X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;ds=sidebyside;f=ir%2Fana%2Firmemory.c;h=a457a5e568fc49533c8bc037897cb7045b6d7dcc;hb=8c62d67c5bd49d4df5534d8441d589d81eace851;hp=90f9175af7e2f2b0e41089f2042563b225fc82ac;hpb=863d31d7a5c8210432fef88b30fc3e8353131538;p=libfirm diff --git a/ir/ana/irmemory.c b/ir/ana/irmemory.c index 90f9175af..a457a5e56 100644 --- a/ir/ana/irmemory.c +++ b/ir/ana/irmemory.c @@ -1,13 +1,28 @@ /* - * Project: libFIRM - * File name: ir/ana/irmemory.c - * Purpose: Memory disambiguator - * Author: Michael Beck - * Modified by: - * Created: 27.12.2006 - * CVS-ID: $Id$ - * Copyright: (c) 2006-2007 Universität Karlsruhe - * Licence: This file protected by GPL - GNU GENERAL PUBLIC LICENSE. + * Copyright (C) 1995-2007 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. + */ + +/** + * @file + * @brief Memory disambiguator + * @author Michael Beck + * @date 27.12.2006 + * @version $Id$ */ #ifdef HAVE_CONFIG_H #include "config.h" @@ -25,6 +40,10 @@ #include "irouts.h" #include "irgwalk.h" #include "irprintf.h" +#include "debug.h" + +/** The debug handle. */ +DEBUG_ONLY(static firm_dbg_module_t *dbg = NULL;) /** The source language specific language disambiguator function. */ static DISAMBIGUATOR_FUNC language_disambuigator = NULL; @@ -69,6 +88,25 @@ static ir_node *find_base_adr(ir_node *sel, ir_entity **pEnt) { return ptr; } /* find_base_adr */ +/** + * Check if the address can be decomposed into base PLUS offset. + */ +static int has_offset(ir_node *adr, int *offset) { + if (is_SymConst(adr)) { + *offset = 0; + return 1; + } + if (is_Sel(adr)) { + ir_entity *ent = get_Sel_entity(adr); + ir_type *owner = get_entity_owner(ent); + + if (get_type_state(owner) != layout_fixed) { + /* The layout is NOT fixed yet, symbolic evaluation needed */ + } + } + return 0; +} /* has_offset */ + /** * Two address expressions have the same base address, * check if there offsets are different. @@ -77,9 +115,175 @@ static ir_node *find_base_adr(ir_node *sel, ir_entity **pEnt) { * @param adr2 The second address. */ static ir_alias_relation different_offsets(ir_node *adr1, ir_node *adr2) { + int offset1, offset2; + if (has_offset(adr1, &offset1) && has_offset(adr2, &offset2)) { + /* */ + } return may_alias; } /* different_offsets */ +/** + * Check if a given Const node is greater or equal a given size. + * + * @return no_alias if the Const is greater, may_alias else + */ +static ir_alias_relation check_const(ir_node *cns, int size) { + tarval *tv = get_Const_tarval(cns); + tarval *tv_size; + + if (size == 0) + return classify_tarval(tv) != TV_CLASSIFY_NULL ? no_alias : may_alias; + tv_size = new_tarval_from_long(size, get_tarval_mode(tv)); + return tarval_cmp(tv_size, tv) & (pn_Cmp_Eq|pn_Cmp_Lt) ? no_alias : may_alias; +} /* check_const */ + +/** + * Treat idx1 and idx2 as integer indexes and check if they differ always more than size. + * + * @return sure_alias iff idx1 == idx2 + * no_alias iff they ALWAYS differ more than size + * may_alias else + */ +static ir_alias_relation different_index(ir_node *idx1, ir_node *idx2, int size) { + if (idx1 == idx2) + return sure_alias; + if (is_Const(idx1) && is_Const(idx2)) { + /* both are const, we can compare them */ + tarval *tv1 = get_Const_tarval(idx1); + tarval *tv2 = get_Const_tarval(idx2); + tarval *tv, *tv_size; + + if (size == 0) + return tv1 == tv2 ? sure_alias : no_alias; + + if (tarval_cmp(tv1, tv2) == pn_Cmp_Gt) { + tarval *t = tv1; + tv1 = tv2; + tv2 = t; + } + /* tv1 is now the "smaller" one */ + tv = tarval_sub(tv2, tv1); + tv_size = new_tarval_from_long(size, get_tarval_mode(tv)); + return tarval_cmp(tv_size, tv) & (pn_Cmp_Eq|pn_Cmp_Lt) ? no_alias : may_alias; + } + + /* Note: we rely here on the fact that normalization puts constants on the RIGHT side */ + if (is_Add(idx1)) { + ir_node *l1 = get_Add_left(idx1); + ir_node *r1 = get_Add_right(idx1); + + if (l1 == idx2) { + /* x + c == y */ + if (is_Const(r1)) + return check_const(r1, size); + } + if (is_Add(idx2)) { + /* both are Adds, check if they are of x + c kind */ + ir_node *l2 = get_Add_left(idx2); + ir_node *r2 = get_Add_right(idx2); + + if (l1 == l2) + return different_index(r1, r2, size); + else if (l1 == r2) + return different_index(r1, l2, size); + else if (r1 == r2) + return different_index(l1, l2, size); + else if (r1 == l2) + return different_index(l1, r2, size); + } + } + if (is_Add(idx2)) { + ir_node *l2 = get_Add_left(idx2); + ir_node *r2 = get_Add_right(idx2); + + if (l2 == idx1) { + /* x + c == y */ + if (is_Const(r2)) + return check_const(r2, size); + } + } + + if (is_Sub(idx1)) { + ir_node *l1 = get_Sub_left(idx1); + ir_node *r1 = get_Sub_right(idx1); + + if (l1 == idx2) { + /* x - c == y */ + if (is_Const(r1)) + return check_const(r1, size); + } + + if (is_Sub(idx2)) { + /* both are Subs, check if they are of x - c kind */ + ir_node *l2 = get_Sub_left(idx2); + + if (l1 == l2) { + ir_node *r2 = get_Sub_right(idx2); + return different_index(r1, r2, size); + } + } + } + if (is_Sub(idx2)) { + ir_node *l2 = get_Sub_left(idx2); + ir_node *r2 = get_Sub_right(idx2); + + if (l2 == idx1) { + /* x - c == y */ + if (is_Const(r2)) + return check_const(r2, size); + } + + } + return may_alias; +} /* different_index */ + +/** + * Two Sel addresses have the same base address, check if there offsets are different. + * + * @param adr1 The first address. + * @param adr2 The second address. + */ +static ir_alias_relation different_sel_offsets(ir_node *sel1, ir_node *sel2) { + ir_entity *ent1 = get_Sel_entity(sel1); + ir_entity *ent2 = get_Sel_entity(sel2); + int i, check_arr = 0; + + if (ent1 == ent2) + check_arr = 1; + else { + ir_type *tp1 = get_entity_type(ent1); + ir_type *tp2 = get_entity_type(ent2); + + if (tp1 == tp2) + check_arr = 1; + else if (get_type_state(tp1) == layout_fixed && get_type_state(tp2) == layout_fixed && + get_type_size_bytes(tp1) == get_type_size_bytes(tp2)) + check_arr = 1; + } + if (check_arr) { + /* we select an entity of same size, check for indexes */ + int n = get_Sel_n_indexs(sel1); + int have_no = 0; + + if (n > 0 && n == get_Sel_n_indexs(sel2)) { + /* same non-zero number of indexes, an array access, check */ + for (i = 0; i < n; ++i) { + ir_node *idx1 = get_Sel_index(sel1, i); + ir_node *idx2 = get_Sel_index(sel2, i); + ir_alias_relation res = different_index(idx1, idx2, 0); /* we can safely IGNORE the size here if it's at least >0 */ + + if (res == may_alias) + return may_alias; + else if (res == no_alias) + have_no = 1; + } + /* if we have at least one no_alias, there is no alias relation, else we have sure */ + return have_no > 0 ? no_alias : sure_alias; + } + } + return may_alias; +} /* different_sel_offsets */ + /** * Determine the alias relation by checking if adr1 and adr2 are pointer * to different type. @@ -132,6 +336,82 @@ static ir_alias_relation different_types(ir_node *adr1, ir_node *adr2) return may_alias; } /* different_types */ +/** + * Check if an offset is a constant and these constant is bigger or equal + * than a given size. + */ +static int check_const_offset(ir_node *offset, int size) { + ir_mode *mode = get_irn_mode(offset); + + /* ok, we found an offset, check for constant */ + if (is_Const(offset) && mode_is_int(mode)) { + tarval *tv = new_tarval_from_long(size, mode); + + /* size <= offset ? */ + if (tarval_cmp(tv, get_Const_tarval(offset)) & (pn_Cmp_Eq|pn_Cmp_Lt)) + return 1; + } + return 0; +} /* check_const_offset */ + +/** + * Check if we can determine that the two pointers always have an offset bigger then size + */ +static ir_alias_relation _different_pointer(ir_node *adr1, ir_node *adr2, int size) { + int found = 