Hi!
On Wed, Mar 01, 2023 at 05:50:47PM -0500, Jason Merrill wrote:
> > And then there is a question whether we want to emit rtti for
> > _Float{16,32,64,128}, _Float{32,64,128}x and decltype(0.0bf16) regardless
> > of whether the target supports them at all or not.
> > Emitting them always would have an advantage, if say bfloat16_t support
> > isn't added for aarch64 for GCC 13 (it is still pending review), we wouldn't
> > need to deal with symbol versioning for it in GCC 14 or later.
> > On the other side, on some arches some types are very unlikely to be
> > supported. And e.g. _Float128x isn't supported on any arch right now.
>
> A good point. Incidentally, it seems problematic for embedded users that
> all the fundamental type_infos are emitted in the same .o, making it hard to
> link in only the ones you care about. And new floating-point variants add
> to that problem. So perhaps until that is addressed, it's better to avoid
> adding a bunch more on targets that don't support them.
Ok, so here is a variant of the patch which still drops the fallback_* stuff,
but for float*_type_node doesn't do the automatic fallback in generic code
and leaves those to a target hook.
So far lightly tested on x86_64-linux -m32/-m64:
2023-03-02 Jakub Jelinek <ja...@redhat.com>
PR target/108883
gcc/
* target.h (emit_support_tinfos_callback): New typedef.
* targhooks.h (default_emit_support_tinfos): Declare.
* targhooks.cc (default_emit_support_tinfos): New function.
* target.def (emit_support_tinfos): New target hook.
* doc/tm.texi.in (emit_support_tinfos): Document it.
* doc/tm.texi: Regenerated.
* config/i386/i386.cc (ix86_emit_support_tinfos): New function.
(TARGET_EMIT_SUPPORT_TINFOS): Redefine.
gcc/cp/
* cp-tree.h (enum cp_tree_index): Remove CPTI_FALLBACK_DFLOAT*_TYPE
enumerators.
(fallback_dfloat32_type, fallback_dfloat64_type,
fallback_dfloat128_type): Remove.
* rtti.cc (emit_support_tinfo_1): If not emitted already, call
emit_tinfo_decl and remove from unemitted_tinfo_decls right away.
(emit_support_tinfos): Move &dfloat*_type_node from fundamentals array
into new fundamentals_with_fallback array. Call emit_support_tinfo_1
on elements of that array too, with the difference that if
the type is NULL, use a fallback REAL_TYPE for it temporarily.
Drop the !targetm.decimal_float_supported_p () handling. Call
targetm.emit_support_tinfos at the end.
* mangle.cc (write_builtin_type): Remove references to
fallback_dfloat*_type. Handle bfloat16_type_node mangling.
--- gcc/target.h.jj 2023-02-17 12:45:08.056638510 +0100
+++ gcc/target.h 2023-03-02 12:06:59.248146213 +0100
@@ -260,6 +260,8 @@ enum poly_value_estimate_kind
POLY_VALUE_LIKELY
};
+typedef void (*emit_support_tinfos_callback) (tree);
+
extern bool verify_type_context (location_t, type_context_kind, const_tree,
bool = false);
--- gcc/targhooks.h.jj 2023-01-02 09:32:50.422880177 +0100
+++ gcc/targhooks.h 2023-03-02 12:06:22.559686384 +0100
@@ -98,6 +98,8 @@ extern int default_builtin_vectorization
extern tree default_builtin_reciprocal (tree);
+extern void default_emit_support_tinfos (emit_support_tinfos_callback);
+
extern HOST_WIDE_INT default_static_rtx_alignment (machine_mode);
extern HOST_WIDE_INT default_constant_alignment (const_tree, HOST_WIDE_INT);
extern HOST_WIDE_INT constant_alignment_word_strings (const_tree,
--- gcc/targhooks.cc.jj 2023-01-02 09:32:52.591848839 +0100
+++ gcc/targhooks.cc 2023-03-02 12:01:39.576868114 +0100
@@ -752,6 +752,11 @@ default_builtin_reciprocal (tree)
return NULL_TREE;
}
+void
+default_emit_support_tinfos (emit_support_tinfos_callback)
+{
+}
+
bool
hook_bool_CUMULATIVE_ARGS_arg_info_false (cumulative_args_t,
const function_arg_info &)
--- gcc/target.def.jj 2023-02-22 15:58:50.252996452 +0100
+++ gcc/target.def 2023-03-02 12:01:52.002684436 +0100
@@ -2606,6 +2606,19 @@ types.",
const char *, (const_tree type),
hook_constcharptr_const_tree_null)
+/* Temporarily add conditional target specific types for the purpose of
+ emitting C++ fundamental type tinfos. */
+DEFHOOK
+(emit_support_tinfos,
+ "If your target defines any fundamental types which depend on ISA flags,\n\
+they might need C++ tinfo symbols in libsupc++/libstdc++ regardless of\n\
+ISA flags the library is compiled with.\n\
+This hook allows creating tinfo symbols even for those cases, by temporarily\n\
+creating corresponding fundamental type trees, calling the @var{callback}\n\
+function on it and setting the type back to @code{nullptr}.",
+ void, (emit_support_tinfos_callback callback),
+ default_emit_support_tinfos)
+
/* Make any adjustments to libfunc names needed for this target. */
DEFHOOK
(init_libfuncs,
--- gcc/doc/tm.texi.in.jj 2023-02-24 09:58:39.963508685 +0100
+++ gcc/doc/tm.texi.in 2023-03-02 11:47:50.044125831 +0100
@@ -1286,6 +1286,8 @@ pattern needs to support both a 32- and
@hook TARGET_MANGLE_TYPE
+@hook TARGET_EMIT_SUPPORT_TINFOS
+
@node Type Layout
@section Layout of Source Language Data Types
--- gcc/doc/tm.texi.jj 2023-02-24 09:58:39.951508859 +0100
+++ gcc/doc/tm.texi 2023-03-02 12:02:18.312295512 +0100
@@ -1525,6 +1525,15 @@ appropriate for a target that does not d
types.
