From patchwork Fri Nov 11 16:28:40 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Richard Sandiford X-Patchwork-Id: 60431 Return-Path: X-Original-To: patchwork@sourceware.org Delivered-To: patchwork@sourceware.org Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id CBEF5384F034 for ; Fri, 11 Nov 2022 16:29:13 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org CBEF5384F034 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1668184153; bh=a53Uw/EzgzgWvMrgiSlpE9YpO5Upf15cP0qDwm0/1ic=; h=To:Subject:Date:List-Id:List-Unsubscribe:List-Archive:List-Post: List-Help:List-Subscribe:From:Reply-To:From; b=Tr+kX6RFdL4enYoqGHFPv70gfyS32wdLfZZ2TVC4kJsIfMk7lPUUIchzwCzMxbt2x LqUvVBsD5RUKmb8T5jbo0zFxpF8kyFUnUr9/ByMovEah+Rg3LZ13W1+wKceVdeUKpg rzaP16UR2jh/H9fGcd9CTZsZ7B+3wNWnlYyY/tok= X-Original-To: gcc-patches@gcc.gnu.org Delivered-To: gcc-patches@gcc.gnu.org Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by sourceware.org (Postfix) with ESMTP id 7684E3858D39 for ; Fri, 11 Nov 2022 16:28:42 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 7684E3858D39 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 6674B1FB for ; Fri, 11 Nov 2022 08:28:48 -0800 (PST) Received: from localhost (e121540-lin.manchester.arm.com [10.32.98.62]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id B5F513F73D for ; Fri, 11 Nov 2022 08:28:41 -0800 (PST) To: gcc-patches@gcc.gnu.org Mail-Followup-To: gcc-patches@gcc.gnu.org, richard.sandiford@arm.com Subject: [PATCH] Add a new target hook: TARGET_START_CALL_ARGS Date: Fri, 11 Nov 2022 16:28:40 +0000 Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.3 (gnu/linux) MIME-Version: 1.0 X-Spam-Status: No, score=-42.4 required=5.0 tests=BAYES_00, GIT_PATCH_0, KAM_DMARC_NONE, KAM_DMARC_STATUS, KAM_LAZY_DOMAIN_SECURITY, SPF_HELO_NONE, SPF_NONE, TXREP autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org X-BeenThere: gcc-patches@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-Patchwork-Original-From: Richard Sandiford via Gcc-patches From: Richard Sandiford Reply-To: Richard Sandiford Errors-To: gcc-patches-bounces+patchwork=sourceware.org@gcc.gnu.org Sender: "Gcc-patches" We have the following two hooks into the call expansion code: - TARGET_CALL_ARGS is called for each argument before arguments are moved into hard registers. - TARGET_END_CALL_ARGS is called after the end of the call sequence (specifically, after any return value has been moved to a pseudo). This patch adds a TARGET_START_CALL_ARGS hook that is called before the TARGET_CALL_ARGS sequence. This means that TARGET_START_CALL_REGS and TARGET_END_CALL_REGS bracket the region in which argument pseudos might be live. They also bracket a region in which the only call emiitted by target-independent code is the call to the target function itself. (For example, TARGET_START_CALL_ARGS happens after any use of memcpy to copy arguments, and TARGET_END_CALL_ARGS happens before any use of memcpy to copy the result.) Also, the patch adds the cumulative argument structure as an argument to the hooks, so that the target can use it to record and retrieve information about the call as a whole. The TARGET_CALL_ARGS docs said: While generating RTL for a function call, this target hook is invoked once for each argument passed to the function, either a register returned by ``TARGET_FUNCTION_ARG`` or a memory location. It is called just - before the point where argument registers are stored. The last bit was true for normal calls, but for libcalls the hook was invoked earlier, before stack arguments have been copied. I don't think this caused a practical difference for nvptx (the only port to use the hooks) since I wouldn't expect any libcalls to take stack parameters. Tested on aarch64-linux-gnu and x86_64-linux-gnu. Also tested by building cc1 for nvptx-none. OK to install? Richard gcc/ * doc/gccint/target-macros/implementing-the-varargs-macros.rst: Add