Wilco Dijkstra <wilco.dijks...@arm.com> writes: > As a minor cleanup remove Cortex-A57 FMA steering pass. Since Cortex-A57 is > pretty old, there isn't any benefit of keeping this. > > Passes regress & bootstrap, OK for commit? > > gcc: > * config.gcc (extra_objs): Remove cortex-a57-fma-steering.o. > * config/aarch64/aarch64-passes.def: Remove pass_fma_steering. > * config/aarch64/aarch64-protos.h: Remove make_pass_fma_steering. > * config/aarch64/aarch64-tuning-flags.def (RENAME_FMA_REGS): Remove. > * config/aarch64/cortex-a57-fma-steering.cc: Delete file. > * config/aarch64/t-aarch64: Remove cortex-a57-fma-steering.o rules. > * config/aarch64/tuning_models/cortexa57.h (cortexa57_tunings): > Remove RENAME_FMA_REGS tuning.
This would probably be a reasonable compromise if the pass ever became a maintenance burden. But I'm not sure the pass is a burden at the moment. TBH, I don't remember having had to think about it for years :) So IMO we should keep the pass, but reconsider removing it if in future it requires non-trivial effort to keep working. That said, the fact the patch requires no testsuite changes suggests that the pass could easily become ineffective without anyone noticing. So I won't object if other maintainers are in favour. Thanks, Richard > > --- > > diff --git a/gcc/config.gcc b/gcc/config.gcc > index > 55e37146ee0356b67b8a1a09d263eccdf69cd91a..97ef3ae77fb97b347ba43e55f7a05f5438a96a43 > 100644 > --- a/gcc/config.gcc > +++ b/gcc/config.gcc > @@ -350,7 +350,7 @@ aarch64*-*-*) > c_target_objs="aarch64-c.o" > cxx_target_objs="aarch64-c.o" > d_target_objs="aarch64-d.o" > - extra_objs="aarch64-builtins.o aarch-common.o aarch64-sve-builtins.o > aarch64-sve-builtins-shapes.o aarch64-sve-builtins-base.o > aarch64-sve-builtins-sve2.o aarch64-sve-builtins-sme.o > cortex-a57-fma-steering.o aarch64-speculation.o aarch-bti-insert.o > aarch64-cc-fusion.o aarch64-early-ra.o aarch64-ldp-fusion.o" > + extra_objs="aarch64-builtins.o aarch-common.o aarch64-sve-builtins.o > aarch64-sve-builtins-shapes.o aarch64-sve-builtins-base.o > aarch64-sve-builtins-sve2.o aarch64-sve-builtins-sme.o aarch64-speculation.o > aarch-bti-insert.o aarch64-cc-fusion.o aarch64-early-ra.o > aarch64-ldp-fusion.o" > target_gtfiles="\$(srcdir)/config/aarch64/aarch64-protos.h > \$(srcdir)/config/aarch64/aarch64-builtins.h > \$(srcdir)/config/aarch64/aarch64-builtins.cc > \$(srcdir)/config/aarch64/aarch64-sve-builtins.h > \$(srcdir)/config/aarch64/aarch64-sve-builtins.cc" > target_has_targetm_common=yes > ;; > diff --git a/gcc/config/aarch64/aarch64-passes.def > b/gcc/config/aarch64/aarch64-passes.def > index > 9cf9d3e13b2cb0d0bf9c34439785e8ca704230fe..d80b9c6f39c3b56aa6251a81590172f70b31e01e > 100644 > --- a/gcc/config/aarch64/aarch64-passes.def > +++ b/gcc/config/aarch64/aarch64-passes.def > @@ -19,7 +19,6 @@ > <http://www.gnu.org/licenses/>. */ > > INSERT_PASS_BEFORE (pass_sched, 1, pass_aarch64_early_ra); > -INSERT_PASS_AFTER (pass_regrename, 1, pass_fma_steering); > INSERT_PASS_BEFORE (pass_reorder_blocks, 1, pass_track_speculation); > INSERT_PASS_BEFORE (pass_late_thread_prologue_and_epilogue, 1, > pass_switch_pstate_sm); > INSERT_PASS_BEFORE (pass_late_thread_prologue_and_epilogue, 1, > pass_late_track_speculation); > diff --git a/gcc/config/aarch64/aarch64-protos.h > b/gcc/config/aarch64/aarch64-protos.h > index > fa7bc8029be04f6530d2aee2ead4d754ba3b2550..afdf7d01adb3bdafd15d0422c3b2dfd680383bef > 100644 > --- a/gcc/config/aarch64/aarch64-protos.h > +++ b/gcc/config/aarch64/aarch64-protos.h > @@ -1199,7 +1199,6 @@ std::string aarch64_get_extension_string_for_isa_flags > (aarch64_feature_flags, > aarch64_feature_flags); > > rtl_opt_pass *make_pass_aarch64_early_ra (gcc::context *); > -rtl_opt_pass *make_pass_fma_steering (gcc::context *); > rtl_opt_pass *make_pass_track_speculation (gcc::context *); > rtl_opt_pass *make_pass_late_track_speculation (gcc::context *); > rtl_opt_pass *make_pass_insert_bti (gcc::context *ctxt); > diff --git a/gcc/config/aarch64/aarch64-tuning-flags.def > b/gcc/config/aarch64/aarch64-tuning-flags.def > index > 1feff3beb348f45c254c5a7c346a1a9674dee362..b1ab068f4073f459e829503f59c9de236cffb63a > 100644 > --- a/gcc/config/aarch64/aarch64-tuning-flags.def > +++ b/gcc/config/aarch64/aarch64-tuning-flags.def > @@ -28,8 +28,6 @@ > INTERNAL_NAME gives the internal name suitable for appending to > AARCH64_TUNE_ to give an enum name. */ > > -AARCH64_EXTRA_TUNING_OPTION ("rename_fma_regs", RENAME_FMA_REGS) > - > /* Some of the optional shift to some arthematic instructions are > considered cheap. Logical shift left <=4 with or without a > zero extend are considered cheap. Sign extend; non logical shift left > diff --git a/gcc/config/aarch64/cortex-a57-fma-steering.cc > b/gcc/config/aarch64/cortex-a57-fma-steering.cc > deleted file mode 100644 > index > fd6da66d855e36cd023b5343c392cd2f7f062d1b..0000000000000000000000000000000000000000 > --- a/gcc/config/aarch64/cortex-a57-fma-steering.cc > +++ /dev/null > @@ -1,1096 +0,0 @@ > -/* FMA steering optimization pass for Cortex-A57. > - Copyright (C) 2015-2025 Free Software Foundation, Inc. > - Contributed by ARM Ltd. > - > - This file is part of GCC. > - > - GCC is free software; you can redistribute it and/or modify it > - under the terms of the GNU General Public License as published by > - the Free Software Foundation; either version 3, or (at your option) > - any later version. > - > - GCC is distributed in the hope that it will be useful, but > - WITHOUT ANY WARRANTY; without even the implied warranty of > - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU > - General Public License for more details. > - > - You should have received a copy of the GNU General Public License > - along with GCC; see the file COPYING3. If not see > - <http://www.gnu.org/licenses/>. */ > - > -#define IN_TARGET_CODE 1 > - > -#include "config.h" > -#define INCLUDE_LIST > -#include "system.h" > -#include "coretypes.h" > -#include "backend.h" > -#include "target.h" > -#include "rtl.h" > -#include "df.h" > -#include "insn-config.h" > -#include "regs.h" > -#include "memmodel.h" > -#include "emit-rtl.h" > -#include "recog.h" > -#include "cfganal.h" > -#include "insn-attr.h" > -#include "context.h" > -#include "tree-pass.h" > -#include "function-abi.h" > -#include "regrename.h" > -#include "aarch64-protos.h" > - > -/* For better performance, the destination of FMADD/FMSUB instructions should > - have the same parity as their accumulator register if the accumulator > - contains the result of a previous FMUL or FMADD/FMSUB instruction if > - targetting Cortex-A57 processors. Performance is also increased by > - otherwise keeping a good balance in the parity of the destination register > - of FMUL or FMADD/FMSUB. > - > - This pass ensure that registers are renamed so that these conditions hold. > - We reuse the existing register renaming facility from regrename.cc to > build > - dependency chains and expose candidate registers for renaming. > - > - > - The algorithm has three steps: > - > - First, the functions of the register renaming pass are called. These > - analyze the instructions and produce a list of def/use chains of > - instructions. > - > - Next, this information is used to build trees of multiply and > - multiply-accumulate instructions. The roots of these trees are any > - multiply, or any multiply-accumulate whose accumulator is not dependent on > - a multiply or multiply-accumulate instruction. A child is added to the > - tree where a dependency chain exists between the result of the parent > - instruction and the accumulator operand of the child, as in the diagram > - below: > - > - fmul s2, s0, s1 > - / \ > - fmadd s0, s1, s1, s2 fmadd s4, s1, s1 s2 > - | > - fmadd s3, s1, s1, s0 > - > - Trees made of a single instruction are permitted. > - > - Finally, renaming is performed. The parity of the destination register at > - the root of a tree is checked against the current balance of multiply and > - multiply-accumulate on each pipeline. If necessary, the root of a tree is > - renamed, in which case the rest of the tree is then renamed to keep the > same > - parity in the destination registers of all instructions in the tree. */ > - > - > - > -/* Forward declarations. */ > -class fma_node; > -class fma_root_node; > -class func_fma_steering; > - > -/* Dependencies between FMUL or FMADD/FMSUB instructions and subsequent > - FMADD/FMSUB instructions form a graph. This is because alternatives can > - make a register be set by several FMUL or FMADD/FMSUB instructions in > - different basic blocks and because of loops. For ease of browsing, the > - connected components of this graph are broken up into forests of trees. > - Forests are represented by fma_forest objects, contained in the > fma_forests > - list. Using a separate object for the forests allows for a better use of > - memory as there is some information that is global to each forest, such as > - the number of FMSUB and FMADD/FMSUB instructions currently scheduled on > each > - floating-point execution pipelines. */ > - > -class fma_forest > -{ > -public: > - fma_forest (func_fma_steering *, fma_root_node *, int); > - ~fma_forest (); > - > - int get_id (); > - std::list<fma_root_node *> *get_roots (); > - func_fma_steering *get_globals (); > - int get_target_parity (); > - void fma_node_created (fma_node *); > - void merge_forest (fma_forest *); > - void dump_info (); > - void dispatch (); > - > -private: > - /* Prohibit copy construction. */ > - fma_forest (const fma_forest &); > - > - /* The list of roots that form this forest. */ > - std::list<fma_root_node *> *m_roots; > - > - /* Target parity the destination register of all FMUL and FMADD/FMSUB > - instructions in this forest should have. */ > - int m_target_parity; > - > - /* Link to the