/*
- * 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"
#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;
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.
* @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.
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.
*
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.
*/
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;
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) */
/* 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;
they are different (R1 a) */
if (ent1 != ent2)
return no_alias;
- else
- return different_offsets(adr1, adr2);
}
}
} else if (is_arg_Proj(base1)) {
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;
}
} /* init_taken_flag */
-#if 0
+#ifdef DEBUG_libfirm
/**
* Print the address taken state of all entities of a given type for debugging.
*/
}
}
} /* print_address_taken_state */
-#endif
+#endif /* DEBUG_libfirm */
/**
* Post-walker: check for global entity address
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());
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;
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