[PATCH] Introduce MODE_SIZE mode attribute
Jakub Jelinek
jakub@redhat.com
Fri Jan 3 23:38:00 GMT 2014
On Fri, Jan 03, 2014 at 03:39:11PM +0000, Joseph S. Myers wrote:
> On Fri, 3 Jan 2014, Jakub Jelinek wrote:
>
> > I've noticed that especially with the AVX512F introduction we use
> > GET_MODE_SIZE (<MODE>mode) quite heavily in the i386 *.md files, and
> > the problem with that is GET_MODE_SIZE isn't a compile time constant,
> > needs to read mode_size array (non-const) at runtime.
>
> It would seem better to me for genmodes to generate appropriate macro /
> inline function definitions that can be used by GET_MODE_SIZE (along the
> lines of (__builtin_constant_p (MODE) && !mode_size_variable (MODE) ?
> get_mode_size_constant (MODE) : (unsigned short) mode_size[MODE]), where
> mode_size_variable and get_mode_size_constant are always_inline functions
> generated by genmodes) - that way all targets are covered automatically,
> without needing such duplication of mode sizes. (Of course such
> optimizations wouldn't apply for a first-stage compiler bootstrapped by a
> compiler not supporting __builtin_constant_p, but lack of optimization in
> the first stage of a bootstrap is not a particular concern.)
That is certainly doable (as attached), but strangely if the patch (that I've
already committed) is reverted and this one applied, the .text savings are
much smaller.
Here are .text and .rodata readelf -WS lines from x86_64 (first 4 pairs) and
i686 (last 4 pairs) builds, always vanilla trunk before r206312, that plus
r206312 patch, without r206312 but with attached patch, with both r206312
and attached patch. So, for .text size the best is both patches, but
for .rodata patches just r206312. I'll try to look at details why this is so
next week.
[12] .text PROGBITS 00000000004f4b00 0f4b00 1131704 00 AX 0 0 16
[14] .rodata PROGBITS 0000000001626240 1226240 4093b4 00 A 0 0 64
[12] .text PROGBITS 00000000004f20a0 0f20a0 11156e4 00 AX 0 0 16
[14] .rodata PROGBITS 00000000016077c0 12077c0 3fcbb4 00 A 0 0 64
[12] .text PROGBITS 00000000004f4c60 0f4c60 112b8b4 00 AX 0 0 16
[14] .rodata PROGBITS 0000000001620540 1220540 40b134 00 A 0 0 64
[12] .text PROGBITS 00000000004f2200 0f2200 1113eb4 00 AX 0 0 16
[14] .rodata PROGBITS 00000000016060c0 12060c0 3fea74 00 A 0 0 64
[12] .text PROGBITS 0811d750 0d5750 12b4464 00 AX 0 0 16
[14] .rodata PROGBITS 093d1c00 1389c00 2d8094 00 A 0 0 64
[12] .text PROGBITS 0811b150 0d3150 12996a4 00 AX 0 0 16
[14] .rodata PROGBITS 093b4840 136c840 2d1354 00 A 0 0 64
[12] .text PROGBITS 0811d840 0d5840 12aa1e4 00 AX 0 0 16
[14] .rodata PROGBITS 093c7a40 137fa40 2d8b94 00 A 0 0 64
[12] .text PROGBITS 0811b240 0d3240 1292914 00 AX 0 0 16
[14] .rodata PROGBITS 093adb80 1365b80 2d1f94 00 A 0 0 64
2014-01-04 Jakub Jelinek <jakub@redhat.com>
* genmodes.c (struct mode_data): Add need_bytesize_adj field.
(blank_mdoe): Initialize it.
(emit_mode_size_inline, emit_mode_nunits_inline,
emit_mode_inner_inline): New functions.
(emit_insn_modes_h): Call them and surround their output with
#if GCC_VERSION >= 4001 ... #endif.
* machmode.h (GET_MODE_SIZE, GET_MODE_NUNITS, GET_MODE_INNER):
For GCC_VERSION >= 4001 use mode_*_inline routines instead of
mode_* arrays if the argument is __builtin_constant_p.
* lower-subreg.c (dump_choices): Make sure GET_MODE_SIZE argument
is enum machine_mode.
fortran/
* trans-types.c (gfc_init_kinds): Make sure GET_MODE_BITSIZE
argument is enum machine_mode.
