[PATCH] Fix PR52977
Michael Matz
matz@suse.de
Thu Apr 19 13:04:00 GMT 2012
Hi,
On Mon, 16 Apr 2012, Richard Guenther wrote:
> This fixes PR52977 - for PCH to work with its pointer relocation code we
> have to avoid dereferencing pointers to compute array lengths in
> structures. So we have to unfortunately keep duplicated info about
> VECTOR_CST vector lengths.
That's a pity and caused me to look a bit at gengtype. We can do better,
and compute the lengths before all fields are accessed (and mangled in the
PCH case). With the patch below we emit such code:
case TS_VECTOR:
{
size_t l0 = (size_t)(TYPE_VECTOR_SUBPARTS (TREE_TYPE ((tree)&((*x).generic.vector))));
if ((void *)(x) == this_obj)
op (&((*x).generic.vector.typed.type), cookie);
{
size_t i0;
for (i0 = 0; i0 != l0; i0++) {
if ((void *)(x) == this_obj)
op (&((*x).generic.vector.elts[i0]), cookie);
}
}
}
Note how .generic.vector.typed.type is only mangled after TREE_TYPE is
used to calculate the length.
I regstrapped this on x86_64-linux, all languages, no regression. Okay
for trunk (saving the all-important memory for vector constants again :)
)?
Ciao,
Michael.
------------------
PR middle-end/52977
* tree.h (VECTOR_CST_NELTS): Use part number of types again.
(struct tree_vector): Adjust GTY length.
* tree.c (make_vector_stat): Don't set VECTOR_CST_NELTS.
* gengtype.c (struct walk_type_data): Add in_record_p and loopcounter
members.
(walk_type, <TYPE_POINTER, TYPE_ARRAY>): Handle case where our
caller emitted the length calulation already.
(walk_type, <TYPE_UNION, TYPE_STRUCT>): Emit length calculations
before handling any of the fields for structs.
Index: tree.h
===================================================================
--- tree.h (revision 186580)
+++ tree.h (working copy)
@@ -1534,14 +1534,13 @@ struct GTY(()) tree_complex {
};
/* In a VECTOR_CST node. */
-#define VECTOR_CST_NELTS(NODE) (VECTOR_CST_CHECK (NODE)->vector.length)
+#define VECTOR_CST_NELTS(NODE) (TYPE_VECTOR_SUBPARTS (TREE_TYPE (NODE)))
#define VECTOR_CST_ELTS(NODE) (VECTOR_CST_CHECK (NODE)->vector.elts)
#define VECTOR_CST_ELT(NODE,IDX) (VECTOR_CST_CHECK (NODE)->vector.elts[IDX])
struct GTY(()) tree_vector {
struct tree_typed typed;
- unsigned length;
- tree GTY ((length ("%h.length"))) elts[1];
+ tree GTY ((length ("TYPE_VECTOR_SUBPARTS (TREE_TYPE ((tree)&%h))"))) elts[1];
};
#include "symtab.h"
Index: tree.c
===================================================================
--- tree.c (revision 186580)
+++ tree.c (working copy)
@@ -1329,7 +1329,6 @@ make_vector_stat (unsigned len MEM_STAT_
TREE_SET_CODE (t, VECTOR_CST);
TREE_CONSTANT (t) = 1;
- VECTOR_CST_NELTS (t) = len;
return t;
}
Index: gengtype.c
===================================================================
--- gengtype.c (revision 186580)
+++ gengtype.c (working copy)
@@ -2291,6 +2291,8 @@ struct walk_type_data
const char *reorder_fn;
bool needs_cast_p;
bool fn_wants_lvalue;
+ bool in_record_p;
+ int loopcounter;
};
/* Print a mangled name representing T to OF. */
@@ -2592,7 +2594,7 @@ walk_type (type_p t, struct walk_type_da
}
else
{
- int loopcounter = d->counter++;
+ int loopcounter = d->loopcounter;
const char *oldval = d->val;
const char *oldprevval3 = d->prev_val[3];
char *newval;
@@ -2602,7 +2604,10 @@ walk_type (type_p t, struct walk_type_da
oprintf (d->of, "%*ssize_t i%d;\n", d->indent, "", loopcounter);
oprintf (d->of, "%*sfor (i%d = 0; i%d != (size_t)(", d->indent,
"", loopcounter, loopcounter);
- output_escaped_param (d, length, "length");
+ if (!d->in_record_p)
+ output_escaped_param (d, length, "length");
+ else
+ oprintf (d->of, "l%d", loopcounter);
oprintf (d->of, "); i%d++) {\n", loopcounter);
d->indent += 2;
d->val = newval = xasprintf ("%s[i%d]", oldval, loopcounter);
@@ -2624,7 +2629,7 @@ walk_type (type_p t, struct walk_type_da
case TYPE_ARRAY:
{
- int loopcounter = d->counter++;
+ int loopcounter;
const char *oldval = d->val;
char *newval;
@@ -2633,6 +2638,11 @@ walk_type (type_p t, struct walk_type_da
if (t->u.a.p->kind == TYPE_SCALAR)
break;
+ if (length)
+ loopcounter = d->loopcounter;
+ else
+ loopcounter = d->counter++;
+
/* When walking an array, compute the length and store it in a
local variable before walking the array elements, instead of
recomputing the length expression each time through the loop.