instance of func_fma_steering holding data related to the > - FMA steering of the current function (cfun). */ > - func_fma_steering *m_globals; > - > - /* Identifier for the forest (used for dumps). */ > - int m_id; > - > - /* Total number of nodes in the forest (for statistics). */ > - int m_nb_nodes; > -}; > - > -class fma_node > -{ > -public: > - fma_node (fma_node *parent, du_chain *chain); > - ~fma_node (); > - > - bool root_p (); > - fma_forest *get_forest (); > - std::list<fma_node *> *get_children (); > - rtx_insn *get_insn (); > - void add_child (fma_node *); > - int get_parity (); > - void set_head (du_head *); > - void rename (fma_forest *); > - void dump_info (fma_forest *); > - > -private: > - /* Prohibit copy construction. */ > - fma_node (const fma_node &); > - > -protected: > - /* Root node that lead to this node. */ > - fma_root_node *m_root; > - > - /* The parent node of this node. If the node belong to a chain with > several > - parent nodes, the first one encountered in a depth-first search is > chosen > - as canonical parent. */ > - fma_node *m_parent; > - > - /* The list of child nodes. If a chain contains several parent nodes, one > is > - chosen as canonical parent and the others will have no children. */ > - std::list<fma_node *> *m_children; > - > - /* The associated DU_HEAD chain that the insn represented by this object > - is (one of) the root of. When a chain contains several roots, the non > - canonical ones have this field set to NULL. */ > - struct du_head *m_head; > - > - /* The FMUL or FMADD/FMSUB instruction this object corresponds to. */ > - rtx_insn *m_insn; > -}; > - > -class fma_root_node : public fma_node > -{ > -public: > - fma_root_node (func_fma_steering *, du_chain *, int); > - > - fma_forest *get_forest (); > - void set_forest (fma_forest *); > - void dump_info (fma_forest *); > - > -private: > - /* The forest this node belonged to when it was created. */ > - fma_forest *m_forest; > -}; > - > -/* Class holding all data and methods relative to the FMA steering of a given > - function. The FMA steering pass could then run in parallel for different > - functions. */ > - > -class func_fma_steering > -{ > -public: > - func_fma_steering (); > - ~func_fma_steering (); > - > - int get_fpu_balance (); > - void remove_forest (fma_forest *); > - bool put_node (fma_node *); > - void update_balance (int); > - fma_node *get_fma_node (rtx_insn *); > - void analyze_fma_fmul_insn (fma_forest *, du_chain *, du_head_p); > - void execute_fma_steering (); > - > -private: > - /* Prohibit copy construction. */ > - func_fma_steering (const func_fma_steering &); > - > - void dfs (void (*) (fma_forest *), void (*) (fma_forest *, fma_root_node > *), > - void (*) (fma_forest *, fma_node *), bool); > - void analyze (); > - void rename_fma_trees (); > - > - /* Mapping between FMUL or FMADD/FMSUB instructions and the associated > - fma_node object. Used when analyzing an instruction that is a root of > - a chain to find if such an object was created because this instruction > - is also a use in another chain. */ > - hash_map<rtx_insn *, fma_node *> *m_insn_fma_head_map; > - > - /* A list of all the forests in a given function. */ > - std::list<fma_forest *> m_fma_forests; > - > - /* Balance of FMUL and FMADD/FMSUB instructions between the two FPU > - pipelines: > - < 0: more instruction dispatched to the first pipeline > - == 0: perfect balance > - > 0: more instruction dispatched to the second pipeline. */ > - int m_fpu_balance; > - > - /* Identifier for the next forest created. */ > - int m_next_forest_id; > -}; > - > -/* Rename the register HEAD->regno in all the insns in the chain HEAD to any > - register not in the set UNAVAILABLE. Adapted from rename_chains in > - regrename.cc. */ > - > -static bool > -rename_single_chain (du_head_p head, HARD_REG_SET *unavailable) > -{ > - int best_new_reg; > - int n_uses = 0; > - struct du_chain *tmp; > - int reg = head->regno; > - enum reg_class super_class = NO_REGS; > - > - if (head->cannot_rename) > - return false; > - > - if (fixed_regs[reg] || global_regs[reg] > - || (frame_pointer_needed && reg == HARD_FRAME_POINTER_REGNUM)) > - return false; > - > - /* Iterate over elements in the chain in order to: > - 1. Count number of uses, and narrow the set of registers we can > - use for renaming. > - 2. Compute the superunion of register classes in this chain. */ > - for (tmp = head->first; tmp; tmp = tmp->next_use) > - { > - if (DEBUG_INSN_P (tmp->insn)) > - continue; > - n_uses++; > - *unavailable |= ~reg_class_contents[tmp->cl]; > - super_class = reg_class_superunion[(int) super_class][(int) tmp->cl]; > - } > - > - if (n_uses < 1) > - return false; > - > - best_new_reg = find_rename_reg (head, super_class, unavailable, reg, > - false); > - > - if (dump_file) > - { > - fprintf (dump_file, "Register %s in insn %d", reg_names[reg], > - INSN_UID (head->first->insn)); > - if (head->call_abis) > - fprintf (dump_file, " crosses a call"); > - } > - > - if (best_new_reg == reg) > - { > - if (dump_file) > - fprintf (dump_file, "; no available better choice\n"); > - return false; > - } > - > - if (regrename_do_replace (head, best_new_reg)) > - { > - if (dump_file) > - fprintf (dump_file, ", renamed as %s\n", reg_names[best_new_reg]); > - df_set_regs_ever_live (best_new_reg, true); > - } > - else > - { > - if (dump_file) > - fprintf (dump_file, ", renaming as %s failed\n", > - reg_names[best_new_reg]); > - return false; > - } > - return true; > -} > - > -/* Return whether T is the attribute of a FMADD/FMSUB-like instruction. */ > - > -static bool > -is_fmac_op (enum attr_type t) > -{ > - return (t == TYPE_FMACS) || (t == TYPE_FMACD) || (t == TYPE_NEON_FP_MLA_S); > -} > - > -/* Return whether T is the attribute of a FMUL instruction. */ > - > -static bool > -is_fmul_op (enum attr_type t) > -{ > - return (t == TYPE_FMULS) || (t == TYPE_FMULD) || (t == TYPE_NEON_FP_MUL_S); > -} > - > -/* Return whether INSN is an FMUL (if FMUL_OK is true) or FMADD/FMSUB > - instruction. */ > - > -static bool > -is_fmul_fmac_insn (rtx_insn *insn, bool fmul_ok) > -{ > - enum attr_type t; > - > - if (!NONDEBUG_INSN_P (insn)) > - return false; > - > - if (recog_memoized (insn) < 0) > - return false; > - > - /* Only consider chain(s) this instruction is a root of if this is an FMUL > or > - FMADD/FMSUB instruction. This allows to avoid browsing chains of all > - instructions for FMUL or FMADD/FMSUB in them. */ > - t = get_attr_type (insn); > - return is_fmac_op (t) || (fmul_ok && is_fmul_op (t)); > -} > - > - > -/* > - * Class fma_forest method definitions. > - */ > - > -fma_forest::fma_forest (func_fma_steering *fma_steer, fma_root_node > *fma_root, > - int id) > -{ > - memset (this, 0, sizeof (*this)); > - this->m_globals = fma_steer; > - this->m_roots = new std::list<fma_root_node *>; > - this->m_roots->push_back (fma_root); > - this->m_id = id; > -} > - > -fma_forest::~fma_forest () > -{ > - delete this->m_roots; > -} > - > -int > -fma_forest::get_id () > -{ > - return this->m_id; > -} > - > -std::list<fma_root_node *> * > -fma_forest::get_roots () > -{ > - return this->m_roots; > -} > - > -func_fma_steering * > -fma_forest::get_globals () > -{ > - return this->m_globals; > -} > - > -int > -fma_forest::get_target_parity () > -{ > - return this->m_target_parity; > -} > - > -/* Act on the creation of NODE by updating statistics in FOREST and adding an > - entry for it in the func_fma_steering hashmap. */ > - > -void fma_forest::fma_node_created (fma_node *node) > -{ > - bool created = !this->m_globals->put_node (node); > - > - gcc_assert (created); > - this->m_nb_nodes++; > -} > - > -/* Merge REF_FOREST and OTHER_FOREST together, making REF_FOREST the > canonical > - fma_forest object to represent both. */ > - > -void > -fma_forest::merge_forest (fma_forest *other_forest) > -{ > - std::list<fma_root_node *> *other_roots; > - std::list<fma_root_node *>::iterator other_root_iter; > - > - if (this == other_forest) > - return; > - > - other_roots = other_forest->m_roots; > - > - /* Update root nodes' pointer to forest. */ > - for (other_root_iter = other_roots->begin (); > - other_root_iter != other_roots->end (); ++other_root_iter) > - (*other_root_iter)->set_forest (this); > - > - /* Remove other_forest from the list of forests and move its tree roots in > - the list of tree roots of ref_forest. */ > - this->m_globals->remove_forest (other_forest); > - this->m_roots->splice (this->m_roots->begin (), *other_roots); > - this->m_nb_nodes += other_forest->m_nb_nodes; > - > - delete other_forest; > -} > - > -/* Dump information about the forest FOREST. */ > - > -void > -fma_forest::dump_info () > -{ > - gcc_assert (dump_file); > - > - fprintf (dump_file, "Forest #%d has %d nodes\n", this->m_id, > - this->m_nb_nodes); > -} > - > -/* Wrapper around fma_forest::dump_info for use as parameter of function > - pointer type in func_fma_steering::dfs. */ > - > -static void > -dump_forest_info (fma_forest *forest) > -{ > - forest->dump_info (); > -} > - > -/* Dispatch forest to the least utilized pipeline. */ > - > -void > -fma_forest::dispatch () > -{ > - this->m_target_parity = this->m_roots->front ()->get_parity (); > - int fpu_balance = this->m_globals->get_fpu_balance (); > - if (fpu_balance != 0) > - this->m_target_parity = (fpu_balance < 0); > - > - if (dump_file) > - fprintf (dump_file, "Target parity for forest #%d: %s\n", this->m_id, > - this->m_target_parity ? "odd" : "even"); > -} > - > -/* Wrapper around fma_forest::dispatch for use as parameter of function > pointer > - type in func_fma_steering::dfs. */ > - > -static void > -dispatch_forest (fma_forest *forest) > -{ > - forest->dispatch (); > -} > - > -fma_node::fma_node (fma_node *parent, du_chain *chain) > -{ > - memset (this, 0, sizeof (*this)); > - this->m_parent = parent; > - this->m_children = new std::list<fma_node *>; > - this->m_insn = chain->insn; > - /* root_p () cannot be used to check for root before root is set. */ > - if (this->m_parent == this) > - this->m_root = static_cast<fma_root_node *> (parent); > - else > - { > - this->m_root = parent->m_root; > - this->get_forest ()->fma_node_created (this); > - } > -} > - > -fma_node::~fma_node () > -{ > - delete this->m_children; > -} > - > -std::list<fma_node *> * > -fma_node::get_children () > -{ > - return this->m_children; > -} > - > -rtx_insn * > -fma_node::get_insn () > -{ > - return this->m_insn; > -} > - > -void > -fma_node::set_head (du_head *head) > -{ > - gcc_assert (!this->m_head); > - this->m_head = head; > -} > - > -/* Add a child to this node in the list of children. */ > - > -void > -fma_node::add_child (fma_node *child) > -{ > - this->m_children->push_back (child); > -} > - > -/* Return the parity of the destination register of the instruction > represented > - by this node. */ > - > -int > -fma_node::get_parity () > -{ > - return this->m_head->regno % 2; > -} > - > -/* Get the actual forest associated with a non root node as the one the node > - points to might have been merged into another one. In that case the > pointer > - in the root nodes are updated so we return the forest pointer of a root > node > - pointed to by the initial forest. Despite being a oneliner, this method > is > - defined here as it references a method from fma_root_node. */ > - > -fma_forest * > -fma_node::get_forest () > -{ > - return this->m_root->get_forest (); > -} > - > -/* Return whether a node is a root node. */ > - > -bool > -fma_node::root_p () > -{ > - return this->m_root == this; > -} > - > -/* Dump information about the children of node FMA_NODE in forest FOREST. */ > - > -void > -fma_node::dump_info (ATTRIBUTE_UNUSED fma_forest *forest) > -{ > - struct du_chain *chain; > - std::list<fma_node *>::iterator fma_child; > - > - gcc_assert (dump_file); > - > - if (this->get_children ()->empty ()) > - return; > - > - fprintf (dump_file, "Instruction(s)"); > - for (chain = this->m_head->first; chain; chain = chain->next_use) > - { > - if (!is_fmul_fmac_insn (chain->insn, true)) > - continue; > - > - if (chain->loc != &SET_DEST (PATTERN (chain->insn))) > - continue; > - > - fprintf (dump_file, " %d", INSN_UID (chain->insn)); > - } > - > - fprintf (dump_file, " is(are) accumulator dependency of instructions"); > - for (fma_child = this->get_children ()->begin (); > - fma_child != this->get_children ()->end (); fma_child++) > - fprintf (dump_file, " %d", INSN_UID ((*fma_child)->m_insn)); > - fprintf (dump_file, "\n"); > -} > - > -/* Wrapper around fma_node::dump_info for use as parameter of function > pointer > - type in func_fma_steering::dfs. */ > - > -static void > -dump_tree_node_info (fma_forest *forest, fma_node *node) > -{ > - node->dump_info (forest); > -} > - > -/* Rename the destination register of a single FMUL or FMADD/FMSUB > instruction > - represented by FMA_NODE to a register that respect the target parity for > - FOREST or with same parity of the instruction represented by its parent > node > - if it has one. */ > - > -void > -fma_node::rename (fma_forest *forest) > -{ > - int cur_parity, target_parity; > - > - /* This is alternate root of a chain and thus has no children. It will be > - renamed when processing the canonical root for that chain. */ > - if (!this->m_head) > - return; > - > - target_parity = forest->get_target_parity (); > - if (this->m_parent) > - target_parity = this->m_parent->get_parity (); > - cur_parity = this->get_parity (); > - > - /* Rename if parity differs. */ > - if (cur_parity != target_parity) > - { > - rtx_insn *insn = this->m_insn; > - HARD_REG_SET unavailable; > - machine_mode mode; > - int reg; > - > - if (dump_file) > - { > - unsigned cur_dest_reg = this->m_head->regno; > - > - fprintf (dump_file, "FMA or FMUL at insn %d but destination " > - "register (%s) has different parity from expected to " > - "maximize FPU pipeline utilization\n", INSN_UID (insn), > - reg_names[cur_dest_reg]); > - } > - > - /* Don't clobber traceback for noreturn functions. */ > - CLEAR_HARD_REG_SET (unavailable); > - if (frame_pointer_needed) > - { > - add_to_hard_reg_set (&unavailable, Pmode, FRAME_POINTER_REGNUM); > - add_to_hard_reg_set (&unavailable, Pmode, HARD_FRAME_POINTER_REGNUM); > - } > - > - /* Exclude registers with wrong parity. */ > - mode = GET_MODE (SET_DEST (PATTERN (insn))); > - for (reg = cur_parity; reg < FIRST_PSEUDO_REGISTER; reg += 2) > - add_to_hard_reg_set (&unavailable, mode, reg); > - > - if (!rename_single_chain (this->m_head, &unavailable)) > - { > - if (dump_file) > - fprintf (dump_file, "Destination register of insn %d could not be " > - "renamed. Dependent FMA insns will use this parity from " > - "there on.