re PR ada/37139 (DEP prevents using Ada tasking)

	PR ada/37139
	PR ada/67205
	* common.opt (-ftrampolines): New option.
	* doc/invoke.texi (Code Gen Options): Document it.
	* doc/tm.texi.in (Trampolines): Add TARGET_CUSTOM_FUNCTION_DESCRIPTORS.
	* doc/tm.texi: Regenerate.
	* builtins.def: Add init_descriptor and adjust_descriptor.
	* builtins.c (expand_builtin_init_trampoline): Do not issue a warning
	on platforms with descriptors.
	(expand_builtin_init_descriptor): New function.
	(expand_builtin_adjust_descriptor): Likewise.
	(expand_builtin) <BUILT_IN_INIT_DESCRIPTOR>: New case.
	<BUILT_IN_ADJUST_DESCRIPTOR>: Likewise.
	* calls.c (prepare_call_address): Remove SIBCALLP parameter and add
	FLAGS parameter.  Deal with indirect calls by descriptor and adjust.
	Set STATIC_CHAIN_REG_P on the static chain register, if any.
	(call_expr_flags): Set ECF_BY_DESCRIPTOR for calls by descriptor.
	(expand_call): Likewise.  Move around call to prepare_call_address
	and pass all flags to it.
	* cfgexpand.c (expand_call_stmt): Reinstate CALL_EXPR_BY_DESCRIPTOR.
	* gimple.h (enum gf_mask): New GF_CALL_BY_DESCRIPTOR value.
	(gimple_call_set_by_descriptor): New setter.
	(gimple_call_by_descriptor_p): New getter.
	* gimple.c (gimple_build_call_from_tree): SetCALL_EXPR_BY_DESCRIPTOR.
	(gimple_call_flags): Deal with GF_CALL_BY_DESCRIPTOR.
	* langhooks.h (struct lang_hooks): Add custom_function_descriptors.
	* langhooks-def.h (LANG_HOOKS_CUSTOM_FUNCTION_DESCRIPTORS): Define.
	(LANG_HOOKS_INITIALIZER): Add LANG_HOOKS_CUSTOM_FUNCTION_DESCRIPTORS.
	* rtl.h (STATIC_CHAIN_REG_P): New macro.
	* rtlanal.c (find_first_parameter_load): Skip static chain registers.
	* target.def (custom_function_descriptors): New POD hook.
	* tree.h (FUNC_ADDR_BY_DESCRIPTOR): New flag on ADDR_EXPR.
	(CALL_EXPR_BY_DESCRIPTOR): New flag on CALL_EXPR.
	* tree-core.h (ECF_BY_DESCRIPTOR): New mask.
	Document FUNC_ADDR_BY_DESCRIPTOR and CALL_EXPR_BY_DESCRIPTOR.
	* tree.c (make_node_stat) <tcc_declaration>: Use FUNCTION_ALIGNMENT.
	(build_common_builtin_nodes): Initialize init_descriptor and
	adjust_descriptor.
	* tree-nested.c: Include target.h.
	(struct nesting_info): Add 'any_descr_created' field.
	(get_descriptor_type): New function.
	(lookup_element_for_decl): New function extracted from...
	(create_field_for_decl): Likewise.
	(lookup_tramp_for_decl): ...here.  Adjust.
	(lookup_descr_for_decl): New function.
	(convert_tramp_reference_op): Deal with descriptors.
	(build_init_call_stmt): New function extracted from...
	(finalize_nesting_tree_1): ...here.  Adjust and deal withdescriptors.
	* defaults.h (FUNCTION_ALIGNMENT): Define.
	(TRAMPOLINE_ALIGNMENT): Set to above instead of FUNCTION_BOUNDARY.
	* config/i386/i386.h (TARGET_CUSTOM_FUNCTION_DESCRIPTORS): Define.
	* config/ia64/ia64.h (TARGET_CUSTOM_FUNCTION_DESCRIPTORS): Likewise.
	* config/rs6000/rs6000.h (TARGET_CUSTOM_FUNCTION_DESCRIPTORS):Likewise.
	* config/sparc/sparc.h (TARGET_CUSTOM_FUNCTION_DESCRIPTORS): Likewise.
ada/
	* gcc-interface/misc.c (LANG_HOOKS_CUSTOM_FUNCTION_DESCRIPTORS):Define.
	* gcc-interface/trans.c (Attribute_to_gnu) <Attr_Access>: Deal with
	a zero TARGET_CUSTOM_FUNCTION_DESCRIPTORS specially for Code_Address.
	Otherwise, if TARGET_CUSTOM_FUNCTION_DESCRIPTORS is positive, set
	FUNC_ADDR_BY_DESCRIPTOR for 'Access/'Unrestricted_Access of nested
	subprograms if the type can use an internal representation.
	(call_to_gnu): Likewise, but set CALL_EXPR_BY_DESCRIPTOR on indirect
	calls if the type can use an internal representation.

From-SVN: r241222

4 files changed, 12 insertions, 0 deletions

diff --git a/gcc/config/i386/i386.h b/gcc/config/i386/i386.h
index add7a64..fe3735d 100644
--- a/gcc/config/i386/i386.h
+++ b/gcc/config/i386/i386.h
@@ -2666,6 +2666,9 @@ extern void debug_dispatch_window (int);
 
 #define TARGET_SUPPORTS_WIDE_INT 1
 
+/* Use custom descriptors instead of trampolines when possible.  */
+#define TARGET_CUSTOM_FUNCTION_DESCRIPTORS 1
+
 /*
 Local variables:
 version-control: t
diff --git a/gcc/config/ia64/ia64.h b/gcc/config/ia64/ia64.h
index ac0cb86..82971a4 100644
--- a/gcc/config/ia64/ia64.h
+++ b/gcc/config/ia64/ia64.h
@@ -1715,4 +1715,7 @@ struct GTY(()) machine_function
 /* Switch on code for querying unit reservations.  */
 #define CPU_UNITS_QUERY 1
 
+/* IA-64 already uses descriptors for its standard calling sequence.  */
+#define TARGET_CUSTOM_FUNCTION_DESCRIPTORS 0
+
 /* End of ia64.h */
diff --git a/gcc/config/rs6000/rs6000.h b/gcc/config/rs6000/rs6000.h
index f53da15..f1c338e 100644
--- a/gcc/config/rs6000/rs6000.h
+++ b/gcc/config/rs6000/rs6000.h
@@ -2922,6 +2922,9 @@ extern GTY(()) tree rs6000_builtin_decls[RS6000_BUILTIN_COUNT];
 
 #define TARGET_SUPPORTS_WIDE_INT 1
 
+/* Use custom descriptors instead of trampolines if not AIX or ELFv1.  */
+#define TARGET_CUSTOM_FUNCTION_DESCRIPTORS (DEFAULT_ABI != ABI_AIX)
+
 #if (GCC_VERSION >= 3000)
 #pragma GCC poison TARGET_FLOAT128 OPTION_MASK_FLOAT128 MASK_FLOAT128
 #endif
diff --git a/gcc/config/sparc/sparc.h b/gcc/config/sparc/sparc.h
index 5389216..108769f 100644
--- a/gcc/config/sparc/sparc.h
+++ b/gcc/config/sparc/sparc.h
@@ -1813,3 +1813,6 @@ extern int sparc_indent_opcode;
 #define SPARC_LOW_FE_EXCEPT_VALUES 0
 
 #define TARGET_SUPPORTS_WIDE_INT 1
+
+/* Use custom descriptors instead of trampolines when possible.  */
+#define TARGET_CUSTOM_FUNCTION_DESCRIPTORS 1