From c32f7df917b01c3636aa85916a36264e807ced9d Mon Sep 17 00:00:00 2001 From: Aldy Hernandez Date: Tue, 28 Sep 2021 11:33:11 +0200 Subject: [PATCH] Enable jump threading at -O1. My previous patch gating all jump threading by -fthread-jumps had the side effect of turning off DOM jump threading at -O1. This causes numerous -Wuninitialized false positives. This patch turns on jump threading at -O1 to minimize the disruption. gcc/ChangeLog: * cfgcleanup.c (pass_jump::execute): Check flag_expensive_optimizations. (pass_jump_after_combine::gate): Same. * doc/invoke.texi (-fthread-jumps): Enable for -O1. * opts.c (default_options_table): Enable -fthread-jumps at -O1. * tree-ssa-threadupdate.c (fwd_jt_path_registry::remove_jump_threads_including): Bail unless flag_thread_jumps. gcc/testsuite/ChangeLog: * gcc.dg/auto-init-uninit-1.c: Adjust. * gcc.dg/auto-init-uninit-15.c: Same. * gcc.dg/guality/example.c: Same. * gcc.dg/loop-8.c: Same. * gcc.dg/strlenopt-40.c: Same. * gcc.dg/tree-ssa/pr18133-2.c: Same. * gcc.dg/tree-ssa/pr18134.c: Same. * gcc.dg/uninit-1.c: Same. * gcc.dg/uninit-pr44547.c: Same. * gcc.dg/uninit-pr59970.c: Same. --- gcc/cfgcleanup.c | 8 ++++++-- gcc/doc/invoke.texi | 2 +- gcc/opts.c | 2 +- gcc/testsuite/gcc.dg/auto-init-uninit-1.c | 2 +- gcc/testsuite/gcc.dg/auto-init-uninit-15.c | 2 +- gcc/testsuite/gcc.dg/guality/example.c | 1 + gcc/testsuite/gcc.dg/loop-8.c | 2 +- gcc/testsuite/gcc.dg/strlenopt-40.c | 2 +- gcc/testsuite/gcc.dg/tree-ssa/pr18133-2.c | 2 +- gcc/testsuite/gcc.dg/tree-ssa/pr18134.c | 2 +- gcc/testsuite/gcc.dg/uninit-1.c | 2 +- gcc/testsuite/gcc.dg/uninit-pr44547.c | 2 +- gcc/testsuite/gcc.dg/uninit-pr59970.c | 2 +- gcc/tree-ssa-threadupdate.c | 2 +- 14 files changed, 19 insertions(+), 14 deletions(-) diff --git a/gcc/cfgcleanup.c b/gcc/cfgcleanup.c index 7b1e1ba6e80..82fc505ff50 100644 --- a/gcc/cfgcleanup.c +++ b/gcc/cfgcleanup.c @@ -3239,7 +3239,8 @@ pass_jump::execute (function *) if (dump_file) dump_flow_info (dump_file, dump_flags); cleanup_cfg ((optimize ? CLEANUP_EXPENSIVE : 0) - | (flag_thread_jumps ? CLEANUP_THREADING : 0)); + | (flag_thread_jumps && flag_expensive_optimizations + ? CLEANUP_THREADING : 0)); return 0; } @@ -3274,7 +3275,10 @@ public: {} /* opt_pass methods: */ - virtual bool gate (function *) { return flag_thread_jumps; } + virtual bool gate (function *) + { + return flag_thread_jumps && flag_expensive_optimizations; + } virtual unsigned int execute (function *); }; // class pass_jump_after_combine diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi index ba98eab68a5..6d9a107acd0 100644 --- a/gcc/doc/invoke.texi +++ b/gcc/doc/invoke.texi @@ -10781,7 +10781,7 @@ so, the first branch is redirected to either the destination of the second branch or a point immediately following it, depending on whether the condition is known to be true or false. -Enabled at levels @option{-O2}, @option{-O3}, @option{-Os}. +Enabled at levels @option{-O1}, @option{-O2}, @option{-O3}, @option{-Os}. @item -fsplit-wide-types @opindex fsplit-wide-types diff --git a/gcc/opts.c b/gcc/opts.c index 38b42db2a4f..6503980cd33 