintf (dump_file, "Varpool alias cannot be created\n\n"); + + return false; + } + else + { + // alias cycle creation check + varpool_node *n = original; + + while (n->alias) + { + n = varpool_alias_target (n); + if (n == alias) + { + if (dump_file) + fprintf (dump_file, "Varpool alias cannot be created (alias cycle).\n\n"); + + return false; + } + } + + alias->analyzed = false; + + DECL_INITIAL (alias->decl) = DECL_INITIAL (alias_var->decl); + alias->remove_all_references (); + + varpool_create_variable_alias (alias_var->decl, decl); + symtab_resolve_alias (alias, original); + + if (dump_file) + fprintf (dump_file, "Varpool alias has been created.\n\n"); + + return true; + } +} + +bool +sem_variable::compare_sections (sem_variable *alias) +{ + const char *source = node->get_section (); + const char *target = alias->node->get_section(); + + if (source == NULL && target == NULL) + return true; + else if(!source || !target) + return false; + else + return strcmp (source, target) == 0; +} + +/* Dump symbol to FILE. */ + +void +sem_variable::dump_to_file (FILE *file) +{ + gcc_assert (file); + + print_node (file, "", decl, 0); + fprintf (file, "\n\n"); +} + +/* Iterates though a constructor and identifies tree references + we are interested in semantic function equality. */ + +void +sem_variable::parse_tree_refs (tree t) +{ + switch (TREE_CODE (t)) + { + case CONSTRUCTOR: + { + unsigned length = vec_safe_length (CONSTRUCTOR_ELTS (t)); + + for (unsigned i = 0; i < length; i++) + parse_tree_refs(CONSTRUCTOR_ELT (t, i)->value); + + break; + } + case NOP_EXPR: + case ADDR_EXPR: + { + tree op = TREE_OPERAND (t, 0); + parse_tree_refs (op); + break; + } + case FUNCTION_DECL: + { + tree_refs.safe_push (t); + break; + } + default: + break; + } +} + +unsigned int sem_item_optimizer::class_id = 0; + +sem_item_optimizer::sem_item_optimizer (): worklist (0), m_classes (0), +m_classes_count (0), m_cgraph_node_hooks (NULL), m_varpool_node_hooks (NULL) +{ + m_items.create (0); + m_removed_items_set = pointer_set_create (); + bitmap_obstack_initialize (&m_bmstack); +} + +sem_item_optimizer::~sem_item_optimizer () +{ + for (unsigned int i = 0; i < m_items.length (); i++) + delete m_items[i]; + + for (hash_table::iterator it = m_classes.begin (); + it != m_classes.end (); ++it) + { + for (unsigned int i = 0; i < (*it)->classes.length (); i++) + delete (*it)->classes[i]; + + (*it)->classes.release (); + } + + m_items.release (); + + bitmap_obstack_release (&m_bmstack); + pointer_set_destroy (m_removed_items_set); +} + +/* Write IPA ICF summary for symbols. */ + +void +sem_item_optimizer::write_summary (void) +{ + unsigned int count = 0; + + struct output_block *ob = create_output_block (LTO_section_ipa_icf); + lto_symtab_encoder_t encoder = ob->decl_state->symtab_node_encoder; + ob->cgraph_node = NULL; + + /* Calculate number of symbols to be serialized. */ + for (lto_symtab_encoder_iterator lsei = lsei_start_in_partition (encoder); + !lsei_end_p (lsei); + lsei_next_in_partition (&lsei)) + { + struct symtab_node *node = lsei_node (lsei); + + if (m_symtab_node_map.get (node)) + count++; + } + + streamer_write_uhwi (ob, count); + + /* Process all of the symbols. */ + for (lto_symtab_encoder_iterator lsei = lsei_start_in_partition (encoder); + !lsei_end_p (lsei); + lsei_next_in_partition (&lsei)) + { + struct symtab_node *node = lsei_node (lsei); + + sem_item **item = m_symtab_node_map.get (node); + + if (item && *item) + { + int node_ref = lto_symtab_encoder_encode (encoder, node); + streamer_write_uhwi_stream (ob->main_stream, node_ref); + + streamer_write_uhwi (ob, (*item)->get_hash ()); + } + } + + streamer_write_char_stream (ob->main_stream, 0); + produce_asm (ob, NULL); + destroy_output_block (ob); +} + +/* Reads a section from LTO stream file FILE_DATA. Input block for DATA + contains LEN bytes. */ + +void +sem_item_optimizer::read_section (struct lto_file_decl_data *file_data, + const char *data, size_t len) +{ + const struct lto_function_header *header = + (const struct lto_function_header *) data; + const int cfg_offset = sizeof (struct lto_function_header); + const int main_offset = cfg_offset + header->cfg_size; + const int string_offset = main_offset + header->main_size; + struct data_in *data_in; + struct lto_input_block ib_main; + unsigned int i; + unsigned int count; + + LTO_INIT_INPUT_BLOCK (ib_main, (const char *) data + main_offset, 0, + header->main_size); + + data_in = + lto_data_in_create (file_data, (const char *) data + string_offset, + header->string_size, vNULL); + + count = streamer_read_uhwi (&ib_main); + + for (i = 0; i < count; i++) + { + unsigned int index; + struct symtab_node *node; + lto_symtab_encoder_t encoder; + + index = streamer_read_uhwi (&ib_main); + encoder = file_data->symtab_node_encoder; + node = lto_symtab_encoder_deref (encoder, index); + + hashval_t hash = streamer_read_uhwi (&ib_main); + + gcc_assert (node->definition); + + if (dump_file) + fprintf (dump_file, "Symbol added:%s (tree: %p, uid:%u)\n", node->asm_name (), + (void *) node->decl, node->order); + + if (is_a_helper::test (node)) + { + cgraph_node *cnode = cgraph (node); + + m_items.safe_push (new sem_function (cnode, hash, &m_bmstack)); + } + else + { + varpool_node *vnode = varpool (node); + + m_items.safe_push (new sem_variable (vnode, hash, &m_bmstack)); + } + } + + lto_free_section_data (file_data, LTO_section_ipa_icf, NULL, data, + len); + lto_data_in_delete (data_in); +} + +/* Read IPA IPA ICF summary for symbols. */ + +void +sem_item_optimizer::read_summary (void) +{ + struct lto_file_decl_data **file_data_vec = lto_get_file_decl_data (); + struct lto_file_decl_data *file_data; + unsigned int j = 0; + + while ((file_data = file_data_vec[j++])) + { + size_t len; + const char *data = lto_get_section_data (file_data, + LTO_section_ipa_icf, NULL, &len); + + if (data) + read_section (file_data, data, len); + } +} + +/* Register callgraph and varpool hooks. */ + +void +sem_item_optimizer::register_hooks (void) +{ + m_cgraph_node_hooks = cgraph_add_node_removal_hook ( + &sem_item_optimizer::cgraph_removal_hook, this); + + m_varpool_node_hooks = varpool_add_node_removal_hook ( + &sem_item_optimizer::varpool_removal_hook, this); +} + +/* Unregister callgraph and varpool hooks. */ + +void +sem_item_optimizer::unregister_hooks (void) +{ + if (m_cgraph_node_hooks) + cgraph_remove_node_removal_hook (m_cgraph_node_hooks); + + if (m_varpool_node_hooks) + varpool_remove_node_removal_hook (m_varpool_node_hooks); +} + +/* Adds a CLS to hashtable associated by hash value. */ + +void +sem_item_optimizer::add_class (congruence_class *cls) +{ + gcc_assert (cls->members.length ()); + + congruence_class_group_t *group = get_group_by_hash ( + cls->members[0]->get_hash (), + cls->members[0]->type); + group->classes.safe_push (cls); +} + +/* Gets a congruence class group based on given HASH value and TYPE. */ + +congruence_class_group_t * +sem_item_optimizer::get_group_by_hash (hashval_t hash, sem_item_type type) +{ + congruence_class_group_t *item = XNEW (congruence_class_group_t); + item->hash = hash; + item->type = type; + + congruence_class_group **slot = m_classes.find_slot (item, INSERT); + + if (*slot) + free (item); + else + { + item->classes.create (1); + *slot = item; + } + + return *slot; +} + +/* Callgraph removal hook called for a NODE with a custom DATA. */ + +void +sem_item_optimizer::cgraph_removal_hook (struct cgraph_node *node, void *data) +{ + sem_item_optimizer *optimizer = (sem_item_optimizer *) data; + optimizer->remove_symtab_node (node); +} + +/* Varpool removal hook called for a NODE with a custom DATA. */ + +void +sem_item_optimizer::varpool_removal_hook (struct varpool_node *node, void *data) +{ + sem_item_optimizer *optimizer = (sem_item_optimizer *) data; + optimizer->remove_symtab_node (node); +} + +/* Remove symtab NODE triggered by symtab removal hooks. */ + +void +sem_item_optimizer::remove_symtab_node (struct symtab_node *node) +{ + gcc_assert (!m_classes.elements()); + + pointer_set_insert (m_removed_items_set, node); +} + +/* Removes all callgraph and varpool nodes that are marked by symtab + as deleted. */ + +void +sem_item_optimizer::filter_removed_items (void) +{ + vec filtered; + filtered.create (m_items.length()); + + for (unsigned int i = 0; i < m_items.length(); i++) + { + sem_item *item = m_items[i]; + + if (!flag_ipa_icf_functions && item->type == FUNC) + continue; + + if (!flag_ipa_icf_variables && item->type == VAR) + continue; + + bool no_body_function = false; + + if (item->type == FUNC) + { + struct cgraph_node *cnode = static_cast (item)->get_node (); + + no_body_function = in_lto_p && (cnode->alias || cnode->body_removed); + } + + if(!pointer_set_contains (m_removed_items_set, m_items[i]->node) + && !no_body_function) + { + if (item->type == VAR || (!DECL_CXX_CONSTRUCTOR_P (item->decl) + && !DECL_CXX_DESTRUCTOR_P (item->decl))) + filtered.safe_push (m_items[i]); + } + } + + m_items.release (); + + for (unsigned int i = 0; i < filtered.length(); i++) + m_items.safe_push (filtered[i]); + + filtered.release (); +} + +/* Optimizer entry point. */ + +void +sem_item_optimizer::execute (void) +{ + filter_removed_items (); + build_hash_based_classes (); + + if (dump_file) + fprintf (dump_file, "Dump after hash based groups\n"); + dump_cong_classes (); + + for (unsigned int i = 0; i < m_items.length(); i++) + m_items[i]->init_wpa (); + + subdivide_classes_by_equality (true); + + if (dump_file) + fprintf (dump_file, "Dump after WPA based types groups\n"); + dump_cong_classes (); + + parse_nonsingleton_classes (); + subdivide_classes_by_equality (); + + if (dump_file) + fprintf (dump_file, "Dump after full equality comparison of groups\n"); + + dump_cong_classes (); + + unsigned int prev_class_count = m_classes_count; + + process_cong_reduction (); + dump_cong_classes (); + merge_classes (prev_class_count); + + if (dump_file && (dump_flags & TDF_DETAILS)) + dump_symtab (dump_file); +} + +/* Function responsible for visiting all potential functions and + read-only variables that can be merged. */ + +void +sem_item_optimizer::parse_funcs_and_vars (void) +{ + struct cgraph_node *cnode; + + if (flag_ipa_icf_functions) + FOR_EACH_DEFINED_FUNCTION (cnode) + { + sem_function *f = sem_function::parse (cnode, &m_bmstack); + if (f) + { + m_items.safe_push (f); + m_symtab_node_map.put (cnode, f); + + if (dump_file) + fprintf (dump_file, "Parsed function:%s\n", f->asm_name ()); + + if (dump_file && (dump_flags & TDF_DETAILS)) + f->dump_to_file (dump_file); + } + else if (dump_file) + fprintf (dump_file, "Not parsed function:%s\n", cnode->asm_name ()); + } + + varpool_node *vnode; + + if (flag_ipa_icf_variables) + FOR_EACH_DEFINED_VARIABLE (vnode) + { + sem_variable *v = sem_variable::parse (vnode, &m_bmstack); + + if (v) + { + m_items.safe_push (v); + m_symtab_node_map.put (vnode, v); + } + } +} + +/* Makes pairing between a congruence class CLS and semantic ITEM. */ + +void +sem_item_optimizer::add_item_to_class (congruence_class *cls, sem_item *item) +{ + item->index_in_class = cls->members.length (); + cls->members.safe_push (item); + item->cls = cls; +} + +/* Congruence classes are built by hash value. */ + +void +sem_item_optimizer::build_hash_based_classes (void) +{ + for (unsigned i = 0; i < m_items.length (); i++) + { + sem_item *item = m_items[i]; + + congruence_class_group_t *group = get_group_by_hash (item->get_hash (), + item->type); + + if (!group->classes.length ()) + { + m_classes_count++; + group->classes.safe_push (new congruence_class (class_id++)); + } + + add_item_to_class (group->classes[0], item); + } +} + +/* Semantic items in classes having more than one element and initialized. + In case of WPA, we load function body. */ + +void +sem_item_optimizer::parse_nonsingleton_classes (void) +{ + for (hash_table ::iterator it = m_classes.begin (); + it != m_classes.end (); ++it) + { + for (unsigned i = 0; i < (*it)->classes.length (); i++) + { + congruence_class *c = (*it)->classes [i]; + + if (c->members.length() > 1) + for (unsigned j = 0; j < c->members.length (); j++) + { + sem_item *item = c->members[j]; + m_decl_map.put (item->decl, item); + } + } + } + + unsigned int init_called_count = 0; + + for (hash_table ::iterator it = m_classes.begin (); + it != m_classes.end (); ++it) + { + /* We fill in all declarations for sem_items. */ + for (unsigned i = 0; i < (*it)->classes.length (); i++) + { + congruence_class *c = (*it)->classes [i]; + + if (c->members.length() > 1) + for (unsigned j = 0; j < c->members.length (); j++) + { + sem_item *item = c->members[j]; + + item->init (); + item->init_refs (); + + init_called_count++; + + for (unsigned j = 0; j < item->tree_refs.length (); j++) + { + sem_item **result = m_decl_map.get (item->tree_refs[j]); + + if(result) + { + sem_item *target = *result; + item->refs.safe_push (target); + + unsigned index = item->refs.length (); + target->usages.safe_push (new sem_usage_pair(item, index)); + bitmap_set_bit (target->usage_index_bitmap, index); + pointer_set_insert (item->tree_refs_set, item->tree_refs[j]); + } + } + } + } + } + + if (dump_file) + fprintf (dump_file, "Init called for %u items (%.2f%%).