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 55A243858CDA for ; Wed, 26 Apr 2023 08:13:36 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 55A243858CDA 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 7820021A04; Wed, 26 Apr 2023 08:13:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1682496815; 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=iQ87i67mEBAARcvlF0j8fKwR7M+ra9k/tFKmsjL2zQM=; b=JZOgcgkwy6ytjAlDmvT9gjFHrxJZ0o4Db+nB0sc7+NDdhZ0Sj0NdU/NCSZPdhuC6JdgnmZ QxuEWuwmK7SqqQSfyFoKIAo5yEJys6v6yyPpE0sg17/ZBp1l/g3uC2OKXpxkbDLMEwPEOM MqCSy7TNxDs0VxV/ahRX4IoFl6hF7Fw= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1682496815; 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=iQ87i67mEBAARcvlF0j8fKwR7M+ra9k/tFKmsjL2zQM=; b=6QHV6pyqZd5oVNZ9fOYCP26GlaCQUnYUER47mc3z6Ae5dx5RkB6I0gYWmPjd6OufpTjKjQ xrxkosYOQeAVp5AA== 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 44F802C141; Wed, 26 Apr 2023 08:13:35 +0000 (UTC) Date: Wed, 26 Apr 2023 08:13:35 +0000 (UTC) From: Richard Biener To: Juzhe-Zhong cc: gcc-patches@gcc.gnu.org, richard.sandiford@arm.com, rep.dot.nop@gmail.com Subject: Re: [PATCH V3] VECT: Add decrement IV iteration loop control by variable amount support In-Reply-To: <20230426035929.330213-1-juzhe.zhong@rivai.ai> Message-ID: References: <20230426035929.330213-1-juzhe.zhong@rivai.ai> 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=-11.0 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,GIT_PATCH_0,SPF_HELO_NONE,SPF_PASS,TXREP,T_SCC_BODY_TEXT_LINE 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 Wed, 26 Apr 2023, juzhe.zhong@rivai.ai wrote: > From: Juzhe-Zhong > > This patch address all comments from Richard && Bernhard. > Fix all codes following their comments: > > 1. Remove ifn-specific handling of WHILE_LEN, so there is no change > in internal-fn.cc in this patch. > > 2. Add comments for changing interface of "create_iv" function. > > 3. Reorder the CODE of interface "create_iv", make CODE argument between > base and step. > > 4. Fix the misleading and incorrect comments of "vect_set_loop_controls_by_while_len". > > 5. remove redundant "enum" of "create_iv" interface and function. > > Feel free to comment if I meet something. > > Thanks. > > gcc/ChangeLog: > > * cfgloopmanip.cc (create_empty_loop_on_edge): Adapt create_iv interface change. > * doc/md.texi: Add WHILE_LEN pattern description. > * gimple-loop-interchange.cc (tree_loop_interchange::map_inductions_to_loop): Adapt create_iv interface change. > * internal-fn.def (WHILE_LEN): New ifn. > * optabs.def (OPTAB_D): New optab pattern. > * tree-ssa-loop-ivcanon.cc (create_canonical_iv): Adapt create_iv interface change. > * tree-ssa-loop-ivopts.cc (create_new_iv): Ditto. > * tree-ssa-loop-manip.cc (create_iv): Ditto. > (tree_transform_and_unroll_loop): Ditto. > (canonicalize_loop_ivs): Ditto. > * tree-ssa-loop-manip.h (create_iv): Add code in the interface. > * tree-vect-data-refs.cc (vect_create_data_ref_ptr): New function. > * tree-vect-loop-manip.cc (vect_set_loop_controls_directly): Add decrementing IV loop control support. > (vect_set_loop_controls_by_while_len): New function. > (vect_set_loop_condition_partial_vectors): Add decrementing IV loop control support. > (vect_set_loop_condition_normal): Adapt create_iv interface change. > * tree-vect-loop.cc (vect_create_epilog_for_reduction): Ditto. > (vect_get_loop_len): Adapt SLP auto-vectorization for WHILE_LEN. > * tree-vect-stmts.cc (get_while_len_data_ref_ptr): New function. > (vectorizable_store): Add WHILE_LEN data reference pointer IV. > (vectorizable_load): Ditto. > * tree-vectorizer.h (vect_get_loop_len): Add new arguments to interface. > > > --- > gcc/cfgloopmanip.cc | 2 +- > gcc/doc/md.texi | 34 ++++ > gcc/gimple-loop-interchange.cc | 2 +- > gcc/internal-fn.def | 1 + > gcc/optabs.def | 1 + > gcc/tree-ssa-loop-ivcanon.cc | 2 +- > gcc/tree-ssa-loop-ivopts.cc | 2 +- > gcc/tree-ssa-loop-manip.cc | 18 ++- > gcc/tree-ssa-loop-manip.h | 4 +- > gcc/tree-vect-data-refs.cc | 8 +- > gcc/tree-vect-loop-manip.cc | 280 +++++++++++++++++++++++++++++++-- > gcc/tree-vect-loop.cc | 29 +++- > gcc/tree-vect-stmts.cc | 95 ++++++++++- > gcc/tree-vectorizer.h | 4 +- > 14 files changed, 445 insertions(+), 37 deletions(-) > > diff --git a/gcc/cfgloopmanip.cc b/gcc/cfgloopmanip.cc > index 0e3ad8ed742..6e09dcbb0b1 100644 > --- a/gcc/cfgloopmanip.cc > +++ b/gcc/cfgloopmanip.cc > @@ -826,7 +826,7 @@ create_empty_loop_on_edge (edge entry_edge, > } > > gsi = gsi_last_bb (loop_header); > - create_iv (initial_value, stride, iv, loop, &gsi, false, > + create_iv (initial_value, PLUS_EXPR, stride, iv, loop, &gsi, false, > iv_before, iv_after); > > /* Insert loop exit condition. */ > diff --git a/gcc/doc/md.texi b/gcc/doc/md.texi > index 07bf8bdebff..307d3c407d8 100644 > --- a/gcc/doc/md.texi > +++ b/gcc/doc/md.texi > @@ -4965,6 +4965,40 @@ for (i = 1; i < operand3; i++) > operand0[i] = operand0[i - 1] && (operand1 + i < operand2); > @end smallexample > > +@cindex @code{while_len@var{m}@var{n}} instruction pattern > +@item @code{while_len@var{m}@var{n}} > +Set operand 0 to the number of active elements in vector will be updated value. > +operand 1 is the total elements need to be updated value. > +operand 2 is the vectorization factor. > +The value of operand 0 is target dependent and flexible in each iteration. I can't really parse the above - there's information missing on what the modes M and N are and how they relate. I suppose you take the while_ult description and mangle it to the while_len semantics? > +The operation of this pattern can be: > + > +@smallexample > +Case 1: > +operand0 = MIN (operand1, operand2); > +operand2 can be const_poly_int or poly_int related to vector mode size. > +Some target like RISC-V has a standalone instruction to get MIN (n, MODE SIZE) so > +that we can reduce a use of general purpose register. > + > +In this case, only the last iteration of the loop is partial iteration. > +@end smallexample > + > +@smallexample > +Case 2: > +if (operand1 <= operand2) > + operand0 = operand1; > +else if (operand1 < 2 * operand2) > + operand0 = IN_RANGE (ceil (operand1 / 2), operand2); > +else > + operand0 = operand2; > + > +This case will evenly distribute work over the last 2 iterations of a stripmine loop. > +@end smallexample > + > +The output of this pattern is not only used as IV of loop control counter, but also > +is used as the IV of address calculation with multiply/shift operation. This allow > +us dynamic adjust the number of elements is processed in each iteration of the loop. > + > @cindex @code{check_raw_ptrs@var{m}} instruction pattern > @item @samp{check_raw_ptrs@var{m}} > Check whether, given two pointers @var{a} and @var{b} and a length @var{len}, > diff --git a/gcc/gimple-loop-interchange.cc b/gcc/gimple-loop-interchange.cc > index 1b77bfd46b2..e5590374e59 100644 > --- a/gcc/gimple-loop-interchange.cc > +++ b/gcc/gimple-loop-interchange.cc > @@ -1185,7 +1185,7 @@ tree_loop_interchange::map_inductions_to_loop (loop_cand &src, loop_cand &tgt) > tree var_before, var_after; > tree base = unshare_expr (iv->init_expr); > tree step = unshare_expr (iv->step); > - create_iv (base, step, SSA_NAME_VAR (iv->var), > + create_iv (base, PLUS_EXPR, step, SSA_NAME_VAR (iv->var), > tgt.m_loop, &incr_pos, false, &var_before, &var_after); > bitmap_set_bit (m_dce_seeds, SSA_NAME_VERSION (var_before)); > bitmap_set_bit (m_dce_seeds, SSA_NAME_VERSION (var_after)); > diff --git a/gcc/internal-fn.def b/gcc/internal-fn.def > index 7fe742c2ae7..9f7269f8f60 100644 > --- a/gcc/internal-fn.def > +++ b/gcc/internal-fn.def > @@ -153,6 +153,7 @@ DEF_INTERNAL_OPTAB_FN (VEC_SET, 0, vec_set, vec_set) > DEF_INTERNAL_OPTAB_FN (LEN_STORE, 0, len_store, len_store) > > DEF_INTERNAL_OPTAB_FN (WHILE_ULT, ECF_CONST | ECF_NOTHROW, while_ult, while) > +DEF_INTERNAL_OPTAB_FN (WHILE_LEN, ECF_CONST | ECF_NOTHROW, while_len, binary) > DEF_INTERNAL_OPTAB_FN (CHECK_RAW_PTRS, ECF_CONST | ECF_NOTHROW, > check_raw_ptrs, check_ptrs) > DEF_INTERNAL_OPTAB_FN (CHECK_WAR_PTRS, ECF_CONST | ECF_NOTHROW, > diff --git a/gcc/optabs.def b/gcc/optabs.def > index 