+++ /dev/null
-/* OSF/rose half-pic support functions.
- Copyright (C) 1992, 1997, 1998, 1999 Free Software Foundation, Inc.
-
-This file is part of GCC.
-
-GCC is free software; you can redistribute it and/or modify it under
-the terms of the GNU General Public License as published by the Free
-Software Foundation; either version 2, or (at your option) any later
-version.
-
-GCC is distributed in the hope that it will be useful, but WITHOUT ANY
-WARRANTY; without even the implied warranty of MERCHANTABILITY or
-FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
-for more details.
-
-You should have received a copy of the GNU General Public License
-along with GCC; see the file COPYING. If not, write to the Free
-Software Foundation, 59 Temple Place - Suite 330, Boston, MA
-02111-1307, USA. */
-
-/* The OSF/rose half-pic model assumes that the non-library code does
- not need to have full PIC (position independent code), but rather,
- that pointers to external references are put into the data section
- and dereferenced as normal pointers. References to static data does
- not need to be PIC-ized.
-
- Another optimization is to have the compiler know what symbols are
- in the shared libraries, and to only lay down the pointers to
- things which in the library proper. */
-
-#include "config.h"
-
-#ifdef HALF_PIC_INIT
-
-#include "system.h"
-#include "tree.h"
-#include "rtl.h"
-#include "expr.h"
-#include "output.h"
-#include "obstack.h"
-#include "halfpic.h"
-
-#define obstack_chunk_alloc xmalloc
-#define obstack_chunk_free free
-
-int flag_half_pic = 0; /* Global half-pic flag. */
-int half_pic_number_ptrs = 0; /* # distinct pointers found */
-int half_pic_number_refs = 0; /* # half-pic references */
-int (*ptr_half_pic_address_p) PARAMS ((rtx)) = half_pic_address_p;
-
-/* Obstack to hold generated pic names. */
-static struct obstack half_pic_obstack;
-
-/* List of pointers created to pic references. */
-
-struct all_refs {
- struct all_refs *hash_next; /* next name in hash chain */
- struct all_refs *next; /* next name created */
- int external_p; /* name is an external reference */
- int pointer_p; /* pointer created. */
- const char *ref_name; /* reference name to ptr to real_name */
- int ref_len; /* reference name length */
- const char *real_name; /* real function/data name */
- int real_len; /* strlen (real_name) */
-};
-
-static struct all_refs *half_pic_names;
-
-static const char *half_pic_prefix;
-static int half_pic_prefix_len;
-
-\f
-/* Return the hash bucket of a name or NULL. The hash chain is
- organized as a self reorganizing circularly linked chain. It is
- assumed that any name passed to use will never be reallocated. For
- names in SYMBOL_REF's this is true, because the names are allocated
- on the permanent obstack. */
-
-#ifndef MAX_HASH_TABLE
-#define MAX_HASH_TABLE 1009
-#endif
-
-#define HASHBITS 30
-
-static struct all_refs *half_pic_hash PARAMS ((const char *, int, int));
-
-static struct all_refs *
-half_pic_hash (name, len, create_p)
- const char *name; /* name to hash */
- int len; /* length of the name (or 0 to call strlen) */
- int create_p; /* != 0 to create new hash bucket if new */
-{
- static struct all_refs *hash_table[MAX_HASH_TABLE];
- static struct all_refs zero_all_refs;
-
- const unsigned char *uname;
- int hash;
- int i;
- int ch;
- struct all_refs *first;
- struct all_refs *ptr;
-
- if (len == 0)
- len = strlen (name);
-
- /* Compute hash code */
- uname = (const unsigned char *)name;
- ch = uname[0];
- hash = len * 613 + ch;
- for (i = 1; i < len; i += 2)
- hash = (hash * 613) + uname[i];
-
- hash &= (1 << HASHBITS) - 1;
- hash %= MAX_HASH_TABLE;
-
- /* See if the name is in the hash table. */
- ptr = first = hash_table[hash];
- if (ptr)
- {
- do
- {
- if (len == ptr->real_len
- && ch == *(ptr->real_name)
- && !strcmp (name, ptr->real_name))
- {
- hash_table[hash] = ptr;
- return ptr;
- }
-
- ptr = ptr->hash_next;
- }
- while (ptr != first);
- }
-
- /* name not in hash table. */
- if (!create_p)
- return (struct all_refs *) 0;
-
- ptr = (struct all_refs *) obstack_alloc (&half_pic_obstack, sizeof (struct all_refs));
- *ptr = zero_all_refs;
-
- ptr->real_name = name;
- ptr->real_len = len;
-
- /* Update circular links. */
- if (first == (struct all_refs *) 0)
- ptr->hash_next = ptr;
-
- else
- {
- ptr->hash_next = first->hash_next;
- first->hash_next = ptr;
- }
-
- hash_table[hash] = ptr;
- return ptr;
-}
-
-\f
-/* Do any half-pic initializations. */
-
-void
-half_pic_init ()
-{
- flag_half_pic = TRUE;
- half_pic_prefix = HALF_PIC_PREFIX;
