From 02e637d86f9ecb6d0e368438291bb6f6f8feb3ab Mon Sep 17 00:00:00 2001 From: Martin Liska Date: Tue, 5 Sep 2017 10:12:27 +0200 Subject: [PATCH] Learn CFG cleanup to transform single case switches to gcond. 2017-09-05 Martin Liska PR tree-optimization/82032 * tree-cfg.c (generate_range_test): New function. * tree-cfg.h (generate_range_test): Declared here. * tree-cfgcleanup.c (convert_single_case_switch): New function. (cleanup_control_expr_graph): Use it. * tree-switch-conversion.c (try_switch_expansion): Remove assert. (emit_case_nodes): Use generate_range_test. 2017-09-05 Martin Liska PR tree-optimization/82032 * g++.dg/other/pr82032.C: New test. * gcc.dg/tree-ssa/pr68198.c: Update scanned pattern. * gcc.dg/tree-ssa/vrp34.c: Likewise. * gcc.dg/switch-10.c: Likewise. From-SVN: r251690 --- gcc/ChangeLog | 11 ++++++ gcc/testsuite/ChangeLog | 8 ++++ gcc/testsuite/g++.dg/other/pr82032.C | 36 ++++++++++++++++++ gcc/testsuite/gcc.dg/switch-10.c | 5 ++- gcc/testsuite/gcc.dg/tree-ssa/pr68198.c | 6 +-- gcc/testsuite/gcc.dg/tree-ssa/vrp34.c | 5 ++- gcc/tree-cfg.c | 24 ++++++++++++ gcc/tree-cfg.h | 2 + gcc/tree-cfgcleanup.c | 49 +++++++++++++++++++++++++ gcc/tree-switch-conversion.c | 27 +++----------- 10 files changed, 144 insertions(+), 29 deletions(-) create mode 100644 gcc/testsuite/g++.dg/other/pr82032.C diff --git a/gcc/ChangeLog b/gcc/ChangeLog index e7e8c2319c2..7a824f82a2e 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,14 @@ +2017-09-05 Martin Liska + + PR tree-optimization/82032 + * tree-cfg.c (generate_range_test): New function. + * tree-cfg.h (generate_range_test): Declared here. + * tree-cfgcleanup.c (convert_single_case_switch): New function. + (cleanup_control_expr_graph): Use it. + * tree-switch-conversion.c (try_switch_expansion): Remove + assert. + (emit_case_nodes): Use generate_range_test. + 2017-09-04 Uros Bizjak PR target/82098 diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 91aa16f5d36..74790654be8 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,11 @@ +2017-09-05 Martin Liska + + PR tree-optimization/82032 + * g++.dg/other/pr82032.C: New test. + * gcc.dg/tree-ssa/pr68198.c: Update scanned pattern. + * gcc.dg/tree-ssa/vrp34.c: Likewise. + * gcc.dg/switch-10.c: Likewise. + 2017-09-04 Uros Bizjak * gcc.target/i386/mpx/mpx-os-support.h: New file. diff --git a/gcc/testsuite/g++.dg/other/pr82032.C b/gcc/testsuite/g++.dg/other/pr82032.C new file mode 100644 index 00000000000..607bf85c8e1 --- /dev/null +++ b/gcc/testsuite/g++.dg/other/pr82032.C @@ -0,0 +1,36 @@ +/* { dg-do compile } */ +/* { dg-options "-O3 -Wno-return-type" } */ + +template class b +{ +public: + typename a::aa operator[] (typename a::c) { } +}; +class d +{ +public: + typedef long c; + typedef int aa; +}; +struct e +{ + int af[4]; + int ag; +}; +b f; +bool +g (e &i) +{ + for (int h; h; ++h) + switch (f[h]) + { + case 'x': + case 'a': + i.af[h] = 3; + break; + default: + return false; + } + + return true; +} diff --git a/gcc/testsuite/gcc.dg/switch-10.c b/gcc/testsuite/gcc.dg/switch-10.c index 0ffc9eb5757..9e5926745b8 100644 --- a/gcc/testsuite/gcc.dg/switch-10.c +++ b/gcc/testsuite/gcc.dg/switch-10.c @@ -1,6 +1,4 @@ /* { dg-options "-O2 -fdump-tree-cfg" } */ -/* { dg-final { scan-tree-dump "case 0:" "cfg" } } */ -/* { dg-final { scan-tree-dump-not "case 1 ... 