{"id":2226306,"url":"http://patchwork.ozlabs.org/api/1.2/patches/2226306/?format=json","web_url":"http://patchwork.ozlabs.org/project/gcc/patch/bmm.hhubwh7m90.gcc.gcc-TEST.pinskia.33.1.2@forge-stage.sourceware.org/","project":{"id":17,"url":"http://patchwork.ozlabs.org/api/1.2/projects/17/?format=json","name":"GNU Compiler Collection","link_name":"gcc","list_id":"gcc-patches.gcc.gnu.org","list_email":"gcc-patches@gcc.gnu.org","web_url":null,"scm_url":null,"webscm_url":null,"list_archive_url":"","list_archive_url_format":"","commit_url_format":""},"msgid":"","list_archive_url":null,"date":"2026-04-22T10:49:11","name":"[v1,02/15] phiopt: Reject hot/cold predictors for early phiopt [PR117935]","commit_ref":null,"pull_url":null,"state":"new","archived":false,"hash":"9df2d01c67ddeddd91e9b2038deb03d84cdf0083","submitter":{"id":93219,"url":"http://patchwork.ozlabs.org/api/1.2/people/93219/?format=json","name":"Andrew Pinski via Sourceware Forge","email":"forge-bot+pinskia@forge-stage.sourceware.org"},"delegate":null,"mbox":"http://patchwork.ozlabs.org/project/gcc/patch/bmm.hhubwh7m90.gcc.gcc-TEST.pinskia.33.1.2@forge-stage.sourceware.org/mbox/","series":[{"id":500990,"url":"http://patchwork.ozlabs.org/api/1.2/series/500990/?format=json","web_url":"http://patchwork.ozlabs.org/project/gcc/list/?series=500990","date":"2026-04-22T10:49:12","name":"copy-prop-arg","version":1,"mbox":"http://patchwork.ozlabs.org/series/500990/mbox/"}],"comments":"http://patchwork.ozlabs.org/api/patches/2226306/comments/","check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/2226306/checks/","tags":{},"related":[],"headers":{"Return-Path":"","X-Original-To":["incoming@patchwork.ozlabs.org","gcc-patches@gcc.gnu.org"],"Delivered-To":["patchwork-incoming@legolas.ozlabs.org","gcc-patches@gcc.gnu.org"],"Authentication-Results":["legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=gcc.gnu.org\n (client-ip=2620:52:6:3111::32; helo=vm01.sourceware.org;\n envelope-from=gcc-patches-bounces~incoming=patchwork.ozlabs.org@gcc.gnu.org;\n receiver=patchwork.ozlabs.org)","sourceware.org; dmarc=none (p=none dis=none)\n header.from=forge-stage.sourceware.org","sourceware.org;\n spf=pass smtp.mailfrom=forge-stage.sourceware.org","server2.sourceware.org;\n arc=none smtp.remote-ip=38.145.34.39"],"Received":["from vm01.sourceware.org (vm01.sourceware.org\n [IPv6:2620:52:6:3111::32])\n\t(using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)\n\t key-exchange x25519 server-signature ECDSA (secp384r1) server-digest SHA384)\n\t(No client certificate requested)\n\tby legolas.ozlabs.org (Postfix) with ESMTPS id 4g0xgs3T7Bz1yD5\n\tfor ; Wed, 22 Apr 2026 21:24:09 +1000 (AEST)","from vm01.sourceware.org (localhost [127.0.0.1])\n\tby sourceware.org (Postfix) with ESMTP id 6D29A42ACFC4\n\tfor ; Wed, 22 Apr 2026 11:24:07 +0000 (GMT)","from forge-stage.sourceware.org (vm08.sourceware.org [38.145.34.39])\n by sourceware.org (Postfix) with ESMTPS id 91C9741627D4\n for ; Wed, 22 Apr 2026 10:50:31 +0000 (GMT)","from forge-stage.sourceware.org (localhost [IPv6:::1])\n (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)\n