X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Fopt%2Freassoc.c;h=e5ac876263f326c1bb58fe7a72e8930c440632e4;hb=1604345e0da0d5a74037dee6a4fa13bb70261ad3;hp=e3ee2563d9b73bcfe1fc5ec39046be17bda68b45;hpb=990ddfa72b25a0ff04c6a12c35484a0a3114c015;p=libfirm diff --git a/ir/opt/reassoc.c b/ir/opt/reassoc.c index e3ee2563d..e5ac87626 100644 --- a/ir/opt/reassoc.c +++ b/ir/opt/reassoc.c @@ -8,23 +8,26 @@ * Copyright: (c) 1998-2004 Universität Karlsruhe * Licence: This file protected by GPL - GNU GENERAL PUBLIC LICENSE. */ - #ifdef HAVE_CONFIG_H -# include +#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 "firmstat.h" +#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 "irloop.h" +#include "debug.h" + +DEBUG_ONLY(static firm_dbg_module_t *dbg;) typedef struct _walker_t { int changes; /* set, if a reassociation take place */ @@ -32,48 +35,74 @@ typedef struct _walker_t { typedef enum { NO_CONSTANT = 0, /**< node is not constant */ - REAL_CONSTANT = 1, /**< node is a constnt that is suitable for constant folding */ - CONST_EXPR = 4 /**< node is not constnt expression in the current context, + 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 wheater 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(ir_node *n, ir_node *block) { ir_op *op = get_irn_op(n); if (op == op_Const) return REAL_CONSTANT; + + /* although SymConst's are of course real constant, we cannot + fold them, so handle them like region constants */ if (op == op_SymConst) - return CONST_EXPR; + return REGION_CONST; + + /* + * 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; } /** * 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 constrants must be returned with higher priority than - * constnt expression, because they might be folded. + * Beware: Real constants must be returned with higher priority than + * 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); + 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*NO_CONSTANT: case REAL_CONSTANT + 2*REAL_CONSTANT: - case REAL_CONSTANT + 2*CONST_EXPR: - case CONST_EXPR + 2*NO_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; @@ -87,15 +116,18 @@ static void get_comm_Binop_ops(ir_node *binop, ir_node **a, ir_node **c) /** * reassociate a Sub: x - c = (-c) + x */ -static int reassoc_Sub(ir_node *n) +static int reassoc_Sub(ir_node **in) { + ir_node *n = *in; ir_node *right = get_Sub_right(n); + ir_mode *rmode = get_irn_mode(right); + ir_node *block; - /* 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; + /* cannot handle SubIs(P, P) */ + if (mode_is_reference(rmode)) + return 0; + + block = get_nodes_block(n); /* handles rule R6: * convert x - c => (-c) + x @@ -103,18 +135,18 @@ static int reassoc_Sub(ir_node *n) * 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) { + if (get_const_class(right, block) == 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 *dbg = get_irn_dbg_info(n); + ir_mode *mode; + dbg_info *dbi; ir_node *irn, *c; - switch (get_const_class(left)) { + 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; @@ -124,25 +156,27 @@ static int reassoc_Sub(ir_node *n) /* already constant, nothing to do */ return 0; } + mode = get_irn_mode(n); + dbi = get_irn_dbg_info(n); - c = new_r_Const(current_ir_graph, block, mode, get_mode_null(mode)); - irn = new_rd_Sub(dbg, current_ir_graph, block, c, right, mode); + /* Beware of SubP(P, Is) */ + c = new_r_Const(current_ir_graph, block, rmode, get_mode_null(rmode)); + irn = new_rd_Sub(dbi, current_ir_graph, block, c, right, rmode); - irn = new_rd_Add(dbg, current_ir_graph, block, left, irn, get_irn_mode(n)); + 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)); -/* - printf("Applied: %s - %s => %s + (-%s)\n", - get_irn_opname(get_Sub_left(n)), get_irn_opname(c), - get_irn_opname(get_Sub_left(n)), get_irn_opname(c) ); -*/ exchange(n, irn); + *in = irn; return 1; } return 0; } -/** 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) @@ -166,11 +200,12 @@ static ir_mode *get_mode_from_ops(ir_node *op1, ir_node *op2) * 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 *n) +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; @@ -187,16 +222,16 @@ static int reassoc_commutative(ir_node *n) if (is_Bad(t2)) return 0; - c_c1 = get_const_class(c1); - c_c2 = get_const_class(c2); - c_t2 = get_const_class(t2); + 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) & 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 + ((((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 onstant so is c2, so we save one test. + * Note that if t2 is a constant so is c2 hence we save one test. */ return 0; } @@ -238,18 +273,17 @@ static int reassoc_commutative(ir_node *n) mode = get_mode_from_ops(in[0], in[1]); irn = optimize_node(new_ir_node(NULL, current_ir_graph, block, op, mode, 2, in)); -/* - printf("Applied: %s .%s. (%s .%s. %s) => (%s .%s. %s) .