diff options
| -rw-r--r-- | gcc/testsuite/gcc.dg/tree-ssa/pr104645.c | 28 | ||||
| -rw-r--r-- | gcc/tree-ssa-phiopt.cc | 63 |
2 files changed, 77 insertions, 14 deletions
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr104645.c b/gcc/testsuite/gcc.dg/tree-ssa/pr104645.c new file mode 100644 index 0000000..83c1dd4 --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/pr104645.c @@ -0,0 +1,28 @@ +/* PR tree-optimization/104645 */ +/* { dg-do compile } */ +/* { dg-options "-O2 -fdump-tree-optimized" } */ +/* { dg-final { scan-tree-dump-not " = PHI <" "optimized" } } */ + +int +foo (unsigned i) +{ + return i ? i % 2 : 0; +} + +int +bar (unsigned i) +{ + int b = 0; + if (i) + { + unsigned a = i & 1; + b = a; + } + return b; +} + +int +baz (unsigned i) +{ + return i ? i + 4 : 4; +} diff --git a/gcc/tree-ssa-phiopt.cc b/gcc/tree-ssa-phiopt.cc index 562468b..4a0c9dd 100644 --- a/gcc/tree-ssa-phiopt.cc +++ b/gcc/tree-ssa-phiopt.cc @@ -1395,11 +1395,22 @@ value_replacement (basic_block cond_bb, basic_block middle_bb, gimple *assign = gsi_stmt (gsi); if (!is_gimple_assign (assign) - || gimple_assign_rhs_class (assign) != GIMPLE_BINARY_RHS || (!INTEGRAL_TYPE_P (TREE_TYPE (arg0)) && !POINTER_TYPE_P (TREE_TYPE (arg0)))) return 0; + if (gimple_assign_rhs_class (assign) != GIMPLE_BINARY_RHS) + { + /* If last stmt of the middle_bb is a conversion, handle it like + a preparation statement through constant evaluation with + checking for UB. */ + enum tree_code sc = gimple_assign_rhs_code (assign); + if (CONVERT_EXPR_CODE_P (sc)) + assign = NULL; + else + return 0; + } + /* Punt if there are (degenerate) PHIs in middle_bb, there should not be. */ if (!gimple_seq_empty_p (phi_nodes (middle_bb))) return 0; @@ -1430,7 +1441,8 @@ value_replacement (basic_block cond_bb, basic_block middle_bb, int prep_cnt; for (prep_cnt = 0; ; prep_cnt++) { - gsi_prev_nondebug (&gsi); + if (prep_cnt || assign) + gsi_prev_nondebug (&gsi); if (gsi_end_p (gsi)) break; @@ -1450,7 +1462,8 @@ value_replacement (basic_block cond_bb, basic_block middle_bb, || !INTEGRAL_TYPE_P (TREE_TYPE (lhs)) || !INTEGRAL_TYPE_P (TREE_TYPE (rhs1)) || !single_imm_use (lhs, &use_p, &use_stmt) - || use_stmt != (prep_cnt ? prep_stmt[prep_cnt - 1] : assign)) + || ((prep_cnt || assign) + && use_stmt != (prep_cnt ? prep_stmt[prep_cnt - 1] : assign))) return 0; switch (gimple_assign_rhs_code (g)) { @@ -1483,10 +1496,6 @@ value_replacement (basic_block cond_bb, basic_block middle_bb, >= 3 * estimate_num_insns (cond, &eni_time_weights)) return 0; - tree lhs = gimple_assign_lhs (assign); - tree rhs1 = gimple_assign_rhs1 (assign); - tree rhs2 = gimple_assign_rhs2 (assign); - enum tree_code code_def = gimple_assign_rhs_code (assign); tree cond_lhs = gimple_cond_lhs (cond); tree cond_rhs = gimple_cond_rhs (cond); @@ -1516,16 +1525,39 @@ value_replacement (basic_block cond_bb, basic_block middle_bb, return 0; } + tree lhs, rhs1, rhs2; + enum tree_code code_def; + if (assign) + { + lhs = gimple_assign_lhs (assign); + rhs1 = gimple_assign_rhs1 (assign); + rhs2 = gimple_assign_rhs2 (assign); + code_def = gimple_assign_rhs_code (assign); + } + else + { + gcc_assert (prep_cnt > 0); + lhs = cond_lhs; + rhs1 = NULL_TREE; + rhs2 = NULL_TREE; + code_def = ERROR_MARK; + } + if (((code == NE_EXPR && e1 == false_edge) || (code == EQ_EXPR && e1 == true_edge)) && arg0 == lhs - && ((arg1 == rhs1 - && operand_equal_for_phi_arg_p (rhs2, cond_lhs) - && neutral_element_p (code_def, cond_rhs, true)) - || (arg1 == rhs2 + && ((assign == NULL + && operand_equal_for_phi_arg_p (arg1, cond_rhs)) + || (assign + && arg1 == rhs1 + && operand_equal_for_phi_arg_p (rhs2, cond_lhs) + && neutral_element_p (code_def, cond_rhs, true)) + || (assign + && arg1 == rhs2 && operand_equal_for_phi_arg_p (rhs1, cond_lhs) && neutral_element_p (code_def, cond_rhs, false)) - || (operand_equal_for_phi_arg_p (arg1, cond_rhs) + || (assign + && operand_equal_for_phi_arg_p (arg1, cond_rhs) && ((operand_equal_for_phi_arg_p (rhs2, cond_lhs) && absorbing_element_p (code_def, cond_rhs, true, rhs2)) || (operand_equal_for_phi_arg_p (rhs1, cond_lhs) @@ -1555,8 +1587,11 @@ value_replacement (basic_block cond_bb, basic_block middle_bb, gsi_from = gsi_for_stmt (prep_stmt[i]); gsi_move_before (&gsi_from, &gsi); } - gsi_from = gsi_for_stmt (assign); - gsi_move_before (&gsi_from, &gsi); + if (assign) + { + gsi_from = gsi_for_stmt (assign); + gsi_move_before (&gsi_from, &gsi); + } replace_phi_edge_with_variable (cond_bb, e1, phi, lhs); return 2; } |