From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by sourceware.org (Postfix) with ESMTP id 2B8353858434 for ; Fri, 11 Nov 2022 16:22:03 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 2B8353858434 Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=arm.com 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 0F83D1FB for ; Fri, 11 Nov 2022 08:22:09 -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 7BBC03F73D for ; Fri, 11 Nov 2022 08:22:02 -0800 (PST) From: Richard Sandiford To: gcc-patches@gcc.gnu.org Mail-Followup-To: gcc-patches@gcc.gnu.org, richard.sandiford@arm.com Subject: [PATCH] Add a target hook for sibcall epilogues Date: Fri, 11 Nov 2022 16:22:01 +0000 Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-Spam-Status: No, score=-42.5 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 List-Id: Epilogues for sibling calls are generated using the sibcall_epilogue pattern. One disadvantage of this approach is that the target doesn't know which call the epilogue is for, even though the code that generates the pattern has the call to hand. Although call instructions are currently rtxes, and so could be passed as an operand to the pattern, the main point of introducing rtx_insn was to move towards separating the rtx and insn types (a good thing IMO). There also isn't an existing practice of passing genuine instructions (as opposed to labels) to instruction patterns. This patch therefore adds a hook that can be defined as an alternative to sibcall_epilogue. The advantage is that it can be passed the call; the disadvantage is that it can't use .md conveniences like generating instructions from textual patterns (although most epilogues are too complex to benefit much from that anyway). Tested on aarch64-linux-gnu and x86_64-linux-gnu. OK to install? Richard gcc/ * doc/gccint/target-macros/miscellaneous-parameters.rst: Add TARGET_EMIT_EPILOGUE_FOR_SIBCALL. * doc/gccint/target-macros/tm.rst.in: Regenerate. * target.def (emit_epilogue_for_sibcall): New hook. * calls.cc (can_implement_as_sibling_call_p): Use it. * function.cc (thread_prologue_and_epilogue_insns): Likewise. (reposition_prologue_and_epilogue_notes): Likewise. * config/aarch64/aarch64-protos.h (aarch64_expand_epilogue): Take an rtx_call_insn * rather than a bool. * config/aarch64/aarch64.cc (aarch64_expand_epilogue): Likewise. (TARGET_EMIT_EPILOGUE_FOR_SIBCALL): Define. * config/aarch64/aarch64.md (epilogue): Update call. (sibcall_epilogue): Delete. --- gcc/calls.cc | 3 ++- gcc/config/aarch64/aarch64-protos.h | 2 +- gcc/config/aarch64/aarch64.cc | 11 +++++++---- gcc/config/aarch64/aarch64.md | 11 +---------- .../target-macros/miscellaneous-parameters.rst | 5 +++++ gcc/doc/gccint/target-macros/tm.rst.in | 11 +++++++++++ gcc/function.cc | 15 +++++++++++++-- gcc/target.def | 9 +++++++++ 8 files changed, 49 insertions(+), 18 deletions(-) diff --git a/gcc/calls.cc b/gcc/calls.cc index 6dd6f73e978..51b664f1b4d 100644 --- a/gcc/calls.cc +++ b/gcc/calls.cc @@ -2493,7 +2493,8 @@ can_implement_as_sibling_call_p (tree exp, tree addr, const args_size &args_size) { - if (!targetm.have_sibcall_epilogue ()) + if (!targetm.have_sibcall_epilogue () + && !targetm.emit_epilogue_for_sibcall) { maybe_complain_about_tail_call (exp, diff --git a/gcc/config/aarch64/aarch64-protos.h b/gcc/config/aarch64/aarch64-protos.h index 238820581c5..3d81c223b01 100644 --- a/gcc/config/aarch64/aarch64-protos.h +++ b/gcc/config/aarch64/aarch64-protos.h @@ -886,7 +886,7 @@ const char * aarch64_gen_far_branch (rtx *, int, const char *, const char *); const char * aarch64_output_probe_stack_range (rtx, rtx); const char * aarch64_output_probe_sve_stack_clash (rtx, rtx, rtx, rtx); void aarch64_err_no_fpadvsimd (machine_mode); -void aarch64_expand_epilogue (bool); +void aarch64_expand_epilogue (rtx_call_insn *); rtx aarch64_ptrue_all (unsigned int); opt_machine_mode aarch64_ptrue_all_mode (rtx); rtx aarch64_convert_sve_data_to_pred (rtx, machine_mode, rtx); diff --git a/gcc/config/aarch64/aarch64.cc b/gcc/config/aarch64/aarch64.cc index d1f979ebcf8..41a2181a7d3 100644 --- a/gcc/config/aarch64/aarch64.cc +++ b/gcc/config/aarch64/aarch64.cc @@ -10003,7 +10003,7 @@ aarch64_use_return_insn_p (void) from a deallocated stack, and we optimize the unwind records by emitting them all together if possible. */ void -aarch64_expand_epilogue (bool for_sibcall) +aarch64_expand_epilogue (rtx_call_insn *sibcall) { poly_int64 initial_adjust = cfun->machine->frame.initial_adjust; HOST_WIDE_INT callee_adjust = cfun->machine->frame.callee_adjust; @@ -10151,7 +10151,7 @@ aarch64_expand_epilogue (bool for_sibcall) explicitly