\n", INSN_UID (insn)); > - } > - else > - cur_parity = target_parity; > - } > - > - forest->get_globals ()->update_balance (cur_parity); > -} > - > -/* Wrapper around fma_node::dump_info for use as parameter of function > pointer > - type in func_fma_steering::dfs. */ > - > -static void > -rename_fma_node (fma_forest *forest, fma_node *node) > -{ > - node->rename (forest); > -} > - > -fma_root_node::fma_root_node (func_fma_steering *globals, du_chain *chain, > - int id) : fma_node (this, chain) > -{ > - this->m_forest = new fma_forest (globals, this, id); > - this->m_forest->fma_node_created (this); > -} > - > -fma_forest * > -fma_root_node::get_forest () > -{ > - return this->m_forest; > -} > - > -void > -fma_root_node::set_forest (fma_forest *ref_forest) > -{ > - this->m_forest = ref_forest; > -} > - > -/* Dump information about the roots of forest FOREST. */ > - > -void > -fma_root_node::dump_info (fma_forest *forest) > -{ > - gcc_assert (dump_file); > - > - if (this == forest->get_roots ()->front ()) > - fprintf (dump_file, "Instruction(s) at root of forest #%d:", > - forest->get_id ()); > - fprintf (dump_file, " %d", INSN_UID (this->m_insn)); > - if (this == forest->get_roots ()->back ()) > - fprintf (dump_file, "\n"); > -} > - > -/* Wrapper around fma_root_node::dump_info for use as parameter of function > - pointer type in func_fma_steering::dfs. */ > - > -static void > -dump_tree_root_info (fma_forest *forest, fma_root_node *node) > -{ > - node->dump_info (forest); > -} > - > -func_fma_steering::func_fma_steering () : m_fpu_balance (0) > -{ > - this->m_insn_fma_head_map = new hash_map<rtx_insn *, fma_node *>; > - this->m_fma_forests.clear (); > - this->m_next_forest_id = 0; > -} > - > -func_fma_steering::~func_fma_steering () > -{ > - delete this->m_insn_fma_head_map; > -} > - > -int > -func_fma_steering::get_fpu_balance () > -{ > - return this->m_fpu_balance; > -} > - > -void > -func_fma_steering::remove_forest (fma_forest *forest) > -{ > - this->m_fma_forests.remove (forest); > -} > - > -/* Memorize the mapping of this instruction to its fma_node object and return > - whether such a mapping existed. */ > - > -bool > -func_fma_steering::put_node (fma_node *node) > -{ > - return this->m_insn_fma_head_map->put (node->get_insn (), node); > -} > - > -/* Update the current balance considering a node with the given PARITY. */ > - > -void > -func_fma_steering::update_balance (int parity) > -{ > - this->m_fpu_balance = parity ? this->m_fpu_balance + 1 > - : this->m_fpu_balance - 1; > -} > - > -/* Return whether an fma_node object exists for instruction INSN and, if not, > - allocate one in *RET. */ > - > -fma_node * > -func_fma_steering::get_fma_node (rtx_insn *insn) > -{ > - fma_node **fma_slot; > - > - fma_slot = this->m_insn_fma_head_map->get (insn); > - if (fma_slot) > - return *fma_slot; > - return NULL; > -} > - > -/* Allocate and initialize fma_node objects for the FMUL or FMADD/FMSUB > - instruction in CHAIN->insn and its dependent FMADD/FMSUB instructions, all > - part of FOREST. For the children, the associated head is left untouched > - (and thus null) as this function will be called again when considering the > - chain where they are def. For the parent, the chain is given in HEAD. */ > - > -void > -func_fma_steering::analyze_fma_fmul_insn (fma_forest *ref_forest, > - du_chain *chain, du_head_p head) > -{ > - fma_forest *forest; > - fma_node *node = this->get_fma_node (chain->insn); > - > - /* This is a root node. */ > - if (!node) > - { > - fma_root_node *root_node; > - > - root_node = new fma_root_node (this, chain, this->m_next_forest_id++); > - forest = root_node->get_forest (); > - node = root_node; > - > - /* Until proved otherwise, assume this root is not part of an existing > - forest and thus add its forest to the list of forests. */ > - this->m_fma_forests.push_back (forest); > - } > - else > - forest = node->get_forest (); > - > - node->set_head (head); > - > - /* fma_node is part of a chain with several defs, one of them having > already > - been processed. The root of that already processed def is the canonical > - one and the root of fma_node is added to its forest. No need to process > - the children nodes as they were already processed when the other def was > - processed. */ > - if (ref_forest) > - { > - ref_forest->merge_forest (forest); > - return; > - } > - > - for (chain = head->first; chain; chain = chain->next_use) > - { > - fma_node *child_fma; > - rtx fma_rtx, *accum_rtx_p; > - > - if (!is_fmul_fmac_insn (chain->insn, false)) > - continue; > - > - /* Get FMA rtx. */ > - fma_rtx = SET_SRC (PATTERN (chain->insn)); > - /* FMA is negated. */ > - if (GET_CODE (fma_rtx) == NEG) > - fma_rtx = XEXP (fma_rtx, 0); > - /* Get accumulator rtx. */ > - accum_rtx_p = &XEXP (fma_rtx, 2); > - /* Accumulator is negated. */ > - if (!REG_P (*accum_rtx_p)) > - accum_rtx_p = &XEXP (*accum_rtx_p, 0); > - > - /* This du_chain structure is not