TARGET_START_CALL_ARGS. * doc/gccint/target-macros/tm.rst.in: Regenerate. * target.def (start_call_args): New hook. (call_args, end_call_args): Add a parameter for the cumulative argument information. * hooks.h (hook_void_rtx_tree): Delete. * hooks.cc (hook_void_rtx_tree): Likewise. * targhooks.h (hook_void_CUMULATIVE_ARGS): Declare. (hook_void_CUMULATIVE_ARGS_rtx_tree): Likewise. * targhooks.cc (hook_void_CUMULATIVE_ARGS): New function. (hook_void_CUMULATIVE_ARGS_rtx_tree): Likewise. * calls.cc (expand_call): Call start_call_args before computing and storing stack parameters. Pass the cumulative argument information to call_args and end_call_args. (emit_library_call_value_1): Likewise. * config/nvptx/nvptx.cc (nvptx_call_args): Add a cumulative argument parameter. (nvptx_end_call_args): Likewise. --- gcc/calls.cc | 61 ++++++++++--------- gcc/config/nvptx/nvptx.cc | 4 +- .../implementing-the-varargs-macros.rst | 5 ++ gcc/doc/gccint/target-macros/tm.rst.in | 53 +++++++++++++--- gcc/hooks.cc | 5 -- gcc/hooks.h | 1 - gcc/target.def | 56 +++++++++++++---- gcc/targhooks.cc | 10 +++ gcc/targhooks.h | 5 +- 9 files changed, 140 insertions(+), 60 deletions(-) diff --git a/gcc/calls.cc b/gcc/calls.cc index 51b664f1b4d..d3287bcc277 100644 --- a/gcc/calls.cc +++ b/gcc/calls.cc @@ -3542,15 +3542,26 @@ expand_call (tree exp, rtx target, int ignore) sibcall_failure = 1; } + /* Set up the next argument register. For sibling calls on machines + with register windows this should be the incoming register. */ + if (pass == 0) + next_arg_reg = targetm.calls.function_incoming_arg + (args_so_far, function_arg_info::end_marker ()); + else + next_arg_reg = targetm.calls.function_arg + (args_so_far, function_arg_info::end_marker ()); + + targetm.calls.start_call_args (args_so_far); + bool any_regs = false; for (i = 0; i < num_actuals; i++) if (args[i].reg != NULL_RTX) { any_regs = true; - targetm.calls.call_args (args[i].reg, funtype); + targetm.calls.call_args (args_so_far, args[i].reg, funtype); } if (!any_regs) - targetm.calls.call_args (pc_rtx, funtype); + targetm.calls.call_args (args_so_far, pc_rtx, funtype); /* Figure out the register where the value, if any, will come back. */ valreg = 0; @@ -3613,15 +3624,6 @@ expand_call (tree exp, rtx target, int ignore) later safely search backwards to find the CALL_INSN. */ before_call = get_last_insn (); - /* Set up next argument register. For sibling calls on machines - with register windows this should be the incoming register. */ - if (pass == 0) - next_arg_reg = targetm.calls.function_incoming_arg - (args_so_far, function_arg_info::end_marker ()); - else - next_arg_reg = targetm.calls.function_arg - (args_so_far, function_arg_info::end_marker ()); - if (pass == 1 && (return_flags & ERF_RETURNS_ARG)) { int arg_nr = return_flags & ERF_RETURN_ARG_MASK; @@ -3920,7 +3922,7 @@ expand_call (tree exp, rtx target, int ignore) for (i = 0; i < num_actuals; ++i) free (args[i].aligned_regs); - targetm.calls.end_call_args (); + targetm.calls.end_call_args (args_so_far); insns = get_insns (); end_sequence (); @@ -4478,17 +4480,9 @@ emit_library_call_value_1 (int retval, rtx orgfun, rtx value, } #endif - /* When expanding a normal call, args are stored in push order, - which is the reverse of what we have here. */ - bool any_regs = false; - for (int i = nargs; i-- > 0; ) - if (argvec[i].reg != NULL_RTX) - { - targetm.calls.call_args (argvec[i].reg, NULL_TREE); - any_regs = true; - } - if (!any_regs) - targetm.calls.call_args (pc_rtx, NULL_TREE); + rtx call_cookie + = targetm.calls.function_arg (args_so_far, + function_arg_info::end_marker ()); /* Push the args that need to be pushed. */ @@ -4606,6 +4600,20 @@ emit_library_call_value_1 (int retval, rtx orgfun, rtx value, fun = prepare_call_address (NULL, fun, NULL, &call_fusage, 0, 0); + targetm.calls.start_call_args (args_so_far); + + /* When expanding a normal call, args are stored in push order, + which is the reverse of what