From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by sourceware.org (Postfix) with ESMTPS id 0A1D13851ABD for ; Fri, 24 Mar 2023 21:59:48 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 0A1D13851ABD Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=redhat.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1679695187; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type; bh=+QeIR2Iy6BRljYcSUmrz2C4u44Quu5YriukHK9Mv70M=; b=Mv/yXTt+lobrWUleIYEyKPZVwW0K2l+b5r4Ah3eTG599O3rMzLFkQTOERJx/6oqGCA4U1o A3xr69smDZPyEEsl7etiKeu8ITdvb8AyVL4OL5qFF8lhwhiHRAu3JPxd+PQCNx+rYNLy8A pNJmaxax180FShNCKMGcjCeNnzc0t8A= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-496-Nlh2AxGFMTa_TbVQSH7a9A-1; Fri, 24 Mar 2023 17:59:46 -0400 X-MC-Unique: Nlh2AxGFMTa_TbVQSH7a9A-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.rdu2.redhat.com [10.11.54.7]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id E11C71C0951B; Fri, 24 Mar 2023 21:59:45 +0000 (UTC) Received: from tucnak.zalov.cz (unknown [10.39.192.16]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 998A4140EBF4; Fri, 24 Mar 2023 21:59:45 +0000 (UTC) Received: from tucnak.zalov.cz (localhost [127.0.0.1]) by tucnak.zalov.cz (8.17.1/8.17.1) with ESMTPS id 32OLxgwC1095645 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NOT); Fri, 24 Mar 2023 22:59:43 +0100 Received: (from jakub@localhost) by tucnak.zalov.cz (8.17.1/8.17.1/Submit) id 32OLxfNF1095644; Fri, 24 Mar 2023 22:59:41 +0100 Date: Fri, 24 Mar 2023 22:59:36 +0100 From: Jakub Jelinek To: Richard Sandiford , Richard Earnshaw Cc: gcc-patches@gcc.gnu.org Subject: [PATCH] aarch64, builtins: Include PR registers in FUNCTION_ARG_REGNO_P etc. [PR109254] Message-ID: Reply-To: Jakub Jelinek MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.7 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline X-Spam-Status: No, score=-3.7 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE,RCVD_IN_MSPIKE_H2,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: Hi! The testcase in the PR (which unfortunately because of my lack of experience with SVE I'm not able to turn into a runtime testcase that verifies it) is miscompiled on aarch64-linux in the regname pass, because while the function takes arguments in the p0 register, FUNCTION_ARG_REGNO_P doesn't reflect that, so DF doesn't know the register is used in register passing. It sees 2 chains with p1 register and wants to replace the second one and as DF doesn't know p0 is live at the start of the function, it will happily use p0 register even when it is used in subsequent instructions. The following patch fixes that. FUNCTION_ARG_REGNO_P returns non-zero for p0-p3 (unconditionally, seems for the floating/vector registers it doesn't conditionalize them on TARGET_FLOAT either, but if you want, I can conditionalize p0-p3 on TARGET_SVE), similarly targetm.calls.function_value_regno_p returns true for p0 register if TARGET_SVE (again for consistency, that function conditionalizes the float/vector on TARGET_FLOAT); looking at the AAPCS, seems p1-p3 could be also used to return values in case of homogenous aggregates, but it doesn't seem GCC supports putting svbool_t as a member of a structure. Now, that change broke bootstrap in libobjc and some __builtin_apply_args/__builtin_apply/__builtin_return tests. The aarch64_get_reg_raw_mode hook already documents that SVE scalable arg/return passing is fundamentally incompatible with those builtins, but unlike the floating/vector regs where it forces a fixed vector mode, I think there is no fixed mode which could be used for p0-p3. So, I have tweaked the generic code so that it uses VOIDmode return from that hook to signal that a register shouldn't be touched by __builtin_apply_args/__builtin_apply/__builtin_return despite being mentioned in FUNCTION_ARG_REGNO_P or targetm.calls.function_value_regno_p. Bootstrapped/regtested on aarch64-linux, ok for trunk? Could somebody please turn the testcase from the PR into something that can be included into the testsuite? 