255:" "cfg" } } */ #include void foo (void); @@ -20,3 +18,6 @@ test (uint8_t ch) break; } } + +/* Switch statement is converted to GIMPLE condition. */ +/* { dg-final { scan-tree-dump-not "switch" "cfg" } } */ diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr68198.c b/gcc/testsuite/gcc.dg/tree-ssa/pr68198.c index 16097d7e2bc..59d562e156c 100644 --- a/gcc/testsuite/gcc.dg/tree-ssa/pr68198.c +++ b/gcc/testsuite/gcc.dg/tree-ssa/pr68198.c @@ -37,7 +37,5 @@ c_finish_omp_clauses (tree clauses) } } -/* There are 3 FSM jump threading opportunities, two of which will - get filtered out. */ -/* { dg-final { scan-tree-dump-times "Registering FSM" 1 "thread1"} } */ -/* { dg-final { scan-tree-dump-times "FSM Thread through multiway branch without threading a multiway branch" 2 "thread1"} } */ +/* There are 3 FSM jump threading opportunities. */ +/* { dg-final { scan-tree-dump-times "Registering FSM" 3 "thread1"} } */ diff --git a/gcc/testsuite/gcc.dg/tree-ssa/vrp34.c b/gcc/testsuite/gcc.dg/tree-ssa/vrp34.c index 142e56c1641..d2a36a706f2 100644 --- a/gcc/testsuite/gcc.dg/tree-ssa/vrp34.c +++ b/gcc/testsuite/gcc.dg/tree-ssa/vrp34.c @@ -15,5 +15,6 @@ foo (int a) } } -/* Both ifs should be optimized. */ -/* { dg-final { scan-tree-dump-times "if \\\(" 0 "vrp1" } } */ +/* Both ifs should be optimized (and switch statement will be the only if + in the function). */ +/* { dg-final { scan-tree-dump-times "if \\\(" 1 "vrp1" } } */ diff --git a/gcc/tree-cfg.c b/gcc/tree-cfg.c index b7593068ea9..b601012cfed 100644 --- a/gcc/tree-cfg.c +++ b/gcc/tree-cfg.c @@ -8927,7 +8927,31 @@ extract_true_false_controlled_edges (basic_block dom, basic_block phiblock, return true; } +/* Generate a range test LHS CODE RHS that determines whether INDEX is in the + range [low, high]. Place associated stmts before *GSI. */ +void +generate_range_test (basic_block bb, tree index, tree low, tree high, + tree *lhs, tree *rhs) +{ + tree type = TREE_TYPE (index); + tree utype = unsigned_type_for (type); + + low = fold_convert (type, low); + high = fold_convert (type, high); + + tree tmp = make_ssa_name (type); + gassign *sub1 + = gimple_build_assign (tmp, MINUS_EXPR, index, low); + + *lhs = make_ssa_name (utype); + gassign *a = gimple_build_assign (*lhs, NOP_EXPR, tmp); + + *rhs = fold_build2 (MINUS_EXPR, utype, high, low); + gimple_stmt_iterator gsi = gsi_last_bb (bb); + gsi_insert_before (&gsi, sub1, GSI_SAME_STMT); + gsi_insert_before (&gsi, a, GSI_SAME_STMT); +} /* Emit return warnings. */ diff --git a/gcc/tree-cfg.h b/gcc/tree-cfg.h index 66be43657bc..7a08cb074f7 100644 --- a/gcc/tree-cfg.h +++ b/gcc/tree-cfg.h @@ -109,6 +109,8 @@ extern basic_block insert_cond_bb (basic_block, gimple *, gimple *, extern bool gimple_find_sub_bbs (gimple_seq, gimple_stmt_iterator *); extern bool extract_true_false_controlled_edges (basic_block, basic_block, edge *, edge *); +extern void generate_range_test (basic_block bb, tree index, tree low, + tree high, tree *lhs, tree *rhs); /* Return true if the LHS of a call should be removed. */ diff --git a/gcc/tree-cfgcleanup.c b/gcc/tree-cfgcleanup.c index c6e5c8da03c..a7053d748c6 100644 --- a/gcc/tree-cfgcleanup.c +++ b/gcc/tree-cfgcleanup.c @@ -74,6 +74,49 @@ remove_fallthru_edge (vec *ev) return false; } +/* Convert a SWTCH with single non-default case to gcond and replace it + at