X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Fopt%2Freassoc.c;h=dee03840c7b78dc4f636e136e4033a9814ed81ed;hb=e27c2b398ce1762ca2108e24295ff8ddcb4a1c1f;hp=4fe6bdc59e7cca173bc5b3cabe497a2c70830ac2;hpb=a36db47fd0769f24dadc0ddd708052855ba349cb;p=libfirm diff --git a/ir/opt/reassoc.c b/ir/opt/reassoc.c index 4fe6bdc59..dee03840c 100644 --- a/ir/opt/reassoc.c +++ b/ir/opt/reassoc.c @@ -1,265 +1,355 @@ /* - * Project: libFIRM - * File name: ir/opt/reassoc.c - * Purpose: Reassociation - * Author: Michael Beck - * Created: - * CVS-ID: $Id$ - * Copyright: (c) 1998-2004 Universität Karlsruhe - * Licence: This file protected by GPL - GNU GENERAL PUBLIC LICENSE. + * Copyright (C) 1995-2008 University of Karlsruhe. All right reserved. + * + * This file is part of libFirm. + * + * This file may be distributed and/or modified under the terms of the + * GNU General Public License version 2 as published by the Free Software + * Foundation and appearing in the file LICENSE.GPL included in the + * packaging of this file. + * + * Licensees holding valid libFirm Professional Edition licenses may use + * this file in accordance with the libFirm Commercial License. + * Agreement provided with the Software. + * + * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE + * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR + * PURPOSE. */ -#ifdef HAVE_CONFIG_H -# include "config.h" -#endif - -# include "irnode_t.h" -# include "irgraph_t.h" -# include "irmode_t.h" -# include "iropt_t.h" -# include "ircons_t.h" -# include "irgmod.h" -# include "dbginfo.h" -# include "iropt_dbg.h" -# include "irflag_t.h" -# include "irgwalk.h" -# include "reassoc_t.h" -# include "irhooks.h" -# include "debug.h" - -static firm_dbg_module_t *dbg; - -typedef struct _walker_t { - int changes; /* set, if a reassociation take place */ -} walker_t; +/** + * @file + * @brief Reassociation + * @author Michael Beck + */ +#include "config.h" + +#include "iroptimize.h" +#include "iropt_t.h" +#include "irnode_t.h" +#include "irgraph_t.h" +#include "irmode_t.h" +#include "ircons_t.h" +#include "irgmod.h" +#include "iropt_dbg.h" +#include "irflag_t.h" +#include "irgwalk.h" +#include "irouts.h" +#include "reassoc_t.h" +#include "opt_init.h" +#include "irhooks.h" +#include "irloop.h" +#include "pdeq.h" +#include "debug.h" +#include "irpass.h" + +DEBUG_ONLY(static firm_dbg_module_t *dbg;) typedef enum { - NO_CONSTANT = 0, /**< node is not constant */ - REAL_CONSTANT = 1, /**< node is a Const that is suitable for constant folding */ - CONST_EXPR = 4 /**< node is a constant expression in the current context, - use 4 here to simplify implementation of get_comm_Binop_ops() */ + NO_CONSTANT = 0, /**< node is not constant */ + REAL_CONSTANT = 1, /**< node is a Const that is suitable for constant folding */ + REGION_CONST = 4 /**< node is a constant expression in the current context, + use 4 here to simplify implementation of get_comm_Binop_ops() */ } const_class_t; /** - * returns whether a node is constant, ie is a constant or - * is loop invariant + * returns whether a node is constant ie is a constant or + * is loop invariant (called region constant) + * + * @param n the node to be checked for constant + * @param block a block that might be in a loop */ -static const_class_t get_const_class(ir_node *n) +static const_class_t get_const_class(const ir_node *n, const ir_node *block) { - ir_op *op = get_irn_op(n); + if (is_Const(n)) + return REAL_CONSTANT; - if (op == op_Const) - return REAL_CONSTANT; - if (op == op_SymConst) - return CONST_EXPR; + /* constant nodes which can't be folded are region constants */ + if (is_irn_constlike(n)) + return