2023-03-24 Jakub Jelinek PR target/109254 * builtins.cc (apply_args_size): If targetm.calls.get_raw_arg_mode returns VOIDmode, handle it like if the register isn't used for passing arguments at all. (apply_result_size): If targetm.calls.get_raw_result_mode returns VOIDmode, handle it like if the register isn't used for returning results at all. * target.def (get_raw_result_mode, get_raw_arg_mode): Document what it means to return VOIDmode. * doc/tm.texi: Regenerated. * config/aarch64/aarch64.cc (aarch64_function_value_regno_p): Return TARGET_SVE for P0_REGNUM. (aarch64_function_arg_regno_p): Also return true for p0-p3. (aarch64_get_reg_raw_mode): Return VOIDmode for PR_REGNUM_P regs. --- gcc/builtins.cc.jj 2023-03-24 10:38:40.185097837 +0100 +++ gcc/builtins.cc 2023-03-24 11:06:49.781725290 +0100 @@ -1446,18 +1446,19 @@ apply_args_size (void) { fixed_size_mode mode = targetm.calls.get_raw_arg_mode (regno); - gcc_assert (mode != VOIDmode); - - align = GET_MODE_ALIGNMENT (mode) / BITS_PER_UNIT; - if (size % align != 0) - size = CEIL (size, align) * align; - size += GET_MODE_SIZE (mode); - apply_args_mode[regno] = mode; + if (mode != VOIDmode) + { + align = GET_MODE_ALIGNMENT (mode) / BITS_PER_UNIT; + if (size % align != 0) + size = CEIL (size, align) * align; + size += GET_MODE_SIZE (mode); + apply_args_mode[regno] = mode; + } + else + apply_args_mode[regno] = as_a (VOIDmode); } else - { - apply_args_mode[regno] = as_a (VOIDmode); - } + apply_args_mode[regno] = as_a (VOIDmode); } return size; } @@ -1481,13 +1482,16 @@ apply_result_size (void) { fixed_size_mode mode = targetm.calls.get_raw_result_mode (regno); - gcc_assert (mode != VOIDmode); - - align = GET_MODE_ALIGNMENT (mode) / BITS_PER_UNIT; - if (size % align != 0) - size = CEIL (size, align) * align; - size += GET_MODE_SIZE (mode); - apply_result_mode[regno] = mode; + if (mode != VOIDmode) + { + align = GET_MODE_ALIGNMENT (mode) / BITS_PER_UNIT; + if (size % align != 0) + size = CEIL (size, align) * align; + size += GET_MODE_SIZE (mode); + apply_result_mode[regno] = mode; + } + else + apply_result_mode[regno] = as_a (VOIDmode); } else apply_result_mode[regno] = as_a (VOIDmode); --- gcc/target.def.jj 2023-03-23 10:00:58.722094571 +0100 +++ gcc/target.def 2023-03-24 11:12:46.978585647 +0100 @@ -5324,7 +5324,8 @@ DEFHOOK (get_raw_result_mode, "This target hook returns the mode to be used when accessing raw return\n\ registers in @code{__builtin_return}. Define this macro if the value\n\ -in @var{reg_raw_mode} is not correct.", +in @var{reg_raw_mode} is not correct. Use @code{VOIDmode} if a register\n\ +should be ignored for @code{__builtin_return} purposes.", fixed_size_mode, (int regno), default_get_reg_raw_mode) @@ -5334,7 +5335,8 @@ DEFHOOK (get_raw_arg_mode, "This target hook returns the mode to be used when accessing raw argument\n\ registers in @code{__builtin_apply_args}. Define this macro if the value\n\ -in @var{reg_raw_mode} is not correct.", +in @var{reg_raw_mode} is not correct. Use @code{VOIDmode} if a register\n\ +should be ignored for @code{__builtin_apply_args} purposes.", fixed_size_mode, (int regno), default_get_reg_raw_mode) --- gcc/doc/tm.texi.jj 2023-03-23 10:00:58.631095885 +0100 +++ gcc/doc/tm.texi 2023-03-24 11:12:52.062512496 +0100 @@ -4820,13 +4820,15 @@ nothing when you use @option{-freg-struc @deftypefn {Target Hook} fixed_size_mode TARGET_GET_RAW_RESULT_MODE (int @var{regno}) This target hook returns the mode to be used when accessing raw return registers in @code{__builtin_return}. Define this macro if the value -in @var{reg_raw_mode} is not correct. +in @var{reg_raw_mode} is not correct. Use @code{VOIDmode} if a register +should be ignored for @code{__builtin_return} purposes. @end deftypefn @deftypefn {Target Hook} fixed_size_mode TARGET_GET_RAW_ARG_MODE (int @var{regno}) This target hook returns the mode to be used when accessing raw argument registers in @code{__builtin_apply_args}. Define this macro if the value -in @var{reg_raw_mode} is not correct. +in @var{reg_raw_mode} is not correct. Use @code{VOIDmode} if a register +should be ignored for @code{__builtin_apply_args} purposes. @end deftypefn @deftypefn {Target Hook} bool TARGET_EMPTY_RECORD_P (const_tree @var{type}) --- gcc/config/aarch64/aarch64.cc.jj 2023-03-23 19:50:46.766715343 +0100 +++ gcc/config/aarch64/aarch64.cc 2023-03-24 11:10:29.166568603 +0100 @@ -7388,6 +7388,9 @@ aarch64_function_value_regno_p (const un if (regno >= V0_REGNUM && regno < V0_REGNUM + HA_MAX_NUM_FLDS) return TARGET_FLOAT; + if (regno == P0_REGNUM) + return TARGET_SVE; + return false; } @@ -7959,7 +7962,8 @@ bool aarch64_function_arg_regno_p (unsigned regno) { return ((GP_REGNUM_P (regno) && regno < R0_REGNUM + NUM_ARG_REGS) - || (FP_REGNUM_P (regno) && regno < V0_REGNUM + NUM_FP_ARG_REGS)); + || (FP_REGNUM_P (regno) && regno < V0_REGNUM + NUM_FP_ARG_REGS) + || (PR_REGNUM_P (regno) && regno < P0_REGNUM + NUM_PR_ARG_REGS)); } /* Implement FUNCTION_ARG_BOUNDARY. Every parameter gets at least @@ -7995,6 +7999,10 @@ aarch64_get_reg_raw_mode (int regno) for SVE types are fundamentally incompatible with the __builtin_return/__builtin_apply interface. */ return as_a (V16QImode); + if (PR_REGNUM_P (regno)) + /* For SVE PR regs, indicate that they should be ignored for + __builtin_apply/__builtin_return. */ + return as_a (VOIDmode); return default_get_reg_raw_mode (regno); } Jakub