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authorLudovic Courtès <ludo@gnu.org>2010-01-23 16:21:13 +0100
committerLudovic Courtès <ludo@gnu.org>2010-01-23 16:21:13 +0100
commitaa42c03669df8acf997d3108f08ce94d5d7611c2 (patch)
tree095caa206925dd04fb17e7a6fb9e2ee54dace271 /libguile/struct.c
parent0e64cbea3d22411564af302a63b670fe0617ccf3 (diff)
downloadguile-aa42c03669df8acf997d3108f08ce94d5d7611c2.tar.gz
Optimize struct initialization and accessors for the common case.
* libguile/struct.c (set_vtable_layout_flags): New function. (scm_i_struct_inherit_vtable_magic): Use it. (scm_struct_init): Optimize the case where HANDLE's vtable has the `SCM_VTABLE_FLAG_SIMPLE' flag. (scm_struct_ref): Likewise. (scm_struct_ref): Likewise, when `SCM_VTABLE_FLAG_SIMPLE_RW' is also set. * libguile/struct.h (SCM_VTABLE_BASE_LAYOUT): Update comment for the next-to-last hidden field. (scm_vtable_index_reserved_6): Rename to... (scm_vtable_index_size): ... this. (SCM_VTABLE_FLAG_RESERVED_0): Rename to... (SCM_VTABLE_FLAG_SIMPLE): ... this. (SCM_VTABLE_FLAG_RESERVED_1): Rename to... (SCM_VTABLE_FLAG_SIMPLE_RW): ... this. * test-suite/tests/structs.test ("low-level struct procedures")["struct-ref", "struct-set!", "struct-ref out-of-range", "struct-set! out-of-range"]: New tests.
Diffstat (limited to 'libguile/struct.c')
-rw-r--r--libguile/struct.c365
1 files changed, 229 insertions, 136 deletions
diff --git a/libguile/struct.c b/libguile/struct.c
index 321f2f199..adebe6f9f 100644
--- a/libguile/struct.c
+++ b/libguile/struct.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 1996,1997,1998,1999,2000,2001, 2003, 2004, 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
+/* Copyright (C) 1996,1997,1998,1999,2000,2001, 2003, 2004, 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public License
@@ -22,6 +22,7 @@
#endif
#include <alloca.h>
+#include <assert.h>
#include "libguile/_scm.h"
#include "libguile/async.h"
@@ -151,6 +152,61 @@ SCM_DEFINE (scm_make_struct_layout, "make-struct-layout", 1, 0, 0,
#undef FUNC_NAME
+/* Check whether VTABLE instances have a simple layout (i.e., either only "pr"
+ or only "pw" fields) and update its flags accordingly. */
+static void
+set_vtable_layout_flags (SCM vtable)
+{
+ size_t len, field;
+ SCM layout;
+ const char *c_layout;
+ scm_t_bits flags = SCM_VTABLE_FLAG_SIMPLE;
+
+ layout = SCM_VTABLE_LAYOUT (vtable);
+ c_layout = scm_i_symbol_chars (layout);
+ len = scm_i_symbol_length (layout);
+
+ assert (len % 2 == 0);
+
+ /* Update FLAGS according to LAYOUT. */
+ for (field = 0;
+ field < len && flags & SCM_VTABLE_FLAG_SIMPLE;
+ field += 2)
+ {
+ if (c_layout[field] != 'p')
+ flags = 0;
+ else
+ switch (c_layout[field + 1])
+ {
+ case 'w':
+ case 'W':
+ if (!(flags & SCM_VTABLE_FLAG_SIMPLE_RW) && field > 0)
+ /* There's a mixture of `w' and `r' flags. */
+ flags = 0;
+ else
+ flags |= SCM_VTABLE_FLAG_SIMPLE_RW;
+ break;
+
+ case 'r':
+ case 'R':
+ if (flags & SCM_VTABLE_FLAG_SIMPLE_RW)
+ /* There's a mixture of `w' and `r' flags. */
+ flags = 0;
+ break;
+
+ default:
+ flags = 0;
+ }
+ }
+
+ if (flags & SCM_VTABLE_FLAG_SIMPLE)