\n", init_called_count, + 100.0f * init_called_count / m_items.length ()); +} + +/* Equality function for semantic items is used to subdivide existing + classes. If IN_WPA, fast equality function is invoked. */ + +void +sem_item_optimizer::subdivide_classes_by_equality (bool in_wpa) +{ + for (hash_table ::iterator it = m_classes.begin (); + it != m_classes.end (); ++it) + { + unsigned int class_count = (*it)->classes.length (); + + for (unsigned i = 0; i < class_count; i++) + { + congruence_class *c = (*it)->classes [i]; + + if (c->members.length() > 1) + { + vec new_vector; + new_vector.create (c->members.length ()); + + sem_item *first = c->members[0]; + new_vector.safe_push (first); + + unsigned class_split_first = (*it)->classes.length (); + + for (unsigned j = 1; j < c->members.length (); j++) + { + sem_item *item = c->members[j]; + + bool equals = in_wpa ? first->equals_wpa (item) : first->equals (item); + + if (equals) + new_vector.safe_push (item); + else + { + bool integrated = false; + + for (unsigned k = class_split_first; k < (*it)->classes.length (); k++) + { + sem_item *x = (*it)->classes[k]->members[0]; + bool equals = in_wpa ? x->equals_wpa (item) : x->equals (item); + + if (equals) + { + integrated = true; + add_item_to_class ((*it)->classes[k], item); + + break; + } + } + + if (!integrated) + { + congruence_class *c = new congruence_class (class_id++); + m_classes_count++; + add_item_to_class (c, item); + + (*it)->classes.safe_push (c); + } + } + } + + // we replace newly created new_vector for the class we've just splitted + c->members.release (); + c->members.create (new_vector.length ()); + + for (unsigned int j = 0; j < new_vector.length (); j++) + add_item_to_class (c, new_vector[j]); + + new_vector.release (); + } + } + } + + verify_classes (); +} + +/* Verify congruence classes if checking is enabled. */ + +void +sem_item_optimizer::verify_classes (void) +{ +#if ENABLE_CHECKING + for (hash_table ::iterator it = m_classes.begin (); + it != m_classes.end (); ++it) + { + for (unsigned int i = 0; i < (*it)->classes.length (); i++) + { + congruence_class *cls = (*it)->classes[i]; + + gcc_checking_assert (cls); + gcc_checking_assert (cls->members.length () > 0); + + for (unsigned int j = 0; j < cls->members.length (); j++) + { + sem_item *item = cls->members[j]; + + gcc_checking_assert (item); + + for (unsigned k = 0; k < item->usages.length (); k++) + { + sem_usage_pair *usage = item->usages[k]; + gcc_checking_assert (usage->item->index_in_class < + usage->item->cls->members.length ()); + } + } + } + } +#endif +} + +/* Disposes split map traverse function. CLS_PTR is pointer to congruence + class, BSLOT is bitmap slot we want to release. DATA is mandatory, + but unused argument. */ + +bool +sem_item_optimizer::release_split_map (__attribute__((__unused__)) congruence_class * + const &cls, + __attribute__((__unused__)) bitmap const &b, + __attribute__((__unused__)) traverse_split_pair *pair) +{ + bitmap bmp = b; + + BITMAP_FREE (bmp); + + return true; +} + +/* Process split operation for a class given as pointer CLS_PTR, + where bitmap B splits congruence class members. DATA is used + as argument of split pair. */ + +bool +sem_item_optimizer::traverse_congruence_split (congruence_class * const &cls, + bitmap const &b, traverse_split_pair *pair) +{ + sem_item_optimizer *optimizer = pair->optimizer; + const congruence_class *splitter_cls = pair->cls; + + /* If counted bits are greater than zero and less than the number of members + a group will be splitted. */ + unsigned popcount = bitmap_count_bits (b); + + if (popcount > 0 && popcount < cls->members.length ()) + { + congruence_class* newclasses[2] = { new congruence_class (class_id++), new congruence_class (class_id++) }; + + for (unsigned int i = 0; i < cls->members.length (); i++) + { + int target = bitmap_bit_p (b, i); + congruence_class *tc = newclasses[target]; + + add_item_to_class (tc, cls->members[i]); + } + +#ifdef ENABLE_CHECKING + for (unsigned int i = 0; i < 2; i++) + gcc_checking_assert (newclasses[i]->members.length ()); +#endif + + if (splitter_cls == cls) + optimizer->splitter_class_removed = true; + + /* Remove old class from worklist if presented. */ + bool in_work_list = optimizer->worklist_contains (cls); + + if (in_work_list) + optimizer->worklist_remove (cls); + + congruence_class_group g; + g.hash = cls->members[0]->get_hash (); + g.type = cls->members[0]->type; + + congruence_class_group *slot = optimizer->m_classes.find(&g); + + for (unsigned int i = 0; i < slot->classes.length (); i++) + if (slot->classes[i] == cls) + { + slot->classes.ordered_remove (i); + break; + } + + /* New class will be inserted and integrated to work list. */ + for (unsigned int i = 0; i < 2; i++) + optimizer->add_class (newclasses[i]); + + /* Two classes replace one, so that increment just by one. */ + optimizer->m_classes_count++; + + /* If OLD class was presented in the worklist, we remove the class + are replace it will both newly created classes. */ + if (in_work_list) + for (unsigned int i = 0; i < 2; i++) + optimizer->worklist_push (newclasses[i]); + else /* Just smaller class is inserted. */ + { + unsigned int smaller_index = newclasses[0]->members.length () < + newclasses[1]->members.length () ? + 0 : 1; + optimizer->worklist_push (newclasses[smaller_index]); + } + + if (dump_file && (dump_flags & TDF_DETAILS)) + { + fprintf (dump_file, " congruence class splitted:\n"); + cls->dump (dump_file, 4); + + fprintf (dump_file, " newly created groups:\n"); + for (unsigned int i = 0; i < 2; i++) + newclasses[i]->dump (dump_file, 4); + } + + delete cls; + } + + + return true; +} + +/* Tests if a class CLS used as INDEXth splits any congruence classes. + Bitmap stack BMSTACK is used for bitmap allocation. */ + +void +sem_item_optimizer::do_congruence_step_for_index (congruence_class *cls, + unsigned int index) +{ + hash_map *split_map = + new hash_map (); + + for (unsigned int i = 0; i < cls->members.length (); i++) + { + sem_item *item = cls->members[i]; + + /* Iterate all usages that have INDEX as usage of the item. */ + for (unsigned int j = 0; j < item->usages.length (); j++) + { + sem_usage_pair *usage = item->usages[j]; + + if (usage->index != index) + continue; + + bitmap *slot = split_map->get (usage->item->cls); + bitmap b; + + if(!slot) + { + b = BITMAP_ALLOC (&m_bmstack); + split_map->put (usage->item->cls, b); + } + else + b = *slot; + +#if ENABLE_CHECKING + gcc_checking_assert (usage->item->cls); + gcc_checking_assert (usage->item->index_in_class < + usage->item->cls->members.length ()); +#endif + + bitmap_set_bit (b, usage->item->index_in_class); + } + } + + traverse_split_pair pair; + pair.optimizer = this; + pair.cls = cls; + + splitter_class_removed = false; + split_map->traverse (&pair); + + /* Bitmap clean-up. */ + split_map->traverse (NULL); +} + +/* Every usage of a congruence class CLS is a candidate that can split the + collection of classes. Bitmap stack BMSTACK is used for bitmap + allocation. */ + +void +sem_item_optimizer::do_congruence_step (congruence_class *cls) +{ + bitmap_iterator bi; + unsigned int i; + + bitmap usage = BITMAP_ALLOC (&m_bmstack); + + for (unsigned int i = 0; i < cls->members.length (); i++) + bitmap_ior_into (usage, cls->members[i]->usage_index_bitmap); + + EXECUTE_IF_SET_IN_BITMAP (usage, 0, i, bi) + { + if (dump_file && (dump_flags & TDF_DETAILS)) + fprintf (dump_file, " processing congruece step for class: %u, index: %u\n", + cls->id, i); + + do_congruence_step_for_index (cls, i); + + if (splitter_class_removed) + break; + } + + BITMAP_FREE (usage); +} + +/* Adds a newly created congruence class CLS to worklist. */ + +void +sem_item_optimizer::worklist_push (congruence_class *cls) +{ + congruence_class **slot = worklist.find_slot (cls, INSERT); + + if (*slot) + return; + + *slot = cls; +} + +/* Pops a class from worklist. */ + +congruence_class * +sem_item_optimizer::worklist_pop (void) +{ + gcc_assert (worklist.elements ()); + + congruence_class *cls = *worklist.begin (); + worklist.remove_elt (cls); + + return cls; +} + +/* Iterative congruence reduction function. */ + +void +sem_item_optimizer::process_cong_reduction (void) +{ + for (hash_table::iterator it = m_classes.begin (); + it != m_classes.end (); ++it) + for (unsigned i = 0; i < (*it)->classes.length (); i++) + if ((*it)->classes[i]->is_class_used ()) + worklist_push ((*it)->classes[i]); + + if (dump_file) + fprintf (dump_file, "Worklist has been filled with: %lu\n", + worklist.elements ()); + + if (dump_file && (dump_flags & TDF_DETAILS)) + fprintf (dump_file, "Congruence class reduction\n"); + + while (worklist.elements ()) + { + congruence_class *cls = worklist_pop (); + do_congruence_step (cls); + } +} + +/* Debug function prints all informations about congruence classes. */ + +void +sem_item_optimizer::dump_cong_classes (void) +{ + if (!dump_file) + return; + + fprintf (dump_file, + "Congruence classes: %u (unique hash values: %lu), with total: %u items\n", + m_classes_count, m_classes.elements(), m_items.length ()); + + /* Histogram calculation. */ + unsigned int max_index = 0; + unsigned int* histogram = XCNEWVEC (unsigned int, m_items.length ()); + + for (hash_table::iterator it = m_classes.begin (); + it != m_classes.end (); ++it) + + for (unsigned i = 0; i < (*it)->classes.length (); i++) + { + unsigned int c = (*it)->classes[i]->members.length (); + histogram[c]++; + + if (c > max_index) + max_index = c; + } + + fprintf (dump_file, + "Class size histogram [num of members]: number of classe number of classess\n"); + + for (unsigned int i = 0; i <= max_index; i++) + if (histogram[i]) + fprintf (dump_file, "[%u]: %u classes\n", i, histogram[i]); + + fprintf (dump_file, "\n\n"); + + + if (dump_flags & TDF_DETAILS) + for (hash_table::iterator it = m_classes.begin (); + it != m_classes.end (); ++it) + { + fprintf (dump_file, " group: with %u classes:\n", (*it)->classes.length ()); + + for (unsigned i = 0; i < (*it)->classes.length (); i++) + { + (*it)->classes[i]->dump (dump_file, 4); + + if(i < (*it)->classes.length () - 1) + fprintf (dump_file, " "); + } + } + + free (histogram); +} + +/* After reduction is done, we can declare all items in a group + to be equal. PREV_CLASS_COUNT is start number of classes + before reduction. */ + +void +sem_item_optimizer::merge_classes (unsigned int prev_class_count) +{ + unsigned int item_count = m_items.length (); + unsigned int class_count = m_classes_count; + unsigned int equal_items = item_count - class_count; + + if (dump_file) + { + fprintf (dump_file, "\nItem count: %u\n", item_count); + fprintf (dump_file, "Congruent classes before: %u, after: %u\n", + prev_class_count, class_count); + fprintf (dump_file, "Average class size before: %.2f, after: %.2f\n", + 1.0f * item_count / prev_class_count, + 1.0f * item_count / class_count); + fprintf (dump_file, "Equal symbols: %u\n", equal_items); + fprintf (dump_file, "Fraction of visited symbols: %.2f%%\n\n", + 100.0f * equal_items / item_count); + } + + for (hash_table::iterator it = m_classes.begin (); + it != m_classes.end (); ++it) + for (unsigned int i = 0; i < (*it)->classes.length (); i++) + { + congruence_class *c = (*it)->classes[i]; + + if (c->members.length () == 1) + continue; + + gcc_assert (c->members.length ()); + + sem_item *source = c->members[0]; + + for (unsigned int j = 1; j < c->members.length (); j++) + { + sem_item *alias = c->members[j]; + + if (dump_file) + { + fprintf (dump_file, "Semantic equality hit:%s->%s\n", + source->name (), alias->name ()); + fprintf (dump_file, "Assembler symbol names:%s->%s\n", + source->asm_name (), alias->asm_name ()); + } + + if (dump_file && (dump_flags & TDF_DETAILS)) + { + source->dump_to_file (dump_file); + alias->dump_to_file (dump_file); + } + + source->merge (alias); + } + } +} + +/* Dump function prints all class members to a FILE with an INDENT. */ + +void +congruence_class::dump (FILE *file, unsigned int indent) const +{ + FPRINTF_SPACES (file, indent, "class with id: %u, hash: %u, items: %u\n", + id, members[0]->get_hash (), members.length ()); + + FPUTS_SPACES (file, indent + 2, ""); + for (unsigned i = 0; i < members.length (); i++) + fprintf (file, "%s(%p/%u)", members[i]->asm_name (), (void *) members[i]->decl, + members[i]->node->order); + + fprintf (file, "\n"); +} + +/* Returns true if there's a member that is used from another group. */ + +bool +congruence_class::is_class_used (void) +{ + for (unsigned int i = 0; i < members.length (); i++) + if (members[i]->usages.length ()) + return true; + + return false; +} + +/* Initialization and computation of symtab node hash, there data + are propagated later on. */ + +static sem_item_optimizer *optimizer = NULL; + +/* Generate pass summary for IPA ICF pass. */ + +static void +ipa_icf_generate_summary (void) +{ + if (!optimizer) + optimizer = new sem_item_optimizer (); + + optimizer->parse_funcs_and_vars (); +} + +/* Write pass summary for IPA ICF pass. */ + +static void +ipa_icf_write_summary (void) +{ + gcc_assert (optimizer); + + optimizer->write_summary (); +} + +/* Read pass summary for IPA ICF pass. */ + +static void +ipa_icf_read_summary (void) +{ + if (!optimizer) + optimizer = new sem_item_optimizer (); + + optimizer->read_summary (); + optimizer->register_hooks (); +} + +/* Semantic equality exection function. */ + +static unsigned int +ipa_icf_driver (void) +{ + gcc_assert (optimizer); + + optimizer->execute (); + optimizer->unregister_hooks (); + + delete optimizer; + + return 0; +} + +const pass_data pass_data_ipa_icf = +{ + IPA_PASS, /* type */ + "icf", /* name */ + OPTGROUP_IPA, /* optinfo_flags */ + true, /* has_execute */ + TV_IPA_ICF, /* tv_id */ + 0, /* properties_required */ + 0, /* properties_provided */ + 0, /* properties_destroyed */ + 0, /* todo_flags_start */ + 