0; + + if (is_Add(adr1)) { + /* first address is the result of a pointer addition */ + ir_node *l1 = get_Add_left(adr1); + ir_node *r1 = get_Add_right(adr1); + + if (l1 == adr2) { + found = check_const_offset(r1, size); + } else if (r1 == adr2) { + found = check_const_offset(l1, size); + } else if (is_Add(adr2)) { + /* second address is the result of a pointer addition */ + ir_node *l2 = get_Add_left(adr2); + ir_node *r2 = get_Add_right(adr2); + + if (l1 == l2) { + return _different_pointer(r1, r2, size); + } else if (l1 == r2) { + return _different_pointer(r1, l2, size); + } else if (r1 == l2) { + return _different_pointer(l1, r2, size); + } else if (r1 == r2) { + return _different_pointer(l1, l2, size); + } + } + } else if (is_Add(adr2)) { + /* second address is the result of a pointer addition */ + ir_node *l2 = get_Add_left(adr2); + ir_node *r2 = get_Add_right(adr2); + + if (l2 == adr1) { + found = check_const_offset(r2, size); + } else if (r2 == adr1) { + found = check_const_offset(l2, size); + } + } else { + return different_index(adr1, adr2, size); + } + return found ? no_alias : may_alias; +} /* _different_pointer */ + +/** + * Check if we can determine that the two pointers always have an offset bigger then the maximum size of mode1, mode2 + */ +static ir_alias_relation different_pointer(ir_node *adr1, ir_mode *mode1, ir_node *adr2, ir_mode *mode2) { + int size = get_mode_size_bytes(mode1); + int n = get_mode_size_bytes(mode2); + + if (n > size) + size = n; + return _different_pointer(adr1, adr2, size); +} /* different_pointer */ + /** * Returns non-zero if a node is a routine parameter. * @@ -146,6 +426,13 @@ static int is_arg_Proj(ir_node *node) { return pn_Start_T_args == get_Proj_proj(node) && is_Start(get_Proj_pred(node)); } /* is_arg_Proj */ +/** + * Returns true if an address represents a global variable. + */ +static INLINE int is_global_var(ir_node *irn) { + return is_SymConst(irn) && get_SymConst_kind(irn) == symconst_addr_ent; +} /* is_global_var */ + /** * Determine the alias relation between two addresses. */ @@ -185,33 +472,33 @@ static ir_alias_relation _get_alias_relation( mode2 = m; } - if (is_SymConst(adr1) && get_SymConst_kind(adr1) == symconst_addr_ent) { + if (is_global_var(adr1)) { /* first address is a global variable */ - if (is_SymConst(adr2) && get_SymConst_kind(adr2) == symconst_addr_ent) { + if (is_global_var(adr2)) { /* both addresses are global variables and we know they are different (R1 a) */ if (get_SymConst_entity(adr1) != get_SymConst_entity(adr2)) return no_alias; else { - /* equal addresses */ + /* equal entity addresses */ return sure_alias; } } if (is_Sel(adr2)) { - ir_node *base = find_base_adr(adr2, &ent2); + ir_node *base2 = find_base_adr(adr2, &ent2); - if (is_SymConst(base) && get_SymConst_kind(base) == symconst_addr_ent) { - /* base address is a global var (R1 a) */ - if (adr1 != base) + if (is_global_var(base2)) { + /* base2 address is a global var (R1 a) */ + if (adr1 != base2) return no_alias; - if (base == adr1) + else return different_offsets(adr1, adr2); - } else if (base == get_irg_frame(irg)) { + } else if (base2 == get_irg_frame(irg)) { /* the second one is a local variable so they are always different (R1 b) */ return no_alias; - } else if (base == get_irg_tls(irg)) { + } else if (base2 == get_irg_tls(irg)) { /* the second one is a TLS variable so they are always different (R1 c) */ return no_alias; @@ -230,18 +517,19 @@ static ir_alias_relation _get_alias_relation( ir_node *base1 = find_base_adr(adr1, &ent1); if (base1 == get_irg_frame(irg)) { - /* the first is a local variable */ + /* first is a local variable ent1 */ if (is_Sel(adr2)) { /* the second address is a Sel */ ir_node *base2 = find_base_adr(adr2, &ent2); - if (base2 == get_irg_frame(irg)) { + if (base1 == base2) { + /* identical