--- gcc/lower-subreg.c.jj 2013-12-10 18:18:39.077943292 +0100
+++ gcc/lower-subreg.c 2014-01-03 18:35:00.510418999 +0100
@@ -1371,7 +1371,7 @@ dump_choices (bool speed_p, const char *
fprintf (dump_file, "Choices when optimizing for %s:\n", description);
for (i = 0; i < MAX_MACHINE_MODE; i++)
- if (GET_MODE_SIZE (i) > UNITS_PER_WORD)
+ if (GET_MODE_SIZE ((enum machine_mode) i) > UNITS_PER_WORD)
fprintf (dump_file, " %s mode %s for copy lowering.\n",
choices[speed_p].move_modes_to_split[i]
? "Splitting"
--- gcc/fortran/trans-types.c.jj 2013-11-21 22:24:18.790939654 +0100
+++ gcc/fortran/trans-types.c 2014-01-03 18:35:00.534418997 +0100
@@ -373,7 +373,7 @@ gfc_init_kinds (void)
/* The middle end doesn't support constants larger than 2*HWI.
Perhaps the target hook shouldn't have accepted these either,
but just to be safe... */
- bitsize = GET_MODE_BITSIZE (mode);
+ bitsize = GET_MODE_BITSIZE ((enum machine_mode) mode);
if (bitsize > 2*HOST_BITS_PER_WIDE_INT)
continue;
--- gcc/machmode.h.jj 2013-11-29 18:22:15.671594951 +0100
+++ gcc/machmode.h 2014-01-03 18:47:30.514374282 +0100
@@ -177,7 +177,13 @@ extern const unsigned char mode_class[NU
/* Get the size in bytes and bits of an object of mode MODE. */
extern CONST_MODE_SIZE unsigned char mode_size[NUM_MACHINE_MODES];
+#if GCC_VERSION >= 4001
+#define GET_MODE_SIZE(MODE) \
+ ((unsigned short) (__builtin_constant_p (MODE) \
+ ? mode_size_inline (MODE) : mode_size[MODE]))
+#else
#define GET_MODE_SIZE(MODE) ((unsigned short) mode_size[MODE])
+#endif
#define GET_MODE_BITSIZE(MODE) \
((unsigned short) (GET_MODE_SIZE (MODE) * BITS_PER_UNIT))
@@ -203,7 +209,13 @@ extern const unsigned HOST_WIDE_INT mode
/* Return the mode of the inner elements in a vector. */
extern const unsigned char mode_inner[NUM_MACHINE_MODES];
+#if GCC_VERSION >= 4001
+#define GET_MODE_INNER(MODE) \
+ ((enum machine_mode) (__builtin_constant_p (MODE) \
+ ? mode_inner_inline (MODE) : mode_inner[MODE]))
+#else
#define GET_MODE_INNER(MODE) ((enum machine_mode) mode_inner[MODE])
+#endif
/* Get the size in bytes or bites of the basic parts of an
object of mode MODE. */
@@ -224,7 +236,13 @@ extern const unsigned char mode_inner[NU
/* Get the number of units in the object. */
extern const unsigned char mode_nunits[NUM_MACHINE_MODES];
+#if GCC_VERSION >= 4001
+#define GET_MODE_NUNITS(MODE) \
+ ((unsigned char) (__builtin_constant_p (MODE) \
+ ? mode_nunits_inline (MODE) : mode_nunits[MODE]))
+#else
#define GET_MODE_NUNITS(MODE) mode_nunits[MODE]
+#endif
/* Get the next wider natural mode (eg, QI -> HI -> SI -> DI -> TI). */
--- gcc/genmodes.c.jj 2013-12-16 23:11:04.982989225 +0100
+++ gcc/genmodes.c 2014-01-03 18:47:16.153375138 +0100
@@ -72,6 +72,8 @@ struct mode_data
unsigned int counter; /* Rank ordering of modes */
unsigned int ibit; /* the number of integral bits */
unsigned int fbit; /* the number of fractional bits */
+ bool need_bytesize_adj; /* true if this mode need dynamic size
+ adjustment */
};
static struct mode_data *modes[MAX_MODE_CLASS];
@@ -82,7 +84,7 @@ static const struct mode_data blank_mode