0, /* todo_flags_finish */ +}; + +class pass_ipa_icf : public ipa_opt_pass_d +{ +public: + pass_ipa_icf (gcc::context *ctxt) + : ipa_opt_pass_d (pass_data_ipa_icf, ctxt, + ipa_icf_generate_summary, /* generate_summary */ + ipa_icf_write_summary, /* write_summary */ + ipa_icf_read_summary, /* read_summary */ + NULL, /* + write_optimization_summary */ + NULL, /* + read_optimization_summary */ + NULL, /* stmt_fixup */ + 0, /* function_transform_todo_flags_start */ + NULL, /* function_transform */ + NULL) /* variable_transform */ + {} + + /* opt_pass methods: */ + virtual bool gate (function *) + { + return flag_ipa_icf_variables || flag_ipa_icf_functions; + } + + virtual unsigned int execute (function *) + { + return ipa_icf_driver(); + } +}; // class pass_ipa_icf + +} // ipa_icf namespace + +ipa_opt_pass_d * +make_pass_ipa_icf (gcc::context *ctxt) +{ + return new ipa_icf::pass_ipa_icf (ctxt); +} diff --git a/gcc/ipa-icf.h b/gcc/ipa-icf.h new file mode 100644 index 0000000..d328dd6 --- /dev/null +++ b/gcc/ipa-icf.h @@ -0,0 +1,743 @@ +/* Interprocedural semantic function equality pass + Copyright (C) 2014 Free Software Foundation, Inc. + + Contributed by Jan Hubicka and Martin Liska + +This file is part of GCC. + +GCC is free software; you can redistribute it and/or modify it under +the terms of the GNU General Public License as published by the Free +Software Foundation; either version 3, or (at your option) any later +version. + +GCC is distributed in the hope that it will be useful, but WITHOUT ANY +WARRANTY; without even the implied warranty of MERCHANTABILITY or +FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License +for more details. + +You should have received a copy of the GNU General Public License +along with GCC; see the file COPYING3. If not see +. */ + +/* Prints string STRING to a FILE with a given number of SPACE_COUNT. */ +#define FPUTS_SPACES(file, space_count, string) \ + do \ + { \ + fprintf (file, "%*s" string, space_count, " "); \ + } \ + while (false); + +/* fprintf function wrapper that transforms given FORMAT to follow given + number for SPACE_COUNT and call fprintf for a FILE. */ +#define FPRINTF_SPACES(file, space_count, format, ...) \ + fprintf (file, "%*s" format, space_count, " ", ##__VA_ARGS__); + +/* Prints a MESSAGE to dump_file if exists. */ +#define SE_DUMP_MESSAGE(message) \ + do \ + { \ + if (dump_file && (dump_flags & TDF_DETAILS)) \ + fprintf (dump_file, " debug message: %s (%s:%u)\n", message, __func__, __LINE__); \ + } \ + while (false); + +/* Logs a MESSAGE to dump_file if exists and returns false. */ +#define SE_EXIT_FALSE_WITH_MSG(message) \ + do \ + { \ + if (dump_file && (dump_flags & TDF_DETAILS)) \ + fprintf (dump_file, " false returned: '%s' (%s:%u)\n", message, __func__, __LINE__); \ + return false; \ + } \ + while (false); + +/* Return false and log that false value is returned. */ +#define SE_EXIT_FALSE() \ + SE_EXIT_FALSE_WITH_MSG("") + +/* Logs return value if RESULT is false. */ +#define SE_EXIT_DEBUG(result) \ + do \ + { \ + if (!(result) && dump_file && (dump_flags & TDF_DETAILS)) \ + fprintf (dump_file, " false returned (%s:%u)\n", __func__, __LINE__); \ + return result; \ + } \ + while (false); + +/* Verbose logging function logging statements S1 and S2 of a CODE. */ +#define SE_DIFF_STATEMENT(s1, s2, code) \ + do \ + { \ + if (dump_file && (dump_flags & TDF_DETAILS)) \ + { \ + fprintf (dump_file, " different statement for code: %s:\n", code); \ + print_gimple_stmt (dump_file, s1, 3, TDF_DETAILS); \ + print_gimple_stmt (dump_file, s2, 3, TDF_DETAILS); \ + } \ + return false; \ + } \ + while (false); + +namespace ipa_icf { + +/* Forward declaration for sem_func class. */ +class sem_item; + +/* A class aggregating all connections and semantic equivalents + for a given pair of semantic function candidates. */ +class func_checker +{ +public: + /* Initializes internal structures according to given number of + source and target SSA names. The number of source names is SSA_SOURCE, + respectively SSA_TARGET. */ + func_checker (unsigned ssa_source, unsigned sss_target); + + /* Memory release routine. */ + ~func_checker(); + + /* Verifies that trees T1 and T2 are equivalent from perspective of ICF. */ + bool compare_ssa_name (tree t1, tree t2); + + /* Verification function for edges E1 and E2. */ + bool compare_edge (edge e1, edge e2); + + /* Verification function for declaration trees T1 and T2 that + come from functions FUNC1 and FUNC2. */ + bool compare_decl (tree t1, tree t2, tree func1, tree func2); + +private: + /* Vector mapping source SSA names to target ones. */ + vec m_source_ssa_names; + + /* Vector mapping target SSA names to source ones. */ + vec m_target_ssa_names; + + /* Source to target edge map. */ + hash_map *m_edge_map; + + /* Source to target declaration map. */ + hash_map *m_decl_map; +}; + +/* Congruence class encompasses a collection of either functions or + read-only variables. These items are considered to be equivalent + if not proved the oposite. */ +class congruence_class +{ +public: + /* Congruence class constructor for a new class with _ID. */ + congruence_class (unsigned int _id): id(_id) + { + members.create (2); + } + + /* Destructor. */ + ~congruence_class () + { + members.release (); + } + + /* Dump function prints all class members to a FILE with an INDENT. */ + void dump (FILE *file, unsigned int indent = 0) const; + + /* Returns true if there's a member that is used from another group. */ + bool is_class_used (void); + + /* Vector of all group members. */ + vec members; + + /* Global unique class identifier. */ + unsigned int id; +}; + +/* Semantic item type enum. */ +enum sem_item_type +{ + FUNC, + VAR +}; + +/* Semantic item usage pair. */ +class sem_usage_pair +{ +public: + /* Constructor for key value pair, where _ITEM is key and _INDEX is a target. */ + sem_usage_pair (sem_item *_item, unsigned int _index); + + /* Target semantic item where an item is used. */ + sem_item *item; + + /* Index of usage of such an item. */ + unsigned int index; +}; + +/* Basic block struct for sematic equality pass. */ +typedef struct sem_bb +{ + /* Basic block the structure belongs to. */ + basic_block bb; + + /* Number of non-debug statements in the basic block. */ + unsigned nondbg_stmt_count; + + /* Number of edges connected to the block. */ + unsigned edge_count; +} sem_bb_t; + +/* Semantic item is a base class that encapsulates all shared functionality + for both semantic function and variable items. */ +class sem_item +{ +public: + /* Semantic item constructor for a node of _TYPE, where STACK is used + for bitmap memory allocation. */ + sem_item (enum sem_item_type _type, bitmap_obstack *stack); + + /* Semantic item constructor for a node of _TYPE, where