REGION_CONST; - return NO_CONSTANT; -} + /* + * Beware: Bad nodes are always loop-invariant, but + * cannot handled in later code, so filter them here. + */ + if (! is_Bad(n) && is_loop_invariant(n, block)) + return REGION_CONST; + + return NO_CONSTANT; +} /* get_const_class */ /** * returns the operands of a commutative bin-op, if one operand is - * a constant in the current context, it is returned as the second one. + * a region constant, it is returned as the second one. * * Beware: Real constants must be returned with higher priority than - * constant expression, because they might be folded. + * region constants, because they might be folded. */ static void get_comm_Binop_ops(ir_node *binop, ir_node **a, ir_node **c) { - ir_node *op_a = get_binop_left(binop); - ir_node *op_b = get_binop_right(binop); - int class_a = get_const_class(op_a); - int class_b = get_const_class(op_b); - - assert(is_op_commutative(get_irn_op(binop))); - - switch (class_a + 2*class_b) { - case REAL_CONSTANT + 2*NO_CONSTANT: - case REAL_CONSTANT + 2*REAL_CONSTANT: - case REAL_CONSTANT + 2*CONST_EXPR: - case CONST_EXPR + 2*NO_CONSTANT: - *a = op_b; - *c = op_a; - break; - default: - *a = op_a; - *c = op_b; - break; - } -} + ir_node *op_a = get_binop_left(binop); + ir_node *op_b = get_binop_right(binop); + ir_node *block = get_nodes_block(binop); + int class_a = get_const_class(op_a, block); + int class_b = get_const_class(op_b, block); + + assert(is_op_commutative(get_irn_op(binop))); + + switch (class_a + 2*class_b) { + case REAL_CONSTANT + 2*REAL_CONSTANT: + /* if both are constants, one might be a + * pointer constant like NULL, return the other + */ + if (mode_is_reference(get_irn_mode(op_a))) { + *a = op_a; + *c = op_b; + } else { + *a = op_b; + *c = op_a; + } + break; + case REAL_CONSTANT + 2*NO_CONSTANT: + case REAL_CONSTANT + 2*REGION_CONST: + case REGION_CONST + 2*NO_CONSTANT: + *a = op_b; + *c = op_a; + break; + default: + *a = op_a; + *c = op_b; + break; + } +} /* get_comm_Binop_ops */ /** - * reassociate a Sub: x - c = (-c) + x + * reassociate a Sub: x - c = x + (-c) */ static int reassoc_Sub(ir_node **in) { ir_node *n = *in; - ir_node *right = get_Sub_right(n); - - /* FIXME: Do not apply this rule for unsigned Sub's because our code - * generation is currently buggy :-) - */ - if (! mode_is_signed(get_irn_mode(n))) - return 0; - - /* handles rule R6: - * convert x - c => (-c) + x - * - * As there is NO real Minus in Firm it makes no sense to do this - * for non-real constants yet. - * */ - if (get_const_class(right) == REAL_CONSTANT) { - ir_node *left = get_Sub_left(n); - ir_node *block = get_nodes_block(n); - ir_mode *mode = get_irn_mode(n); - dbg_info *dbi = get_irn_dbg_info(n); - ir_node *irn, *c; - - switch (get_const_class(left)) { - case REAL_CONSTANT: - irn = optimize_in_place(n); - if (irn != n) { - exchange(n, irn); - *in = irn; - return 1; - } - return 0; - case NO_CONSTANT: - break; - default: - /* already constant, nothing to do */ - return 0; - } - - c = new_r_Const(current_ir_graph, block, mode, get_mode_null(mode)); - irn = new_rd_Sub(dbi, current_ir_graph, block, c, right, mode); - - irn = new_rd_Add(dbi, current_ir_graph, block, left, irn, get_irn_mode(n)); - - DBG((dbg, LEVEL_5, "Applied: %n - %n => %n + (-%n)\n", - get_Sub_left(n), c, get_Sub_left(n), c)); - - exchange(n, irn); + ir_node *right = get_Sub_right(n); + ir_mode *rmode = get_irn_mode(right); + ir_node *block; + + /* cannot handle SubIs(P, P) */ + if (mode_is_reference(rmode)) + return 0; + + block = get_nodes_block(n); + + /* handles rule R6: + * convert x - c => x + (-c) + */ + if (get_const_class(right, block) == REAL_CONSTANT) { + ir_node *left = get_Sub_left(n); + ir_mode *mode; + dbg_info *dbi; + ir_node *irn; + + switch (get_const_class(left, block)) { + case REAL_CONSTANT: + irn = optimize_in_place(n); + if (irn != n) { + exchange(n, irn); + *in = irn; + return 1; + } + return 0; + case NO_CONSTANT: + break; + default: + /* already constant, nothing to do */ + return 0; + } + + mode = get_irn_mode(n); + dbi = get_irn_dbg_info(n); + + /* Beware of SubP(P, Is) */ + irn = new_rd_Minus(dbi, block, right, rmode); + irn = new_rd_Add(dbi, block, left, irn, mode); + + DBG((dbg, LEVEL_5, "Applied: %n - %n => %n + (-%n)\n", + get_Sub_left(n), right, get_Sub_left(n), right)); + + if (n == irn) + return 0; + + exchange(n, irn); *in = irn; - return 1; - } - return 0; -} + return 1; + } + return 0; +} /* reassoc_Sub */ -/** Retrieve a mode form the operands. We need this, because +/** Retrieve a mode from the operands. We need this, because * Add and Sub are allowed to operate on (P, Is) */ static ir_mode *get_mode_from_ops(ir_node *op1, ir_node *op2) { - ir_mode *m1, *m2; + ir_mode *m1, *m2; - m1 = get_irn_mode(op1); - if (mode_is_reference(m1)) - return m1; + m1 = get_irn_mode(op1); + if (mode_is_reference(m1)) + return m1; - m2 = get_irn_mode(op2); - if (mode_is_reference(m2)) - return m2; + m2 = get_irn_mode(op2); + if (mode_is_reference(m2)) + return m2; - assert(m1 == m2); + assert(m1 == m2); - return m1; -} + return m1; +} /* get_mode_from_ops */ /** * reassociate a commutative Binop * * BEWARE: this rule leads to a potential loop, if - * all two operands are are constant expressions and the third is a + * two operands are region constants and the third is a * constant, so avoid this situation. */ static int reassoc_commutative(ir_node **node) { ir_node *n = *node; - ir_op *op = get_irn_op(n); - ir_node *block = get_nodes_block(n); - ir_node *t1, *c1; - - get_comm_Binop_ops(n, &t1, &c1); - - if (get_irn_op(t1) == op) { - ir_node *t2, *c2; - const_class_t c_c1, c_c2, c_t2; - - get_comm_Binop_ops(t1, &t2, &c2); - - /* do not optimize Bad nodes, will fail later */ - if (is_Bad(t2)) - return 0; - - c_c1 = get_const_class(c1); - c_c2 = get_const_class(c2); - c_t2 = get_const_class(t2); - - if ( ((c_c1 > NO_CONSTANT) & (c_t2 > NO_CONSTANT)) && - ((((c_c1 ^ c_c2 ^ c_t2) & CONST_EXPR) == 0) || ((c_c1 & c_c2 & c_t2) == CONST_EXPR)) ) { - /* all three are constant and either all are constant expressions or two of them are: - * then, applying this rule would lead into a cycle - * - * Note that if t2 is a constant so is c2, so we save one test. - */ - return 0; - } - - if ((c_c1 != NO_CONSTANT) & (c_c2 != NO_CONSTANT)) { - /* handles rules R7, R8, R9, R10: - * convert c1 .OP. (c2 .OP. x) => (c1 .OP. c2) .OP. x - */ - ir_node *irn, *in[2]; - ir_mode *mode, *mode_c1 = get_irn_mode(c1), *mode_c2 = get_irn_mode(c2); - - /* It might happen, that c1 and c2 have different modes, for instance Is and Iu. - * Handle this here. - */ - if (mode_c1 != mode_c2) { - if (mode_is_int(mode_c1) && mode_is_int(mode_c2)) { - /* get the bigger one */ - if (get_mode_size_bits(mode_c1) > get_mode_size_bits(mode_c2)) - c2 = new_r_Conv(current_ir_graph, block, c2, mode_c1); - else if (get_mode_size_bits(mode_c1) < get_mode_size_bits(mode_c2)) - c1 = new_r_Conv(current_ir_graph, block, c1, mode_c2); - else { - /* Try to cast the real const */ - if (c_c1 == REAL_CONSTANT) - c1 = new_r_Conv(current_ir_graph, block, c1, mode_c2); - else - c2 = new_r_Conv(current_ir_graph, block, c2, mode_c1); - } - } - } - - in[0] = c1; - in[1] = c2; - - mode = get_mode_from_ops(in[0], in[1]); - in[0] = optimize_node(new_ir_node(NULL, current_ir_graph, block, op, mode, 2, in)); - in[1] = t2; - - mode = get_mode_from_ops(in[0], in[1]); - irn = optimize_node(new_ir_node(NULL, current_ir_graph, block, op, mode, 2, in)); - - DBG((dbg, LEVEL_5, "Applied: %n .