@end deftypefn
+@deftypefn {Target Hook} void TARGET_EMIT_SUPPORT_TINFOS
(emit_support_tinfos_callback @var{callback})
+If your target defines any fundamental types which depend on ISA flags,
+they might need C++ tinfo symbols in libsupc++/libstdc++ regardless of
+ISA flags the library is compiled with.
+This hook allows creating tinfo symbols even for those cases, by temporarily
+creating corresponding fundamental type trees, calling the @var{callback}
+function on it and setting the type back to @code{nullptr}.
+@end deftypefn
+
@node Type Layout
@section Layout of Source Language Data Types
--- gcc/config/i386/i386.cc.jj 2023-02-22 15:58:50.109998489 +0100
+++ gcc/config/i386/i386.cc 2023-03-02 12:02:13.193371183 +0100
@@ -22775,6 +22775,27 @@ ix86_mangle_type (const_tree type)
}
}
+/* Create C++ tinfo symbols for only conditionally available fundamental
+ types. */
+
+static void
+ix86_emit_support_tinfos (emit_support_tinfos_callback callback)
+{
+ extern tree ix86_float16_type_node;
+ extern tree ix86_bf16_type_node;
+
+ if (!TARGET_SSE2)
+ {
+ gcc_checking_assert (!float16_type_node && !bfloat16_type_node);
+ float16_type_node = ix86_float16_type_node;
+ bfloat16_type_node = ix86_bf16_type_node;
+ callback (float16_type_node);
+ callback (bfloat16_type_node);
+ float16_type_node = NULL_TREE;
+ bfloat16_type_node = NULL_TREE;
+ }
+}
+
static GTY(()) tree ix86_tls_stack_chk_guard_decl;
static tree
@@ -24954,6 +24975,9 @@ ix86_libgcc_floating_mode_supported_p
#undef TARGET_MANGLE_TYPE
#define TARGET_MANGLE_TYPE ix86_mangle_type
+#undef TARGET_EMIT_SUPPORT_TINFOS
+#define TARGET_EMIT_SUPPORT_TINFOS ix86_emit_support_tinfos
+
#undef TARGET_STACK_PROTECT_GUARD
#define TARGET_STACK_PROTECT_GUARD ix86_stack_protect_guard
--- gcc/cp/cp-tree.h.jj 2023-03-02 08:49:09.569844225 +0100
+++ gcc/cp/cp-tree.h 2023-03-02 11:45:41.972008622 +0100
@@ -235,10 +235,6 @@ enum cp_tree_index
CPTI_PSEUDO_CONTRACT_VIOLATION,
- CPTI_FALLBACK_DFLOAT32_TYPE,
- CPTI_FALLBACK_DFLOAT64_TYPE,
- CPTI_FALLBACK_DFLOAT128_TYPE,
-
CPTI_MAX
};
@@ -397,13 +393,6 @@ extern GTY(()) tree cp_global_trees[CPTI
access nodes in tree.h. */
#define access_default_node null_node
-
-/* Variant of dfloat{32,64,128}_type_node only used for fundamental
- rtti purposes if DFP is disabled. */
-#define fallback_dfloat32_type
cp_global_trees[CPTI_FALLBACK_DFLOAT32_TYPE]
-#define fallback_dfloat64_type
cp_global_trees[CPTI_FALLBACK_DFLOAT64_TYPE]
-#define fallback_dfloat128_type
cp_global_trees[CPTI_FALLBACK_DFLOAT128_TYPE]
-
#include "name-lookup.h"
--- gcc/cp/rtti.cc.jj 2023-02-28 11:28:56.579180090 +0100
+++ gcc/cp/rtti.cc 2023-03-02 11:49:41.380484925 +0100
@@ -1577,6 +1577,15 @@ emit_support_tinfo_1 (tree bltn)
gcc_assert (TREE_PUBLIC (tinfo) && !DECL_COMDAT (tinfo));
DECL_INTERFACE_KNOWN (tinfo) = 1;
}
+
+ /* Emit it right away if not emitted already. */
+ if (DECL_INITIAL (tinfo) == NULL_TREE)
+ {
+ gcc_assert (unemitted_tinfo_decls->last () == tinfo);
+ bool ok = emit_tinfo_decl (tinfo);
+ gcc_assert (ok);
+ unemitted_tinfo_decls->pop ();
+ }
}
}
@@ -1602,12 +1611,18 @@ emit_support_tinfos (void)
&long_integer_type_node, &long_unsigned_type_node,
