From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 2136) id 305403857802; Thu, 28 Oct 2021 12:32:40 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 305403857802 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="utf-8" From: Aldy Hernandez To: gcc-cvs@gcc.gnu.org Subject: [gcc r12-4766] Improve backward threading with switches. X-Act-Checkin: gcc X-Git-Author: Aldy Hernandez X-Git-Refname: refs/heads/master X-Git-Oldrev: 7f6c22585229b43b13fc9c8d3c08aedd9f7c493a X-Git-Newrev: 113dab2b9d511f3aadc30a6a921fc30bd5f93706 Message-Id: <20211028123240.305403857802@sourceware.org> Date: Thu, 28 Oct 2021 12:32:40 +0000 (GMT) X-BeenThere: gcc-cvs@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-cvs mailing list List-Unsubscribe: , List-Archive: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 28 Oct 2021 12:32:40 -0000 https://gcc.gnu.org/g:113dab2b9d511f3aadc30a6a921fc30bd5f93706 commit r12-4766-g113dab2b9d511f3aadc30a6a921fc30bd5f93706 Author: Aldy Hernandez Date: Thu Oct 28 11:44:13 2021 +0200 Improve backward threading with switches. We've been essentially using find_taken_edge_switch_expr() in the backward threader, but this is suboptimal because said function only works with singletons. VRP has a much smarter find_case_label_range that works with ranges. Tested on x86-64 Linux with: a) Bootstrap & regtests. b) Verifying we get more threads than before. c) Asserting that the new code catches everything the old one code caught (over a set of bootstrap .ii files). gcc/ChangeLog: * tree-ssa-threadbackward.c (back_threader::find_taken_edge_switch): Use find_case_label_range instead of find_taken_edge. gcc/testsuite/ChangeLog: * gcc.dg/tree-ssa/vrp106.c: Adjust for threading. * gcc.dg/tree-ssa/vrp113.c: Same. Diff: --- gcc/testsuite/gcc.dg/tree-ssa/vrp106.c | 4 ++-- gcc/testsuite/gcc.dg/tree-ssa/vrp113.c | 2 -- gcc/tree-ssa-threadbackward.c | 8 ++++---- 3 files changed, 6 insertions(+), 8 deletions(-) diff --git a/gcc/testsuite/gcc.dg/tree-ssa/vrp106.c b/gcc/testsuite/gcc.dg/tree-ssa/vrp106.c index f25ea9c3826..dc5021a57b5 100644 --- a/gcc/testsuite/gcc.dg/tree-ssa/vrp106.c +++ b/gcc/testsuite/gcc.dg/tree-ssa/vrp106.c @@ -1,6 +1,6 @@ /* PR tree-optimization/18046 */ -/* { dg-options "-O2 -fdump-tree-vrp-thread1-details" } */ -/* { dg-final { scan-tree-dump-times "Threaded jump" 1 "vrp-thread1" } } */ +/* { dg-options "-O2 -fdump-tree-ethread-details" } */ +/* { dg-final { scan-tree-dump-times "Registering jump thread" 1 "ethread" } } */ /* During VRP we expect to thread the true arm of the conditional through the switch and to the BB that corresponds to the 7 ... 9 case label. */ extern void foo (void); diff --git a/gcc/testsuite/gcc.dg/tree-ssa/vrp113.c b/gcc/testsuite/gcc.dg/tree-ssa/vrp113.c index ab8d91e0f10..dfe4989d313 100644 --- a/gcc/testsuite/gcc.dg/tree-ssa/vrp113.c +++ b/gcc/testsuite/gcc.dg/tree-ssa/vrp113.c @@ -13,5 +13,3 @@ int f(int a) { case 7: return 19; } } - -/* { dg-final { scan-tree-dump "return 3;" "vrp1" { xfail *-*-* } } } */ diff --git a/gcc/tree-ssa-threadbackward.c b/gcc/tree-ssa-threadbackward.c index 6c1b15904ce..456effca5e1 100644 --- a/gcc/tree-ssa-threadbackward.c +++ b/gcc/tree-ssa-threadbackward.c @@ -195,11 +195,11 @@ back_threader::find_taken_edge_switch (const vec &path, if (r.varying_p ()) return NULL; - tree val; - if (r.singleton_p (&val)) - return ::find_taken_edge (gimple_bb (sw), val); + tree label = find_case_label_range (sw, &r); + if (!label) + return NULL; - return NULL; + return find_edge (gimple_bb (sw), label_to_block (cfun, CASE_LABEL (label))); } // Same as find_taken_edge, but for paths ending in a GIMPLE_COND.