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varasm.c (mark_constant_pool): Improve initial comments.

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2001-01-05  Jeffrey Oldham  <oldham@codesourcery.com>

	* varasm.c (mark_constant_pool): Improve initial comments.
	(mark_constants): Move marking of constants to mark_constant.
	(mark_constant): New function to recursively mark all constants
	referred to by a constant.

From-SVN: r38721
This commit is contained in:
Jeffrey Oldham 2001-01-05 20:25:09 +00:00 committed by Jeffrey D. Oldham
parent ebb0cdf335
commit fcbd8ef220
2 changed files with 66 additions and 50 deletions
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7
gcc/ChangeLog
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@ -1,3 +1,10 @@
2001-01-05 Jeffrey Oldham <oldham@codesourcery.com>
* varasm.c (mark_constant_pool): Improve initial comments.
(mark_constants): Move marking of constants to mark_constant.
(mark_constant): New function to recursively mark all constants
referred to by a constant.
2001-01-05 Catherine Moore <clm@redhat.com>
* dbxout.c ((dbxout_parms): Handle invisible ref where decl is a REG.

109
gcc/varasm.c
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@ -169,6 +169,7 @@ static struct constant_descriptor *record_constant_rtx PARAMS ((enum machine_mod
static struct pool_constant *find_pool_constant PARAMS ((struct function *, rtx));
static void mark_constant_pool PARAMS ((void));
static void mark_constants PARAMS ((rtx));
static int mark_constant PARAMS ((rtx *current_rtx, void *data));
static int output_addressed_constants PARAMS ((tree));
static void output_after_function_constants PARAMS ((void));
static unsigned HOST_WIDE_INT array_size_for_constructor PARAMS ((tree));
@ -3927,7 +3928,8 @@ output_constant_pool (fnname, fndecl)
}
/* Look through the instructions for this function, and mark all the
entries in the constant pool which are actually being used. */
entries in the constant pool which are actually being used.
Emit used deferred strings. */
static void
mark_constant_pool ()
@ -3950,41 +3952,16 @@ mark_constant_pool ()
insn = XEXP (insn, 1))
if (INSN_P (insn))
mark_constants (PATTERN (insn));
/* It's possible that the only reference to a symbol is in a symbol
that's in the constant pool. This happens in Fortran under some
situations. (When the constant contains the address of another
constant, and only the first is used directly in an insn.)
This is potentially suboptimal if there's ever a possibility of
backwards (in pool order) 2'd level references. However, it's
not clear that 2'd level references can happen. */
for (pool = first_pool; pool; pool = pool->next)
{
struct pool_constant *tem;
const char *label;
/* skip unmarked entries; no insn refers to them. */
if (!pool->mark)
continue;
/* Skip everything except SYMBOL_REFs. */
if (GET_CODE (pool->constant) != SYMBOL_REF)
continue;
label = XSTR (pool->constant, 0);
/* Be sure the symbol's value is marked. */
for (tem = const_rtx_sym_hash_table[SYMHASH (label)]; tem;
tem = tem->next)
if (tem->label == label)
tem->mark = 1;
/* If we didn't find it, there's something truly wrong here, but it
will be announced by the assembler. */
}
}
/* Look through appropriate parts of X, marking all entries in the
constant pool which are actually being used. Entries that are only
referenced by other constants are also marked as used. Emit
deferred strings that are used. */
static void
mark_constants (x)
register rtx x;
rtx x;
{
register int i;
register const char *format_ptr;
@ -3994,24 +3971,7 @@ mark_constants (x)
if (GET_CODE (x) == SYMBOL_REF)
{
if (CONSTANT_POOL_ADDRESS_P (x))
find_pool_constant (cfun, x)->mark = 1;
else if (STRING_POOL_ADDRESS_P (x))
{
struct deferred_string **defstr;
defstr = (struct deferred_string **)
htab_find_slot_with_hash (const_str_htab, XSTR (x, 0),
STRHASH (XSTR (x, 0)), NO_INSERT);
if (defstr)
{
struct deferred_string *p = *defstr;
STRING_POOL_ADDRESS_P (x) = 0;
output_constant_def_contents (p->exp, 0, p->labelno);
htab_clear_slot (const_str_htab, (void **) defstr);
}
}
mark_constant (&x, NULL);
return;
}
/* Never search inside a CONST_DOUBLE, because CONST_DOUBLE_MEM may be
@ -4062,6 +4022,55 @@ mark_constants (x)
}
}
}
/* Given a SYMBOL_REF CURRENT_RTX, mark it and all constants it refers
to as used. Emit referenced deferred strings. This function can
be used with for_each_rtx () to mark all SYMBOL_REFs in an rtx. */
static int
mark_constant (current_rtx, data)
rtx *current_rtx;
void *data ATTRIBUTE_UNUSED;
{
rtx x = *current_rtx;
if (x == NULL_RTX)
return 0;
else if (GET_CODE(x) == CONST_DOUBLE)
/* Never search inside a CONST_DOUBLE because CONST_DOUBLE_MEM may
be a MEM but does not constitute a use of that MEM. */
return -1;
else if (GET_CODE (x) == SYMBOL_REF)
{
if (CONSTANT_POOL_ADDRESS_P (x))
{
struct pool_constant *pool = find_pool_constant (cfun, x);
if (pool->mark == 0) {
pool->mark = 1;
for_each_rtx (&(pool->constant), &mark_constant, NULL);
}
else
return -1;
}
else if (STRING_POOL_ADDRESS_P (x))
{
struct deferred_string **defstr;
defstr = (struct deferred_string **)
htab_find_slot_with_hash (const_str_htab, XSTR (x, 0),
STRHASH (XSTR (x, 0)), NO_INSERT);
if (defstr)
{
struct deferred_string *p = *defstr;
STRING_POOL_ADDRESS_P (x) = 0;
output_constant_def_contents (p->exp, 0, p->labelno);
htab_clear_slot (const_str_htab, (void **) defstr);
}
}
}
return 0;
}
/* Find all the constants whose addresses are referenced inside of EXP,
and make sure assembler code with a label has been output for each one.