hooks.c (hook_bool_mode_rtx_true): New function.

	* hooks.c (hook_bool_mode_rtx_true): New function.
	* hooks.h (hook_bool_mode_rtx_true): Declare.
	* toplev.c (compile_file): Call output_shared_constant_pool.
	* varasm.c (shared_constant_pool): New variable.
	(assemble_start_function, assemble_end_function): Remove arguments
	from call to output_constant_pool.
	(create_constant_pool): New function, split out from...
	(init_varasm_status): ...here.
	(force_const_mem): Choose between the shared and per-function constant
	pools.  Set current_function_uses_const_pool when reusing old entries
	as well as when creating new ones.
	(mark_constant): Ignore data argument.
	(mark_constants): Remove pool argument.
	(mark_constant_pool): Likewise.  Use current_function_uses_const_pool
	to decide whether the function uses a constant pool.
	(output_constant_pool_contents): New function, split out from...
	(output_constant_pool): ...here.
	(output_shared_constant_pool): New function.
	(init_varasm_once): Initialize shared_constant_pool.
	* output.h (output_constant_pool): Delete.
	(output_shared_constant_pool): Declare.
	* config/s390/s390-protos.h (s390_output_constant_pool): Delete.
	* config/i386/i386.c (TARGET_USE_BLOCKS_FOR_CONSTANT_P): Override.

From-SVN: r111804

gcc/ChangeLog

+2006-03-07  Richard Sandiford  <richard@codesourcery.com>
+
+	* hooks.c (hook_bool_mode_rtx_true): New function.
+	* hooks.h (hook_bool_mode_rtx_true): Declare.
+	* toplev.c (compile_file): Call output_shared_constant_pool.
+	* varasm.c (shared_constant_pool): New variable.
+	(assemble_start_function, assemble_end_function): Remove arguments
+	from call to output_constant_pool.
+	(create_constant_pool): New function, split out from...
+	(init_varasm_status): ...here.
+	(force_const_mem): Choose between the shared and per-function constant
+	pools.  Set current_function_uses_const_pool when reusing old entries
+	as well as when creating new ones.
+	(mark_constant): Ignore data argument.
+	(mark_constants): Remove pool argument.
+	(mark_constant_pool): Likewise.  Use current_function_uses_const_pool
+	to decide whether the function uses a constant pool.
+	(output_constant_pool_contents): New function, split out from...
+	(output_constant_pool): ...here.
+	(output_shared_constant_pool): New function.
+	(init_varasm_once): Initialize shared_constant_pool.
+	* output.h (output_constant_pool): Delete.
+	(output_shared_constant_pool): Declare.
+	* config/s390/s390-protos.h (s390_output_constant_pool): Delete.
+	* config/i386/i386.c (TARGET_USE_BLOCKS_FOR_CONSTANT_P): Override.
+
 2006-03-06  Nick Clifton  <nickc@redhat.com>
 
 	* config/m32r/m32r.h (OPTIMIZATION_OPTIONS): Remove reference to

gcc/config/i386/i386.c

@@ -1261,6 +1261,8 @@ static section *x86_64_elf_select_section (tree decl, int reloc,
 #endif
 #undef TARGET_CANNOT_FORCE_CONST_MEM
 #define TARGET_CANNOT_FORCE_CONST_MEM ix86_cannot_force_const_mem
+#undef TARGET_USE_BLOCKS_FOR_CONSTANT_P
+#define TARGET_USE_BLOCKS_FOR_CONSTANT_P hook_bool_mode_rtx_true
 