%s. %s\n", - get_irn_opname(c1), get_irn_opname(n), get_irn_opname(c2), get_irn_opname(n), get_irn_opname(t2), - get_irn_opname(c1), get_irn_opname(n), get_irn_opname(c2), get_irn_opname(n), get_irn_opname(t2)); - */ + 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. + * 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; } } @@ -258,16 +292,20 @@ static int reassoc_commutative(ir_node *n) } #define reassoc_Add reassoc_commutative +#define reassoc_And reassoc_commutative +#define reassoc_Or reassoc_commutative +#define reassoc_Eor reassoc_commutative /** - * reassociate using distibutive law for Mul and Add/Sub + * reassociate using distributive law for Mul and Add/Sub */ -static int reassoc_Mul(ir_node *n) +static int reassoc_Mul(ir_node **node) { + ir_node *n = *node; ir_node *add_sub, *c; ir_op *op; - if (reassoc_commutative(n)) + if (reassoc_commutative(&n)) return 1; get_comm_Binop_ops(n, &add_sub, &c); @@ -282,52 +320,65 @@ static int reassoc_Mul(ir_node *n) t1 = get_binop_left(add_sub); t2 = get_binop_right(add_sub); - 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); + /* we can only multiplication rules on integer arithmetic */ + if (mode_is_int(get_irn_mode(t1)) && mode_is_int(get_irn_mode(t2))) { + 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); - mode = get_mode_from_ops(in[0], in[1]); - irn = optimize_node(new_ir_node(NULL, current_ir_graph, block, op, mode, 2, in)); + mode = get_mode_from_ops(in[0], in[1]); + irn = optimize_node(new_ir_node(NULL, current_ir_graph, block, op, mode, 2, in)); -/* - printf("Applied: (%s .%s. %s) %s %s => (%s %s %s) .%s. (%s %s %s)\n", - get_irn_opname(t1), get_op_name(op), get_irn_opname(t2), get_irn_opname(n), get_irn_opname(c), - get_irn_opname(t1), get_irn_opname(n), get_irn_opname(c), - get_op_name(op), - get_irn_opname(t2), get_irn_opname(n), get_irn_opname(c)); -*/ - exchange(n, irn); + /* 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; - return 1; + return 1; + } + } } return 0; } /** - * The walker for the reassociation + * The walker for the reassociation. */ static void do_reassociation(ir_node *n, void *env) { walker_t *wenv = env; int res; - /* reassociation must run until fixpoint */ + hook_reassociate(1); + + /* reassociation must run until a fixpoint is reached. */ do { ir_op *op = get_irn_op(n); ir_mode *mode = get_irn_mode(n); res = 0; - /* reassociation works only for integer or reference modes */ - if (op->reassociate && (mode_is_int(mode) || mode_is_reference(mode))) { - res = op->reassociate(n); - if (res) { - wenv->changes = 1; + /* for FP these optimizations are only allowed if fp_strict_algebraic is disabled */ + if (mode_is_float(mode) && get_irg_fp_model(current_ir_graph) & fp_strict_algebraic) + break; - /* we need a skip here, or we will see an Id in the next iteration */ - n = skip_Id(n); - } + if (op->ops.reassociate) { + res = op->ops.reassociate(&n); + + wenv->changes |= res; } } while (res == 1); + + hook_reassociate(0); } /* @@ -336,33 +387,61 @@ static void do_reassociation(ir_node *n, void *env) void optimize_reassociation(ir_graph *irg) { walker_t env; + irg_loopinfo_state state; assert(get_irg_phase_state(irg) != phase_building); + assert(get_irg_pinned(irg) != op_pin_state_floats && + "Reassociation needs pinned graph to work properly"); /* reassociation needs constant folding */ if (!get_opt_reassociation() || !get_opt_constant_folding()) return; - env.changes = 0; + /* + * Calculate loop info, so we could identify loop-invariant + * code and threat it like a constant. + * We only need control flow loops here but can handle generic + * INTRA info as well. + */ + state = get_irg_loopinfo_state(irg); + if ((state & loopinfo_inter) || + (state & (loopinfo_constructed | loopinfo_valid)) != (loopinfo_constructed | loopinfo_valid)) + construct_cf_backedges(irg); - irg_walk_graph(irg, NULL, do_reassociation, &env); + env.changes = 0; /* now we have collected enough information, optimize */ irg_walk_graph(irg, NULL, do_reassociation, &env); /* Handle graph state */ if (env.changes) { - if (get_irg_outs_state(current_ir_graph) == outs_consistent) - set_irg_outs_inconsistent(current_ir_graph); + set_irg_outs_inconsistent(irg); + set_irg_loopinfo_inconsistent(irg); } } -/* initialise the reassociation by adding operations to some opcodes */ -void firm_init_reassociation(void) +/* Sets the default reassociation operation for an ir_op_ops. */ +ir_op_ops *firm_set_default_reassoc(opcode code, ir_op_ops *ops) { -#define INIT(a) op_##a->reassociate = reassoc_##a; - INIT(Mul); - INIT(Add); - INIT(Sub); +#define CASE(a) case iro_##a: ops->reassociate = reassoc_##a; break + + switch (code) { + CASE(Mul); + CASE(Add); + CASE(Sub); + CASE(And); + CASE(Or); + CASE(Eor); + default: + /* leave NULL */; + } + + return ops; #undef CASE } + +/* initialize the reassociation by adding operations to some opcodes */ +void firm_init_reassociation(void) +{ + FIRM_DBG_REGISTER(dbg, "firm.opt.reassoc"); +}