From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp-out1.suse.de (smtp-out1.suse.de [IPv6:2001:67c:2178:6::1c]) by sourceware.org (Postfix) with ESMTPS id 882143858D35 for ; Fri, 9 Jun 2023 12:57:48 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 882143858D35 Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=suse.cz Authentication-Results: sourceware.org; spf=fail smtp.mailfrom=suse.cz Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id 805C9219DC; Fri, 9 Jun 2023 12:57:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1686315467; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=2Am6pTimncspkoMsYf4gAJaU9P57xUKQEfovyEhKiMs=; b=cb4J0p/6ygh3fUyfi0copW6XhGcEcJhjCk8FjSTot/7J/nKbHnJOqUXxJAtWXTHE73zw27 lwpSROIi/SI1I7Lg34qrNg35LYLbKrtVqqWQMd0ctetlDIpQ6+XKQ+kjqAlDc+LvEdQWug u4d7eLxAGuBr31lcUNTecXuRIyfZNvA= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1686315467; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=2Am6pTimncspkoMsYf4gAJaU9P57xUKQEfovyEhKiMs=; b=tSEB3P8Tas/pY3qY1OaMDiZsVPpomixDLR9DVj8xgyJZBsUTDlnNz17fByeFQ5290Hc73W WOXoeUd0PQu1/cBw== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 7358213A47; Fri, 9 Jun 2023 12:57:47 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id U0cZHMshg2RdSwAAMHmgww (envelope-from ); Fri, 09 Jun 2023 12:57:47 +0000 From: Martin Jambor To: Richard Biener Cc: GCC Patches , Jan Hubicka Subject: Re: [PATCH 2/2] ipa-cp: Feed results of IPA-CP into value numbering In-Reply-To: References: User-Agent: Notmuch/0.37 (https://notmuchmail.org) Emacs/28.2 (x86_64-suse-linux-gnu) Date: Fri, 09 Jun 2023 14:57:47 +0200 Message-ID: MIME-Version: 1.0 Content-Type: text/plain X-Spam-Status: No, score=-10.9 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,GIT_PATCH_0,SPF_HELO_NONE,SPF_SOFTFAIL,TXREP,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: Hi, thanks for looking at this. On Fri, Jun 02 2023, Richard Biener wrote: > On Mon, 29 May 2023, Martin Jambor wrote: > [...] >> diff --git a/gcc/tree-ssa-sccvn.cc b/gcc/tree-ssa-sccvn.cc >> index 27c84e78fcf..33215b5fc82 100644 >> --- a/gcc/tree-ssa-sccvn.cc >> +++ b/gcc/tree-ssa-sccvn.cc >> @@ -74,6 +74,9 @@ along with GCC; see the file COPYING3. If not see >> #include "ipa-modref-tree.h" >> #include "ipa-modref.h" >> #include "tree-ssa-sccvn.h" >> +#include "alloc-pool.h" >> +#include "symbol-summary.h" >> +#include "ipa-prop.h" >> >> /* This algorithm is based on the SCC algorithm presented by Keith >> Cooper and L. Taylor Simpson in "SCC-Based Value numbering" >> @@ -2327,7 +2330,7 @@ vn_walk_cb_data::push_partial_def (pd_data pd, >> with the current VUSE and performs the expression lookup. */ >> >> static void * >> -vn_reference_lookup_2 (ao_ref *op ATTRIBUTE_UNUSED, tree vuse, void *data_) >> +vn_reference_lookup_2 (ao_ref *op, tree vuse, void *data_) >> { >> vn_walk_cb_data *data = (vn_walk_cb_data *)data_; >> vn_reference_t vr = data->vr; >> @@ -2361,6 +2364,37 @@ vn_reference_lookup_2 (ao_ref *op ATTRIBUTE_UNUSED, tree vuse, void *data_) >> return *slot; >> } >> >> + if (SSA_NAME_IS_DEFAULT_DEF (vuse)) >> + { >> + HOST_WIDE_INT offset, size; >> + tree v = NULL_TREE; >> + if (op->base && TREE_CODE (op->base) == PARM_DECL >> + && op->offset.is_constant (&offset) >> + && op->size.is_constant (&size) >> + && op->max_size_known_p () >> + && known_eq (op->size, op->max_size)) >> + v = ipcp_get_aggregate_const (cfun, op->base, false, offset, size); > > We've talked about partial definition support, this does not > have this implemented AFAICS. But that means you cannot simply > do ->finish () without verifying data->partial_defs.is_empty (). > You are right, partial definitions are not implemented. I have added the is_empty check to the patch. I'll continue looking into adding the support as a follow-up. >> + else if (op->ref) >> + { > > does this ever happen to imrpove things? Yes, this branch is necessary for propagation of all known constants passed in memory pointed to by a POINTER_TYPE_P parameter. It handles the second testcase added by the patch. > There's the remote > possibility op->base