{"id":2226760,"url":"http://patchwork.ozlabs.org/api/patches/2226760/?format=json","web_url":"http://patchwork.ozlabs.org/project/gcc/patch/bmm.hhup4p5wp2.gcc.gcc-TEST.pinskia.84.1.1@forge-stage.sourceware.org/","project":{"id":17,"url":"http://patchwork.ozlabs.org/api/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":"2026-04-22T18:49:09","name":"[v1,01/10] fab/forwprop: Move memcmp->memcmp_eq to forwprop","commit_ref":null,"pull_url":null,"state":"new","archived":false,"hash":"73e89c7274a40876bbc03b4809c0a0cb5aabdb1e","submitter":{"id":93219,"url":"http://patchwork.ozlabs.org/api/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.hhup4p5wp2.gcc.gcc-TEST.pinskia.84.1.1@forge-stage.sourceware.org/mbox/","series":[{"id":501092,"url":"http://patchwork.ozlabs.org/api/series/501092/?format=json","web_url":"http://patchwork.ozlabs.org/project/gcc/list/?series=501092","date":"2026-04-22T18:49:11","name":"remove_fab","version":1,"mbox":"http://patchwork.ozlabs.org/series/501092/mbox/"}],"comments":"http://patchwork.ozlabs.org/api/patches/2226760/comments/","check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/2226760/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; 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server2.sourceware.org","From":"Andrew Pinski via Sourceware Forge\n ","Date":"Wed, 22 Apr 2026 18:49:09 +0000","Subject":"[PATCH v1 01/10] fab/forwprop: Move memcmp->memcmp_eq to forwprop","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/84","References":"\n ","In-Reply-To":"\n ","X-Patch-URL":"\n https://forge.sourceware.org/pinskia/gcc-TEST/commit/934f80e6fb2acb7594c843278a5218c4bf583284","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\nThis moves from the memcmp->memcmp_eq to forwprop by\nchecking PROP_last_full_fold.\n\nNote this means at -Og, we no longer optimize some\nmemcmp. That will be fixed when I exchange fab/copyprop\nfor a (late) forwprop.\n\nBootstrapped and tested on x86_64-linux-gnu.\n\ngcc/ChangeLog:\n\n\t* tree-ssa-ccp.cc (optimize_memcmp_eq): Remove.\n\t(pass_fold_builtins::execute): Remove handling of memcmp.\n\t* tree-ssa-forwprop.cc (simplify_builtin_memcmp): Add folding\n\tof memcmp to memcmp_eq for PROP_last_full_fold.\n\nSigned-off-by: Andrew Pinski \n---\n gcc/tree-ssa-ccp.cc | 34 ----------------------------------\n gcc/tree-ssa-forwprop.cc | 10 +++++++++-\n 2 files changed, 9 insertions(+), 35 deletions(-)","diff":"diff --git a/gcc/tree-ssa-ccp.cc b/gcc/tree-ssa-ccp.cc\nindex 4165e596033f..1fbc3de2bfe7 100644\n--- a/gcc/tree-ssa-ccp.cc\n+++ b/gcc/tree-ssa-ccp.cc\n@@ -4205,36 +4205,6 @@ public:\n \n }; // class pass_fold_builtins\n \n-/* Optimize memcmp STMT into memcmp_eq if it is only used with\n- `== 0` or `!= 0`. */\n-\n-static void\n-optimize_memcmp_eq (gcall *stmt)\n-{\n- /* Make sure memcmp arguments are the correct type. */\n- if (gimple_call_num_args (stmt) != 3)\n- return;\n- tree arg1 = gimple_call_arg (stmt, 0);\n- tree arg2 = gimple_call_arg (stmt, 1);\n- tree len = gimple_call_arg (stmt, 2);\n-\n- if (!POINTER_TYPE_P (TREE_TYPE (arg1)))\n- return;\n- if (!POINTER_TYPE_P (TREE_TYPE (arg2)))\n- return;\n- if (!INTEGRAL_TYPE_P (TREE_TYPE (len)))\n- return;\n- /* The return value of the memcmp has to be used\n- equality comparison to zero. */\n- tree res = gimple_call_lhs (stmt);\n-\n- if (!res || !use_in_zero_equality (res))\n- return;\n-\n- gimple_call_set_fndecl (stmt, builtin_decl_explicit (BUILT_IN_MEMCMP_EQ));\n- update_stmt (stmt);\n-}\n-\n unsigned int\n pass_fold_builtins::execute (function *fun)\n {\n@@ -4291,10 +4261,6 @@ pass_fold_builtins::execute (function *fun)\n \t\t gsi_next (&i);\n \t\t continue;\n \n-\t\tcase BUILT_IN_MEMCMP:\n-\t\t optimize_memcmp_eq (as_a(stmt));\n-\t\t break;\n-\n \t\tcase BUILT_IN_UNREACHABLE:\n \t\t if (optimize_unreachable (i))\n \t\t cfg_changed = true;\ndiff --git a/gcc/tree-ssa-forwprop.cc b/gcc/tree-ssa-forwprop.cc\nindex 4c438a0f86c9..917f3d90f6c2 100644\n--- a/gcc/tree-ssa-forwprop.cc\n+++ b/gcc/tree-ssa-forwprop.cc\n@@ -1842,7 +1842,15 @@ simplify_builtin_memcmp (gimple_stmt_iterator *gsi_p, gcall *stmt)\n \t return true;\n \t}\n }\n- return false;\n+\n+ /* Replace memcmp with memcmp_eq if the above fails. */\n+ if (DECL_FUNCTION_CODE (gimple_call_fndecl (stmt)) == BUILT_IN_MEMCMP_EQ)\n+ return false;\n+ if (!(cfun->curr_properties & (PROP_last_full_fold)))\n+ return false;\n+ gimple_call_set_fndecl (stmt, builtin_decl_explicit (BUILT_IN_MEMCMP_EQ));\n+ update_stmt (stmt);\n+ return true;\n }\n \n /* Optimizes builtin memchrs for small constant sizes with a const string.\n","prefixes":["v1","01/10"]}