X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Fopt%2Fopt_confirms.c;h=28e0ef7d5588b7ad8c1738481bfd5d684fefb1f2;hb=b490cca90e691cdf88fbe624da45c44199ae7b92;hp=95df834e57d9a75d9a3ae886081855027e2407bf;hpb=0d470055af1b3bc6c917e6f004123e5aab47de8f;p=libfirm diff --git a/ir/opt/opt_confirms.c b/ir/opt/opt_confirms.c index 95df834e5..28e0ef7d5 100644 --- a/ir/opt/opt_confirms.c +++ b/ir/opt/opt_confirms.c @@ -1,5 +1,5 @@ /* - * Copyright (C) 1995-2007 University of Karlsruhe. All right reserved. + * Copyright (C) 1995-2008 University of Karlsruhe. All right reserved. * * This file is part of libFirm. * @@ -105,7 +105,17 @@ int value_not_zero(ir_node *n, ir_node **confirm) { pn_Cmp pnc; *confirm = NULL; - while (get_irn_op(n) == op_Confirm) { + + /* there might be several Confirms one after other that form an interval */ + for (;;) { + if (is_Minus(n) || is_Abs(n)) { + /* we can safely skip Minus and Abs when checking for != 0 */ + n = get_unop_op(n); + continue; + } + if (! is_Confirm(n)) + break; + /* * Note: A Confirm is never after a Const. So, * we simply can check the bound for being a Const @@ -141,8 +151,6 @@ int value_not_zero(ir_node *n, ir_node **confirm) { default: break; } - - /* there might be several Confirms one after other that form an interval */ n = get_Confirm_value(n); } tv = value_of(n); @@ -172,6 +180,7 @@ int value_not_null(ir_node *n, ir_node **confirm) { *confirm = NULL; n = skip_Cast(n); + op = get_irn_op(n); assert(mode_is_reference(get_irn_mode(n))); if (get_opt_sel_based_null_check_elim()) { @@ -181,18 +190,25 @@ int value_not_null(ir_node *n, ir_node **confirm) { op = get_irn_op(n); } } - if (op == op_SymConst && get_SymConst_kind(n) == symconst_addr_ent) + if (is_Global(n)) { + /* global references are never NULL */ + return 1; + } else if (n == get_irg_frame(current_ir_graph)) { + /* local references are never NULL */ return 1; - if (op == op_Const) { - tarval *tv = get_Const_tarval(n); - - if (tv != tarval_bad && classify_tarval(tv) != TV_CLASSIFY_NULL) - return 1; - } else if (op == op_Confirm) { - if (get_Confirm_cmp(n) == pn_Cmp_Lg && - classify_Const(get_Confirm_bound(n)) == CNST_NULL) { - *confirm = n; - return 1; + } else if (op == op_Const) { + /* explicit non-NULL addresses */ + return !is_Const_null(n); + } else { + /* check for more Confirms */ + for (; is_Confirm(n); n = skip_Cast(get_Confirm_value(n))) { + if (get_Confirm_cmp(n) != pn_Cmp_Lg) { + ir_node *bound = get_Confirm_bound(n); + if (is_Const(bound) && is_Const_null(bound)) { + *confirm = n; + return 1; + } + } } } return 0; @@ -207,7 +223,23 @@ value_classify_sign classify_value_sign(ir_node *n) { tarval *tv, *c; ir_mode *mode; pn_Cmp cmp, ncmp; + int negate = 1; + + for (;;) { + ir_opcode code = get_irn_opcode(n); + switch (code) { + case iro_Minus: + negate *= -1; + n = get_Minus_op(n); + continue; + case iro_Confirm: + break; + default: + return value_classified_unknown; + } + break; + } if (get_irn_op(n) != op_Confirm) return value_classified_unknown; @@ -250,7 +282,7 @@ value_classify_sign classify_value_sign(ir_node *n) { return value_classified_unknown; /* yep, negative */ - return value_classified_negative; + return value_classified_negative * negate; case pn_Cmp_Ge: /* @@ -281,7 +313,7 @@ value_classify_sign classify_value_sign(ir_node *n) { } /* yep, positive */ - return value_classified_positive; + return value_classified_positive * negate; default: return value_classified_unknown; @@ -571,7 +603,6 @@ static int is_transitive(pn_Cmp pnc) { return (pn_Cmp_False < pnc && pnc < pn_Cmp_Lg); } /* is_transitive */ - /** * Return the value of a Cmp if one or both predecessors * are Confirm nodes. @@ -582,40 +613,39 @@ static int is_transitive(pn_Cmp pnc) { * @param pnc the compare relation */ tarval *computed_value_Cmp_Confirm(ir_node *cmp, ir_node *left, ir_node *right, pn_Cmp pnc) { - ir_node *l_bound; - pn_Cmp l_pnc, res_pnc, neg_pnc; - interval_t l_iv, r_iv; - tarval *tv; - ir_mode *mode; - - if (get_irn_op(right) == op_Confirm) { - ir_node *t; + ir_node *l_bound; + pn_Cmp l_pnc, res_pnc, neg_pnc; + interval_t l_iv, r_iv; + tarval *tv; + ir_mode *mode; + if (is_Confirm(right)) { /* we want the Confirm on the left side */ - t = left; - left = right; - right = t; + ir_node *t = right; + right = left; + left = t; pnc = get_inversed_pnc(pnc); - } else if (get_irn_op(left) != op_Confirm) { - /* no Confirm on either one side, finish */ - return tarval_bad; + } else if (! is_Confirm(left)) { + /* nothing more found */ + tv = tarval_bad; + goto check_null_case; } /* ok, here at least left is a Confirm, right might be */ l_bound = get_Confirm_bound(left); l_pnc = get_Confirm_cmp(left); - if (get_irn_op(right) == op_Confirm) { + if (is_Confirm(right)) { /* - * both sides are Confirm's. Check some rare cases first. - */ + * both sides are Confirm's. Check some rare cases first. + */ ir_node *r_bound = get_Confirm_bound(right); - pn_Cmp r_pnc = get_Confirm_cmp(right); + pn_Cmp r_pnc = get_Confirm_cmp(right); /* - * some check can be made WITHOUT constant bounds - */ + * some check can be made WITHOUT constant bounds + */ if (r_bound == l_bound) { if (is_transitive(l_pnc)) { pn_Cmp r_inc_pnc = get_inversed_pnc(r_pnc); @@ -732,6 +762,24 @@ tarval *computed_value_Cmp_Confirm(ir_node *cmp, ir_node *left, ir_node *right, get_interval(&l_iv, l_bound, l_pnc), get_interval_from_tv(&r_iv, tv), pnc); + } else { +check_null_case: + /* check some other cases */ + if ((pnc == pn_Cmp_Eq || pnc == pn_Cmp_Lg) && + is_Const(right) && is_Const_null(right)) { + /* for == 0 or != 0 we have some special tools */ + ir_mode *mode = get_irn_mode(left); + ir_node *dummy; + if (mode_is_reference(mode)) { + if (value_not_null(left, &dummy)) { + tv = pnc == pn_Cmp_Eq ? tarval_b_false : tarval_b_true; + } + } else { + if (value_not_zero(left, &dummy)) { + tv = pnc == pn_Cmp_Eq ? tarval_b_false : tarval_b_true; + } + } + } } if (tv != tarval_bad)