&long_long_integer_type_node, &long_long_unsigned_type_node,
&float_type_node, &double_type_node, &long_double_type_node,
- &dfloat32_type_node, &dfloat64_type_node, &dfloat128_type_node,
&bfloat16_type_node, &float16_type_node, &float32_type_node,
&float64_type_node, &float128_type_node, &float32x_type_node,
&float64x_type_node, &float128x_type_node, &nullptr_type_node,
0
};
+ /* Similar, but for floating point types only which should get type info
+ regardless whether they are non-NULL or NULL. */
+ static tree *const fundamentals_with_fallback[] =
+ {
+ &dfloat32_type_node, &dfloat64_type_node, &dfloat128_type_node,
+ 0
+ };
int ix;
/* Look for a defined class. */
@@ -1627,8 +1642,20 @@ emit_support_tinfos (void)
location_t saved_loc = input_location;
input_location = BUILTINS_LOCATION;
doing_runtime = 1;
+ tree fallback = NULL_TREE;
for (ix = 0; fundamentals[ix]; ix++)
emit_support_tinfo_1 (*fundamentals[ix]);
+ for (ix = 0; fundamentals_with_fallback[ix]; ix++)
+ if (*fundamentals_with_fallback[ix])
+ emit_support_tinfo_1 (*fundamentals_with_fallback[ix]);
+ else
+ {
+ if (fallback == NULL_TREE)
+ fallback = make_node (REAL_TYPE);
+ *fundamentals_with_fallback[ix] = fallback;
+ emit_support_tinfo_1 (fallback);
+ *fundamentals_with_fallback[ix] = NULL_TREE;
+ }
for (ix = 0; ix < NUM_INT_N_ENTS; ix ++)
if (int_n_enabled_p[ix])
{
@@ -1637,20 +1664,10 @@ emit_support_tinfos (void)
}
for (tree t = registered_builtin_types; t; t = TREE_CHAIN (t))
emit_support_tinfo_1 (TREE_VALUE (t));
- /* For compatibility, emit DFP typeinfos even when DFP isn't enabled,
- because we've emitted that in the past. */
- if (!targetm.decimal_float_supported_p ())
- {
- gcc_assert (dfloat32_type_node == NULL_TREE
- && dfloat64_type_node == NULL_TREE
- && dfloat128_type_node == NULL_TREE);
- fallback_dfloat32_type = make_node (REAL_TYPE);
- fallback_dfloat64_type = make_node (REAL_TYPE);
- fallback_dfloat128_type = make_node (REAL_TYPE);
- emit_support_tinfo_1 (fallback_dfloat32_type);
- emit_support_tinfo_1 (fallback_dfloat64_type);
- emit_support_tinfo_1 (fallback_dfloat128_type);
- }
+
+ /* Emit additional typeinfos as requested by target. */
+ targetm.emit_support_tinfos (emit_support_tinfo_1);
+
input_location = saved_loc;
}
--- gcc/cp/mangle.cc.jj 2023-02-28 11:28:56.532180773 +0100
+++ gcc/cp/mangle.cc 2023-03-02 11:45:41.973008607 +0100
@@ -2732,11 +2732,11 @@ write_builtin_type (tree type)
write_char ('d');
else if (type == long_double_type_node)
write_char ('e');
- else if (type == dfloat32_type_node || type == fallback_dfloat32_type)
+ else if (type == dfloat32_type_node)
write_string ("Df");
- else if (type == dfloat64_type_node || type == fallback_dfloat64_type)
+ else if (type == dfloat64_type_node)
write_string ("Dd");
- else if (type == dfloat128_type_node || type == fallback_dfloat128_type)
+ else if (type == dfloat128_type_node)
write_string ("De");
else if (type == float16_type_node)
write_string ("DF16_");
@@ -2752,6 +2752,8 @@ write_builtin_type (tree type)
write_string ("DF64x");
else if (type == float128x_type_node)
write_string ("DF128x");
+ else if (type == bfloat16_type_node)
+ write_string ("DF16b");
else
gcc_unreachable ();
break;
Jakub