%s. (%n .%s. %n) => (%n .%s. %n) .%s. %n\n", - c1, get_irn_opname(n), c2, get_irn_opname(n), - t2, c1, get_irn_opname(n), c2, get_irn_opname(n), t2)); - /* - * in some rare cases it can really happen that we get the same node back. - * This might be happen in dead loops, were the Phi nodes are already gone away. - * So check this. - */ - if (n != irn) { - exchange(n, irn); + ir_op *op = get_irn_op(n); + ir_node *block = get_nodes_block(n); + ir_node *t1, *c1; + + get_comm_Binop_ops(n, &t1, &c1); + + if (get_irn_op(t1) == op) { + ir_node *t2, *c2; + const_class_t c_c1, c_c2, c_t2; + + get_comm_Binop_ops(t1, &t2, &c2); + + /* do not optimize Bad nodes, will fail later */ + if (is_Bad(t2)) + return 0; + + c_c1 = get_const_class(c1, block); + c_c2 = get_const_class(c2, block); + c_t2 = get_const_class(t2, block); + + if ( ((c_c1 > NO_CONSTANT) & (c_t2 > NO_CONSTANT)) && + ((((c_c1 ^ c_c2 ^ c_t2) & REGION_CONST) == 0) || ((c_c1 & c_c2 & c_t2) == REGION_CONST)) ) { + /* All three are constant and either all are constant expressions + * or two of them are: + * then applying this rule would lead into a cycle + * + * Note that if t2 is a constant so is c2 hence we save one test. + */ + return 0; + } + + if ((c_c1 != NO_CONSTANT) /* & (c_c2 != NO_CONSTANT) */) { + /* handles rules R7, R8, R9, R10: + * convert c1 .OP. (c2 .OP. x) => x .OP. (c1 .OP. c2) + */ + ir_node *irn, *in[2]; + ir_mode *mode, *mode_c1 = get_irn_mode(c1), *mode_c2 = get_irn_mode(c2); + ir_graph *irg = get_irn_irg(c1); + + /* It might happen, that c1 and c2 have different modes, for + * instance Is and Iu. + * Handle this here. + */ + if (mode_c1 != mode_c2) { + if (mode_is_int(mode_c1) && mode_is_int(mode_c2)) { + /* get the bigger one */ + if (get_mode_size_bits(mode_c1) > get_mode_size_bits(mode_c2)) + c2 = new_r_Conv(block, c2, mode_c1); + else if (get_mode_size_bits(mode_c1) < get_mode_size_bits(mode_c2)) + c1 = new_r_Conv(block, c1, mode_c2); + else { + /* Try to cast the real const */ + if (c_c1 == REAL_CONSTANT) + c1 = new_r_Conv(block, c1, mode_c2); + else + c2 = new_r_Conv(block, c2, mode_c1); + } + } + } + + in[0] = c1; + in[1] = c2; + + mode = get_mode_from_ops(in[0], in[1]); + in[1] = optimize_node(new_ir_node(NULL, irg, block, op, mode, 2, in)); + in[0] = t2; + + mode = get_mode_from_ops(in[0], in[1]); + irn = optimize_node(new_ir_node(NULL, irg, block, op, mode, 2, in)); + + DBG((dbg, LEVEL_5, "Applied: %n .%s. (%n .%s. %n) => %n .%s. (%n .%s. %n)\n", + c1, get_irn_opname(n), c2, get_irn_opname(n), t2, + t2, get_irn_opname(n), c1, get_irn_opname(n), c2)); + /* + * In some rare cases it can really happen that we get the same + * node back. This might be happen in dead loops, were the Phi + * nodes are already gone away. So check this. + */ + if (n != irn) { + exchange(n, irn); *node = irn; - return 1; - } - } - } - return 0; -} + return 1; + } + } + } + if (get_irn_op(c1) == op) { + ir_node *t = c1; + c1 = t1; + t1 = t; + } + if (get_irn_op(t1) == op) { + ir_node *l = get_binop_left(t1); + ir_node *r = get_binop_right(t1); + const_class_t c_r; + + if (r == c1) { + ir_node *t = r; + r = l; + l = t; + } + c_r = get_const_class(r, block); + if (c_r != NO_CONSTANT) { + /* + * Beware: don't do the following op if a constant was + * placed below, else we will fall into a loop. + */ + return 0; + } + + if (l == c1) { + /* convert x .OP. (x .OP. y) => y .OP. (x .OP. x) */ + ir_mode *mode_res = get_irn_mode(n); + ir_mode *mode_c1 = get_irn_mode(c1); + ir_graph *irg = get_irn_irg(c1); + ir_node *irn, *in[2]; + + in[0] = c1; + in[1] = c1; + + in[1] = optimize_node(new_ir_node(NULL, irg, block, op, mode_c1, 2, in)); + in[0] = r; + + irn = optimize_node(new_ir_node(NULL, irg, block, op, mode_res, 2, in)); + + DBG((dbg, LEVEL_5, "Applied: %n .