+ {
+ /* VTABLE is simple so update its flags and record the size of its
+ instances. */
+ SCM_SET_VTABLE_FLAGS (vtable, flags);
+ SCM_STRUCT_DATA_SET (vtable, scm_vtable_index_size, len / 2);
+ }
+}
void
scm_i_struct_inherit_vtable_magic (SCM vtable, SCM obj)
@@ -171,6 +227,8 @@ scm_i_struct_inherit_vtable_magic (SCM vtable, SCM obj)
scm_misc_error (FUNC_NAME, "invalid layout for new vtable",
scm_list_1 (SCM_VTABLE_LAYOUT (obj)));
+ set_vtable_layout_flags (obj);
+
/* if obj's vtable is compatible with the required vtable (class) layout, it
is a metaclass */
olayout = scm_symbol_to_string (SCM_VTABLE_LAYOUT (obj));
@@ -215,60 +273,74 @@ static void
scm_struct_init (SCM handle, SCM layout, size_t n_tail,
size_t n_inits, scm_t_bits *inits)
{
- scm_t_wchar prot = 0;
- int n_fields = scm_i_symbol_length (layout) / 2;
- int tailp = 0;
- int i;
- size_t inits_idx = 0;
- scm_t_bits *mem = SCM_STRUCT_DATA (handle);
-
- i = -2;
- while (n_fields)
+ SCM vtable;
+ scm_t_bits *mem;
+
+ vtable = SCM_STRUCT_VTABLE (handle);
+ mem = SCM_STRUCT_DATA (handle);
+
+ if (SCM_UNPACK (vtable) != 0
+ && SCM_VTABLE_FLAG_IS_SET (vtable, SCM_VTABLE_FLAG_SIMPLE)
+ && n_tail == 0
+ && n_inits == SCM_STRUCT_DATA_REF (vtable, scm_vtable_index_size))
+ /* The fast path: HANDLE has N_INITS "p" fields. */
+ memcpy (mem, inits, n_inits * sizeof (SCM));
+ else
{
- if (!tailp)
+ scm_t_wchar prot = 0;
+ int n_fields = scm_i_symbol_length (layout) / 2;
+ int tailp = 0;
+ int i;
+ size_t inits_idx = 0;
+
+ i = -2;
+ while (n_fields)
{
- i += 2;
- prot = scm_i_symbol_ref (layout, i+1);
- if (SCM_LAYOUT_TAILP (prot))
+ if (!tailp)
{
- tailp = 1;
- prot = prot == 'R' ? 'r' : prot == 'W' ? 'w' : 'o';
- *mem++ = (scm_t_bits)n_tail;
- n_fields += n_tail - 1;
- if (n_fields == 0)
- break;
+ i += 2;
+ prot = scm_i_symbol_ref (layout, i+1);
+ if (SCM_LAYOUT_TAILP (prot))
+ {
+ tailp = 1;
+ prot = prot == 'R' ? 'r' : prot == 'W' ? 'w' : 'o';
+ *mem++ = (scm_t_bits)n_tail;
+ n_fields += n_tail - 1;
+ if (n_fields == 0)
+ break;
+ }
}
- }
- switch (scm_i_symbol_ref (layout, i))
- {
- case 'u':
- if ((prot != 'r' && prot != 'w') || inits_idx == n_inits)
- *mem = 0;
- else
- {
- *mem = scm_to_ulong (SCM_PACK (inits[inits_idx]));
- inits_idx++;
- }
- break;
-
- case 'p':
- if ((prot != 'r' && prot != 'w') || inits_idx == n_inits)
- *mem = SCM_UNPACK (SCM_BOOL_F);
- else
+ switch (scm_i_symbol_ref (layout, i))
{
- *mem = inits[inits_idx];
- inits_idx++;
+ case 'u':
+ if ((prot != 'r' && prot != 'w') || inits_idx == n_inits)
+ *mem = 0;
+ else
+ {
+ *mem = scm_to_ulong (SCM_PACK (inits[inits_idx]));
+ inits_idx++;
+ }
+ break;
+
+ case 'p':
+ if ((prot != 'r' && prot != 'w') || inits_idx == n_inits)
+ *mem = SCM_UNPACK (SCM_BOOL_F);
+ else
+ {
+ *mem = inits[inits_idx];
+ inits_idx++;
+ }
+
+ break;
+
+ case 's':
+ *mem = SCM_UNPACK (handle);
+ break;
}
-
- break;
- case 's':
- *mem = SCM_UNPACK (handle);
- break;
+ n_fields--;
+ mem++;
}
-
- n_fields--;
- mem++;
}
}
@@ -627,71 +699,81 @@ SCM_DEFINE (scm_struct_ref, "struct-ref", 2, 0, 0,
"integer value small enough to fit in one machine word.")