 #undef TARGET_DELEGITIMIZE_ADDRESS
 #define TARGET_DELEGITIMIZE_ADDRESS ix86_delegitimize_address

gcc/config/s390/s390-protos.h

@@ -90,7 +90,6 @@ extern void s390_split_access_reg (rtx, rtx *, rtx *);
 extern bool s390_output_addr_const_extra (FILE*, rtx);
 extern void print_operand_address (FILE *, rtx);
 extern void print_operand (FILE *, rtx, int);
-extern void s390_output_constant_pool (rtx, rtx);
 extern void s390_output_pool_entry (rtx, enum machine_mode, unsigned int);
 extern void s390_trampoline_template (FILE *);
 extern void s390_initialize_trampoline (rtx, rtx, rtx);

gcc/hooks.c

@@ -77,6 +77,14 @@ hook_bool_mode_rtx_false (enum machine_mode mode ATTRIBUTE_UNUSED,
   return false;
 }
 
+/* Generic hook that takes (enum machine_mode, rtx) and returns true.  */
+bool
+hook_bool_mode_rtx_true (enum machine_mode mode ATTRIBUTE_UNUSED,
+			 rtx value ATTRIBUTE_UNUSED)
+{
+  return true;
+}
+
 /* Generic hook that takes (FILE *, const char *) and does nothing.  */
 void
 hook_void_FILEptr_constcharptr (FILE *a ATTRIBUTE_UNUSED, const char *b ATTRIBUTE_UNUSED)

gcc/hooks.h

@@ -29,6 +29,7 @@ extern bool hook_bool_void_true (void);
 extern bool hook_bool_bool_false (bool);
 extern bool hook_bool_mode_false (enum machine_mode);
 extern bool hook_bool_mode_rtx_false (enum machine_mode, rtx);
+extern bool hook_bool_mode_rtx_true (enum machine_mode, rtx);
 extern bool hook_bool_tree_false (tree);
 extern bool hook_bool_tree_true (tree);
 extern bool hook_bool_tree_hwi_hwi_tree_false (tree, HOST_WIDE_INT, HOST_WIDE_INT,

gcc/output.h

@@ -272,8 +272,7 @@ extern int get_pool_size (void);
 extern rtx peephole (rtx);
 #endif
 
-/* Write all the constants in the constant pool.  */
-extern void output_constant_pool (const char *, tree);
+extern void output_shared_constant_pool (void);
 
 extern void output_object_blocks (void);
 

gcc/toplev.c

@@ -1022,6 +1022,7 @@ compile_file (void)
   if (flag_mudflap)
     mudflap_finish_file ();
 
+  output_shared_constant_pool ();
   output_object_blocks ();
 
   /* Write out any pending weak symbol declarations.  */

gcc/varasm.c

@@ -139,6 +139,7 @@ static void asm_output_aligned_bss (FILE *, tree, const char *,
 #endif
 #endif /* BSS_SECTION_ASM_OP */
 static void mark_weak (tree);
+static void output_constant_pool (void);
 
 /* Well-known sections, each one associated with some sort of *_ASM_OP.  */
 section *text_section;
@@ -196,6 +197,9 @@ static GTY((param_is (struct object_block))) htab_t object_block_htab;
 /* The next number to use for internal anchor labels.  */
 static GTY(()) int anchor_labelno;
 
+/* A pool of constants that can be shared between functions.  */
+static GTY(()) struct rtx_constant_pool *shared_constant_pool;
+
 /* Helper routines for maintaining section_htab.  */
 
 static int
@@ -1328,7 +1332,7 @@ assemble_start_function (tree decl, const char *fnname)
   app_disable ();
 
   if (CONSTANT_POOL_BEFORE_FUNCTION)
-    output_constant_pool (fnname, decl);
+    output_constant_pool ();
 
   resolve_unique_section (decl, 0, flag_function_sections);
 
@@ -1446,7 +1450,7 @@ assemble_end_function (tree decl, const char *fnname)
 #endif
   if (! CONSTANT_POOL_BEFORE_FUNCTION)
     {
-      output_constant_pool (fnname, decl);
+      output_constant_pool ();
       switch_to_section (function_section (decl)); /* need to switch back */
     }
   /* Output labels for end of hot/cold text sections (to be used by
@@ -3122,25 +3126,34 @@ const_rtx_hash (rtx x)
 }
 