we have here. */ + bool any_regs = false; + for (int i = nargs; i-- > 0; ) + if (argvec[i].reg != NULL_RTX) + { + targetm.calls.call_args (args_so_far, argvec[i].reg, NULL_TREE); + any_regs = true; + } + if (!any_regs) + targetm.calls.call_args (args_so_far, pc_rtx, NULL_TREE); + /* Now load any reg parms into their regs. */ /* ARGNUM indexes the ARGVEC array in the order in which the arguments @@ -4712,10 +4720,7 @@ emit_library_call_value_1 (int retval, rtx orgfun, rtx value, get_identifier (XSTR (orgfun, 0)), build_function_type (tfom, NULL_TREE), original_args_size.constant, args_size.constant, - struct_value_size, - targetm.calls.function_arg (args_so_far, - function_arg_info::end_marker ()), - valreg, + struct_value_size, call_cookie, valreg, old_inhibit_defer_pop + 1, call_fusage, flags, args_so_far); if (flag_ipa_ra) @@ -4735,7 +4740,7 @@ emit_library_call_value_1 (int retval, rtx orgfun, rtx value, valreg = gen_rtx_REG (TYPE_MODE (tfom), REGNO (valreg)); } - targetm.calls.end_call_args (); + targetm.calls.end_call_args (args_so_far); /* For calls to `setjmp', etc., inform function.cc:setjmp_warnings that it should complain if nonvolatile values are live. For diff --git a/gcc/config/nvptx/nvptx.cc b/gcc/config/nvptx/nvptx.cc index 2fe120b3873..0fa0aefe613 100644 --- a/gcc/config/nvptx/nvptx.cc +++ b/gcc/config/nvptx/nvptx.cc @@ -1790,7 +1790,7 @@ nvptx_get_drap_rtx (void) argument to the next call. */ static void -nvptx_call_args (rtx arg, tree fntype) +nvptx_call_args (cumulative_args_t, rtx arg, tree fntype) { if (!cfun->machine->doing_call) { @@ -1818,7 +1818,7 @@ nvptx_call_args (rtx arg, tree fntype) information we recorded. */ static void -nvptx_end_call_args (void) +nvptx_end_call_args (cumulative_args_t) { cfun->machine->doing_call = false; free_EXPR_LIST_list (&cfun->machine->call_args); diff --git a/gcc/doc/gccint/target-macros/implementing-the-varargs-macros.rst b/gcc/doc/gccint/target-macros/implementing-the-varargs-macros.rst index 1c940945056..8dd1ffab1b4 100644 --- a/gcc/doc/gccint/target-macros/implementing-the-varargs-macros.rst +++ b/gcc/doc/gccint/target-macros/implementing-the-varargs-macros.rst @@ -91,6 +91,11 @@ These machine description macros help implement varargs: :end-before: [TARGET_STRICT_ARGUMENT_NAMING] +.. include:: tm.rst.in + :start-after: [TARGET_START_CALL_ARGS] + :end-before: [TARGET_START_CALL_ARGS] + + .. include:: tm.rst.in :start-after: [TARGET_CALL_ARGS] :end-before: [TARGET_CALL_ARGS] diff --git a/gcc/doc/gccint/target-macros/tm.rst.in b/gcc/doc/gccint/target-macros/tm.rst.in index a19fa38b811..04be4bda3f6 100644 --- a/gcc/doc/gccint/target-macros/tm.rst.in +++ b/gcc/doc/gccint/target-macros/tm.rst.in @@ -4346,31 +4346,64 @@ [TARGET_SETUP_INCOMING_VARARGS] +[TARGET_START_CALL_ARGS] +.. function:: void TARGET_START_CALL_ARGS (cumulative_args_t complete_args) + + This target hook is invoked while generating RTL for a function call, + after the argument values have been computed, and after stack arguments + have been initialized, but before register arguments have been moved into + their ABI-defined hard register locations. It precedes calls to the related + hooks ``TARGET_CALL_ARGS`` and ``TARGET_END_CALL_ARGS``. The significance + of this position in the call expansion is that: + + * No argument registers are live. + + * Although a call sequence can in general involve subcalls (such as using + ``memcpy`` to copy large arguments), no such subcall will occur between + the call to this hook and the generation of the main call instruction. + + The single argument :samp:`complete_args` is the state of the target + function's cumulative argument information after the final call to + ``TARGET_FUNCTION_ARG``. + + The hook can be used for things like switching processor mode, in cases + where different calls need different processor modes. Most ports do not + need to implement anything for this