100644 --- a/gcc/opts.c +++ b/gcc/opts.c @@ -569,6 +569,7 @@ static const struct default_options default_options_table[] = { OPT_LEVELS_1_PLUS, OPT_freorder_blocks, NULL, 1 }, { OPT_LEVELS_1_PLUS, OPT_fshrink_wrap, NULL, 1 }, { OPT_LEVELS_1_PLUS, OPT_fsplit_wide_types, NULL, 1 }, + { OPT_LEVELS_1_PLUS, OPT_fthread_jumps, NULL, 1 }, { OPT_LEVELS_1_PLUS, OPT_ftree_builtin_call_dce, NULL, 1 }, { OPT_LEVELS_1_PLUS, OPT_ftree_ccp, NULL, 1 }, { OPT_LEVELS_1_PLUS, OPT_ftree_ch, NULL, 1 }, @@ -629,7 +630,6 @@ static const struct default_options default_options_table[] = #endif { OPT_LEVELS_2_PLUS, OPT_fstrict_aliasing, NULL, 1 }, { OPT_LEVELS_2_PLUS, OPT_fstore_merging, NULL, 1 }, - { OPT_LEVELS_2_PLUS, OPT_fthread_jumps, NULL, 1 }, { OPT_LEVELS_2_PLUS, OPT_ftree_pre, NULL, 1 }, { OPT_LEVELS_2_PLUS, OPT_ftree_switch_conversion, NULL, 1 }, { OPT_LEVELS_2_PLUS, OPT_ftree_tail_merge, NULL, 1 }, diff --git a/gcc/testsuite/gcc.dg/auto-init-uninit-1.c b/gcc/testsuite/gcc.dg/auto-init-uninit-1.c index ce8909623ab..502db591222 100644 --- a/gcc/testsuite/gcc.dg/auto-init-uninit-1.c +++ b/gcc/testsuite/gcc.dg/auto-init-uninit-1.c @@ -1,5 +1,5 @@ /* Spurious uninitialized variable warnings, case 1. Taken from cppfiles.c (merge_include_chains) */ /* { dg-do compile } */ -/* { dg-options "-O -Wuninitialized -fthread-jumps -ftrivial-auto-var-init=zero" } */ +/* { dg-options "-O -Wuninitialized -ftrivial-auto-var-init=zero" } */ #include "uninit-1.c" diff --git a/gcc/testsuite/gcc.dg/auto-init-uninit-15.c b/gcc/testsuite/gcc.dg/auto-init-uninit-15.c index b8f6e2b57d5..121f0cff274 100644 --- a/gcc/testsuite/gcc.dg/auto-init-uninit-15.c +++ b/gcc/testsuite/gcc.dg/auto-init-uninit-15.c @@ -5,7 +5,7 @@ But it is of course ok if we warn in bar about uninitialized use of j. (not xfailed alternative) */ /* { dg-do compile } */ -/* { dg-options "-O1 -Wuninitialized -fthread-jumps -ftrivial-auto-var-init=zero" } */ +/* { dg-options "-O1 -Wuninitialized -ftrivial-auto-var-init=zero" } */ inline int foo (int i) diff --git a/gcc/testsuite/gcc.dg/guality/example.c b/gcc/testsuite/gcc.dg/guality/example.c index 37564e55cd1..32014e2b4c0 100644 --- a/gcc/testsuite/gcc.dg/guality/example.c +++ b/gcc/testsuite/gcc.dg/guality/example.c @@ -1,4 +1,5 @@ /* { dg-options "-g" } */ +/* { dg-do run { xfail { ! aarch64*-*-* } } } */ /* { dg-xfail-run-if "" aarch64*-*-* "*" { "-O[01g]" } } */ #define GUALITY_DONT_FORCE_LIVE_AFTER -1 diff --git a/gcc/testsuite/gcc.dg/loop-8.c b/gcc/testsuite/gcc.dg/loop-8.c index e5218eb4053..90ea1c45524 100644 --- a/gcc/testsuite/gcc.dg/loop-8.c +++ b/gcc/testsuite/gcc.dg/loop-8.c @@ -1,5 +1,5 @@ /* { dg-do compile } */ -/* { dg-options "-O1 -fthread-jumps -fdump-rtl-loop2_invariant" } */ +/* { dg-options "-O1 -fdump-rtl-loop2_invariant" } */ /* { dg-skip-if "unexpected IV" { "hppa*-*-* mips*-*-* visium-*-* powerpc*-*-* riscv*-*-* mmix-*-* vax-*-*" } } */ /* Load immediate on condition is available from z13 on and prevents moving the load out of the loop, so always run this test with -march=zEC12 that diff --git a/gcc/testsuite/gcc.dg/strlenopt-40.c