GSI. */ + +static bool +convert_single_case_switch (gswitch *swtch, gimple_stmt_iterator &gsi) +{ + if (gimple_switch_num_labels (swtch) != 2) + return false; + + tree index = gimple_switch_index (swtch); + tree default_label = CASE_LABEL (gimple_switch_default_label (swtch)); + tree label = gimple_switch_label (swtch, 1); + tree low = CASE_LOW (label); + tree high = CASE_HIGH (label); + + basic_block default_bb = label_to_block_fn (cfun, default_label); + basic_block case_bb = label_to_block_fn (cfun, CASE_LABEL (label)); + + basic_block bb = gimple_bb (swtch); + gcond *cond; + + /* Replace switch statement with condition statement. */ + if (high) + { + tree lhs, rhs; + generate_range_test (bb, index, low, high, &lhs, &rhs); + cond = gimple_build_cond (LE_EXPR, lhs, rhs, NULL_TREE, NULL_TREE); + } + else + cond = gimple_build_cond (EQ_EXPR, index, + fold_convert (TREE_TYPE (index), low), + NULL_TREE, NULL_TREE); + + gsi_replace (&gsi, cond, true); + + /* Update edges. */ + edge case_edge = find_edge (bb, case_bb); + edge default_edge = find_edge (bb, default_bb); + + case_edge->flags |= EDGE_TRUE_VALUE; + default_edge->flags |= EDGE_FALSE_VALUE; + return true; +} /* Disconnect an unreachable block in the control expression starting at block BB. */ @@ -93,6 +136,12 @@ cleanup_control_expr_graph (basic_block bb, gimple_stmt_iterator gsi, bool warned; tree val = NULL_TREE; + /* Try to convert a switch with just a single non-default case to + GIMPLE condition. */ + if (gimple_code (stmt) == GIMPLE_SWITCH + && convert_single_case_switch (as_a (stmt), gsi)) + stmt = gsi_stmt (gsi); + fold_defer_overflow_warnings (); switch (gimple_code (stmt)) { diff --git a/gcc/tree-switch-conversion.c b/gcc/tree-switch-conversion.c index d0d08972804..6d7c2c4902f 100644 --- a/gcc/tree-switch-conversion.c +++ b/gcc/tree-switch-conversion.c @@ -2057,9 +2057,8 @@ try_switch_expansion (gswitch *stmt) expressions being INTEGER_CST. */ gcc_assert (TREE_CODE (index_expr) != INTEGER_CST); - /* Optimization of switch statements with only one label has already - occurred, so we should never see them at this point. */ - gcc_assert (ncases > 1); + if (ncases == 1) + return false; /* Find the default case target label. */ tree default_label = CASE_LABEL (gimple_switch_default_label (stmt)); @@ -2701,27 +2700,13 @@ emit_case_nodes (basic_block bb, tree index, case_node_ptr node, } else if (!low_bound && !high_bound) { - tree type = TREE_TYPE (index); - tree utype = unsigned_type_for (type); - - tree lhs = make_ssa_name (type); - gassign *sub1 - = gimple_build_assign (lhs, MINUS_EXPR, index, node->low); - - tree converted = make_ssa_name (utype); - gassign *a = gimple_build_assign (converted, NOP_EXPR, lhs); - - tree rhs = fold_build2 (MINUS_EXPR, utype, - fold_convert (type, node->high), - fold_convert (type, node->low)); - gimple_stmt_iterator gsi = gsi_last_bb (bb); - gsi_insert_before (&gsi, sub1, GSI_SAME_STMT); - gsi_insert_before (&gsi, a, GSI_SAME_STMT); - + tree lhs, rhs; + generate_range_test (bb, index, node->low, node->high, + &lhs, &rhs); probability = conditional_probability (default_prob, subtree_prob + default_prob); - bb = emit_cmp_and_jump_insns (bb, converted, rhs, GT_EXPR, + bb = emit_cmp_and_jump_insns (bb, lhs, rhs, GT_EXPR, default_bb, probability, phi_mapping); } -- 2.30.2