added some optimalizations
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eck
parent
9915ed4bc2
commit
2f0275ba3c
4 changed files with 51 additions and 19 deletions
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@ -27,8 +27,13 @@ extern char *symbol2str();
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depending on the constancy of the operands.
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*/
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#define commutative_binop(expp, oper, expr) mk_binop(expp, oper, expr, 1)
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/*
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* Although the relational operators are generally not commutative, we can
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* switch the arguments if the operator is adapted (e.g. < becomes >)
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*/
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#define non_commutative_binop(expp, oper, expr) mk_binop(expp, oper, expr, 0)
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#define commutative_binop(expp, oper, expr) mk_binop(expp, oper, expr, 1)
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#define non_commutative_relop(expp, oper, expr) mk_binop(expp, oper, expr, 1)
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ch3bin(expp, oper, expr)
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register struct expr **expp;
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@ -182,7 +187,7 @@ ch3bin(expp, oper, expr)
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case EQUAL:
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case NOTEQUAL:
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relbalance(expp, oper, &expr);
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non_commutative_binop(expp, oper, expr);
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non_commutative_relop(expp, oper, expr);
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(*expp)->ex_type = int_type;
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break;
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@ -301,6 +306,23 @@ pntminuspnt(expp, oper, expr)
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if (int_size != pointer_size) (*expp)->ex_flags |= EX_PTRDIFF;
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}
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/*
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* The function arg_switched() returns the operator that should be used
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* when the arguments are switched. This is special for some relational
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* operators.
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*/
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int
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arg_switched(oper)
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{
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switch (oper) {
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case '<': return '>';
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case '>': return '<';
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case LESSEQ: return GREATEREQ;
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case GREATEREQ: return LESSEQ;
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default: return oper;
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}
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}
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mk_binop(expp, oper, expr, commutative)
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struct expr **expp;
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register struct expr *expr;
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@ -315,14 +337,13 @@ mk_binop(expp, oper, expr, commutative)
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cstbin(expp, oper, expr);
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else if (is_fp_cst(expr) && is_fp_cst(ex))
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fltcstbin(expp, oper, expr);
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else {
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*expp = (commutative &&
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! (ex->ex_flags & EX_VOLATILE) &&
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( expr->ex_depth > ex->ex_depth ||
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(expr->ex_flags & EX_SIDEEFFECTS) ||
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is_cp_cst(ex)))
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? new_oper(ex->ex_type, expr, oper, ex)
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: new_oper(ex->ex_type, ex, oper, expr);
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else {
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*expp = (commutative
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&& !(ex->ex_flags & EX_VOLATILE)
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&& ( expr->ex_depth > ex->ex_depth
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|| is_cp_cst(ex)))
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? new_oper(ex->ex_type, expr, arg_switched(oper), ex)
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: new_oper(ex->ex_type, ex, oper, expr);
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}
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}
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@ -279,14 +279,14 @@ end_proc(fbytes)
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DfaEndFunction();
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#endif DATAFLOW
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C_df_ilb(return2_label);
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if (return_expr_occurred) C_asp(-func_size);
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if (return_expr_occurred && func_res_label == 0) {
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C_asp(-func_size);
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}
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C_df_ilb(return_label);
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prc_exit();
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#ifndef LINT
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if (return_expr_occurred) {
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if (func_res_label != 0) {
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C_lae_dlb(func_res_label, (arith)0);
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store_block(func_size, func_type->tp_align);
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C_lae_dlb(func_res_label, (arith)0);
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C_ret(pointer_size);
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}
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@ -347,6 +347,10 @@ do_return_expr(expr)
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*/
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ch3cast(&expr, RETURN, func_type);
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code_expr(expr, RVAL, TRUE, NO_LABEL, NO_LABEL);
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if (func_res_label != 0) {
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C_lae_dlb(func_res_label, (arith)0);
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store_block(func_size, func_type->tp_align);
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}
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C_bra(return_label);
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return_expr_occurred = 1;
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}
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@ -67,13 +67,13 @@ declaration
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short typedef yepp;
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makes all hope of writing a specific grammar for typedefs illusory.
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*/
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/* Accept a single declaration specifier. Then accept zero or more
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type-specifiers. There can be a conflict on both TYPE_IDENTIFIER
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and IDENTIFIER.
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/* Accept a single declaration specifier. Then accept zero or more
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declaration specifiers. There can be a conflict on both
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TYPE_IDENTIFIER and IDENTIFIER.
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The following rule is used:
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When we see a TYPE_IDENTIFIER, we accept it if no type-specifier
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was given, and it is not directly followed by an identifier.
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If no type-dpecifier was given, it is taken as the identifier being
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When we see a TYPE_IDENTIFIER, we accept it if no type-specifier was
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given, and it is not directly followed by an identifier. If a
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type-specifier was given, it is taken as the identifier being
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declared. If it is followed by an identifier, we assume that an
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error has been made, (e.g. unsigned typedeffed_int x;) and that
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this will be detected later on.
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@ -383,6 +383,13 @@ new_oper(tp, e1, oper, e2)
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expr->ex_flags = (e1_flags | e2->ex_flags)
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& ~(EX_PARENS | EX_READONLY | EX_VOLATILE );
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}
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/*
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* A function call should be evaluated first when possible. Just say
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* that the expression tree is very deep.
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*/
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if (oper == '(') {
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expr->ex_depth = 50;
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}
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op = &expr->ex_object.ex_oper;
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op->op_type = tp;
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op->op_oper = oper;
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