%s. (%n .%s. %n) => %n .%s. (%n .%s. %n)\n", + c1, get_irn_opname(n), l, get_irn_opname(n), r, + r, get_irn_opname(n), c1, get_irn_opname(n), c1)); + + if (n != irn) { + exchange(n, irn); + *node = irn; + return 1; + } + } + } + return 0; +} /* reassoc_commutative */ #define reassoc_Add reassoc_commutative #define reassoc_And reassoc_commutative @@ -267,71 +357,425 @@ static int reassoc_commutative(ir_node **node) #define reassoc_Eor reassoc_commutative /** - * reassociate using distributive law for Mul and Add/Sub + * Reassociate using commutative law for Mul and distributive law for Mul and Add/Sub: */ static int reassoc_Mul(ir_node **node) { ir_node *n = *node; - ir_node *add_sub, *c; - ir_op *op; + ir_node *add_sub, *c; + ir_op *op; + + if (reassoc_commutative(&n)) + return 1; + + get_comm_Binop_ops(n, &add_sub, &c); + op = get_irn_op(add_sub); + + /* handles rules R11, R12, R13, R14, R15, R16, R17, R18, R19, R20 */ + if (op == op_Add || op == op_Sub) { + ir_mode *mode = get_irn_mode(n); + ir_node *irn, *block, *t1, *t2, *in[2]; + + block = get_nodes_block(n); + t1 = get_binop_left(add_sub); + t2 = get_binop_right(add_sub); + + /* we can only multiplication rules on integer arithmetic */ + if (mode_is_int(get_irn_mode(t1)) && mode_is_int(get_irn_mode(t2))) { + ir_graph *irg = get_irn_irg(t1); + in[0] = new_rd_Mul(NULL, block, c, t1, mode); + in[1] = new_rd_Mul(NULL, block, c, t2, mode); + + irn = optimize_node(new_ir_node(NULL, irg, block, op, mode, 2, in)); + + /* In some cases it might happen that the new irn is equal the old one, for + * instance in: + * (x - 1) * y == x * y - y + * will be transformed back by simpler optimization + * We could switch simple optimizations off, but this only happens iff y + * is a loop-invariant expression and that it is not clear if the new form + * is better. + * So, we let the old one. + */ + if (irn != n) { + DBG((dbg, LEVEL_5, "Applied: (%n .%s. %n) %n %n => (%n %n %n) .%s. (%n %n %n)\n", + t1, get_op_name(op), t2, n, c, t1, n, c, get_op_name(op), t2, n, c)); + exchange(n, irn); + *node = irn; - if (reassoc_commutative(&n)) - return 1; + return 1; + } + } + } + return 0; +} /* reassoc_Mul */ - get_comm_Binop_ops(n, &add_sub, &c); - op = get_irn_op(add_sub); +/** + * Reassociate Shl. We transform Shl(x, const) into Mul's if possible. + */ +static int reassoc_Shl(ir_node **node) +{ + ir_node *n = *node; + ir_node *c = get_Shl_right(n); + ir_node *x, *blk, *irn; + ir_graph *irg; + ir_mode *mode; + ir_tarval *tv; + + if (! is_Const(c)) + return 0; - /* handles rules R11, R12, R13, R14, R15, R16, R17, R18, R19, R20 */ - if (op == op_Add || op == op_Sub) { - ir_mode *mode = get_irn_mode(n); - ir_node *irn, *block, *t1, *t2, *in[2]; + x = get_Shl_left(n); + mode = get_irn_mode(x); - block = get_nodes_block(n); - t1 = get_binop_left(add_sub); - t2 = get_binop_right(add_sub); + tv = get_mode_one(mode); + tv = tarval_shl(tv, get_Const_tarval(c)); - in[0] = new_rd_Mul(NULL, current_ir_graph, block, c, t1, mode); - in[1] = new_rd_Mul(NULL, current_ir_graph, block, c, t2, mode); + if (tv == tarval_bad) + return 0; - mode = get_mode_from_ops(in[0], in[1]); - irn = optimize_node(new_ir_node(NULL, current_ir_graph, block, op, mode, 2, in)); + blk = get_nodes_block(n); + irg = get_irn_irg(blk); + c = new_r_Const(irg, tv); + irn = new_rd_Mul(get_irn_dbg_info(n), blk, x, c, mode); - DBG((dbg, LEVEL_5, "Applied: (%n .