 
+/* Create and return a new rtx constant pool.  */
+
+static struct rtx_constant_pool *
+create_constant_pool (void)
+{
+  struct rtx_constant_pool *pool;
+
+  pool = ggc_alloc (sizeof (struct rtx_constant_pool));
+  pool->const_rtx_htab = htab_create_ggc (31, const_desc_rtx_hash,
+					  const_desc_rtx_eq, NULL);
+  pool->first = NULL;
+  pool->last = NULL;
+  pool->offset = 0;
+  return pool;
+}
+
 /* Initialize constant pool hashing for a new function.  */
 
 void
 init_varasm_status (struct function *f)
 {
   struct varasm_status *p;
-  struct rtx_constant_pool *pool;
 
   p = ggc_alloc (sizeof (struct varasm_status));
   f->varasm = p;
 
-  pool = ggc_alloc (sizeof (struct rtx_constant_pool));
-  p->pool = pool;
+  p->pool = create_constant_pool ();
   p->deferred_constants = 0;
-
-  pool->const_rtx_htab = htab_create_ggc (31, const_desc_rtx_hash,
-					  const_desc_rtx_eq, NULL);
-  pool->first = pool->last = NULL;
-  pool->offset = 0;
 }
 
 /* Given a MINUS expression, simplify it if both sides
@@ -3160,7 +3173,7 @@ rtx
 force_const_mem (enum machine_mode mode, rtx x)
 {
   struct constant_descriptor_rtx *desc, tmp;
-  struct rtx_constant_pool *pool = cfun->varasm->pool;
+  struct rtx_constant_pool *pool;
   char label[256];
   rtx def, symbol;
   hashval_t hash;
@@ -3171,6 +3184,14 @@ force_const_mem (enum machine_mode mode, rtx x)
   if (targetm.cannot_force_const_mem (x))
     return NULL_RTX;
 
+  /* Record that this function has used a constant pool entry.  */
+  current_function_uses_const_pool = 1;
+
+  /* Decide which pool to use.  */
+  pool = (targetm.use_blocks_for_constant_p (mode, x)
+	  ? shared_constant_pool
+	  : cfun->varasm->pool);
+
   /* Lookup the value in the hashtable.  */
   tmp.constant = x;
   tmp.mode = mode;
@@ -3233,7 +3254,6 @@ force_const_mem (enum machine_mode mode, rtx x)
   SYMBOL_REF_FLAGS (symbol) |= SYMBOL_FLAG_LOCAL;
   CONSTANT_POOL_ADDRESS_P (symbol) = 1;
   SET_SYMBOL_REF_CONSTANT (symbol, desc);
-  current_function_uses_const_pool = 1;
 
   /* Construct the MEM.  */
   desc->mem = def = gen_const_mem (mode, symbol);
@@ -3404,9 +3424,8 @@ output_constant_pool_1 (struct constant_descriptor_rtx *desc,
    be used with for_each_rtx to mark all SYMBOL_REFs in an rtx.  */
 
 static int
-mark_constant (rtx *current_rtx, void *data)
+mark_constant (rtx *current_rtx, void *data ATTRIBUTE_UNUSED)
 {
-  struct rtx_constant_pool *pool = data;
   rtx x = *current_rtx;
 
   if (x == NULL_RTX || GET_CODE (x) != SYMBOL_REF)
@@ -3418,7 +3437,7 @@ mark_constant (rtx *current_rtx, void *data)
       if (desc->mark == 0)
 	{
 	  desc->mark = 1;
-	  for_each_rtx (&desc->constant, mark_constant, pool);
+	  for_each_rtx (&desc->constant, mark_constant, NULL);
 	}
     }
   else if (TREE_CONSTANT_POOL_ADDRESS_P (x))
@@ -3440,7 +3459,7 @@ mark_constant (rtx *current_rtx, void *data)
    deferred strings that are used.  */
 
 static void
-mark_constants (struct rtx_constant_pool *pool, rtx insn)
+mark_constants (rtx insn)
 {
   if (!INSN_P (insn))
     return;
@@ -3456,11 +3475,11 @@ mark_constants (struct rtx_constant_pool *pool, rtx insn)
 	{
 	  rtx subinsn = XVECEXP (seq, 0, i);
 	  if (INSN_P (subinsn))
-	    for_each_rtx (&PATTERN (subinsn), mark_constant, pool);
+	    for_each_rtx (&PATTERN (subinsn), mark_constant, NULL);
 	}
     }
   else
-    for_each_rtx (&PATTERN (insn), mark_constant, pool);
+    for_each_rtx (&PATTERN (insn), mark_constant, NULL);
 }
 