hook. + +[TARGET_START_CALL_ARGS] + [TARGET_CALL_ARGS] -.. function:: void TARGET_CALL_ARGS (rtx, tree) +.. function:: void TARGET_CALL_ARGS (cumulative_args_t complete_args, rtx loc, tree type) While generating RTL for a function call, this target hook is invoked once for each argument passed to the function, either a register returned by ``TARGET_FUNCTION_ARG`` or a memory location. It is called just - before the point where argument registers are stored. The type of the - function to be called is also passed as the second argument; it is - ``NULL_TREE`` for libcalls. The ``TARGET_END_CALL_ARGS`` hook is - invoked just after the code to copy the return reg has been emitted. - This functionality can be used to perform special setup of call argument - registers if a target needs it. + before the point where argument registers are stored. + + :samp:`complete_args` is the state of the target function's cumulative + argument information after the final call to ``TARGET_FUNCTION_ARG``. + :samp:`loc` is the location of the argument. :samp:`type` is the type of + the function being called, or ``NULL_TREE`` for libcalls. + For functions without arguments, the hook is called once with ``pc_rtx`` passed instead of an argument register. - Most ports do not need to implement anything for this hook. + + This functionality can be used to perform special setup of call argument + registers, if a target needs it. Most ports do not need to implement + anything for this hook. [TARGET_CALL_ARGS] [TARGET_END_CALL_ARGS] -.. function:: void TARGET_END_CALL_ARGS (void) +.. function:: void TARGET_END_CALL_ARGS (cumulative_args_t complete_args) This target hook is invoked while generating RTL for a function call, just after the point where the return reg is copied into a pseudo. It signals that all the call argument and return registers for the just - emitted call are now no longer in use. + emitted call are now no longer in use. :samp:`complete_args` is the + state of the target function's cumulative argument information after + the final call to ``TARGET_FUNCTION_ARG``. + Most ports do not need to implement anything for this hook. [TARGET_END_CALL_ARGS] diff --git a/gcc/hooks.cc b/gcc/hooks.cc index b29233f4f85..0f4e7ce1047 100644 --- a/gcc/hooks.cc +++ b/gcc/hooks.cc @@ -280,11 +280,6 @@ hook_void_FILEptr_tree (FILE *, tree) { } -void -hook_void_rtx_tree (rtx, tree) -{ -} - void hook_void_constcharptr (const char *) { diff --git a/gcc/hooks.h b/gcc/hooks.h index 1056e1e9e4d..e2a742f4325 100644 --- a/gcc/hooks.h +++ b/gcc/hooks.h @@ -83,7 +83,6 @@ extern void hook_void_FILEptr_constcharptr (FILE *, const char *); extern void hook_void_FILEptr_constcharptr_const_tree (FILE *, const char *, const_tree); extern bool hook_bool_FILEptr_rtx_false (FILE *, rtx); -extern void hook_void_rtx_tree (rtx, tree); extern void hook_void_FILEptr_tree (FILE *, tree); extern void hook_void_tree (tree); extern void hook_void_tree_treeptr (tree, tree *); diff --git a/gcc/target.def b/gcc/target.def index 15fd939200b..e6a388f9675 100644 --- a/gcc/target.def +++ b/gcc/target.def @@ -4732,32 +4732,64 @@ not generate any instructions in this case.", int *pretend_args_size, int second_time), default_setup_incoming_varargs) +DEFHOOK +(start_call_args, + "This target hook is invoked while generating RTL for a function call,\n\ +after the argument values have been computed, and after stack arguments\n\ +have been initialized, but before register arguments have been moved into\n\ +their ABI-defined hard register locations. It precedes calls to the related\n\ +hooks ``TARGET_CALL_ARGS`` and ``TARGET_END_CALL_ARGS``. The significance\n\ +of this position in the call expansion is that:\n\ +\n\ +* No argument registers are live.\n\ +\n\ +* Although a call sequence can in general involve subcalls (such as using\n\ + ``memcpy`` to copy large arguments), no such subcall will occur between\n\ + the call to this hook and the generation of the main call instruction.