STACK is used + for bitmap memory allocation. The item is based on symtab node _NODE + with computed _HASH. */ + sem_item (enum sem_item_type _type, struct symtab_node *_node, hashval_t _hash, + bitmap_obstack *stack); + + virtual ~sem_item (); + + /* Dump function for debugging purpose. */ + DEBUG_FUNCTION void dump (void); + + /* Initialize semantic item by info reachable during LTO WPA phase. */ + virtual void init_wpa (void) = 0; + + /* Semantic item initialization function. */ + virtual void init (void) = 0; + + /* Gets symbol name of the item. */ + const char *name (void) + { + return node->name (); + } + + /* Gets assembler name of the item. */ + const char *asm_name (void) + { + return node->asm_name (); + } + + /* Initializes references to other semantic functions/variables. */ + virtual void init_refs () = 0; + + /* Fast equality function based on knowledge known in WPA. */ + virtual bool equals_wpa (sem_item *item) = 0; + + /* Returns true if the item equals to ITEM given as arguemnt. */ + virtual bool equals (sem_item *item) = 0; + + /* References independent hash function. */ + virtual hashval_t get_hash (void) = 0; + + /* Merges instance with an ALIAS_ITEM, where alias, thunk or redirection can + be applied. */ + virtual bool merge (sem_item *alias_item) = 0; + + /* Dump symbol to FILE. */ + virtual void dump_to_file (FILE *file) = 0; + + /* Compare two types if are same aliases in case of strict aliasing + is enabled. */ + static bool compare_for_aliasing (tree t1, tree t2); + + /* Item type. */ + enum sem_item_type type; + + /* Global unique function index. */ + unsigned int index; + + /* Symtab node. */ + struct symtab_node *node; + + /* Declaration tree node. */ + tree decl; + + /* Semantic references used that generate congruence groups. */ + vec refs; + + /* Pointer to a congruence class the item belongs to. */ + congruence_class *cls; + + /* Index of the item in a class belonging to. */ + unsigned int index_in_class; + + /* List of semantic items where the instance is used. */ + vec usages; + + /* A bitmap with indices of all classes referencing this item. */ + bitmap usage_index_bitmap; + + /* List of tree references (either FUNC_DECL or VAR_DECL). */ + vec tree_refs; + + /* A set with tree references (either FUNC_DECL or VAR_DECL). */ + pointer_set_t *tree_refs_set; + +protected: + /* Cached, once calculated hash for the item. */ + hashval_t hash; + +private: + /* Initialize internal data structures. Bitmap STACK is used for + bitmap memory allocation process. */ + void setup (bitmap_obstack *stack); +}; // class sem_item + +class sem_function: public sem_item +{ +public: + /* Semantic function constructor that uses STACK as bitmap memory stack. */ + sem_function (bitmap_obstack *stack); + + /* Constructor based on callgraph node _NODE with computed hash _HASH. + Bitmap STACK is used for memory allocation. */ + sem_function (cgraph_node *_node, hashval_t _hash, bitmap_obstack *stack); + + ~sem_function (); + + inline virtual void init_wpa (void) + { + parse_tree_args (); + } + + virtual void init (void); + virtual bool equals_wpa (sem_item *item); + virtual hashval_t get_hash (void); + virtual bool equals (sem_item *item); + virtual void init_refs (); + virtual bool merge (sem_item *alias_item); + + /* Dump symbol to FILE. */ + virtual void dump_to_file (FILE *file) + { + gcc_assert (file); + dump_function_to_file (decl, file, TDF_DETAILS); + } + + /* Parses function arguments and result type. */ + void parse_tree_args (void); + + /* Returns cgraph_node. */ + inline struct cgraph_node *get_node (void) + { + return cgraph (node); + } + + /* For a given call graph NODE, the function constructs new + semantic function item. */ + static sem_function *parse (struct cgraph_node *node, bitmap_obstack *stack); + + /* Exception handling region tree. */ + eh_region region_tree; + + /* Result type tree node. */ + tree result_type; + + /* Array of argument tree types. */ + vec arg_types; + + /* Number of function arguments. */ + unsigned int arg_count; + + /* Total amount of edges in the function. */ + unsigned int edge_count; + + /* Vector of sizes of all basic blocks. */ + vec bb_sizes; + + /* Control flow graph checksum. */ + hashval_t cfg_checksum; + + /* GIMPLE codes hash value. */ + hashval_t gcode_hash; + + /* Total number of SSA names used in the function. */ + unsigned ssa_names_size; + + /* Array of structures for all basic blocks. */ + vec bb_sorted; + +private: + /* Calculates hash value based on a BASIC_BLOCK. */ + hashval_t get_bb_hash (const sem_bb_t *basic_block); + + /* Basic block equivalence comparison function that returns true if + basic blocks BB1 and BB2 (from functions FUNC1 and FUNC2) correspond. */ + bool compare_bb (sem_bb_t *bb1, sem_bb_t *bb2, tree func1, tree func2); + + /* For given basic blocks BB1 and BB2 (from functions FUNC1 and FUNC), + true value is returned if phi nodes are sematically + equivalent in these blocks . */ + bool compare_phi_node (basic_block bb1, basic_block bb2, tree func1, + tree func2); + + /* For given basic blocks BB1 and BB2 (from functions FUNC1 and FUNC), + true value is returned if exception handling regions are equivalent + in these blocks. */ + bool compare_eh_region (eh_region r1, eh_region r2, tree func1, tree func2); + + /* Verifies that trees T1 and T2, representing function declarations + are equivalent from perspective of ICF. */ + bool compare_function_decl (tree t1, tree t2); + + /* Verifies that trees T1 and T2 do correspond. */ + bool compare_variable_decl (tree t1, tree t2, tree func1, tree func2); + + /* Verifies for given GIMPLEs S1 and S2 (from function FUNC1, resp. FUNC2) that + call statements are semantically equivalent. */ + bool compare_gimple_call (gimple s1, gimple s2, + tree func1, tree func2); + + /* Verifies for given GIMPLEs S1 and S2 (from function FUNC1, resp. FUNC2) that + assignment statements are semantically equivalent. */ + bool compare_gimple_assign (gimple s1, gimple s2, tree func1, tree func2); + + /* Verifies for given GIMPLEs S1 and S2 (from function FUNC1, resp. FUNC2) that + condition statements are semantically equivalent. */ + bool compare_gimple_cond (gimple s1, gimple s2, tree func1, tree func2); + + /* Verifies for given GIMPLEs S1 and S2 (from function FUNC1, resp. FUNC2) that + label statements are semantically equivalent. */ + bool compare_gimple_label (gimple s1, gimple s2, tree func1, tree func2); + + /* Verifies for given GIMPLEs S1 and S2 (from function FUNC1, resp. FUNC2) that + switch statements are semantically equivalent. */ + bool compare_gimple_switch (gimple s1, gimple s2, tree func1, tree func2); + + /* Verifies for given GIMPLEs S1 and S2 (from function FUNC1, resp. FUNC2) that + return statements