for the accumulator register. */ > - if (accum_rtx_p != chain->loc) > - continue; > - > - /* If object already created, this is a loop carried dependency. We > - don't include this object in the children as we want trees for > - rename_fma_trees to not be an infinite loop. */ > - if (this->get_fma_node (chain->insn)) > - continue; > - > - child_fma = new fma_node (node, chain); > - > - /* Memorize the mapping of this instruction to its fma_node object > - as it will be processed for the chain starting at its destination > - register later. */ > - > - /* Link to siblings. */ > - node->add_child (child_fma); > - } > -} > - > -/* Perform a depth-first search of the forests of fma_node in > - THIS->m_fma_forests, calling PROCESS_FOREST () on each fma_forest object > in > - THIS->m_fma_forests list, PROCESS_ROOT () on each tree root and > - PROCESS_NODE () on each node. If FREE is true, free all std::list in the > - same dfs. */ > - > -void > -func_fma_steering::dfs (void (*process_forest) (fma_forest *), > - void (*process_root) (fma_forest *, fma_root_node *), > - void (*process_node) (fma_forest *, fma_node *), > - bool free) > -{ > - auto_vec<fma_node *> to_process; > - auto_vec<fma_node *> to_free; > - std::list<fma_forest *>::iterator forest_iter; > - > - /* For each forest. */ > - for (forest_iter = this->m_fma_forests.begin (); > - forest_iter != this->m_fma_forests.end (); ++forest_iter) > - { > - std::list<fma_root_node *>::iterator root_iter; > - > - if (process_forest) > - process_forest (*forest_iter); > - > - /* For each tree root in this forest. */ > - for (root_iter = (*forest_iter)->get_roots ()->begin (); > - root_iter != (*forest_iter)->get_roots ()->end (); ++root_iter) > - { > - if (process_root) > - process_root (*forest_iter, *root_iter); > - to_process.safe_push (*root_iter); > - } > - > - /* For each tree node in this forest. */ > - while (!to_process.is_empty ()) > - { > - fma_node *node; > - std::list<fma_node *>::iterator child_iter; > - > - node = to_process.pop (); > - > - if (process_node) > - process_node (*forest_iter, node); > - > - for (child_iter = node->get_children ()->begin (); > - child_iter != node->get_children ()->end (); ++child_iter) > - to_process.safe_push (*child_iter); > - > - /* Defer freeing so that the process_node callback can access the > - parent and children of the node being processed. */ > - if (free) > - to_free.safe_push (node); > - } > - > - if (free) > - { > - delete *forest_iter; > - > - while (!to_free.is_empty ()) > - { > - fma_node *node = to_free.pop (); > - if (node->root_p ()) > - delete static_cast<fma_root_node *> (node); > - else > - delete node; > - } > - } > - } > -} > - > -/* Build the dependency trees of FMUL and FMADD/FMSUB instructions. */ > - > -void > -func_fma_steering::analyze () > -{ > - int i, n_blocks, *bb_dfs_preorder; > - basic_block bb; > - rtx_insn *insn; > - > - bb_dfs_preorder = XNEWVEC (int, last_basic_block_for_fn (cfun)); > - n_blocks = pre_and_rev_post_order_compute (bb_dfs_preorder, NULL, false); > - > - /* Browse the graph of basic blocks looking for FMUL or FMADD/FMSUB > - instructions. */ > - for (i = 0; i < n_blocks; i++) > - { > - bb = BASIC_BLOCK_FOR_FN (cfun, bb_dfs_preorder[i]); > - FOR_BB_INSNS (bb, insn) > - { > - operand_rr_info *dest_op_info; > - struct du_chain *chain = NULL; > - unsigned dest_regno; > - fma_forest *forest = NULL; > - du_head_p head = NULL; > - int i; > - > - if (!is_fmul_fmac_insn (insn, true)) > - continue; > - > - /* Search the chain where this instruction is (one of) the root. */ > - dest_op_info = insn_rr[INSN_UID (insn)].op_info; > - dest_regno = REGNO (SET_DEST (PATTERN (insn))); > - for (i = 0; i < dest_op_info->n_chains; i++) > - { > - /* The register tracked by this chain does not match the > - destination register of insn. */ > - if (dest_op_info->heads[i]->regno != dest_regno) > - continue; > - > - head = dest_op_info->heads[i]; > - /* The chain was merged in another, find the new head. */ > - if (!head->first) > - head = regrename_chain_from_id (head->id); > - > - /* Search the chain element for this instruction and, if another > - FMUL or FMADD/FMSUB instruction was already processed, note > - the forest of its tree. */ > - forest = NULL; > - for (chain = head->first; chain; chain = chain->next_use) > - { > - fma_node **fma_slot; > - > - if (!is_fmul_fmac_insn (chain->insn, true)) > - continue; > - > - /* This is a use, continue. */ > - if (chain->loc != &SET_DEST (PATTERN (chain->insn))) > - continue; > - > - if (chain->insn == insn) > - break; > - > - fma_slot = this->m_insn_fma_head_map->get (chain->insn); > - if (fma_slot && (*fma_slot)->get_children ()) > - forest = (*fma_slot)->get_forest (); > - } > - if (chain) > - break; > - } > - > - /* Due to implementation of regrename, dest register can slip away > - from regrename's analysis. As a result, there is no chain for > - the