@@ -2643,13 +2653,16 @@ walk_type (type_p t, struct walk_type_da
oprintf (d->of, "%*s{\n", d->indent, "");
d->indent += 2;
oprintf (d->of, "%*ssize_t i%d;\n", d->indent, "", loopcounter);
- oprintf (d->of, "%*ssize_t l%d = (size_t)(",
- d->indent, "", loopcounter);
- if (length)
- output_escaped_param (d, length, "length");
- else
- oprintf (d->of, "%s", t->u.a.len);
- oprintf (d->of, ");\n");
+ if (!d->in_record_p || !length)
+ {
+ oprintf (d->of, "%*ssize_t l%d = (size_t)(",
+ d->indent, "", loopcounter);
+ if (length)
+ output_escaped_param (d, length, "length");
+ else
+ oprintf (d->of, "%s", t->u.a.len);
+ oprintf (d->of, ");\n");
+ }
oprintf (d->of, "%*sfor (i%d = 0; i%d != l%d; i%d++) {\n",
d->indent, "",
@@ -2678,6 +2691,9 @@ walk_type (type_p t, struct walk_type_da
const int union_p = t->kind == TYPE_UNION;
int seen_default_p = 0;
options_p o;
+ int lengths_seen = 0;
+ int endcounter;
+ bool any_length_seen = false;
if (!t->u.s.line.file)
error_at_line (d->line, "incomplete structure `%s'", t->u.s.tag);
@@ -2713,6 +2729,45 @@ walk_type (type_p t, struct walk_type_da
d->indent += 2;
oprintf (d->of, "%*s{\n", d->indent, "");
}
+
+ for (f = t->u.s.fields; f; f = f->next)
+ {
+ options_p oo;
+ int skip_p = 0;
+ const char *fieldlength = NULL;
+
+ d->reorder_fn = NULL;
+ for (oo = f->opt; oo; oo = oo->next)
+ if (strcmp (oo->name, "skip") == 0)
+ skip_p = 1;
+ else if (strcmp (oo->name, "length") == 0
+ && oo->kind == OPTION_STRING)
+ fieldlength = oo->info.string;
+
+ if (skip_p)
+ continue;
+ if (fieldlength)
+ {
+ lengths_seen++;
+ d->counter++;
+ if (!union_p)
+ {
+ if (!any_length_seen)
+ {
+ oprintf (d->of, "%*s{\n", d->indent, "");
+ d->indent += 2;
+ }
+ any_length_seen = true;
+
+ oprintf (d->of, "%*ssize_t l%d = (size_t)(",
+ d->indent, "", d->counter - 1);
+ output_escaped_param (d, fieldlength, "length");
+ oprintf (d->of, ");\n");
+ }
+ }
+ }
+ endcounter = d->counter;
+
for (f = t->u.s.fields; f; f = f->next)
{
options_p oo;
@@ -2721,6 +2776,7 @@ walk_type (type_p t, struct walk_type_da
int skip_p = 0;
int default_p = 0;
int use_param_p = 0;
+ const char *fieldlength = NULL;
char *newval;
d->reorder_fn = NULL;
@@ -2741,6 +2797,9 @@ walk_type (type_p t, struct walk_type_da
else if (strncmp (oo->name, "use_param", 9) == 0
&& (oo->name[9] == '\0' || ISDIGIT (oo->name[9])))
use_param_p = 1;
+ else if (strcmp (oo->name, "length") == 0
+ && oo->kind == OPTION_STRING)
+ fieldlength = oo->info.string;
if (skip_p)
continue;
@@ -2774,16 +2833,24 @@ walk_type (type_p t, struct walk_type_da
"field `%s' is missing `tag' or `default' option",
f->name);
+ if (fieldlength)
+ {
+ d->loopcounter = endcounter - lengths_seen--;
+ }
+
d->line = &f->line;
d->val = newval = xasprintf ("%s%s%s", oldval, dot, f->name);
d->opt = f->opt;
d->used_length = false;
+ d->in_record_p = !union_p;
if (union_p && use_param_p && d->param == NULL)
oprintf (d->of, "%*sgcc_unreachable ();\n", d->indent, "");
else
walk_type (f->type, d);
+ d->in_record_p = false;
+
free (newval);
if (union_p)
@@ -2808,6 +2875,11 @@ walk_type (type_p t, struct walk_type_da
oprintf (d->of, "%*s}\n", d->indent, "");
d->indent -= 2;
}
+ if (any_length_seen)
+ {
+ d->indent -= 2;
+ oprintf (d->of, "%*s}\n", d->indent, "");
+ }
}
break;
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