authenticate. */ if (aarch64_return_address_signing_enabled () - && (for_sibcall || !TARGET_ARMV8_3)) + && (sibcall || !TARGET_ARMV8_3)) { switch (aarch64_ra_sign_key) { @@ -10169,7 +10169,7 @@ aarch64_expand_epilogue (bool for_sibcall) } /* Stack adjustment for exception handler. */ - if (crtl->calls_eh_return && !for_sibcall) + if (crtl->calls_eh_return && !sibcall) { /* We need to unwind the stack by the offset computed by EH_RETURN_STACKADJ_RTX. We have already reset the CFA @@ -10180,7 +10180,7 @@ aarch64_expand_epilogue (bool for_sibcall) } emit_use (gen_rtx_REG (DImode, LR_REGNUM)); - if (!for_sibcall) + if (!sibcall) emit_jump_insn (ret_rtx); } @@ -27906,6 +27906,9 @@ aarch64_libgcc_floating_mode_supported_p #undef TARGET_HAVE_SHADOW_CALL_STACK #define TARGET_HAVE_SHADOW_CALL_STACK true +#undef TARGET_EMIT_EPILOGUE_FOR_SIBCALL +#define TARGET_EMIT_EPILOGUE_FOR_SIBCALL aarch64_expand_epilogue + struct gcc_target targetm = TARGET_INITIALIZER; #include "gt-aarch64.h" diff --git a/gcc/config/aarch64/aarch64.md b/gcc/config/aarch64/aarch64.md index f2e3d905dbb..c4581cb823f 100644 --- a/gcc/config/aarch64/aarch64.md +++ b/gcc/config/aarch64/aarch64.md @@ -868,16 +868,7 @@ (define_expand "epilogue" [(clobber (const_int 0))] "" " - aarch64_expand_epilogue (false); - DONE; - " -) - -(define_expand "sibcall_epilogue" - [(clobber (const_int 0))] - "" - " - aarch64_expand_epilogue (true); + aarch64_expand_epilogue (nullptr); DONE; " ) diff --git a/gcc/doc/gccint/target-macros/miscellaneous-parameters.rst b/gcc/doc/gccint/target-macros/miscellaneous-parameters.rst index b48f91d3fd2..29d6b87b3c3 100644 --- a/gcc/doc/gccint/target-macros/miscellaneous-parameters.rst +++ b/gcc/doc/gccint/target-macros/miscellaneous-parameters.rst @@ -556,6 +556,11 @@ Here are several miscellaneous parameters. :end-before: [TARGET_USE_LATE_PROLOGUE_EPILOGUE] +.. include:: tm.rst.in + :start-after: [TARGET_EMIT_EPILOGUE_FOR_SIBCALL] + :end-before: [TARGET_EMIT_EPILOGUE_FOR_SIBCALL] + + .. include:: tm.rst.in :start-after: [TARGET_MACHINE_DEPENDENT_REORG] :end-before: [TARGET_MACHINE_DEPENDENT_REORG] diff --git a/gcc/doc/gccint/target-macros/tm.rst.in b/gcc/doc/gccint/target-macros/tm.rst.in index 2e789f8723d..a19fa38b811 100644 --- a/gcc/doc/gccint/target-macros/tm.rst.in +++ b/gcc/doc/gccint/target-macros/tm.rst.in @@ -3724,6 +3724,17 @@ [TARGET_USE_LATE_PROLOGUE_EPILOGUE] +[TARGET_EMIT_EPILOGUE_FOR_SIBCALL] +.. function:: void TARGET_EMIT_EPILOGUE_FOR_SIBCALL (rtx_call_insn *call) + + If defined, this hook emits an epilogue sequence for sibling (tail) + call instruction :samp:`call`. Another way of providing epilogues + for sibling calls is to define the ``sibcall_epilogue`` instruction + pattern; the main advantage of this hook over the pattern is that it + has access to the call instruction. + +[TARGET_EMIT_EPILOGUE_FOR_SIBCALL] + [TARGET_MACHINE_DEPENDENT_REORG] .. function:: void TARGET_MACHINE_DEPENDENT_REORG (void) diff --git a/gcc/function.cc b/gcc/function.cc index 3b1ab5d09e5..ecd656da332 100644 --- a/gcc/function.cc +++ b/gcc/function.cc @@ -6224,7 +6224,17 @@ thread_prologue_and_epilogue_insns (void) if (!(CALL_P (insn) && SIBLING_CALL_P (insn))) continue; - if (rtx_insn *ep_seq = targetm.gen_sibcall_epilogue ()) + rtx_insn *ep_seq; + if (targetm.emit_epilogue_for_sibcall) + { + start_sequence (); + targetm.emit_epilogue_for_sibcall (as_a (insn)); + ep_seq = get_insns (); + end_sequence (); + } + else + ep_seq = targetm.gen_sibcall_epilogue (); + if (ep_seq) { start_sequence (); emit_note (NOTE_INSN_EPILOGUE_BEG); @@ -6284,7 +6294,8 @@ reposition_prologue_and_epilogue_notes (void) { if (!targetm.have_prologue () && !targetm.have_epilogue () - && !targetm.have_sibcall_epilogue ()) + && !targetm.have_sibcall_epilogue () + && !targetm.emit_epilogue_for_sibcall) return; /* Since the hash table is created on demand, the fact that it is diff --git a/gcc/target.def b/gcc/target.def index 8b8aef982e8..15fd939200b 100644 --- a/gcc/target.def +++ b/gcc/target.def @@ -4083,6 +4083,15 @@ between instruction sets.", bool, (), hook_bool_void_false) +DEFHOOK +(emit_epilogue_for_sibcall, + "If defined, this hook emits an epilogue sequence for sibling (tail)\n\ +call instruction :samp:`call`. Another way of providing epilogues\n\ +for sibling calls is to define the ``sibcall_epilogue`` instruction\n\ +pattern; the main advantage of this hook over the pattern is that it\n\ +has access to the call instruction.", + void, (rtx_call_insn *call), NULL) + /* Do machine-dependent code transformations. Called just before delayed-branch scheduling. */ DEFHOOK -- 2.25.1