%s. %n) %n %n => (%n %n %n) .%s. (%n %n %n)\n", - t1, get_op_name(op), t2, n, c, t1, n, c, get_op_name(op), t2, n, c)); - exchange(n, irn); + if (irn != n) { + exchange(n, irn); *node = irn; + return 1; + } + return 0; +} /* reassoc_Shl */ - return 1; - } - return 0; -} +/** + * The walker for the reassociation. + */ +static void wq_walker(ir_node *n, void *env) +{ + waitq *const wq = (waitq*)env; + + set_irn_link(n, NULL); + if (!is_Block(n)) { + waitq_put(wq, n); + set_irn_link(n, wq); + } +} /* wq_walker */ /** - * The walker for the reassociation + * The walker for the reassociation. */ -static void do_reassociation(ir_node *n, void *env) +static void do_reassociation(waitq *const wq) { - walker_t *wenv = env; - int res; + int i, res, changed; + ir_node *n; + + while (! waitq_empty(wq)) { + n = (ir_node*)waitq_get(wq); + set_irn_link(n, NULL); + + hook_reassociate(1); + + /* reassociation must run until a fixpoint is reached. */ + changed = 0; + do { + ir_op *op = get_irn_op(n); + ir_mode *mode = get_irn_mode(n); + + res = 0; + + /* for FP these optimizations are only allowed if fp_strict_algebraic is disabled */ + if (mode_is_float(mode) && get_irg_fp_model(get_irn_irg(n)) & fp_strict_algebraic) + break; + + if (op->ops.reassociate) { + res = op->ops.reassociate(&n); - hook_reassociate(1); + changed |= res; + } + } while (res == 1); + hook_reassociate(0); - /* reassociation must run until fixpoint */ - do { - ir_op *op = get_irn_op(n); - ir_mode *mode = get_irn_mode(n); + if (changed) { + for (i = get_irn_arity(n) - 1; i >= 0; --i) { + ir_node *pred = get_irn_n(n, i); - res = 0; + if (get_irn_link(pred) != wq) { + waitq_put(wq, pred); + set_irn_link(pred, wq); + } + } + } + } +} /* do_reassociation */ - /* reassociation works only for integer or reference modes */ - if (op->reassociate && (mode_is_int(mode) || mode_is_reference(mode))) { - res = op->reassociate(&n); +/** + * Returns the earliest were a,b are available. + * Note that we know that a, b both dominate + * the block of the previous operation, so one must dominate the other. + * + * If the earliest block is the start block, return curr_blk instead + */ +static ir_node *earliest_block(ir_node *a, ir_node *b, ir_node *curr_blk) +{ + ir_node *blk_a = get_nodes_block(a); + ir_node *blk_b = get_nodes_block(b); + ir_node *res; + + /* if blk_a != blk_b, one must dominate the other */ + if (block_dominates(blk_a, blk_b)) + res = blk_b; + else + res = blk_a; + if (res == get_irg_start_block(get_irn_irg(curr_blk))) + return curr_blk; + return res; +} /* earliest_block */ + +/** + * Checks whether a node is a Constant expression. + * The following trees are constant expressions: + * + * Const, SymConst, Const + SymConst + * + * Handling SymConsts as const might be not a good idea for all + * architectures ... + */ +static int is_constant_expr(ir_node *irn) +{ + switch (get_irn_opcode(irn)) { + case iro_Const: + case iro_SymConst: + return 1; + + case iro_Add: { + ir_node *const l = get_Add_left(irn); + if (!is_Const(l) && !is_SymConst(l)) + return 0; + ir_node *const r = get_Add_right(irn); + if (!is_Const(r) && !is_SymConst(r)) + return 0; + return 1; + } + + default: + return 0; + } +} /* is_constant_expr */ + +/** + * Apply distributive Law for Mul and Add/Sub + */ +static int reverse_rule_distributive(ir_node **node) +{ + ir_node *n = *node; + ir_node *left = get_binop_left(n); + ir_node *right = get_binop_right(n); + ir_node *x, *blk, *curr_blk; + ir_node *a, *b, *irn; + ir_op *op; + ir_mode *mode; + dbg_info *dbg; + + op = get_irn_op(left); + if (op != get_irn_op(right)) + return 0; + + if (op == op_Shl) { + x = get_Shl_right(left); + + if (x == get_Shl_right(right)) { + /* (a << x) +/- (b << x) ==> (a +/- b) << x */ + a = get_Shl_left(left); + b = get_Shl_left(right); + goto transform; + } + } else if (op == op_Mul) { + x = get_Mul_left(left); + + if (x == get_Mul_left(right)) { + /* (x * a) +/- (x * b) ==> (a +/- b) * x */ + a = get_Mul_right(left); + b = get_Mul_right(right); + goto transform; + } else if (x == get_Mul_right(right)) { + /* (x * a) +/- (b * x) ==> (a +/- b) * x */ + a = get_Mul_right(left); + b = get_Mul_left(right); + goto transform; + } + + x = get_Mul_right(left); + + if (x == get_Mul_right(right)) { + /* (a * x) +/- (b * x) ==> (a +/- b) * x */ + a = get_Mul_left(left); + b = get_Mul_left(right); + goto transform; + } else if (x == get_Mul_left(right)) { + /* (a * x) +/- (x * b) ==> (a +/- b) * x */ + a = get_Mul_left(left); + b = get_Mul_right(right); + goto transform; + } + } + return 0; + +transform: + curr_blk = get_nodes_block(n); + + blk = earliest_block(a, b, curr_blk); + + dbg = get_irn_dbg_info(n); + mode = get_irn_mode(n); + + if (is_Add(n)) + irn = new_rd_Add(dbg, blk, a, b, mode); + else + irn = new_rd_Sub(dbg, blk, a, b, mode); + + blk = earliest_block(irn, x, curr_blk); + + if (op == op_Mul) + irn = new_rd_Mul(dbg, blk, irn, x, mode); + else + irn = new_rd_Shl(dbg, blk, irn, x, mode); + + exchange(n, irn); + *node = irn; + return 1; +} /* reverse_rule_distributive */ - wenv->changes |= res; - } - } while (res == 1); +/** + * Move Constants towards the root. + */ +static int move_consts_up(ir_node **node) +{ + ir_node *n = *node; + ir_op *op; + ir_node *l, *r, *a, *b, *c, *blk, *irn, *in[2]; + ir_mode *mode, *ma, *mb; + dbg_info *dbg; + ir_graph *irg; + + l = get_binop_left(n); + r = get_binop_right(n); + + /* check if one is already a constant expression */ + if (is_constant_expr(l) || is_constant_expr(r)) + return 0; + + dbg = get_irn_dbg_info(n); + op = get_irn_op(n); + if (get_irn_op(l) == op) { + /* (a .op. b) .op. r */ + a = get_binop_left(l); + b = get_binop_right(l); + + if (is_constant_expr(a)) { + /* (C .op. b) .op. r ==> (r .op. b) .op. C */ + c = a; + a = r; + blk = get_nodes_block(l); + dbg = dbg == get_irn_dbg_info(l) ? dbg : NULL; + goto transform; + } else if (is_constant_expr(b)) { + /* (a .op. C) .op. r ==> (a .op. r) .op. C */ + c = b; + b = r; + blk = get_nodes_block(l); + dbg = dbg == get_irn_dbg_info(l) ? dbg : NULL; + goto transform; + } + } + if (get_irn_op(r) == op) { + /* l .op. (a .op. b) */ + a = get_binop_left(r); + b = get_binop_right(r); + + if (is_constant_expr(a)) { + /* l .op. (C .op. b) ==> (l .op. b) .op. C */ + c = a; + a = l; + blk = get_nodes_block(r); + dbg = dbg == get_irn_dbg_info(r) ? dbg : NULL; + goto transform; + } else if (is_constant_expr(b)) { + /* l .op. (a .op. C) ==> (a .op. l) .op. C */ + c = b; + b = l; + blk = get_nodes_block(r); + dbg = dbg == get_irn_dbg_info(r) ? dbg : NULL; + goto transform; + } + } + return 0; + +transform: + /* In some cases a and b might be both of different integer mode, and c a SymConst. + * in that case we could either + * 1.) cast into unsigned mode + * 2.) ignore + * we implement the second here + */ + ma = get_irn_mode(a); + mb = get_irn_mode(b); + if (ma != mb && mode_is_int(ma) && mode_is_int(mb)) + return 0; + + /* check if (a .op. b) can be calculated in the same block is the old instruction */ + if (! block_dominates(get_nodes_block(a), blk)) + return 0; + if (! block_dominates(get_nodes_block(b), blk)) + return 0; + /* ok */ + in[0] = a; + in[1] = b; + + mode = get_mode_from_ops(a, b); + irg = get_irn_irg(blk); + in[0] = irn = optimize_node(new_ir_node(dbg, irg, blk, op, mode, 