From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp-out1.suse.de (smtp-out1.suse.de [IPv6:2001:67c:2178:6::1c]) by sourceware.org (Postfix) with ESMTPS id 6EE33385C6ED for ; Tue, 10 Oct 2023 13:43:55 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 6EE33385C6ED Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=suse.de Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=suse.de Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out1.suse.de (Postfix) with ESMTP id 94D8321863; Tue, 10 Oct 2023 13:43:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1696945434; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=ksimgkedjZMniMNbWBQh1ePMzcgaSL0Bhk08EtArdr8=; b=izuldaWhlCpJJo4q6rAO947crK+T0jUpAKBdIBbpdwOcPqpyLntT5OrUA1Ytp8ajfmuG0Z beqpxwTAAJch2yYNR+cSeXOI7LCDlynHK0E0sf6vriCi2n5MCCQDVjEIjwVd05450+ngeD 575+ksui7tRb3w3wByauUX5cyNliwYg= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1696945434; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=ksimgkedjZMniMNbWBQh1ePMzcgaSL0Bhk08EtArdr8=; b=bB6BqAQg1OJ/vgztwHSaFKs/bVZn/JIb3RP745vpkQtAsihpLHW+wszdB5zU4SoyqAIgEW Fm/ow83hPx+QZlCg== Received: from wotan.suse.de (wotan.suse.de [10.160.0.1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by relay2.suse.de (Postfix) with ESMTPS id 655832C454; Tue, 10 Oct 2023 13:43:54 +0000 (UTC) Date: Tue, 10 Oct 2023 13:43:54 +0000 (UTC) From: Richard Biener To: Jakub Jelinek cc: Jason Merrill , gcc-patches@gcc.gnu.org Subject: Re: [PATCH] dwarf2out: Stop using wide_int in GC structures In-Reply-To: Message-ID: References: User-Agent: Alpine 2.22 (LSU 394 2020-01-19) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII X-Spam-Status: No, score=-5.0 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,SPF_HELO_NONE,SPF_PASS,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: On Tue, 10 Oct 2023, Jakub Jelinek wrote: > Hi! > > On Tue, Oct 10, 2023 at 09:30:31AM +0000, Richard Biener wrote: > > On Mon, 9 Oct 2023, Jakub Jelinek wrote: > > > > This makes wide_int unusable in GC structures, so for dwarf2out > > > > which was the only place which needed it there is a new rwide_int type > > > > (restricted wide_int) which supports only up to RWIDE_INT_MAX_ELTS limbs > > > > inline and is trivially copyable (dwarf2out should never deal with large > > > > _BitInt constants, those should have been lowered earlier). > > > > > > As discussed on IRC, the dwarf2out.{h,cc} needs are actually quite limited, > > > it just needs to allocate new GC structures val_wide points to (constructed > > > from some const wide_int_ref &) and needs to call operator==, > > > get_precision, elt, get_len and get_val methods on it. > > > Even trailing_wide_int would be overkill for that, the following just adds > > > a new struct with precision/len and trailing val array members and > > > implements the needed methods (only 2 of them using wide_int_ref constructed > > > from those). > > > > > > Incremental patch, so far compile time tested only: > > > > LGTM, wonder if we can push this separately as prerequesite? > > Here it is as a separate independent patch. Even without the > wide_int changing patch it should save some memory, by not always > allocating room for 9 limbs, but say just the 2/3 or how many we actually > need. And, another advantage is that if we really need it at some point, > it could support even more than 9 limbs if it is created from a wide_int_ref > with get_len () > 9. > > Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk? OK by me if Jason doesn't object. Thanks, Richard. > 2023-10-10 Jakub Jelinek > > * dwarf2out.h (wide_int_ptr): Remove. > (dw_wide_int_ptr): New typedef. > (struct dw_val_node): Change type of val_wide from wide_int_ptr > to dw_wide_int_ptr. > (struct dw_wide_int): New type. > (dw_wide_int::elt): New method. > (dw_wide_int::operator ==): Likewise. > * dwarf2out.cc (get_full_len): Change argument type to > const dw_wide_int & from const wide_int &. Use CEIL. Call > get_precision method instead of calling wi::get_precision. > (alloc_dw_wide_int): New function. > (add_AT_wide): Change w argument type to const wide_int_ref & > from const wide_int &. Use alloc_dw_wide_int. > (mem_loc_descriptor, loc_descriptor): Use alloc_dw_wide_int. > (insert_wide_int): Change val argument type to const wide_int_ref & > from const wide_int &. > (add_const_value_attribute): Pass rtx_mode_t temporary directly to > add_AT_wide instead of using a temporary variable. > > --- gcc/dwarf2out.h.jj 2023-10-09 14:37:45.890939965 +0200 > +++ gcc/dwarf2out.h 2023-10-09 16:46:14.705816928 +0200 > @@ -30,7 +30,7 @@ typedef struct dw_cfi_node *dw_cfi_ref; > typedef struct dw_loc_descr_node *dw_loc_descr_ref; > typedef struct dw_loc_list_struct *dw_loc_list_ref; > typedef struct dw_discr_list_node *dw_discr_list_ref; > -typedef wide_int *wide_int_ptr; > +typedef struct dw_wide_int *dw_wide_int_ptr; > > > /* Call frames are described using a sequence of Call Frame > @@ -252,7 +252,7 @@ struct GTY(()) dw_val_node { > unsigned HOST_WIDE_INT > GTY ((tag ("dw_val_class_unsigned_const"))) val_unsigned; > double_int GTY ((tag ("dw_val_class_const_double"))) val_double; > - wide_int_ptr GTY ((tag ("dw_val_class_wide_int"))) val_wide; > + dw_wide_int_ptr GTY ((tag ("dw_val_class_wide_int"))) val_wide; > dw_vec_const GTY ((tag ("dw_val_class_vec"))) val_vec; > struct dw_val_die_union > { > @@ -313,6 +313,35 @@ struct GTY(()) dw_discr_list_node { > int dw_discr_range; > }; > > +struct GTY((variable_size)) dw_wide_int { > + unsigned int precision; > + unsigned int len; > + HOST_WIDE_INT val[1]; > + > + unsigned int get_precision () const { return precision; } > + unsigned int get_len () const { return len; } > + const HOST_WIDE_INT *get_val () const { return val; } > + inline HOST_WIDE_INT elt (unsigned int) const; > + inline bool operator == (const dw_wide_int &) const; > +}; > + > +inline HOST_WIDE_INT > +dw_wide_int::elt (unsigned int i) const > +{ > + if (i < len) > + return val[i]; > + wide_int_ref ref = wi::storage_ref (val, len, precision); > + return wi::sign_mask (ref); > +} > + > +inline bool > +dw_wide_int::operator == (const dw_wide_int &o) const > +{ > + wide_int_ref ref1 = wi::storage_ref (val, len, precision); > + wide_int_ref ref2 = wi::storage_ref (o.val, o.len, o.precision); > + return ref1 == ref2; > +} > + > /* Interface from dwarf2out.cc to dwarf2cfi.cc. */ > extern struct dw_loc_descr_node *build_cfa_loc > (dw_cfa_location *, poly_int64); > --- gcc/dwarf2out.cc.jj 2023-10-09 14:37:45.894939909 +0200 > +++ gcc/dwarf2out.cc 2023-10-09 16:48:24.565014459 +0200 > @@ -397,11 +397,9 @@ dump_struct_debug (tree type, enum debug > of the number. */ > > static unsigned int > -get_full_len (const wide_int &op) > +get_full_len (const dw_wide_int &op) > { > - int prec = wi::get_precision (op); > - return ((prec + HOST_BITS_PER_WIDE_INT - 1) > - / HOST_BITS_PER_WIDE_INT); > + return CEIL (op.get_precision (), HOST_BITS_PER_WIDE_INT); > } > > static bool > @@ -3900,7 +3898,7 @@ static void add_data_member_location_att > struct vlr_context *); > static bool add_const_value_attribute (dw_die_ref, machine_mode, rtx); > static void insert_int (HOST_WIDE_INT, unsigned, unsigned char *); > -static void insert_wide_int (const wide_int &, unsigned char *, int); > +static void insert_wide_int (const wide_int_ref &, unsigned char *, int); > static unsigned insert_float (const_rtx, unsigned char *); > static rtx rtl_for_decl_location (tree); > static bool add_location_or_const_value_attribute (dw_die_ref, tree, bool); > @@ -4594,19 +4592,31 @@ AT_unsigned (dw_attr_node *a) > return a->dw_attr_val.v.val_unsigned; > } > > +dw_wide_int * > +alloc_dw_wide_int (const wide_int_ref &w) > +{ > + dw_wide_int *p > + = (dw_wide_int *) ggc_internal_alloc (sizeof (dw_wide_int) > + + ((w.get_len () - 1) > + * sizeof (HOST_WIDE_INT))); > + p->precision = w.get_precision (); > + p->len = w.get_len (); > + memcpy (p->val, w.get_val (), p->len * sizeof (HOST_WIDE_INT)); > + return p; > +} > + > /* Add an unsigned wide integer attribute value to a DIE. */ > > static inline void > add_AT_wide (dw_die_ref die, enum dwarf_attribute attr_kind, > - const wide_int& w) > + const wide_int_ref &w) > { > dw_attr_node attr; > > attr.dw_attr = attr_kind; > attr.dw_attr_val.val_class = dw_val_class_wide_int; > attr.dw_attr_val.val_entry = NULL; > - attr.dw_attr_val.v.val_wide = ggc_alloc (); > - *attr.dw_attr_val.v.val_wide = w; > + attr.dw_attr_val.v.val_wide = alloc_dw_wide_int (w); > add_dwarf_attr (die, &attr); > } > > @@ -16714,8 +16724,8 @@ mem_loc_descriptor (rtx rtl, machine_mod > mem_loc_result->dw_loc_oprnd1.v.val_die_ref.external = 0; > mem_loc_result->dw_loc_oprnd2.val_class > = dw_val_class_wide_int; > - mem_loc_result->dw_loc_oprnd2.v.val_wide = ggc_alloc (); > - *mem_loc_result->dw_loc_oprnd2.v.val_wide = rtx_mode_t (rtl, mode); > + mem_loc_result->dw_loc_oprnd2.v.val_wide > + = alloc_dw_wide_int (rtx_mode_t (rtl, mode)); > } > break; > > @@ -17288,8 +17298,8 @@ loc_descriptor (rtx rtl, machine_mode mo > loc_result = new_loc_descr (DW_OP_implicit_value, > GET_MODE_SIZE (int_mode), 0); > loc_result->dw_loc_oprnd2.val_class = dw_val_class_wide_int; > - loc_result->dw_loc_oprnd2.v.val_wide = ggc_alloc (); > - *loc_result->dw_loc_oprnd2.v.val_wide = rtx_mode_t (rtl, int_mode); > + loc_result->dw_loc_oprnd2.v.val_wide > + = alloc_dw_wide_int (rtx_mode_t (rtl, int_mode)); > } > break; > > @@ -20189,7 +20199,7 @@ extract_int (const unsigned char *src, u > /* Writes wide_int values to dw_vec_const array. */ > > static void > -insert_wide_int (const wide_int &val, unsigned char *dest, int elt_size) > +insert_wide_int (const wide_int_ref &val, unsigned char *dest, int elt_size) > { > int i; > > @@ -20274,8 +20284,7 @@ add_const_value_attribute (dw_die_ref di > && (GET_MODE_PRECISION (int_mode) > & (HOST_BITS_PER_WIDE_INT - 1)) == 0) > { > - wide_int w = rtx_mode_t (rtl, int_mode); > - add_AT_wide (die, DW_AT_const_value, w); > + add_AT_wide (die, DW_AT_const_value, rtx_mode_t (rtl, int_mode)); > return true; > } > return false; > > > Jakub > > -- Richard Biener SUSE Software Solutions Germany GmbH, Frankenstrasse 146, 90461 Nuernberg, Germany; GF: Ivo Totev, Andrew McDonald, Werner Knoblich; (HRB 36809, AG Nuernberg)