key-exchange x25519 server-signature ECDSA (prime256v1) server-digest SHA256)\n (No client certificate requested)\n by forge-stage.sourceware.org (Postfix) with ESMTPS id 6793E42BD7\n for ; Wed, 22 Apr 2026 10:50:31 +0000 (UTC)"],"DKIM-Filter":["OpenDKIM Filter v2.11.0 sourceware.org 6D29A42ACFC4","OpenDKIM Filter v2.11.0 sourceware.org 91C9741627D4"],"DMARC-Filter":"OpenDMARC Filter v1.4.2 sourceware.org 91C9741627D4","ARC-Filter":"OpenARC Filter v1.0.0 sourceware.org 91C9741627D4","ARC-Seal":"i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1776855031; cv=none;\n b=kpmo3WBdveCiAcZVvPbmZYsA5jXnUGN44U6nc2F7QxNrUvzaoT6dX3ZE9TJoZRBZQmYVlhbF2q1DCQMGf7pT6yAuOm7RJouwxU7JjHorCOkRL4HlYfOUbm+Ynpg+VU50N3Iu8PGKSdgOmgSO8ojJ8BKKs46fFFUDUFKqYyJb8yM=","ARC-Message-Signature":"i=1; a=rsa-sha256; d=sourceware.org; s=key;\n t=1776855031; c=relaxed/simple;\n bh=/vVoovrUCUNBdyY0g1c+ooGsPkoPs8CJNCevLpafdsI=;\n h=From:Date:Subject:To:Message-ID;\n b=OWeQAuW6qnSZqPSFcYbvxYfjyMdX1U6qzraxpQMx8p2msmrmgev081pam+QW7JY2OHaC9wvlQSEgegNwjLQV7oGzXBYp7gGQD8bHmybODospssEzQC+nNEsj3zctPe12HGic0n1HnXOTpZrGIHOn1VQgd8sJGJCS9DVsjg9PoOk=","ARC-Authentication-Results":"i=1; server2.sourceware.org","From":"Andrew Pinski via Sourceware Forge\n ","Date":"Wed, 22 Apr 2026 10:49:11 +0000","Subject":"[PATCH v1 02/15] phiopt: Reject hot/cold predictors for early phiopt\n [PR117935]","To":"gcc-patches mailing list ","Message-ID":"\n ","X-Mailer":"batrachomyomachia","X-Pull-Request-Organization":"gcc","X-Pull-Request-Repository":"gcc-TEST","X-Pull-Request":"https://forge.sourceware.org/gcc/gcc-TEST/pulls/33","References":"\n ","In-Reply-To":"\n ","X-Patch-URL":"\n https://forge.sourceware.org/pinskia/gcc-TEST/commit/94e9a7d5886e90e9a3a6239cdaf075fc8d43d17e","X-BeenThere":"gcc-patches@gcc.gnu.org","X-Mailman-Version":"2.1.30","Precedence":"list","List-Id":"Gcc-patches mailing list ","List-Unsubscribe":",\n ","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n ","Reply-To":"gcc-patches mailing list ,\n pinskia@gcc.gnu.org","Errors-To":"gcc-patches-bounces~incoming=patchwork.ozlabs.org@gcc.gnu.org"},"content":"From: Andrew Pinski \n\nIn this case, early phiopt would get rid of the user provided predicator\nfor hot/cold as it would remove the basic blocks. The easiest and best option is\nfor early phi-opt don't do phi-opt if the middle basic-block(s) have either\na hot or cold predict statement. Then after inlining, jump threading will most likely\nhappen and that will keep around the predictor.\n\nNote this only needs to be done for match_simplify_replacement and not the other\nphi-opt functions because currently only match_simplify_replacement is able to skip\nmiddle bb with predicator statements in it.\n\nOK? Bootstrapped and tested on x86_64-linux-gnu.\n\n\tPR tree-optimization/117935\n\ngcc/ChangeLog:\n\n\t* tree-ssa-phiopt.cc (contains_hot_cold_predict): New function.\n\t(match_simplify_replacement): Return early if early_p and one of\n\tthe middle bb(s) have a hot/cold predict statement.\n\ngcc/testsuite/ChangeLog:\n\n\t* gcc.dg/predict-24.c: New test.