diff options
Diffstat (limited to 'gcc/tree-ssa-math-opts.c')
| -rw-r--r-- | gcc/tree-ssa-math-opts.c | 134 |
1 files changed, 134 insertions, 0 deletions
diff --git a/gcc/tree-ssa-math-opts.c b/gcc/tree-ssa-math-opts.c index 2ca17c7..90ede52 100644 --- a/gcc/tree-ssa-math-opts.c +++ b/gcc/tree-ssa-math-opts.c @@ -1260,3 +1260,137 @@ struct gimple_opt_pass pass_optimize_bswap = 0 /* todo_flags_finish */ } }; + +/* Find integer multiplications where the operands are extended from + smaller types, and replace the MULT_EXPR with a WIDEN_MULT_EXPR + where appropriate. */ + +static unsigned int +execute_optimize_widening_mul (void) +{ + bool changed = false; + basic_block bb; + + FOR_EACH_BB (bb) + { + gimple_stmt_iterator gsi; + + for (gsi = gsi_after_labels (bb); !gsi_end_p (gsi); gsi_next (&gsi)) + { + gimple stmt = gsi_stmt (gsi); + gimple rhs1_stmt = NULL, rhs2_stmt = NULL; + tree type, type1 = NULL, type2 = NULL; + tree rhs1, rhs2, rhs1_convop = NULL, rhs2_convop = NULL; + enum tree_code rhs1_code, rhs2_code; + + if (!is_gimple_assign (stmt) + || gimple_assign_rhs_code (stmt) != MULT_EXPR) + continue; + + type = TREE_TYPE (gimple_assign_lhs (stmt)); + + if (TREE_CODE (type) != INTEGER_TYPE) + continue; + + rhs1 = gimple_assign_rhs1 (stmt); + rhs2 = gimple_assign_rhs2 (stmt); + + if (TREE_CODE (rhs1) == SSA_NAME) + { + rhs1_stmt = SSA_NAME_DEF_STMT (rhs1); + if (!is_gimple_assign (rhs1_stmt)) + continue; + rhs1_code = gimple_assign_rhs_code (rhs1_stmt); + if (!CONVERT_EXPR_CODE_P (rhs1_code)) + continue; + rhs1_convop = gimple_assign_rhs1 (rhs1_stmt); + type1 = TREE_TYPE (rhs1_convop); + if (TYPE_PRECISION (type1) * 2 != TYPE_PRECISION (type)) + continue; + } + else if (TREE_CODE (rhs1) != INTEGER_CST) + continue; + + if (TREE_CODE (rhs2) == SSA_NAME) + { + rhs2_stmt = SSA_NAME_DEF_STMT (rhs2); + if (!is_gimple_assign (rhs2_stmt)) + continue; + rhs2_code = gimple_assign_rhs_code (rhs2_stmt); + if (!CONVERT_EXPR_CODE_P (rhs2_code)) + continue; + rhs2_convop = gimple_assign_rhs1 (rhs2_stmt); + type2 = TREE_TYPE (rhs2_convop); + if (TYPE_PRECISION (type2) * 2 != TYPE_PRECISION (type)) + continue; + } + else if (TREE_CODE (rhs2) != INTEGER_CST) + continue; + + if (rhs1_stmt == NULL && rhs2_stmt == NULL) + continue; + + /* Verify that the machine can perform a widening multiply in this + mode/signedness combination, otherwise this transformation is + likely to pessimize code. */ + if ((rhs1_stmt == NULL || TYPE_UNSIGNED (type1)) + && (rhs2_stmt == NULL || TYPE_UNSIGNED (type2)) + && (optab_handler (umul_widen_optab, TYPE_MODE (type)) + ->insn_code == CODE_FOR_nothing)) + continue; + else if ((rhs1_stmt == NULL || !TYPE_UNSIGNED (type1)) + && (rhs2_stmt == NULL || !TYPE_UNSIGNED (type2)) + && (optab_handler (smul_widen_optab, TYPE_MODE (type)) + ->insn_code == CODE_FOR_nothing)) + continue; + else if (rhs1_stmt != NULL && rhs2_stmt != 0 + && (TYPE_UNSIGNED (type1) != TYPE_UNSIGNED (type2)) + && (optab_handler (usmul_widen_optab, TYPE_MODE (type)) + ->insn_code == CODE_FOR_nothing)) + continue; + + if ((rhs1_stmt == NULL && !int_fits_type_p (rhs1, type2)) + || (rhs2_stmt == NULL && !int_fits_type_p (rhs2, type1))) + continue; + + if (rhs1_stmt == NULL) + gimple_assign_set_rhs1 (stmt, fold_convert (type2, rhs1)); + else + gimple_assign_set_rhs1 (stmt, rhs1_convop); + if (rhs2_stmt == NULL) + gimple_assign_set_rhs2 (stmt, fold_convert (type1, rhs2)); + else + gimple_assign_set_rhs2 (stmt, rhs2_convop); + gimple_assign_set_rhs_code (stmt, WIDEN_MULT_EXPR); + update_stmt (stmt); + changed = true; + } + } + return (changed ? TODO_dump_func | TODO_update_ssa | TODO_verify_ssa + | TODO_verify_stmts : 0); +} + +static bool +gate_optimize_widening_mul (void) +{ + return flag_expensive_optimizations && optimize; +} + +struct gimple_opt_pass pass_optimize_widening_mul = +{ + { + GIMPLE_PASS, + "widening_mul", /* name */ + gate_optimize_widening_mul, /* gate */ + execute_optimize_widening_mul, /* execute */ + NULL, /* sub */ + NULL, /* next */ + 0, /* static_pass_number */ + TV_NONE, /* tv_id */ + PROP_ssa, /* properties_required */ + 0, /* properties_provided */ + 0, /* properties_destroyed */ + 0, /* todo_flags_start */ + 0 /* todo_flags_finish */ + } +}; |