diff options
Diffstat (limited to 'gcc/fold-const.c')
| -rw-r--r-- | gcc/fold-const.c | 62 |
1 files changed, 40 insertions, 22 deletions
diff --git a/gcc/fold-const.c b/gcc/fold-const.c index 05fa7fead4e..c36f37834af 100644 --- a/gcc/fold-const.c +++ b/gcc/fold-const.c @@ -3923,6 +3923,7 @@ fold (expr) && (! TREE_SIDE_EFFECTS (arg0) || current_function_decl != 0)) { tree test, true_value, false_value; + tree lhs = 0, rhs = 0; if (TREE_CODE (arg1) == COND_EXPR) { @@ -3945,26 +3946,37 @@ fold (expr) to make this SAVE_EXPR. Since we do this optimization primarily to see if we do end up with constant and this SAVE_EXPR interferes with later optimizations, suppressing - it when we can is important. */ + it when we can is important. - if (TREE_CODE (arg0) != SAVE_EXPR + If we are not in a function, we can't make a SAVE_EXPR, so don't + try to do so. Don't try to see if the result is a constant + if an arm is a COND_EXPR since we get exponential behavior + in that case. */ + + if (TREE_CODE (arg0) != SAVE_EXPR && ! TREE_CONSTANT (arg0) + && current_function_decl != 0 && ((TREE_CODE (arg0) != VAR_DECL && TREE_CODE (arg0) != PARM_DECL) || TREE_SIDE_EFFECTS (arg0))) { - tree lhs = fold (build (code, type, arg0, true_value)); - tree rhs = fold (build (code, type, arg0, false_value)); + if (TREE_CODE (true_value) != COND_EXPR) + lhs = fold (build (code, type, arg0, true_value)); - if (TREE_CONSTANT (lhs) || TREE_CONSTANT (rhs)) - return fold (build (COND_EXPR, type, test, lhs, rhs)); + if (TREE_CODE (false_value) != COND_EXPR) + rhs = fold (build (code, type, arg0, false_value)); - if (current_function_decl != 0) - arg0 = save_expr (arg0); + if ((lhs == 0 || ! TREE_CONSTANT (lhs)) + && (rhs == 0 || !TREE_CONSTANT (rhs))) + arg0 = save_expr (arg0), lhs = rhs = 0; } - test = fold (build (COND_EXPR, type, test, - fold (build (code, type, arg0, true_value)), - fold (build (code, type, arg0, false_value)))); + if (lhs == 0) + lhs = fold (build (code, type, arg0, true_value)); + if (rhs == 0) + rhs = fold (build (code, type, arg0, false_value)); + + test = fold (build (COND_EXPR, type, test, lhs, rhs)); + if (TREE_CODE (arg0) == SAVE_EXPR) return build (COMPOUND_EXPR, type, convert (void_type_node, arg0), @@ -3982,6 +3994,7 @@ fold (expr) && (! TREE_SIDE_EFFECTS (arg1) || current_function_decl != 0)) { tree test, true_value, false_value; + tree lhs = 0, rhs = 0; if (TREE_CODE (arg0) == COND_EXPR) { @@ -3997,25 +4010,30 @@ fold (expr) false_value = convert (testtype, integer_zero_node); } - if (TREE_CODE (arg1) != SAVE_EXPR + if (TREE_CODE (arg1) != SAVE_EXPR && ! TREE_CONSTANT (arg0) + && current_function_decl != 0 && ((TREE_CODE (arg1) != VAR_DECL && TREE_CODE (arg1) != PARM_DECL) || TREE_SIDE_EFFECTS (arg1))) { - tree lhs = fold (build (code, type, true_value, arg1)); - tree rhs = fold (build (code, type, false_value, arg1)); + if (TREE_CODE (true_value) != COND_EXPR) + lhs = fold (build (code, type, true_value, arg1)); - if (TREE_CONSTANT (lhs) || TREE_CONSTANT (rhs) - || TREE_CONSTANT (arg1)) - return fold (build (COND_EXPR, type, test, lhs, rhs)); + if (TREE_CODE (false_value) != COND_EXPR) + rhs = fold (build (code, type, false_value, arg1)); - if (current_function_decl != 0) - arg1 = save_expr (arg1); + if ((lhs == 0 || ! TREE_CONSTANT (lhs)) + && (rhs == 0 || !TREE_CONSTANT (rhs))) + arg1 = save_expr (arg1), lhs = rhs = 0; } - test = fold (build (COND_EXPR, type, test, - fold (build (code, type, true_value, arg1)), - fold (build (code, type, false_value, arg1)))); + if (lhs == 0) + lhs = fold (build (code, type, true_value, arg1)); + + if (rhs == 0) + rhs = fold (build (code, type, false_value, arg1)); + + test = fold (build (COND_EXPR, type, test, lhs, rhs)); if (TREE_CODE (arg1) == SAVE_EXPR) return build (COMPOUND_EXPR, type, convert (void_type_node, arg1), |