\n\nSigned-off-by: Andrew Pinski \n---\n gcc/testsuite/gcc.dg/predict-24.c | 24 +++++++++++++++++++++\n gcc/tree-ssa-phiopt.cc | 35 +++++++++++++++++++++++++++++++\n 2 files changed, 59 insertions(+)\n create mode 100644 gcc/testsuite/gcc.dg/predict-24.c","diff":"diff --git a/gcc/testsuite/gcc.dg/predict-24.c b/gcc/testsuite/gcc.dg/predict-24.c\nnew file mode 100644\nindex 000000000000..b2c8a77c323f\n--- /dev/null\n+++ b/gcc/testsuite/gcc.dg/predict-24.c\n@@ -0,0 +1,24 @@\n+/* { dg-do compile } */\n+/* { dg-options \"-O2 -fdump-tree-profile_estimate\" } */\n+/* PR tree-optimization/117935 */\n+\n+static inline bool has_value(bool b)\n+{\n+ if (b)\n+ {\n+ [[gnu::hot, gnu::unused]] label1:\n+ return true;\n+ }\n+ else\n+ return false;\n+}\n+/* The hot label should last until it gets inlined into value_or and jump_threaded. */\n+int value_or(bool b, int def0, int def1)\n+{\n+ if (has_value(b))\n+ return def0;\n+ else\n+ return def1;\n+}\n+/* { dg-final { scan-tree-dump-times \"first match heuristics: 90.00%\" 2 \"profile_estimate\"} } */\n+/* { dg-final { scan-tree-dump-times \"hot label heuristics of edge \\[0-9\\]+->\\[0-9]+: 90.00%\" 2 \"profile_estimate\"} } */\ndiff --git a/gcc/tree-ssa-phiopt.cc b/gcc/tree-ssa-phiopt.cc\nindex f67f52d2d69a..fb918f8825dd 100644\n--- a/gcc/tree-ssa-phiopt.cc\n+++ b/gcc/tree-ssa-phiopt.cc\n@@ -56,6 +56,7 @@ along with GCC; see the file COPYING3. If not see\n #include \"tree-ssa-dce.h\"\n #include \"calls.h\"\n #include \"tree-ssa-loop-niter.h\"\n+#include \"gimple-predict.h\"\n \n /* Return the singleton PHI in the SEQ of PHIs for edges E0 and E1. */\n \n@@ -916,6 +917,27 @@ auto_flow_sensitive::~auto_flow_sensitive ()\n p.second.restore (p.first);\n }\n \n+/* Returns true if BB contains an user provided predictor\n+ (PRED_HOT_LABEL/PRED_COLD_LABEL). */\n+\n+static bool\n+contains_hot_cold_predict (basic_block bb)\n+{\n+ gimple_stmt_iterator gsi;\n+ gsi = gsi_start_nondebug_after_labels_bb (bb);\n+ for (; !gsi_end_p (gsi); gsi_next_nondebug (&gsi))\n+ {\n+ gimple *s = gsi_stmt (gsi);\n+ if (gimple_code (s) != GIMPLE_PREDICT)\n+\tcontinue;\n+ auto predict = gimple_predict_predictor (s);\n+ if (predict == PRED_HOT_LABEL\n+\t || predict == PRED_COLD_LABEL)\n+\treturn true;\n+ }\n+ return false;\n+}\n+\n /* The function match_simplify_replacement does the main work of doing the\n replacement using match and simplify. Return true if the replacement is done.\n Otherwise return false.\n@@ -953,6 +975,19 @@ match_simplify_replacement (basic_block cond_bb, basic_block middle_bb,\n \t\t\t\t\t stmt_to_move_alt))\n return false;\n \n+ /* For early phiopt, we don't want to lose user generated predictors,\n+ that is if either middle bb contains either a hot or cold label predict,\n+ the phiopt should be skipped. */\n+ if (early_p)\n+ {\n+ if (contains_hot_cold_predict (middle_bb))\n+\treturn false;\n+ if (threeway_p\n+\t && middle_bb != middle_bb_alt\n+\t && contains_hot_cold_predict (middle_bb_alt))\n+\treturn false;\n+ }\n+\n /* Do not make conditional undefs unconditional. */\n if ((TREE_CODE (arg0) == SSA_NAME\n && ssa_name_maybe_undef_p (arg0))\n","prefixes":["v1","02/15"]}