#define FUNC_NAME s_scm_struct_ref
{
- SCM answer = SCM_UNDEFINED;
- scm_t_bits * data;
- SCM layout;
- size_t layout_len;
+ SCM vtable, answer = SCM_UNDEFINED;
+ scm_t_bits *data;
size_t p;
- scm_t_bits n_fields;
- scm_t_wchar field_type = 0;
-
SCM_VALIDATE_STRUCT (1, handle);
- layout = SCM_STRUCT_LAYOUT (handle);
+ vtable = SCM_STRUCT_VTABLE (handle);
data = SCM_STRUCT_DATA (handle);
p = scm_to_size_t (pos);
- layout_len = scm_i_symbol_length (layout);
- n_fields = layout_len / 2;
- if (SCM_LAYOUT_TAILP (scm_i_symbol_ref (layout, layout_len - 1)))
- n_fields += data[n_fields - 1];
-
- SCM_ASSERT_RANGE(1, pos, p < n_fields);
-
- if (p * 2 < layout_len)
+ if (SCM_LIKELY (SCM_VTABLE_FLAG_IS_SET (vtable, SCM_VTABLE_FLAG_SIMPLE)
+ && p < SCM_STRUCT_DATA_REF (vtable, scm_vtable_index_size)))
{
- scm_t_wchar ref;
- field_type = scm_i_symbol_ref (layout, p * 2);
- ref = scm_i_symbol_ref (layout, p * 2 + 1);
- if ((ref != 'r') && (ref != 'w') && (ref != 'h'))
- {
- if ((ref == 'R') || (ref == 'W'))
- field_type = 'u';
- else
- SCM_MISC_ERROR ("ref denied for field ~A", scm_list_1 (pos));
- }
+ /* The fast path: HANDLE is a struct with only "p" fields. */
+ answer = SCM_PACK (data[p]);
}
- else if (scm_i_symbol_ref (layout, layout_len - 1) != 'O')
- field_type = scm_i_symbol_ref(layout, layout_len - 2);
else
- SCM_MISC_ERROR ("ref denied for field ~A", scm_list_1 (pos));
-
- switch (field_type)
{
- case 'u':
- answer = scm_from_ulong (data[p]);
- break;
+ SCM layout;
+ size_t layout_len, n_fields;
+ scm_t_wchar field_type = 0;
+
+ layout = SCM_STRUCT_LAYOUT (handle);
+ layout_len = scm_i_symbol_length (layout);
+ n_fields = layout_len / 2;
+
+ if (SCM_LAYOUT_TAILP (scm_i_symbol_ref (layout, layout_len - 1)))
+ n_fields += data[n_fields - 1];
+
+ SCM_ASSERT_RANGE (1, pos, p < n_fields);
+
+ if (p * 2 < layout_len)
+ {
+ scm_t_wchar ref;
+ field_type = scm_i_symbol_ref (layout, p * 2);
+ ref = scm_i_symbol_ref (layout, p * 2 + 1);
+ if ((ref != 'r') && (ref != 'w') && (ref != 'h'))
+ {
+ if ((ref == 'R') || (ref == 'W'))
+ field_type = 'u';
+ else
+ SCM_MISC_ERROR ("ref denied for field ~A", scm_list_1 (pos));
+ }
+ }
+ else if (scm_i_symbol_ref (layout, layout_len - 1) != 'O')
+ field_type = scm_i_symbol_ref(layout, layout_len - 2);
+ else
+ SCM_MISC_ERROR ("ref denied for field ~A", scm_list_1 (pos));
+
+ switch (field_type)
+ {
+ case 'u':
+ answer = scm_from_ulong (data[p]);
+ break;
#if 0
- case 'i':
- answer = scm_from_long (data[p]);
- break;
+ case 'i':
+ answer = scm_from_long (data[p]);
+ break;
- case 'd':
- answer = scm_make_real (*((double *)&(data[p])));
- break;
+ case 'd':
+ answer = scm_make_real (*((double *)&(data[p])));
+ break;
#endif
- case 's':
- case 'p':
- answer = SCM_PACK (data[p]);
- break;
+ case 's':
+ case 'p':
+ answer = SCM_PACK (data[p]);
+ break;
- default:
- SCM_MISC_ERROR ("unrecognized field type: ~S",
- scm_list_1 (SCM_MAKE_CHAR (field_type)));
+ default:
+ SCM_MISC_ERROR ("unrecognized field type: ~S",
+ scm_list_1 (SCM_MAKE_CHAR (field_type)));
+ }
}
return answer;
@@ -706,65 +788,76 @@ SCM_DEFINE (scm_struct_set_x, "struct-set!", 3, 0, 0,
"to.")