- half_pic_prefix_len = strlen (half_pic_prefix);
- obstack_init (&half_pic_obstack);
-}
-
-\f
-/* Write out all pointers to pic references. */
-
-void
-half_pic_finish (stream)
- FILE *stream;
-{
- struct all_refs *p = half_pic_names;
-
- if (!p)
- return;
-
- data_section ();
- for (; p != 0; p = p->next)
- {
- /* Emit the pointer if used. */
- if (p->pointer_p)
- {
- ASM_OUTPUT_LABEL (stream, p->ref_name);
- assemble_aligned_integer (POINTER_SIZE / BITS_PER_UNIT,
- gen_rtx_SYMBOL_REF (Pmode, p->real_name));
- }
- }
-}
-
-\f
-/* Encode in a declaration whether or not it is half-pic. */
-
-void
-half_pic_encode (decl)
- tree decl;
-{
- enum tree_code code = TREE_CODE (decl);
- tree asm_name;
- struct all_refs *ptr;
-
- if (!flag_half_pic)
- return;
-
- if (code != VAR_DECL && code != FUNCTION_DECL)
- return;
-
- asm_name = DECL_ASSEMBLER_NAME (decl);
-
- if (!asm_name)
- return;
-
-#ifdef HALF_PIC_DEBUG
- if (HALF_PIC_DEBUG)
- {
- fprintf (stderr, "\n========== Half_pic_encode %.*s\n",
- IDENTIFIER_LENGTH (asm_name),
- IDENTIFIER_POINTER (asm_name));
- debug_tree (decl);
- }
-#endif
-
- /* If this is not an external reference, it can't be half-pic. */
- if (!DECL_EXTERNAL (decl) && (code != VAR_DECL || !TREE_PUBLIC (decl)))
- return;
-
- ptr = half_pic_hash (IDENTIFIER_POINTER (asm_name),
- IDENTIFIER_LENGTH (asm_name),
- TRUE);
-
- ptr->external_p = TRUE;
-
-#ifdef HALF_PIC_DEBUG
- if (HALF_PIC_DEBUG)
- fprintf (stderr, "\n%.*s is half-pic\n",
- IDENTIFIER_LENGTH (asm_name),
- IDENTIFIER_POINTER (asm_name));
-#endif
-}
-
-\f
-/* Mark that an object is now local, and no longer needs half-pic. */
-
-void
-half_pic_declare (name)
- const char *name;
-{
- struct all_refs *ptr;
-
- if (!flag_half_pic)
- return;
-
- ptr = half_pic_hash (name, 0, FALSE);
- if (!ptr)
- return;
-
- ptr->external_p = FALSE;
-
-#ifdef HALF_PIC_DEBUG
- if (HALF_PIC_DEBUG)
- fprintf (stderr, "\n========== Half_pic_declare %s\n", name);
-#endif
-}
-
-\f
-/* Mark that an object is explicitly external. */
-
-void
-half_pic_external (name)
- const char *name;
-{
- struct all_refs *ptr;
-
- if (!flag_half_pic)
- return;
-
- ptr = half_pic_hash (name, 0, TRUE);
- if (!ptr)
- return;
-
- ptr->external_p = TRUE;
-
-#ifdef HALF_PIC_DEBUG
- if (HALF_PIC_DEBUG)
- fprintf (stderr, "\n========== Half_pic_external %s\n", name);
-#endif
-}
-
-\f
-/* Return whether an address is half-pic. */
-
-int
-half_pic_address_p (addr)
- rtx addr;
-{
- const char *name;
- int len;
- struct all_refs *ptr;
-
- if (!flag_half_pic)
- return FALSE;
-
- switch (GET_CODE (addr))
- {
- default:
- break;
-
- case CONST:
- {
- rtx offset = const0_rtx;
- addr = eliminate_constant_term (XEXP (addr, 0), &offset);
- if (GET_CODE (addr) != SYMBOL_REF)
- return FALSE;
- }
- /* fall through */
-
- case SYMBOL_REF:
- name = XSTR (addr, 0);
-
-#ifdef HALF_PIC_DEBUG
- if (HALF_PIC_DEBUG)
- fprintf (stderr, "\n========== Half_pic_address_p %s\n", name);
-#endif
-
- /* If this is a label, it will have a '*' in front of it. */
- if (name[0] == '*')
- return FALSE;
-
- /* If this is a reference to the actual half-pic pointer, it
- is obviously not half-pic. */
-
- len = strlen (name);
- if (len > half_pic_prefix_len
- && half_pic_prefix[0] == name[0]
- && !strncmp (name, half_pic_prefix, half_pic_prefix_len))
- return FALSE;
-
- ptr = half_pic_hash (name, len, FALSE);
- if (ptr == (struct all_refs *) 0)
- return FALSE;
-
- if (ptr->external_p)
- {
-#ifdef HALF_PIC_DEBUG
- if (HALF_PIC_DEBUG)
- fprintf (stderr, "%s is half-pic\n", name);
-#endif
- return TRUE;
- }
- }
-
- return FALSE;
-}
-
-\f
-/* Return the name of the pointer to the PIC function, allocating
- it if need be. */
-
-struct rtx_def *
-half_pic_ptr (operand)
- rtx operand;
-{
- const char *name;
- struct all_refs *p;
- int len;
-
- if (GET_CODE (operand) != SYMBOL_REF)
- return operand;
-
- name = XSTR (operand, 0);
- len = strlen (name);
- p = half_pic_hash (name, len, FALSE);
- if (p == (struct all_refs *) 0 || !p->external_p)
- return operand;
-
- if (!p->pointer_p)
- { /* first time, create pointer */
- obstack_grow (&half_pic_obstack, half_pic_prefix, half_pic_prefix_len);
- obstack_grow (&half_pic_obstack, name, len+1);
-
- p->next = half_pic_names;
- p->ref_name = (char *) obstack_finish (&half_pic_obstack);
- p->ref_len = len + half_pic_prefix_len;
- p->pointer_p = TRUE;
-
- half_pic_names = p;
- half_pic_number_ptrs++;
- }
-
- half_pic_number_refs++;
- return gen_rtx_SYMBOL_REF (Pmode, p->ref_name);
-}
-
-#endif /* HALF_PIC_INIT */
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