isn't initialized yet, for this reason > above you should use ao_ref_base (op) instead of accessing > op->base directly. OK > >> + HOST_WIDE_INT offset, size; >> + bool reverse; >> + tree base = get_ref_base_and_extent_hwi (op->ref, &offset, >> + &size, &reverse); >> + if (base >> + && TREE_CODE (base) == MEM_REF >> + && integer_zerop (TREE_OPERAND (base, 1)) >> + && TREE_CODE (TREE_OPERAND (base, 0)) == SSA_NAME > > And this then should be done within the above branch as well, > just keyed off base == MEM_REF. I am sorry but I don't understand this comment, can you please try to re-phrase it? The previous branch handles direct accesses to PARM_DECLs, MEM_REFs don't need to be there at all. Updated (bootstrap and testing passing) patch is below for reference, but I obviously expect to incorporate the above comment as well before proposing to push it. Thanks, Martin Subject: [PATCH 2/2] ipa-cp: Feed results of IPA-CP into value numbering PRs 68930 and 92497 show that when IPA-CP figures out constants in aggregate parameters or when passed by reference but the loads happen in an inlined function the information is lost. This happens even when the inlined function itself was known to have - or even cloned to have - such constants in incoming parameters because the transform phase of IPA passes is not run on them. See discussion in the bugs for reasons why. Honza suggested that we can plug the results of IPA-CP analysis into value numbering, so that FRE can figure out that some loads fetch known constants. This is what this patch attempts to do. This version of the patch uses the new way we represent aggregate constants discovered IPA-CP and so avoids linear scan to find them. Similarly, it depends on the previous patch which avoids potentially slow linear look ups of indices of PARM_DECLs when there are many of them. gcc/ChangeLog: 2023-06-07 Martin Jambor PR ipa/68930 PR ipa/92497 * ipa-prop.h (ipcp_get_aggregate_const): Declare. * ipa-prop.cc (ipcp_get_aggregate_const): New function. (ipcp_transform_function): Do not deallocate transformation info. * tree-ssa-sccvn.cc: Include alloc-pool.h, symbol-summary.h and ipa-prop.h. (vn_reference_lookup_2): When hitting default-def vuse, query IPA-CP transformation info for any known constants. gcc/testsuite/ChangeLog: 2023-06-07 Martin Jambor PR ipa/68930 PR ipa/92497 * gcc.dg/ipa/pr92497-1.c: New test. * gcc.dg/ipa/pr92497-2.c: Likewise. --- gcc/ipa-prop.cc | 33 +++++++++++++++++++++---- gcc/ipa-prop.h | 3 +++ gcc/testsuite/gcc.dg/ipa/pr92497-1.c | 26 +++++++++++++++++++ gcc/testsuite/gcc.dg/ipa/pr92497-2.c | 26 +++++++++++++++++++ gcc/tree-ssa-sccvn.cc | 37 +++++++++++++++++++++++++++- 5 files changed, 119 insertions(+), 6 deletions(-) create mode 100644 gcc/testsuite/gcc.dg/ipa/pr92497-1.c create mode 100644 gcc/testsuite/gcc.dg/ipa/pr92497-2.c diff --git a/gcc/ipa-prop.cc b/gcc/ipa-prop.cc index f0976e363f7..fb2c0c0466b 100644 --- a/gcc/ipa-prop.cc +++ b/gcc/ipa-prop.cc @@ -5765,6 +5765,34 @@ ipcp_modif_dom_walker::before_dom_children (basic_block bb) return NULL; } +/* If IPA-CP discovered a constant in parameter PARM at OFFSET of a given SIZE + - whether passed by reference or not is given by BY_REF - return that + constant. Otherwise return NULL_TREE. */ + +tree +ipcp_get_aggregate_const (struct function *func, tree parm, bool by_ref, + HOST_WIDE_INT bit_offset, HOST_WIDE_INT bit_size) +{ + cgraph_node *node = cgraph_node::get (func->decl); + ipcp_transformation *ts = ipcp_get_transformation_summary (node); + + if (!ts || !ts->m_agg_values) + return NULL_TREE; + + int index = ts->get_param_index (func->decl, parm); + if (index < 0) + return NULL_TREE; + + ipa_argagg_value_list avl (ts); + unsigned unit_offset = bit_offset / BITS_PER_UNIT; + tree v = avl.get_value (index, unit_offset, by_ref); + if (!v + || maybe_ne (tree_to_poly_int64 (TYPE_SIZE (TREE_TYPE (v))), bit_size)) + return NULL_TREE; + + return v; +} + /* Return true if we have recorded VALUE and MASK about PARM. Set VALUE and MASk accordingly. */ @@ -6037,11 +6065,6 @@ ipcp_transform_function (struct