#define FUNC_NAME s_scm_struct_set_x
{
- scm_t_bits * data;
- SCM layout;
- size_t layout_len;
+ SCM vtable;
+ scm_t_bits *data;
size_t p;
- int n_fields;
- scm_t_wchar field_type = 0;
SCM_VALIDATE_STRUCT (1, handle);
- layout = SCM_STRUCT_LAYOUT (handle);
+ vtable = SCM_STRUCT_VTABLE (handle);
data = SCM_STRUCT_DATA (handle);
p = scm_to_size_t (pos);
- layout_len = scm_i_symbol_length (layout);
- n_fields = layout_len / 2;
- if (SCM_LAYOUT_TAILP (scm_i_symbol_ref (layout, layout_len - 1)))
- n_fields += data[n_fields - 1];
+ if (SCM_LIKELY (SCM_VTABLE_FLAG_IS_SET (vtable, SCM_VTABLE_FLAG_SIMPLE)
+ && SCM_VTABLE_FLAG_IS_SET (vtable, SCM_VTABLE_FLAG_SIMPLE_RW)
+ && p < SCM_STRUCT_DATA_REF (vtable, scm_vtable_index_size)))
+ /* The fast path: HANDLE is a struct with only "p" fields. */
+ data[p] = SCM_UNPACK (val);
+ else
+ {
+ SCM layout;
+ size_t layout_len, n_fields;
+ scm_t_wchar field_type = 0;
- SCM_ASSERT_RANGE (1, pos, p < n_fields);
+ layout = SCM_STRUCT_LAYOUT (handle);
+ layout_len = scm_i_symbol_length (layout);
+ n_fields = layout_len / 2;
- if (p * 2 < layout_len)
- {
- char set_x;
- field_type = scm_i_symbol_ref (layout, p * 2);
- set_x = scm_i_symbol_ref (layout, p * 2 + 1);
- if (set_x != 'w' && set_x != 'h')
+ if (SCM_LAYOUT_TAILP (scm_i_symbol_ref (layout, layout_len - 1)))
+ n_fields += data[n_fields - 1];
+
+ SCM_ASSERT_RANGE (1, pos, p < n_fields);
+
+ if (p * 2 < layout_len)
+ {
+ char set_x;
+ field_type = scm_i_symbol_ref (layout, p * 2);
+ set_x = scm_i_symbol_ref (layout, p * 2 + 1);
+ if (set_x != 'w' && set_x != 'h')
+ SCM_MISC_ERROR ("set! denied for field ~A", scm_list_1 (pos));
+ }
+ else if (scm_i_symbol_ref (layout, layout_len - 1) == 'W')
+ field_type = scm_i_symbol_ref (layout, layout_len - 2);
+ else
SCM_MISC_ERROR ("set! denied for field ~A", scm_list_1 (pos));
- }
- else if (scm_i_symbol_ref (layout, layout_len - 1) == 'W')
- field_type = scm_i_symbol_ref (layout, layout_len - 2);
- else
- SCM_MISC_ERROR ("set! denied for field ~A", scm_list_1 (pos));
-
- switch (field_type)
- {
- case 'u':
- data[p] = SCM_NUM2ULONG (3, val);
- break;
+
+ switch (field_type)
+ {
+ case 'u':
+ data[p] = SCM_NUM2ULONG (3, val);
+ break;
#if 0
- case 'i':
- data[p] = SCM_NUM2LONG (3, val);
- break;
+ case 'i':
+ data[p] = SCM_NUM2LONG (3, val);
+ break;
- case 'd':
- *((double *)&(data[p])) = scm_num2dbl (val, (char *)SCM_ARG3);
- break;
+ case 'd':
+ *((double *)&(data[p])) = scm_num2dbl (val, (char *)SCM_ARG3);
+ break;
#endif
- case 'p':
- data[p] = SCM_UNPACK (val);
- break;
+ case 'p':
+ data[p] = SCM_UNPACK (val);
+ break;
- case 's':
- SCM_MISC_ERROR ("self fields immutable", SCM_EOL);
+ case 's':
+ SCM_MISC_ERROR ("self fields immutable", SCM_EOL);
- default:
- SCM_MISC_ERROR ("unrecognized field type: ~S",
- scm_list_1 (SCM_MAKE_CHAR (field_type)));
+ default:
+ SCM_MISC_ERROR ("unrecognized field type: ~S",
+ scm_list_1 (SCM_MAKE_CHAR (field_type)));
+ }
}
return val;