bases: check for different offsets */ + return different_sel_offsets(adr1, adr2); + } else if (base2 == get_irg_frame(irg)) { /* both addresses are local variables and we know they are different (R1 a) */ if (ent1 != ent2) return no_alias; - else - return different_offsets(adr1, adr2); } else if (base2 == get_irg_tls(irg)) { /* the second one is a TLS variable so they are always different (R1 d) */ @@ -261,7 +549,9 @@ static ir_alias_relation _get_alias_relation( /* the second address is a Sel */ ir_node *base2 = find_base_adr(adr2, &ent2); - if (base2 == get_irg_frame(irg)) { + if (base1 == base2) + return different_sel_offsets(adr1, adr2); + else if (base2 == get_irg_frame(irg)) { /* the second one is a local variable so they are always different (R1 d) */ return no_alias; @@ -270,8 +560,6 @@ static ir_alias_relation _get_alias_relation( they are different (R1 a) */ if (ent1 != ent2) return no_alias; - else - return different_offsets(adr1, adr2); } } } else if (is_arg_Proj(base1)) { @@ -286,9 +574,46 @@ static ir_alias_relation _get_alias_relation( return no_alias; } } + } else if (is_global_var(base1)) { + /* the first one is a global variable */ + ent1 = get_SymConst_entity(base1); + if (is_Sel(adr2)) { + /* the second address is a Sel */ + ir_node *base2 = find_base_adr(adr2, &ent2); + + if (base1 == base2) + return different_sel_offsets(adr1, adr2); + else if (base2 == get_irg_frame(irg)) { + /* the second one is a local variable so they are always + different (R1 a) */ + return no_alias; + } else if (base2 == get_irg_tls(irg)) { + /* the second one is a TLS variable so they are always + different (R1 a) */ + return no_alias; + } else if (is_arg_Proj(base2)) { + if (get_entity_address_taken(ent1) == ir_address_not_taken) { + /* The address of the global variable was never taken, so + the pointer cannot match (R2). */ + return no_alias; + } + } else if (is_global_var(base2)) { + ent2 = get_SymConst_entity(base2); + /* both addresses are global variables and we know + they are different (R1 a) */ + if (ent1 != ent2) + return no_alias; + } + } } + } else { + /* some pointers, check if they have the same base buf constant offset */ + ir_alias_relation rel = different_pointer(adr1, mode1, adr2, mode2); + if (rel != may_alias) + return rel; } + if (options & aa_opt_type_based) { /* Type based alias analysis */ ir_alias_relation rel; @@ -568,7 +893,7 @@ static void init_taken_flag(ir_type * tp) { } } /* init_taken_flag */ -#if 0 +#ifdef DEBUG_libfirm /** * Print the address taken state of all entities of a given type for debugging. */ @@ -584,7 +909,7 @@ static void print_address_taken_state(ir_type *tp) { } } } /* print_address_taken_state */ -#endif +#endif /* DEBUG_libfirm */ /** * Post-walker: check for global entity address @@ -603,7 +928,7 @@ static void check_global_address(ir_node *irn, void *env) { } else return; - if (get_entity_address_taken(ent) == ir_address_not_taken) { + if (get_entity_address_taken(ent) >= ir_address_taken) { /* Already at the maximum. */ return; } @@ -618,6 +943,8 @@ static void check_global_address(ir_node *irn, void *env) { static void analyse_irp_globals_address_taken(void) { int i; + FIRM_DBG_REGISTER(dbg, "firm.ana.irmemory"); + init_taken_flag(get_glob_type()); init_taken_flag(get_tls_type()); @@ -627,8 +954,13 @@ static void analyse_irp_globals_address_taken(void) { assure_irg_outs(irg); irg_walk_graph(irg, NULL, check_global_address, get_irg_tls(irg)); } - //print_address_taken_state(get_glob_type()); - //print_address_taken_state(get_tls_type()); + +#ifdef DEBUG_libfirm + if (firm_dbg_get_mask(dbg) & LEVEL_1) { + print_address_taken_state(get_glob_type()); + print_address_taken_state(get_tls_type()); + } +#endif /* DEBUG_libfirm */ /* now computed */ irp->globals_adr_taken_state = ir_address_taken_computed;