 /* Look through the instructions for this function, and mark all the
@@ -3468,40 +3487,29 @@ mark_constants (struct rtx_constant_pool *pool, rtx insn)
    which have indeed been used.  */
 
 static void
-mark_constant_pool (struct rtx_constant_pool *pool)
+mark_constant_pool (void)
 {
   rtx insn, link;
 
-  if (pool->first == 0 && n_deferred_constants == 0)
+  if (!current_function_uses_const_pool && n_deferred_constants == 0)
     return;
 
   for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
-    mark_constants (pool, insn);
+    mark_constants (insn);
 
   for (link = current_function_epilogue_delay_list;
        link;
        link = XEXP (link, 1))
-    mark_constants (pool, XEXP (link, 0));
+    mark_constants (XEXP (link, 0));
 }
 
-/* Write all the constants in the constant pool.  */
+/* Write all the constants in POOL.  */
 
-void
-output_constant_pool (const char *fnname ATTRIBUTE_UNUSED,
-		      tree fndecl ATTRIBUTE_UNUSED)
+static void
+output_constant_pool_contents (struct rtx_constant_pool *pool)
 {
-  struct rtx_constant_pool *pool = cfun->varasm->pool;
   struct constant_descriptor_rtx *desc;
 
-  /* It is possible for gcc to call force_const_mem and then to later
-     discard the instructions which refer to the constant.  In such a
-     case we do not need to output the constant.  */
-  mark_constant_pool (pool);
-
-#ifdef ASM_OUTPUT_POOL_PROLOGUE
-  ASM_OUTPUT_POOL_PROLOGUE (asm_out_file, fnname, fndecl, pool->offset);
-#endif
-
   for (desc = pool->first; desc ; desc = desc->next)
     if (desc->mark)
       {
@@ -3519,12 +3527,40 @@ output_constant_pool (const char *fnname ATTRIBUTE_UNUSED,
 	    output_constant_pool_1 (desc, desc->align);
 	  }
       }
+}
+
+/* Mark all constants that are used in the current function, then write
+   out the function's private constant pool.  */
+
+static void
+output_constant_pool (void)
+{
+  struct rtx_constant_pool *pool = cfun->varasm->pool;
+
+  /* It is possible for gcc to call force_const_mem and then to later
+     discard the instructions which refer to the constant.  In such a
+     case we do not need to output the constant.  */
+  mark_constant_pool ();
+
+#ifdef ASM_OUTPUT_POOL_PROLOGUE
+  ASM_OUTPUT_POOL_PROLOGUE (asm_out_file, fnname, fndecl, pool->offset);
+#endif
+
+  output_constant_pool_contents (pool);
 
 #ifdef ASM_OUTPUT_POOL_EPILOGUE
   ASM_OUTPUT_POOL_EPILOGUE (asm_out_file, fnname, fndecl, pool->offset);
 #endif
 }
 
+/* Write the contents of the shared constant pool.  */
+
+void
+output_shared_constant_pool (void)
+{
+  output_constant_pool_contents (shared_constant_pool);
+}
+
 /* Determine what kind of relocations EXP may need.  */
 
 int
@@ -5064,6 +5100,7 @@ init_varasm_once (void)
 				     const_desc_eq, NULL);
 
   const_alias_set = new_alias_set ();
+  shared_constant_pool = create_constant_pool ();
 
 #ifdef TEXT_SECTION_ASM_OP
   text_section = get_unnamed_section (SECTION_CODE, output_section_asm_op,