are semantically equivalent. */ + bool compare_gimple_return (gimple s1, gimple s2, tree func1, tree func2); + + /* Verifies for given GIMPLEs S1 and S2 (from function FUNC1, resp. FUNC2) that + goto statements are semantically equivalent. */ + bool compare_gimple_goto (gimple s1, gimple s2, tree func1, tree func2); + + /* Verifies for given GIMPLEs S1 and S2 (from function FUNC1, resp. FUNC2) that + resx statements are semantically equivalent. */ + bool compare_gimple_resx (gimple s1, gimple s2); + + /* Verifies for given GIMPLEs S1 and S2 that ASM statements are equivalent. + For the beginning, the pass only supports equality for + '__asm__ __volatile__ ("", "", "", "memory")'. */ + bool compare_gimple_asm (gimple s1, gimple s2); + + /* Verifies that tree labels T1 and T2 correspond in FUNC1 and FUNC2. */ + bool compare_tree_ssa_label (tree t1, tree t2, tree func1, tree func2); + + /* Function compares two operands T1 and T2 and returns true if these + two trees from FUNC1 (respectively FUNC2) are semantically equivalent. */ + bool compare_operand (tree t1, tree t2, tree func1, tree func2); + + /* If T1 and T2 are SSA names, dictionary comparison is processed. Otherwise, + declaration comparasion is executed. */ + bool compare_ssa_name (tree t1, tree t2, tree func1, tree func2); + + /* Basic blocks dictionary BB_DICT returns true if SOURCE index BB + corresponds to TARGET. */ + bool bb_dict_test (int* bb_dict, int source, int target); + + /* Iterates all tree types in T1 and T2 and returns true if all types + are compatible. */ + bool compare_type_list (tree t1, tree t2); + + /* Processes function equality comparison. */ + bool equals_private (sem_item *item); + + /* Initializes references to another sem_item for gimple STMT of type assign. */ + void init_refs_for_assign (gimple stmt); + + /* Initializes references to another sem_item for tree T. */ + void init_refs_for_tree (tree t); + + /* Returns true if tree T can be compared as a handled component. */ + static bool icf_handled_component_p (tree t); + + /* Function checker stores binding between functions. */ + func_checker *m_checker; + + /* COMPARED_FUNC is a function that we compare to. */ + sem_function *m_compared_func; +}; // class sem_function + +class sem_variable: public sem_item +{ +public: + /* Semantic variable constructor that uses STACK as bitmap memory stack. */ + sem_variable (bitmap_obstack *stack); + + /* Constructor based on callgraph node _NODE with computed hash _HASH. + Bitmap STACK is used for memory allocation. */ + + sem_variable (varpool_node *_node, hashval_t _hash, bitmap_obstack *stack); + + inline virtual void init_wpa (void) {} + + /* Semantic variable initialization function. */ + inline virtual void init (void) + { + decl = get_node ()->decl; + ctor = ctor_for_folding (decl); + } + + /* Initializes references to other semantic functions/variables. */ + inline virtual void init_refs () + { + parse_tree_refs (ctor); + } + + virtual hashval_t get_hash (void); + virtual bool merge (sem_item *alias_item); + virtual void dump_to_file (FILE *file); + virtual bool equals (sem_item *item); + + /* Fast equality variable based on knowledge known in WPA. */ + inline virtual bool equals_wpa (sem_item *item) + { + gcc_assert (item->type == VAR); + return true; + } + + /* Returns varpool_node. */ + inline struct varpool_node *get_node (void) + { + return varpool (node); + } + + /* Parser function that visits a varpool NODE. */ + static sem_variable *parse (struct varpool_node *node, bitmap_obstack *stack); + + /* Variable constructor. */ + tree ctor; + +private: + /* Iterates though a constructor and identifies tree references + we are interested in semantic function equality. */ + void parse_tree_refs (tree t); + + /* Compares trees T1 and T2 for semantic equality. */ + static bool equals (tree t1, tree t2); + + /* Compare that symbol sections are either NULL or have same name. */ + bool compare_sections (sem_variable *alias); + +}; // class sem_variable + +class sem_item_optimizer; + +/* Congruence class set structure. */ +struct congruence_class_var_hash: typed_noop_remove +{ + typedef congruence_class value_type; + typedef congruence_class compare_type; + + static inline hashval_t hash (const value_type *item) + { + return htab_hash_pointer (item); + } + + static inline int equal (const value_type *item1, const compare_type *item2) + { + return item1 == item2; + } +}; + +typedef struct congruence_class_group +{ + hashval_t hash; + sem_item_type type; + vec classes; +} congruence_class_group_t; + +/* Congruence class set structure. */ +struct congruence_class_group_hash: typed_noop_remove +{ + typedef congruence_class_group value_type; + typedef congruence_class_group compare_type; + + static inline hashval_t hash (const value_type *item) + { + return item->hash; + } + + static inline int equal (const value_type *item1, const compare_type *item2) + { + return item1->hash == item2->hash && item1->type == item2->type; + } +}; + +struct traverse_split_pair +{ + sem_item_optimizer *optimizer; + class congruence_class *cls; +}; + +/* Semantic item optimizer includes all top-level logic + related to semantic equality comparison. */ +class sem_item_optimizer +{ +public: + sem_item_optimizer (); + ~sem_item_optimizer (); + + /* Function responsible for visiting all potential functions and + read-only variables that can be merged. */ + void parse_funcs_and_vars (void); + + /* Optimizer entry point. */ + void execute (void); + + /* Dump function. */ + void dump (void); + + /* Verify congruence classes if checking is enabled. */ + void verify_classes (void); + + /* Write IPA ICF summary for symbols. */ + void write_summary (void); + + /* Read IPA IPA ICF summary for symbols. */ + void read_summary (void); + + /* Callgraph removal hook called for a NODE with a custom DATA. */ + static void cgraph_removal_hook (struct cgraph_node *node, void *data); + + /* Varpool removal hook called for a NODE with a custom DATA. */ + static void varpool_removal_hook (struct varpool_node *node, void *data); + + /* Worklist of congruence classes that can potentially + refine classes of congruence. */ + hash_table worklist; + + /* Remove symtab NODE triggered by symtab removal hooks. */ + void remove_symtab_node (struct symtab_node *node); + + /* Register callgraph and varpool hooks. */ + void register_hooks (void); + + /* Unregister callgraph and varpool hooks. */ + void unregister_hooks (void); + + /* Adds a CLS to hashtable associated by hash value. */ + void add_class (congruence_class *cls); + + /* Gets a congruence class group based on given HASH value and TYPE. */ + congruence_class_group_t *get_group_by_hash (hashval_t hash, + sem_item_type type); + +private: + + /* Congruence