\n\ +\n\ +The single argument :samp:`complete_args` is the state of the target\n\ +function's cumulative argument information after the final call to\n\ +``TARGET_FUNCTION_ARG``.\n\ +\n\ +The hook can be used for things like switching processor mode, in cases\n\ +where different calls need different processor modes. Most ports do not\n\ +need to implement anything for this hook.", + void, (cumulative_args_t complete_args), + hook_void_CUMULATIVE_ARGS) + DEFHOOK (call_args, "While generating RTL for a function call, this target hook is invoked once\n\ for each argument passed to the function, either a register returned by\n\ ``TARGET_FUNCTION_ARG`` or a memory location. It is called just\n\ -before the point where argument registers are stored. The type of the\n\ -function to be called is also passed as the second argument; it is\n\ -``NULL_TREE`` for libcalls. The ``TARGET_END_CALL_ARGS`` hook is\n\ -invoked just after the code to copy the return reg has been emitted.\n\ -This functionality can be used to perform special setup of call argument\n\ -registers if a target needs it.\n\ +before the point where argument registers are stored.\n\ +\n\ +:samp:`complete_args` is the state of the target function's cumulative\n\ +argument information after the final call to ``TARGET_FUNCTION_ARG``.\n\ +:samp:`loc` is the location of the argument. :samp:`type` is the type of\n\ +the function being called, or ``NULL_TREE`` for libcalls.\n\ +\n\ For functions without arguments, the hook is called once with ``pc_rtx``\n\ passed instead of an argument register.\n\ -Most ports do not need to implement anything for this hook.", - void, (rtx, tree), - hook_void_rtx_tree) +\n\ +This functionality can be used to perform special setup of call argument\n\ +registers, if a target needs it. Most ports do not need to implement\n\ +anything for this hook.", + void, (cumulative_args_t complete_args, rtx loc, tree type), + hook_void_CUMULATIVE_ARGS_rtx_tree) DEFHOOK (end_call_args, "This target hook is invoked while generating RTL for a function call,\n\ just after the point where the return reg is copied into a pseudo. It\n\ signals that all the call argument and return registers for the just\n\ -emitted call are now no longer in use.\n\ +emitted call are now no longer in use. :samp:`complete_args` is the\n\ +state of the target function's cumulative argument information after\n\ +the final call to ``TARGET_FUNCTION_ARG``.\n\ +\n\ Most ports do not need to implement anything for this hook.", - void, (void), - hook_void_void) + void, (cumulative_args_t complete_args), + hook_void_CUMULATIVE_ARGS) DEFHOOK (push_argument, diff --git a/gcc/targhooks.cc b/gcc/targhooks.cc index 12a58456b39..f8b9a01b817 100644 --- a/gcc/targhooks.cc +++ b/gcc/targhooks.cc @@ -773,12 +773,22 @@ hook_int_CUMULATIVE_ARGS_arg_info_0 (cumulative_args_t, return 0; } +void +hook_void_CUMULATIVE_ARGS (cumulative_args_t) +{ +} + void hook_void_CUMULATIVE_ARGS_tree (cumulative_args_t ca ATTRIBUTE_UNUSED, tree ATTRIBUTE_UNUSED) { } +void +hook_void_CUMULATIVE_ARGS_rtx_tree (cumulative_args_t, rtx, tree) +{ +} + /* Default implementation of TARGET_PUSH_ARGUMENT. */ bool diff --git a/gcc/targhooks.h b/gcc/targhooks.h index a6a423c1abb..1c43cefdcae 100644 --- a/gcc/targhooks.h +++ b/gcc/targhooks.h @@ -138,8 +138,9 @@ extern bool hook_bool_CUMULATIVE_ARGS_arg_info_true (cumulative_args_t, const function_arg_info &); extern int hook_int_CUMULATIVE_ARGS_arg_info_0 (cumulative_args_t, const function_arg_info &); -extern void hook_void_CUMULATIVE_ARGS_tree - (cumulative_args_t, tree); +extern void hook_void_CUMULATIVE_ARGS (cumulative_args_t); +extern void hook_void_CUMULATIVE_ARGS_tree (cumulative_args_t, tree); +extern void hook_void_CUMULATIVE_ARGS_rtx_tree (cumulative_args_t, rtx, tree); extern const char *hook_invalid_arg_for_unprototyped_fn (const_tree, const_tree, const_tree); extern void default_function_arg_advance