>
> yes I see, I was hoping to avoid a new hook, but as you said it seems
> mandatory for the mere declaration case.
>
> Here is one proposal, it defaults to nothing and the ARM implementation does
> not need to handle the vptr bit setting. so that simplifies a lot the things.
>
> The hook is called from rest_of_decl_compilation for mere declarations and
> allocate_struct_function for definitions.
I'm not sure we have testsuite coverage for this - can you add a test or 2 ?
>
>
>
>
>
>
>
> align_hook.patch
>
>
> 2015-09-29 Christian Bruel <christian.br...@st.com>
>
> PR target/67745
> * config/arm/arm.h (FUNCTION_BOUNDARY): Use FUNCTION_BOUNDARY_P.
> (FUNCTION_BOUNDARY_P): New macro:
> * config/arm/arm.c (TARGET_RELAYOUT_FUNCTION, arm_relayout_function):
> New hook.
The ARM changes look ok to me. Please as usual watch out for any regressions.
> * doc/tm.texi.in (TARGET_RELAYOUT_FUNCTION): Document.
> * doc/tm.texi (TARGET_RELAYOUT_FUNCTION): New hook.
> * gcc/target.def (TARGET_RELAYOUT_FUNCTION): Likewise.
> * gcc/function.c (allocate_struct_function): Call relayout_function
> hook.
> * gcc/passes.c (rest_of_decl_compilation): Likewise.
> * gcc/targhooks.c (default_relayout_function): New function.
> * gcc/targhooks.h (default_relayout_function): Declare.
>
> --- gnu_trunk.p0/gcc/gcc/config/arm/arm.c 2015-10-12 10:34:27.599740376
> +0200
> +++ gnu_trunk.devs/gcc/gcc/config/arm/arm.c 2015-10-12 12:26:51.607398021
> +0200
> @@ -250,6 +250,7 @@ static void arm_override_options_after_c
> static void arm_option_print (FILE *, int, struct cl_target_option *);
> static void arm_set_current_function (tree);
> static bool arm_can_inline_p (tree, tree);
> +static void arm_relayout_function (tree);
> static bool arm_valid_target_attribute_p (tree, tree, tree, int);
> static unsigned HOST_WIDE_INT arm_shift_truncation_mask (machine_mode);
> static bool arm_macro_fusion_p (void);
> @@ -405,6 +406,9 @@ static const struct attribute_spec arm_a
> #undef TARGET_CAN_INLINE_P
> #define TARGET_CAN_INLINE_P arm_can_inline_p
>
> +#undef TARGET_RELAYOUT_FUNCTION
> +#define TARGET_RELAYOUT_FUNCTION arm_relayout_function
> +
> #undef TARGET_OPTION_OVERRIDE
> #define TARGET_OPTION_OVERRIDE arm_option_override
>
> @@ -29825,6 +29829,23 @@ arm_can_inline_p (tree caller ATTRIBUTE_
> return true;
> }
>
> +/* Hook to fix function's alignment affected by target attribute. */
> +
> +static void
> +arm_relayout_function (tree fndecl)
> +{
> + if (DECL_USER_ALIGN (fndecl))
> + return;
> +
> + tree callee_tree = DECL_FUNCTION_SPECIFIC_TARGET (fndecl);
> +
> + if (!callee_tree)
> + callee_tree = target_option_default_node;
> +
> + DECL_ALIGN (fndecl) =
> + FUNCTION_BOUNDARY_P (TREE_TARGET_OPTION (callee_tree)->x_target_flags);
> +}
> +
> /* Inner function to process the attribute((target(...))), take an argument
> and
> set the current options from the argument. If we have a list, recursively
> go over the list. */
> diff '--exclude=.svn' '--exclude=*~' -r -up
> gnu_trunk.p0/gcc/gcc/config/arm/arm.h gnu_trunk.devs/gcc/gcc/config/arm/arm.h
> --- gnu_trunk.p0/gcc/gcc/config/arm/arm.h 2015-10-12 10:34:27.607740391
> +0200
> +++ gnu_trunk.devs/gcc/gcc/config/arm/arm.h 2015-10-12 12:27:55.507546958
> +0200
> @@ -565,7 +565,8 @@ extern int arm_arch_crc;
> #define PREFERRED_STACK_BOUNDARY \
> (arm_abi == ARM_ABI_ATPCS ? 64 : STACK_BOUNDARY)
>
> -#define FUNCTION_BOUNDARY (TARGET_THUMB ? 16 : 32)
> +#define FUNCTION_BOUNDARY_P(flags) (TARGET_THUMB_P (flags) ? 16 : 32)
> +#define FUNCTION_BOUNDARY (FUNCTION_BOUNDARY_P (target_flags))
>
> /* The lowest bit is used to indicate Thumb-mode functions, so the
> vbit must go into the delta field of pointers to member
> diff '--exclude=.svn' '--exclude=*~' -r -up gnu_trunk.p0/gcc/gcc/doc/tm.texi
> gnu_trunk.devs/gcc/gcc/doc/tm.texi
> --- gnu_trunk.p0/gcc/gcc/doc/tm.texi 2015-10-12 10:33:29.907630642 +0200
> +++ gnu_trunk.devs/gcc/gcc/doc/tm.texi 2015-10-12 12:33:33.880332253
> +0200
> @@ -9985,6 +9985,10 @@ default, inlining is not allowed if the
> specific target options and the caller does not use the same options.