classes are built by hash value. */ + void build_hash_based_classes (void); + + /* Semantic items in classes having more than one element and initialized. + In case of WPA, we load function body. */ + void parse_nonsingleton_classes (void); + + /* Equality function for semantic items is used to subdivide existing + classes. If IN_WPA, fast equality function is invoked. */ + void subdivide_classes_by_equality (bool in_wpa = false); + + /* Debug function prints all informations about congruence classes. */ + void dump_cong_classes (void); + + /* Iterative congruence reduction function. */ + void process_cong_reduction (void); + + /* After reduction is done, we can declare all items in a group + to be equal. PREV_CLASS_COUNT is start number of classes + before reduction. */ + void merge_classes (unsigned int prev_class_count); + + /* Adds a newly created congruence class CLS to worklist. */ + void worklist_push (congruence_class *cls); + + /* Pops a class from worklist. */ + congruence_class *worklist_pop (); + + /* Returns true if a congruence class CLS is presented in worklist. */ + inline bool worklist_contains (const congruence_class *cls) + { + return worklist.find (cls); + } + + /* Removes given congruence class CLS from worklist. */ + inline void worklist_remove (const congruence_class *cls) + { + worklist.remove_elt (cls); + } + + /* Every usage of a congruence class CLS is a candidate that can split the + collection of classes. Bitmap stack BMSTACK is used for bitmap + allocation. */ + void do_congruence_step (congruence_class *cls); + + /* Tests if a class CLS used as INDEXth splits any congruence classes. + Bitmap stack BMSTACK is used for bitmap allocation. */ + void do_congruence_step_for_index (congruence_class *cls, unsigned int index); + + /* Makes pairing between a congruence class CLS and semantic ITEM. */ + static void add_item_to_class (congruence_class *cls, sem_item *item); + + /* Disposes split map traverse function. CLS is congruence + class, BSLOT is bitmap slot we want to release. DATA is mandatory, + but unused argument. */ + static bool release_split_map (congruence_class * const &cls, bitmap const &b, + traverse_split_pair *pair); + + /* Process split operation for a cognruence class CLS, + where bitmap B splits congruence class members. DATA is used + as argument of split pair. */ + static bool traverse_congruence_split (congruence_class * const &cls, bitmap const &b, + traverse_split_pair *pair); + + /* Reads a section from LTO stream file FILE_DATA. Input block for DATA + contains LEN bytes. */ + void read_section (struct lto_file_decl_data *file_data, const char *data, + size_t len); + + /* Removes all callgraph and varpool nodes that are marked by symtab + as deleted. */ + void filter_removed_items (void); + + /* Vector of semantic items. */ + vec m_items; + + /* A set containing all items removed by hooks. */ + pointer_set_t *m_removed_items_set; + + /* Hashtable of congruence classes */ + hash_table m_classes; + + /* Count of congruence classes. */ + unsigned int m_classes_count; + + /* Map data structure maps trees to semantic items. */ + hash_map m_decl_map; + + /* Map data structure maps symtab nodes to semantic items. */ + hash_map m_symtab_node_map; + + /* Set to true if a splitter class is removed. */ + bool splitter_class_removed; + + /* Global unique class id counter. */ + static unsigned int class_id; + + /* Callgraph node removal hook holder. */ + struct cgraph_node_hook_list *m_cgraph_node_hooks; + + /* Varpool node removal hook holder. */ + struct varpool_node_hook_list *m_varpool_node_hooks; + + /* Bitmap stack. */ + bitmap_obstack m_bmstack; +}; // class sem_item_optimizer + +} // ipa_icf namespace diff --git a/gcc/lto-section-in.c b/gcc/lto-section-in.c index d887763..f9587cf 100644 --- a/gcc/lto-section-in.c +++ b/gcc/lto-section-in.c @@ -60,7 +60,8 @@ const char *lto_section_name[LTO_N_SECTION_TYPES] = "opts", "cgraphopt", "inline", - "ipcp_trans" + "ipcp_trans", + "icf" }; diff --git a/gcc/lto-streamer.h b/gcc/lto-streamer.h index cfa965c..435d976 100644 --- a/gcc/lto-streamer.h +++ b/gcc/lto-streamer.h @@ -248,6 +248,7 @@ enum lto_section_type LTO_section_cgraph_opt_sum, LTO_section_inline_summary, LTO_section_ipcp_transform, + LTO_section_ipa_icf, LTO_N_SECTION_TYPES /* Must be last. */ }; diff --git a/gcc/opts.c b/gcc/opts.c index 19203dc..d4da27c 100644 --- a/gcc/opts.c +++ b/gcc/opts.c @@ -497,6 +497,7 @@ static const struct default_options default_options_table[] = { OPT_LEVELS_2_PLUS, OPT_fvect_cost_model_, NULL, VECT_COST_MODEL_CHEAP }, { OPT_LEVELS_2_PLUS_SPEED_ONLY, OPT_foptimize_strlen, NULL, 1 }, { OPT_LEVELS_2_PLUS, OPT_fhoist_adjacent_loads, NULL, 1 }, + { OPT_LEVELS_2_PLUS, OPT_fipa_icf, NULL, 1 }, { OPT_LEVELS_2_PLUS, OPT_fisolate_erroneous_paths_dereference, NULL, 1 }, { OPT_LEVELS_2_PLUS, OPT_fuse_caller_save, NULL, 1 }, @@ -1915,6 +1916,11 @@ common_handle_option (struct gcc_options *opts, opts->x_flag_wrapv = 0; break; + case OPT_fipa_icf: + opts->x_flag_ipa_icf_functions = value; + opts->x_flag_ipa_icf_variables = value; + break; + default: /* If the flag was handled in a standard way, assume the lack of processing here is intentional. */ diff --git a/gcc/passes.def b/gcc/passes.def index 280cf16..898a1ea 100644 --- a/gcc/passes.def +++ b/gcc/passes.def @@ -104,6 +104,7 @@ along with GCC; see the file COPYING3. If not see NEXT_PASS (pass_ipa_whole_program_visibility); NEXT_PASS (pass_ipa_profile); NEXT_PASS (pass_ipa_devirt); + NEXT_PASS (pass_ipa_icf); NEXT_PASS (pass_ipa_cp); NEXT_PASS (pass_ipa_cdtor_merge); NEXT_PASS (pass_ipa_inline); diff --git a/gcc/timevar.def b/gcc/timevar.def index 6b1b6df..7476796 100644 --- a/gcc/timevar.def +++ b/gcc/timevar.def @@ -89,6 +89,7 @@ DEFTIMEVAR (TV_WHOPR_LTRANS , "whopr ltrans") DEFTIMEVAR (TV_IPA_REFERENCE , "ipa reference") DEFTIMEVAR (TV_IPA_PROFILE , "ipa profile") DEFTIMEVAR (TV_IPA_PURE_CONST , "ipa pure const") +DEFTIMEVAR (TV_IPA_ICF , "ipa icf") DEFTIMEVAR (TV_IPA_PTA , "ipa points-to") DEFTIMEVAR (TV_IPA_SRA , "ipa SRA") DEFTIMEVAR (TV_IPA_FREE_LANG_DATA , "ipa free lang data") diff --git a/gcc/tree-pass.h b/gcc/tree-pass.h index b3a9de2..3a9490e 100644 --- a/gcc/tree-pass.h +++ b/gcc/tree-pass.h @@ -464,6 +464,7 @@ extern simple_ipa_opt_pass *make_pass_ipa_free_lang_data (gcc::context *ctxt); extern simple_ipa_opt_pass *make_pass_ipa_free_inline_summary (gcc::context *ctxt); extern ipa_opt_pass_d *make_pass_ipa_cp (gcc::context *ctxt); +extern ipa_opt_pass_d *make_pass_ipa_icf (gcc::context *ctxt); extern ipa_opt_pass_d *make_pass_ipa_devirt (gcc::context *ctxt); extern ipa_opt_pass_d *make_pass_ipa_reference (gcc::context *ctxt); extern ipa_opt_pass_d *make_pass_ipa_pure_const (gcc::context *ctxt); -- 1.8.4.5