b/gcc/testsuite/gcc.dg/strlenopt-40.c index 7b799104708..7a97ebb8fe5 100644 --- a/gcc/testsuite/gcc.dg/strlenopt-40.c +++ b/gcc/testsuite/gcc.dg/strlenopt-40.c @@ -1,7 +1,7 @@ /* PR tree-optimization/83671 - fix for false positive reported by -Wstringop-overflow does not work with inlining { dg-do compile } - { dg-options "-O1 -fthread-jumps -fdump-tree-optimized" } */ + { dg-options "-O1 -fdump-tree-optimized" } */ #include "strlenopt.h" diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr18133-2.c b/gcc/testsuite/gcc.dg/tree-ssa/pr18133-2.c index 1b409852189..8717640e327 100644 --- a/gcc/testsuite/gcc.dg/tree-ssa/pr18133-2.c +++ b/gcc/testsuite/gcc.dg/tree-ssa/pr18133-2.c @@ -1,5 +1,5 @@ /* { dg-do compile } */ -/* { dg-options "-O1 -fthread-jumps -fdump-tree-optimized-blocks" } */ +/* { dg-options "-O1 -fdump-tree-optimized-blocks" } */ int c, d; diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr18134.c b/gcc/testsuite/gcc.dg/tree-ssa/pr18134.c index d7f5d241eb9..cd40ab2c162 100644 --- a/gcc/testsuite/gcc.dg/tree-ssa/pr18134.c +++ b/gcc/testsuite/gcc.dg/tree-ssa/pr18134.c @@ -1,5 +1,5 @@ /* { dg-do compile } */ -/* { dg-options "-O1 -fthread-jumps -fdump-tree-optimized" } */ +/* { dg-options "-O1 -fdump-tree-optimized" } */ int foo (int a) { diff --git a/gcc/testsuite/gcc.dg/uninit-1.c b/gcc/testsuite/gcc.dg/uninit-1.c index 156d34ff732..060ec250ba7 100644 --- a/gcc/testsuite/gcc.dg/uninit-1.c +++ b/gcc/testsuite/gcc.dg/uninit-1.c @@ -1,7 +1,7 @@ /* Spurious uninitialized variable warnings, case 1. Taken from cppfiles.c (merge_include_chains) */ /* { dg-do compile } */ -/* { dg-options "-O -Wuninitialized -fthread-jumps" } */ +/* { dg-options "-O -Wuninitialized" } */ struct list { diff --git a/gcc/testsuite/gcc.dg/uninit-pr44547.c b/gcc/testsuite/gcc.dg/uninit-pr44547.c index f1c3b034d14..ee1035ad7b8 100644 --- a/gcc/testsuite/gcc.dg/uninit-pr44547.c +++ b/gcc/testsuite/gcc.dg/uninit-pr44547.c @@ -1,7 +1,7 @@ /* PR tree-optimization/44547 - -Wuninitialized reports false warning in nested switch statements { dg-do compile } - { dg-options "-O1 -Wall -fthread-jumps" } */ + { dg-options "-O1 -Wall" } */ __attribute__ ((noipa)) int test_O1 (int argc) { diff --git a/gcc/testsuite/gcc.dg/uninit-pr59970.c b/gcc/testsuite/gcc.dg/uninit-pr59970.c index d0c41b8480d..145af657a76 100644 --- a/gcc/testsuite/gcc.dg/uninit-pr59970.c +++ b/gcc/testsuite/gcc.dg/uninit-pr59970.c @@ -41,7 +41,7 @@ d_demangle_callback_O1 (const char *mangled) #pragma GCC pop_options -#pragma GCC optimize ("Og,thread-jumps") +#pragma GCC optimize ("Og") __attribute__ ((noipa)) int d_demangle_callback_Og (const char *mangled) diff --git a/gcc/tree-ssa-threadupdate.c b/gcc/tree-ssa-threadupdate.c index cf96c903668..71e602ffa2d 100644 --- a/gcc/tree-ssa-threadupdate.c +++ b/gcc/tree-ssa-threadupdate.c @@ -2570,7 +2570,7 @@ valid_jump_thread_path (vec *path) void fwd_jt_path_registry::remove_jump_threads_including (edge_def *e) { - if (!m_paths.exists ()) + if (!m_paths.exists () || !flag_thread_jumps) return; edge *slot = m_removed_edges->find_slot (e, INSERT);