2, in)); + + /* beware: optimize_node might have changed the opcode, check again */ + if (is_Add(irn) || is_Sub(irn)) { + reverse_rule_distributive(&in[0]); + } + in[1] = c; + + mode = get_mode_from_ops(in[0], in[1]); + irn = optimize_node(new_ir_node(dbg, irg, blk, op, mode, 2, in)); + + exchange(n, irn); + *node = irn; + return 1; +} /* move_consts_up */ - hook_reassociate(0); +/** + * Apply the rules in reverse order, removing code that was not collapsed + */ +static void reverse_rules(ir_node *node, void *env) +{ + (void)env; + + ir_graph *irg = get_irn_irg(node); + ir_mode *mode = get_irn_mode(node); + int res; + + /* for FP these optimizations are only allowed if fp_strict_algebraic is disabled */ + if (mode_is_float(mode) && get_irg_fp_model(irg) & fp_strict_algebraic) + return; + + do { + ir_op *op = get_irn_op(node); + + res = 0; + if (is_op_commutative(op)) { + res = move_consts_up(&node); + } + /* beware: move_consts_up might have changed the opcode, check again */ + if (is_Add(node) || is_Sub(node)) { + res = reverse_rule_distributive(&node); + } + } while (res); } /* @@ -339,39 +783,56 @@ static void do_reassociation(ir_node *n, void *env) */ void optimize_reassociation(ir_graph *irg) { - walker_t env; + assert(get_irg_pinned(irg) != op_pin_state_floats && + "Reassociation needs pinned graph to work properly"); + + assure_irg_properties(irg, + IR_GRAPH_PROPERTY_CONSISTENT_DOMINANCE + | IR_GRAPH_PROPERTY_CONSISTENT_LOOPINFO); - assert(get_irg_phase_state(irg) != phase_building); + waitq *const wq = new_waitq(); - /* reassociation needs constant folding */ - if (!get_opt_reassociation() || !get_opt_constant_folding()) - return; + /* disable some optimizations while reassoc is running to prevent endless loops */ + set_reassoc_running(1); + { + /* now we have collected enough information, optimize */ + irg_walk_graph(irg, NULL, wq_walker, wq); + do_reassociation(wq); - env.changes = 0; + /* reverse those rules that do not result in collapsed constants */ + irg_walk_graph(irg, NULL, reverse_rules, NULL); + } + set_reassoc_running(0); - irg_walk_graph(irg, NULL, do_reassociation, &env); + del_waitq(wq); - /* now we have collected enough information, optimize */ - irg_walk_graph(irg, NULL, do_reassociation, &env); + confirm_irg_properties(irg, IR_GRAPH_PROPERTIES_CONTROL_FLOW); +} /* optimize_reassociation */ - /* Handle graph state */ - if (env.changes) { - if (get_irg_outs_state(current_ir_graph) == outs_consistent) - set_irg_outs_inconsistent(current_ir_graph); - } +/* create a pass for the reassociation */ +ir_graph_pass_t *optimize_reassociation_pass(const char *name) +{ + return def_graph_pass(name ? name : "reassoc", optimize_reassociation); +} /* optimize_reassociation_pass */ + +static void register_node_reassoc_func(ir_op *op, reassociate_func func) +{ + op->ops.reassociate = func; +} + +void ir_register_reassoc_node_ops(void) +{ + register_node_reassoc_func(op_Mul, reassoc_Mul); + register_node_reassoc_func(op_Add, reassoc_Add); + register_node_reassoc_func(op_Sub, reassoc_Sub); + register_node_reassoc_func(op_And, reassoc_And); + register_node_reassoc_func(op_Or, reassoc_Or); + register_node_reassoc_func(op_Eor, reassoc_Eor); + register_node_reassoc_func(op_Shl, reassoc_Shl); } /* initialize the reassociation by adding operations to some opcodes */ void firm_init_reassociation(void) { -#define INIT(a) op_##a->reassociate = reassoc_##a; - INIT(Mul); - INIT(Add); - INIT(Sub); - INIT(And); - INIT(Or); - INIT(Eor); -#undef INIT - - dbg = firm_dbg_register("firm.opt.reassoc"); -} + FIRM_DBG_REGISTER(dbg, "firm.opt.reassoc"); +} /* firm_init_reassociation */