From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 59701 invoked by alias); 17 Aug 2015 02:35:49 -0000 Mailing-List: contact gcc-patches-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-patches-owner@gcc.gnu.org Received: (qmail 59687 invoked by uid 89); 17 Aug 2015 02:35:48 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-2.6 required=5.0 tests=AWL,BAYES_00,KAM_LAZY_DOMAIN_SECURITY,RP_MATCHES_RCVD,SPF_HELO_PASS autolearn=no version=3.3.2 X-HELO: mx1.redhat.com Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (AES256-GCM-SHA384 encrypted) ESMTPS; Mon, 17 Aug 2015 02:35:46 +0000 Received: from int-mx14.intmail.prod.int.phx2.redhat.com (int-mx14.intmail.prod.int.phx2.redhat.com [10.5.11.27]) by mx1.redhat.com (Postfix) with ESMTPS id CEB2191FF9; Mon, 17 Aug 2015 02:35:44 +0000 (UTC) Received: from freie.home (ovpn01.gateway.prod.ext.phx2.redhat.com [10.5.9.1]) by int-mx14.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id t7H2ZYf8004023 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Sun, 16 Aug 2015 22:35:41 -0400 Received: from livre.home (livre.home [172.31.160.2]) by freie.home (8.14.8/8.14.8) with ESMTP id t7H2Z17u016882; Sun, 16 Aug 2015 23:35:03 -0300 From: Alexandre Oliva To: Andreas Schwab Cc: Patrick Marlier , Jeff Law , James Greenhalgh , "H.J. Lu" , Segher Boessenkool , Richard Biener , GCC Patches , Christophe Lyon , David Edelsohn , Eric Botcazou Subject: Re: [PR64164] drop copyrename, integrate into expand References: <20150723203112.GB27818@gate.crashing.org> <20150810082355.GA31149@arm.com> <55C8BFC3.3030603@redhat.com> Date: Mon, 17 Aug 2015 02:57:00 -0000 In-Reply-To: (Andreas Schwab's message of "Sun, 16 Aug 2015 11:54:23 +0200") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-SW-Source: 2015-08/txt/msg00873.txt.bz2 On Aug 16, 2015, Andreas Schwab wrote: > On m68k: > FAIL: gcc.c-torture/execute/20050316-1.c -O0 execution test > FAIL: gcc.c-torture/execute/20050316-2.c -O0 execution test > FAIL: gcc.c-torture/execute/20050316-3.c -O0 execution test > FAIL: gcc.c-torture/execute/simd-4.c -O0 execution test > FAIL: gcc.c-torture/execute/simd-6.c -O0 execution test > FAIL: gcc.dg/compat/vector-1 c_compat_x_tst.o-c_compat_y_tst.o execute Thanks. Interesting. This exposes a more general situation than the one I covered with the byref params: the general case does not require the params to be passed by reference, but rather that the params require a stack address that, if determined by cfgexpand, will cause them to be computed too late for assign_parms' use. The following patch appears to fix the problem, applying the same logic of limited coalescing and deferred address assignment to all params that can't live in pseudos, and extending assign_parms' remaining case of copying incoming params to new stack slots to fill in the blank address with that of the newly-allocated stack slot. Would you be so kind as to give it a spin on a m68k native? TIA, diff --git a/gcc/cfgexpand.c b/gcc/cfgexpand.c index 0bc20f6..56571ce 100644 --- a/gcc/cfgexpand.c +++ b/gcc/cfgexpand.c @@ -172,17 +172,23 @@ leader_merge (tree cur, tree next) return cur; } -/* Return true if VAR is a PARM_DECL or a RESULT_DECL of type BLKmode. +/* Return true if VAR is a PARM_DECL or a RESULT_DECL that ought to be + assigned to a stack slot. We can't have expand_one_ssa_partition + choose their address: the pseudo holding the address would be set + up too late for assign_params to copy the parameter if needed. + Such parameters are likely passed as a pointer to the value, rather than as a value, and so we must not coalesce them, nor allocate stack space for them before determining the calling conventions for - them. For their SSA_NAMEs, expand_one_ssa_partition emits RTL as - MEMs with pc_rtx as the address, and then it replaces the pc_rtx - with NULL so as to make sure the MEM is not used before it is - adjusted in assign_parm_setup_reg. */ + them. + + For their SSA_NAMEs, expand_one_ssa_partition emits RTL as MEMs + with pc_rtx as the address, and then it replaces the pc_rtx with + NULL so as to make sure the MEM is not used before it is adjusted + in assign_parm_setup_reg. */ bool -parm_maybe_byref_p (tree var) +parm_in_stack_slot_p (tree var) { if (!var || VAR_P (var)) return false; @@ -190,7 +196,7 @@ parm_maybe_byref_p (tree var) gcc_assert (TREE_CODE (var) == PARM_DECL || TREE_CODE (var) == RESULT_DECL); - return TYPE_MODE (TREE_TYPE (var)) == BLKmode; + return !use_register_for_decl (var); } /* Return the partition of the default SSA_DEF for decl VAR. */ @@ -1343,13 +1349,15 @@ expand_one_ssa_partition (tree var) if (!use_register_for_decl (var)) { - if (parm_maybe_byref_p (SSA_NAME_VAR (var)) + /* We can't risk having the parm assigned to a MEM location + whose address references a pseudo, for the pseudo will only + be set up after arguments are copied to the stack slot. */ + if (parm_in_stack_slot_p (SSA_NAME_VAR (var)) && ssa_default_def_partition (SSA_NAME_VAR (var)) == part) { expand_one_stack_var_at (var, pc_rtx, 0, 0); rtx x = SA.partition_to_pseudo[part]; gcc_assert (GET_CODE (x) == MEM); - gcc_assert (GET_MODE (x) == BLKmode); gcc_assert (XEXP (x, 0) == pc_rtx); /* Reset the address, so that any attempt to use it will ICE. It will be adjusted in assign_parm_setup_reg. */ diff --git a/gcc/cfgexpand.h b/gcc/cfgexpand.h index 987cf356..d168672 100644 --- a/gcc/cfgexpand.h +++ b/gcc/cfgexpand.h @@ -22,7 +22,7 @@ along with GCC; see the file COPYING3. If not see extern tree gimple_assign_rhs_to_tree (gimple); extern HOST_WIDE_INT estimated_stack_frame_size (struct cgraph_node *); -extern bool parm_maybe_byref_p (tree); +extern bool parm_in_stack_slot_p (tree); extern rtx get_rtl_for_parm_ssa_default_def (tree var); diff --git a/gcc/function.c b/gcc/function.c index 715c19f..eccd8c6 100644 --- a/gcc/function.c +++ b/gcc/function.c @@ -2934,6 +2934,16 @@ assign_parm_setup_block_p (struct assign_parm_data_one *data) return false; } +static bool +parm_in_unassigned_mem_p (tree decl, rtx from_expand) +{ + bool result = MEM_P (from_expand) && !XEXP (from_expand, 0); + + gcc_assert (result == parm_in_stack_slot_p (decl)); + + return result; +} + /* A subroutine of assign_parms. Arrange for the parameter to be present and valid in DATA->STACK_RTL. */ @@ -2956,8 +2966,7 @@ assign_parm_setup_block (struct assign_parm_data_all *all, { DECL_ALIGN (parm) = MAX (DECL_ALIGN (parm), BITS_PER_WORD); rtx from_expand = rtl_for_parm (all, parm); - if (from_expand && (!parm_maybe_byref_p (parm) - || XEXP (from_expand, 0) != NULL_RTX)) + if (from_expand && !parm_in_unassigned_mem_p (parm, from_expand)) stack_parm = copy_rtx (from_expand); else { @@ -2968,8 +2977,7 @@ assign_parm_setup_block (struct assign_parm_data_all *all, if (from_expand) { gcc_assert (GET_CODE (stack_parm) == MEM); - gcc_assert (GET_CODE (from_expand) == MEM); - gcc_assert (XEXP (from_expand, 0) == NULL_RTX); + gcc_assert (parm_in_unassigned_mem_p (parm, from_expand)); XEXP (from_expand, 0) = XEXP (stack_parm, 0); PUT_MODE (from_expand, GET_MODE (stack_parm)); stack_parm = copy_rtx (from_expand); @@ -3121,7 +3129,7 @@ assign_parm_setup_reg (struct assign_parm_data_all *all, tree parm, if (GET_MODE (parmreg) != promoted_nominal_mode) parmreg = gen_lowpart (promoted_nominal_mode, parmreg); } - else if (!from_expand || parm_maybe_byref_p (parm)) + else if (!from_expand || parm_in_unassigned_mem_p (parm, from_expand)) { parmreg = gen_reg_rtx (promoted_nominal_mode); if (!DECL_ARTIFICIAL (parm)) @@ -3349,7 +3357,7 @@ assign_parm_setup_reg (struct assign_parm_data_all *all, tree parm, did_conversion = true; } else if (GET_MODE (parmreg) == BLKmode) - gcc_assert (parm_maybe_byref_p (parm)); + gcc_assert (parm_in_stack_slot_p (parm)); else emit_move_insn (parmreg, src); @@ -3455,12 +3463,15 @@ assign_parm_setup_stack (struct assign_parm_data_all *all, tree parm, if (data->entry_parm != data->stack_parm) { rtx src, dest; + rtx from_expand = NULL_RTX; if (data->stack_parm == 0) { - rtx x = data->stack_parm = rtl_for_parm (all, parm); - if (x) - gcc_assert (GET_MODE (x) == GET_MODE (data->entry_parm)); + from_expand = rtl_for_parm (all, parm); + if (from_expand) + gcc_assert (GET_MODE (from_expand) == GET_MODE (data->entry_parm)); + else if (!parm_in_unassigned_mem_p (parm, from_expand)) + data->stack_parm = from_expand; } if (data->stack_parm == 0) @@ -3472,7 +3483,16 @@ assign_parm_setup_stack (struct assign_parm_data_all *all, tree parm, = assign_stack_local (GET_MODE (data->entry_parm), GET_MODE_SIZE (GET_MODE (data->entry_parm)), align); - set_mem_attributes (data->stack_parm, parm, 1); + if (!from_expand) + set_mem_attributes (data->stack_parm, parm, 1); + else + { + gcc_assert (GET_CODE (data->stack_parm) == MEM); + gcc_assert (parm_in_unassigned_mem_p (parm, from_expand)); + XEXP (from_expand, 0) = XEXP (data->stack_parm, 0); + PUT_MODE (from_expand, GET_MODE (data->stack_parm)); + data->stack_parm = copy_rtx (from_expand); + } } dest = validize_mem (copy_rtx (data->stack_parm)); diff --git a/gcc/tree-ssa-coalesce.c b/gcc/tree-ssa-coalesce.c index 08ce72c..6468012 100644 --- a/gcc/tree-ssa-coalesce.c +++ b/gcc/tree-ssa-coalesce.c @@ -1386,8 +1386,8 @@ gimple_can_coalesce_p (tree name1, tree name2) because it may be passed by reference. */ return ((!var1 || VAR_P (var1)) && (!var2 || VAR_P (var2))) || (/* The case var1 == var2 is already covered above. */ - !parm_maybe_byref_p (var1) - && !parm_maybe_byref_p (var2) + !parm_in_stack_slot_p (var1) + && !parm_in_stack_slot_p (var2) && promote_ssa_mode (name1, NULL) == promote_ssa_mode (name2, NULL)); } -- Alexandre Oliva, freedom fighter http://FSFLA.org/~lxoliva/ You must be the change you wish to see in the world. -- Gandhi Be Free! -- http://FSFLA.org/ FSF Latin America board member Free Software Evangelist|Red Hat Brasil GNU Toolchain Engineer