diff options
Diffstat (limited to 'gcc/tree-ssa-forwprop.c')
| -rw-r--r-- | gcc/tree-ssa-forwprop.c | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/gcc/tree-ssa-forwprop.c b/gcc/tree-ssa-forwprop.c index 965f441..349272d 100644 --- a/gcc/tree-ssa-forwprop.c +++ b/gcc/tree-ssa-forwprop.c @@ -1886,6 +1886,54 @@ simplify_bitwise_binary (gimple_stmt_iterator *gsi) return true; } + + /* Simplify (A & B) OP0 (C & B) to (A OP0 C) & B. */ + if (def1_code == def2_code + && def1_code == BIT_AND_EXPR + && operand_equal_for_phi_arg_p (gimple_assign_rhs2 (def1), + gimple_assign_rhs2 (def2))) + { + tree b = gimple_assign_rhs2 (def1); + tree a = def1_arg1; + tree c = def2_arg1; + tree inner = fold_build2 (code, TREE_TYPE (arg2), a, c); + /* If A OP0 C (this usually means C is the same as A) is 0 + then fold it down correctly. */ + if (integer_zerop (inner)) + { + gimple_assign_set_rhs_from_tree (gsi, inner); + update_stmt (stmt); + return true; + } + /* If A OP0 C (this usually means C is the same as A) is a ssa_name + then fold it down correctly. */ + else if (TREE_CODE (inner) == SSA_NAME) + { + tree outer = fold_build2 (def1_code, TREE_TYPE (inner), + inner, b); + gimple_assign_set_rhs_from_tree (gsi, outer); + update_stmt (stmt); + return true; + } + else + { + gimple newop; + tree tem; + tem = create_tmp_reg (TREE_TYPE (arg2), NULL); + newop = gimple_build_assign_with_ops (code, tem, a, c); + tem = make_ssa_name (tem, newop); + gimple_assign_set_lhs (newop, tem); + gimple_set_location (newop, gimple_location (stmt)); + /* Make sure to re-process the new stmt as it's walking upwards. */ + gsi_insert_before (gsi, newop, GSI_NEW_STMT); + gimple_assign_set_rhs1 (stmt, tem); + gimple_assign_set_rhs2 (stmt, b); + gimple_assign_set_rhs_code (stmt, def1_code); + update_stmt (stmt); + return true; + } + } + /* (a | CST1) & CST2 -> (a & CST2) | (CST1 & CST2). */ if (code == BIT_AND_EXPR && def1_code == BIT_IOR_EXPR |