destination register of insn. We simply skip the insn even > - it is a fmul/fmac instruction. This can happen when the dest > - register is also a source register of insn and one of the below > - conditions is satisfied: > - 1) the source reg is setup in larger mode than this insn; > - 2) the source reg is uninitialized; > - 3) the source reg is passed in as parameter. */ > - if (i < dest_op_info->n_chains) > - this->analyze_fma_fmul_insn (forest, chain, head); > - } > - } > - free (bb_dfs_preorder); > - > - if (dump_file) > - this->dfs (dump_forest_info, dump_tree_root_info, dump_tree_node_info, > - false); > -} > - > -/* Perform the renaming of all chains with FMUL or FMADD/FMSUB involved with > - the objective of keeping FPU pipeline balanced in term of instructions and > - having FMADD/FMSUB with dependencies on previous FMUL or FMADD/FMSUB be > - scheduled on the same pipeline. */ > - > -void > -func_fma_steering::rename_fma_trees () > -{ > - this->dfs (dispatch_forest, NULL, rename_fma_node, true); > - > - if (dump_file && !this->m_fma_forests.empty ()) > - { > - fprintf (dump_file, "Function %s has ", current_function_name ()); > - if (this->m_fpu_balance == 0) > - fprintf (dump_file, "perfect balance of FMUL/FMA chains between the " > - "two FPU pipelines\n"); > - else if (this->m_fpu_balance > 0) > - fprintf (dump_file, "%d more FMUL/FMA chains scheduled on the second " > - "FPU pipeline\n", this->m_fpu_balance); > - else /* this->m_fpu_balance < 0 */ > - fprintf (dump_file, "%d more FMUL/FMA chains scheduled on the first " > - "FPU pipeline\n", - this->m_fpu_balance); > - } > -} > - > -/* Execute FMA steering pass. */ > - > -void > -func_fma_steering::execute_fma_steering () > -{ > - df_set_flags (DF_LR_RUN_DCE); > - df_note_add_problem (); > - df_analyze (); > - df_set_flags (DF_DEFER_INSN_RESCAN); > - > - regrename_init (true); > - regrename_analyze (NULL); > - this->analyze (); > - this->rename_fma_trees (); > - regrename_finish (); > -} > - > -const pass_data pass_data_fma_steering = > -{ > - RTL_PASS, /* type */ > - "fma_steering", /* name */ > - OPTGROUP_NONE, /* optinfo_flags */ > - TV_NONE, /* tv_id */ > - 0, /* properties_required */ > - 0, /* properties_provided */ > - 0, /* properties_destroyed */ > - 0, /* todo_flags_start */ > - TODO_df_finish, /* todo_flags_finish */ > -}; > - > -class pass_fma_steering : public rtl_opt_pass > -{ > -public: > - pass_fma_steering (gcc::context *ctxt) > - : rtl_opt_pass (pass_data_fma_steering, ctxt) > - {} > - > - /* opt_pass methods: */ > - virtual bool gate (function *) > - { > - return (aarch64_tune_params.extra_tuning_flags > - & AARCH64_EXTRA_TUNE_RENAME_FMA_REGS) > - && optimize >= 2; > - } > - > - virtual unsigned int execute (function *) > - { > - func_fma_steering *fma_steering = new func_fma_steering; > - fma_steering->execute_fma_steering (); > - delete fma_steering; > - return 0; > - } > - > -}; // class pass_fma_steering > - > -/* Create a new fma steering pass instance. */ > - > -rtl_opt_pass * > -make_pass_fma_steering (gcc::context *ctxt) > -{ > - return new pass_fma_steering (ctxt); > -} > diff --git a/gcc/config/aarch64/t-aarch64 b/gcc/config/aarch64/t-aarch64 > index > 5aa7780994834a1ae3424b23e77679d7e1e187ed..0bde167cc043f358fa7131504a44eb185f1864aa > 100644 > --- a/gcc/config/aarch64/t-aarch64 > +++ b/gcc/config/aarch64/t-aarch64 > @@ -151,15 +151,6 @@ aarch64-d.o: $(srcdir)/config/aarch64/aarch64-d.cc > > PASSES_EXTRA += $(srcdir)/config/aarch64/aarch64-passes.def > > -cortex-a57-fma-steering.o: > $(srcdir)/config/aarch64/cortex-a57-fma-steering.cc \ > - $(CONFIG_H) $(SYSTEM_H) $(TM_H) $(REGS_H) insn-config.h $(RTL_BASE_H) \ > - dominance.h cfg.h cfganal.h $(BASIC_BLOCK_H) $(INSN_ATTR_H) $(RECOG_H) \ > - output.h hash-map.h $(DF_H) $(OBSTACK_H) $(TARGET_H) $(RTL_H) \ > - $(CONTEXT_H) $(TREE_PASS_H) regrename.h \ > - $(srcdir)/config/aarch64/aarch64-protos.h > - $(COMPILER) -c $(ALL_COMPILERFLAGS) $(ALL_CPPFLAGS) $(INCLUDES) \ > - $(srcdir)/config/aarch64/cortex-a57-fma-steering.cc > - > aarch64-speculation.o: $(srcdir)/config/aarch64/aarch64-speculation.cc \ > $(CONFIG_H) \ > $(SYSTEM_H) \ > diff --git a/gcc/config/aarch64/tuning_models/cortexa57.h > b/gcc/config/aarch64/tuning_models/cortexa57.h > index > 8da7fa9d80df983c640c1870d2f4de6c35808760..8df67f4c512e3e3f38d92d4e18a0763ac9d23648 > 100644 > --- a/gcc/config/aarch64/tuning_models/cortexa57.h > +++ b/gcc/config/aarch64/tuning_models/cortexa57.h > @@ -99,7 +99,7 @@ static const struct tune_params cortexa57_tunings = > 2, /* min_div_recip_mul_df. */ > 0, /* max_case_values. */ > tune_params::AUTOPREFETCHER_WEAK, /* autoprefetcher_model. */ > - (AARCH64_EXTRA_TUNE_RENAME_FMA_REGS), /* tune_flags. */ > + (AARCH64_EXTRA_TUNE_NONE), /* tune_flags. */ > &generic_prefetch_tune, > AARCH64_LDP_STP_POLICY_ALWAYS, /* ldp_policy_model. */ > AARCH64_LDP_STP_POLICY_ALWAYS /* stp_policy_model. */