cgraph_node *node) free_ipa_bb_info (bi); fbi.bb_infos.release (); - ipcp_transformation *s = ipcp_transformation_sum->get (node); - s->m_agg_values = NULL; - s->bits = NULL; - s->m_vr = NULL; - vec_free (descriptors); if (cfg_changed) delete_unreachable_blocks_update_callgraph (node, false); diff --git a/gcc/ipa-prop.h b/gcc/ipa-prop.h index c570e8ec25a..9f25b44c71b 100644 --- a/gcc/ipa-prop.h +++ b/gcc/ipa-prop.h @@ -1232,6 +1232,9 @@ void ipa_dump_param (FILE *, class ipa_node_params *info, int i); void ipa_release_body_info (struct ipa_func_body_info *); tree ipa_get_callee_param_type (struct cgraph_edge *e, int i); bool ipcp_get_parm_bits (tree, tree *, widest_int *); +tree ipcp_get_aggregate_const (struct function *func, tree parm, bool by_ref, + HOST_WIDE_INT bit_offset, + HOST_WIDE_INT bit_size); bool unadjusted_ptr_and_unit_offset (tree op, tree *ret, poly_int64 *offset_ret); diff --git a/gcc/testsuite/gcc.dg/ipa/pr92497-1.c b/gcc/testsuite/gcc.dg/ipa/pr92497-1.c new file mode 100644 index 00000000000..dcece15963c --- /dev/null +++ b/gcc/testsuite/gcc.dg/ipa/pr92497-1.c @@ -0,0 +1,26 @@ +/* { dg-do run } */ +/* { dg-options "-O2 -fno-early-inlining" } */ + +struct a {int a;}; +static int +foo (struct a a) +{ + if (!__builtin_constant_p (a.a)) + __builtin_abort (); + return a.a; +} + +static int __attribute__ ((noinline)) +bar (struct a a) +{ + return foo(a); +} + +volatile int r; + +int main() +{ + struct a a={1}; + r = bar (a); + return 0; +} diff --git a/gcc/testsuite/gcc.dg/ipa/pr92497-2.c b/gcc/testsuite/gcc.dg/ipa/pr92497-2.c new file mode 100644 index 00000000000..c64090d1a7a --- /dev/null +++ b/gcc/testsuite/gcc.dg/ipa/pr92497-2.c @@ -0,0 +1,26 @@ +/* { dg-do run } */ +/* { dg-options "-O2 -fno-early-inlining -fno-ipa-sra" } */ + +struct a {int a;}; +static int +foo (struct a *a) +{ + if (!__builtin_constant_p (a->a)) + __builtin_abort (); + return a->a; +} + +static int __attribute__ ((noinline)) +bar (struct a *a) +{ + return foo(a); +} + +volatile int r; + +int main() +{ + struct a a={1}; + r = bar (&a); + return 0; +} diff --git a/gcc/tree-ssa-sccvn.cc b/gcc/tree-ssa-sccvn.cc index 27c84e78fcf..ce88b9bc95f 100644 --- a/gcc/tree-ssa-sccvn.cc +++ b/gcc/tree-ssa-sccvn.cc @@ -74,6 +74,9 @@ along with GCC; see the file COPYING3. If not see #include "ipa-modref-tree.h" #include "ipa-modref.h" #include "tree-ssa-sccvn.h" +#include "alloc-pool.h" +#include "symbol-summary.h" +#include "ipa-prop.h" /* This algorithm is based on the SCC algorithm presented by Keith Cooper and L. Taylor Simpson in "SCC-Based Value numbering" @@ -2327,7 +2330,7 @@ vn_walk_cb_data::push_partial_def (pd_data pd, with the current VUSE and performs the expression lookup. */ static void * -vn_reference_lookup_2 (ao_ref *op ATTRIBUTE_UNUSED, tree vuse, void *data_) +vn_reference_lookup_2 (ao_ref *op, tree vuse, void *data_) { vn_walk_cb_data *data = (vn_walk_cb_data *)data_; vn_reference_t vr = data->vr; @@ -2361,6 +2364,38 @@ vn_reference_lookup_2 (ao_ref *op ATTRIBUTE_UNUSED, tree vuse, void *data_) return *slot; } + if (SSA_NAME_IS_DEFAULT_DEF (vuse)) + { + HOST_WIDE_INT offset, size; + tree v = NULL_TREE; + if (ao_ref_base (op) && TREE_CODE (ao_ref_base (op)) == PARM_DECL + && op->offset.is_constant (&offset) + && op->size.is_constant (&size) + && op->max_size_known_p () + && known_eq (op->size, op->max_size)) + v = ipcp_get_aggregate_const (cfun, ao_ref_base (op), false, offset, + size); + else if (op->ref) + { + HOST_WIDE_INT offset, size; + bool reverse; + tree base = get_ref_base_and_extent_hwi (op->ref, &offset, + &size, &reverse); + if (base + && TREE_CODE (base) == MEM_REF + && integer_zerop (TREE_OPERAND (base, 1)) + && TREE_CODE (TREE_OPERAND (base, 0)) == SSA_NAME + && SSA_NAME_IS_DEFAULT_DEF (TREE_OPERAND (base, 0)) + && (TREE_CODE (SSA_NAME_VAR (TREE_OPERAND (base, 0))) + == PARM_DECL)) + v = ipcp_get_aggregate_const (cfun, + SSA_NAME_VAR (TREE_OPERAND (base, 0)), + true, offset, size); + } + if (v && data->partial_defs.is_empty ()) + return data->finish (vr->set, vr->base_set, v); + } + return NULL; } -- 2.40.1