0, "<unknown>", MAX_MODE_CLASS,
-1U, -1U, -1U, -1U,
0, 0, 0, 0, 0,
- "<unknown>", 0, 0, 0, 0
+ "<unknown>", 0, 0, 0, 0, false
};
static htab_t modes_by_name;
@@ -904,6 +906,105 @@ emit_max_int (void)
printf ("#define MAX_BITSIZE_MODE_ANY_MODE (%d*BITS_PER_UNIT)\n", mmax);
}
+/* Emit mode_size_inline routine into insn-modes.h header. */
+static void
+emit_mode_size_inline (void)
+{
+ int c;
+ struct mode_adjust *a;
+ struct mode_data *m;
+
+ /* Size adjustments must be propagated to all containing modes. */
+ for (a = adj_bytesize; a; a = a->next)
+ {
+ a->mode->need_bytesize_adj = true;
+ for (m = a->mode->contained; m; m = m->next_cont)
+ m->need_bytesize_adj = true;
+ }
+
+ printf ("\
+#ifdef __cplusplus\n\
+inline __attribute__((__always_inline__))\n\
+#else\n\
+extern __inline__ __attribute__((__always_inline__, __gnu_inline__))\n\
+#endif\n\
+unsigned char\n\
+mode_size_inline (enum machine_mode mode)\n\
+{\n\
+ extern %sunsigned char mode_size[NUM_MACHINE_MODES];\n\
+ switch (mode)\n\
+ {\n", adj_bytesize ? "" : "const ");
+
+ for_all_modes (c, m)
+ if (!m->need_bytesize_adj)
+ printf (" case %smode: return %u;\n", m->name, m->bytesize);
+
+ puts ("\
+ default: return mode_size[mode];\n\
+ }\n\
+}\n");
+}
+
+/* Emit mode_nunits_inline routine into insn-modes.h header. */
+static void
+emit_mode_nunits_inline (void)
+{
+ int c;
+ struct mode_data *m;
+
+ puts ("\
+#ifdef __cplusplus\n\
+inline __attribute__((__always_inline__))\n\
+#else\n\
+extern __inline__ __attribute__((__always_inline__, __gnu_inline__))\n\
+#endif\n\
+unsigned char\n\
+mode_nunits_inline (enum machine_mode mode)\n\
+{\n\
+ extern const unsigned char mode_nunits[NUM_MACHINE_MODES];\n\
+ switch (mode)\n\
+ {");
+
+ for_all_modes (c, m)
+ printf (" case %smode: return %u;\n", m->name, m->ncomponents);
+
+ puts ("\
+ default: return mode_nunits[mode];\n\
+ }\n\
+}\n");
+}
+
+/* Emit mode_inner_inline routine into insn-modes.h header. */
+static void
+emit_mode_inner_inline (void)
+{
+ int c;
+ struct mode_data *m;
+
+ puts ("\
+#ifdef __cplusplus\n\
+inline __attribute__((__always_inline__))\n\
+#else\n\
+extern __inline__ __attribute__((__always_inline__, __gnu_inline__))\n\
+#endif\n\
+unsigned char\n\
+mode_inner_inline (enum machine_mode mode)\n\
+{\n\
+ extern const unsigned char mode_inner[NUM_MACHINE_MODES];\n\
+ switch (mode)\n\
+ {");
+
+ for_all_modes (c, m)
+ printf (" case %smode: return %smode;\n", m->name,
+ c != MODE_PARTIAL_INT && m->component
+ ? m->component->name : void_mode->name);
+
+ puts ("\
+ default: return mode_inner[mode];\n\
+ }\n\
+}\n");
+}
+
static void
emit_insn_modes_h (void)
{
@@ -969,6 +1070,12 @@ enum machine_mode\n{");
printf ("#define CONST_MODE_IBIT%s\n", adj_ibit ? "" : " const");
printf ("#define CONST_MODE_FBIT%s\n", adj_fbit ? "" : " const");
emit_max_int ();
+ puts ("\n#if GCC_VERSION >= 4001\n");
+ emit_mode_size_inline ();
+ emit_mode_nunits_inline ();
+ emit_mode_inner_inline ();
+ puts ("#endif /* GCC_VERSION >= 4001 */");
+
puts ("\
\n\
#endif /* insn-modes.h */");
Jakub
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