> @end deftypefn
>
> +@deftypefn {Target Hook} void TARGET_RELAYOUT_FUNCTION (tree @var{fndecl})
> +This target hook fixes function @var{fndecl} after attributes are processed.
> Default does nothing. On ARM, the default function's alignment is updated
> with the attribute target.
> +@end deftypefn
> +
> @node Emulated TLS
> @section Emulating TLS
> @cindex Emulated TLS
> diff '--exclude=.svn' '--exclude=*~' -r -up
> gnu_trunk.p0/gcc/gcc/doc/tm.texi.in gnu_trunk.devs/gcc/gcc/doc/tm.texi.in
> --- gnu_trunk.p0/gcc/gcc/doc/tm.texi.in 2015-10-12 10:33:29.919630666
> +0200
> +++ gnu_trunk.devs/gcc/gcc/doc/tm.texi.in 2015-10-12 11:28:16.350590629
> +0200
> @@ -7274,6 +7274,8 @@ on this implementation detail.
>
> @hook TARGET_CAN_INLINE_P
>
> +@hook TARGET_RELAYOUT_FUNCTION
> +
> @node Emulated TLS
> @section Emulating TLS
> @cindex Emulated TLS
> diff '--exclude=.svn' '--exclude=*~' -r -up gnu_trunk.p0/gcc/gcc/function.c
> gnu_trunk.devs/gcc/gcc/function.c
> --- gnu_trunk.p0/gcc/gcc/function.c 2015-10-12 10:33:32.715635978 +0200
> +++ gnu_trunk.devs/gcc/gcc/function.c 2015-10-12 10:04:42.764482359 +0200
> @@ -4840,6 +4840,9 @@ allocate_struct_function (tree fndecl, b
> for (tree parm = DECL_ARGUMENTS (fndecl); parm;
> parm = DECL_CHAIN (parm))
> relayout_decl (parm);
> +
> + /* Similarly relayout the function decl. */
> + targetm.target_option.relayout_function (fndecl);
> }
>
> if (!abstract_p && aggregate_value_p (result, fndecl))
> --- gnu_trunk.p0/gcc/gcc/passes.c 2015-10-05 14:22:31.082400039 +0200
> +++ gnu_trunk.devs/gcc/gcc/passes.c 2015-10-12 11:31:55.343150983 +0200
> @@ -253,6 +253,11 @@ rest_of_decl_compilation (tree decl,
> }
> #endif
>
> + /* Now that we have activated any function-specific attributes
> + that might affect function decl, particularly align, relayout it. */
> + if (TREE_CODE (decl) == FUNCTION_DECL)
> + targetm.target_option.relayout_function (decl);
> +
> timevar_pop (TV_VARCONST);
> }
> else if (TREE_CODE (decl) == TYPE_DECL
> diff '--exclude=.svn' '--exclude=*~' -r -up gnu_trunk.p0/gcc/gcc/target.def
> gnu_trunk.devs/gcc/gcc/target.def
> --- gnu_trunk.p0/gcc/gcc/target.def 2015-10-05 14:22:20.142374948 +0200
> +++ gnu_trunk.devs/gcc/gcc/target.def 2015-10-12 12:34:23.744447530 +0200
> @@ -5620,6 +5620,12 @@ specific target options and the caller d
> bool, (tree caller, tree callee),
> default_target_can_inline_p)
>
> +DEFHOOK
> +(relayout_function,
> +"This target hook fixes function @var{fndecl} after attributes are
> processed. Default does nothing. On ARM, the default function's alignment is
> updated with the attribute target.",
> + void, (tree fndecl),
> + default_relayout_function)
Can this just be hook_void_tree ? Then you don't need the empty
default_relayout_function ?
> +
> HOOK_VECTOR_END (target_option)
>
> /* For targets that need to mark extra registers as live on entry to
> diff '--exclude=.svn' '--exclude=*~' -r -up gnu_trunk.p0/gcc/gcc/targhooks.c
> gnu_trunk.devs/gcc/gcc/targhooks.c
> --- gnu_trunk.p0/gcc/gcc/targhooks.c 2015-08-25 10:28:00.504946542 +0200
> +++ gnu_trunk.devs/gcc/gcc/targhooks.c 2015-10-12 11:24:50.866063124
> +0200
> @@ -1311,6 +1311,11 @@ default_target_option_pragma_parse (tree
> return false;
> }
>
> +void
> +default_relayout_function (tree fndecl)
> +{
> +}
> +
> bool
> default_target_can_inline_p (tree caller, tree callee)
> {
> diff '--exclude=.svn' '--exclude=*~' -r -up gnu_trunk.p0/gcc/gcc/targhooks.h
> gnu_trunk.devs/gcc/gcc/targhooks.h
> --- gnu_trunk.p0/gcc/gcc/targhooks.h 2015-10-05 14:22:17.774369515 +0200
> +++ gnu_trunk.devs/gcc/gcc/targhooks.h 2015-10-12 11:24:40.914042025
> +0200
> @@ -161,6 +161,7 @@ extern bool default_hard_regno_scratch_o
> extern bool default_mode_dependent_address_p (const_rtx, addr_space_t);
> extern bool default_target_option_valid_attribute_p (tree, tree, tree, int);
> extern bool default_target_option_pragma_parse (tree, tree);
> +extern void default_relayout_function (tree);
> extern bool default_target_can_inline_p (tree, tree);
> extern bool default_valid_pointer_mode (machine_mode);
> extern bool default_ref_may_alias_errno (struct ao_ref *);
>