695f5911b30..f5938bd2c24 100644 > --- a/gcc/optabs.def > +++ b/gcc/optabs.def > @@ -476,3 +476,4 @@ OPTAB_DC (vec_series_optab, "vec_series$a", VEC_SERIES) > OPTAB_D (vec_shl_insert_optab, "vec_shl_insert_$a") > OPTAB_D (len_load_optab, "len_load_$a") > OPTAB_D (len_store_optab, "len_store_$a") > +OPTAB_D (while_len_optab, "while_len$a") But your description mentions two modes? > diff --git a/gcc/tree-ssa-loop-ivcanon.cc b/gcc/tree-ssa-loop-ivcanon.cc > index 9f72d534b7c..6941d0a4d1d 100644 > --- a/gcc/tree-ssa-loop-ivcanon.cc > +++ b/gcc/tree-ssa-loop-ivcanon.cc > @@ -113,7 +113,7 @@ create_canonical_iv (class loop *loop, edge exit, tree niter, > niter, > build_int_cst (type, 1)); > incr_at = gsi_last_bb (in->src); > - create_iv (niter, > + create_iv (niter, PLUS_EXPR, > build_int_cst (type, -1), > NULL_TREE, loop, > &incr_at, false, var_before, &var); > diff --git a/gcc/tree-ssa-loop-ivopts.cc b/gcc/tree-ssa-loop-ivopts.cc > index 0dd47910f97..a7377f91f9e 100644 > --- a/gcc/tree-ssa-loop-ivopts.cc > +++ b/gcc/tree-ssa-loop-ivopts.cc > @@ -7267,7 +7267,7 @@ create_new_iv (struct ivopts_data *data, struct iv_cand *cand) > > base = unshare_expr (cand->iv->base); > > - create_iv (base, unshare_expr (cand->iv->step), > + create_iv (base, PLUS_EXPR, unshare_expr (cand->iv->step), > cand->var_before, data->current_loop, > &incr_pos, after, &cand->var_before, &cand->var_after); > } > diff --git a/gcc/tree-ssa-loop-manip.cc b/gcc/tree-ssa-loop-manip.cc > index a52277abdbf..b0d254b0c89 100644 > --- a/gcc/tree-ssa-loop-manip.cc > +++ b/gcc/tree-ssa-loop-manip.cc > @@ -47,7 +47,9 @@ along with GCC; see the file COPYING3. If not see > so that we can free them all at once. */ > static bitmap_obstack loop_renamer_obstack; > > -/* Creates an induction variable with value BASE + STEP * iteration in LOOP. > +/* Creates an induction variable with value BASE (+/-) STEP * iteration in LOOP. > + If CODE is PLUS_EXPR, the induction variable is BASE + STEP * iteration. > + If CODE is MINUS_EXPR, the induction variable is BASE - STEP * iteration. > It is expected that neither BASE nor STEP are shared with other expressions > (unless the sharing rules allow this). Use VAR as a base var_decl for it > (if NULL, a new temporary will be created). The increment will occur at > @@ -57,8 +59,8 @@ static bitmap_obstack loop_renamer_obstack; > VAR_AFTER (unless they are NULL). */ > > void > -create_iv (tree base, tree step, tree var, class loop *loop, > - gimple_stmt_iterator *incr_pos, bool after, > +create_iv (tree base, tree_code code, tree step, tree var, > + class loop *loop, gimple_stmt_iterator *incr_pos, bool after, > tree *var_before, tree *var_after) > { > gassign *stmt; > @@ -66,7 +68,9 @@ create_iv (tree base, tree step, tree var, class loop *loop, > tree initial, step1; > gimple_seq stmts; > tree vb, va; > - enum tree_code incr_op = PLUS_EXPR; > + /* The code can only be PLUS_EXPR or MINUS_EXPR. */ > + gcc_assert (code == PLUS_EXPR || code == MINUS_EXPR); Ah, you already have an assert. > + tree_code incr_op = code; If you name the parameter incr_op you can get rid of this assignment. > edge pe = loop_preheader_edge (loop); > > if (var != NULL_TREE) > @@ -1368,7 +1372,7 @@ tree_transform_and_unroll_loop (class loop *loop, unsigned factor, > tree ctr_before, ctr_after; > gimple_stmt_iterator bsi = gsi_last_nondebug_bb (new_exit->src); > exit_if = as_a (gsi_stmt (bsi)); > - create_iv (exit_base, exit_step, NULL_TREE, loop, > + create_iv (exit_base, PLUS_EXPR, exit_step, NULL_TREE, loop, > &bsi, false, &ctr_before, &ctr_after); > gimple_cond_set_code (exit_if, exit_cmp); > gimple_cond_set_lhs (exit_if, ctr_after); > @@ -1583,8 +1587,8 @@ canonicalize_loop_ivs (class loop *loop, tree *nit, bool bump_in_latch) > gsi = gsi_last_bb (loop->latch); > else > gsi = gsi_last_nondebug_bb (loop->header); > - create_iv (build_int_cst_type (type, 0), build_int_cst (type, 1), NULL_TREE, > - loop, &gsi, bump_in_latch, &var_before, NULL); > + create_iv (build_int_cst_type (type, 0), PLUS_EXPR, build_int_cst (type, 1), > + NULL_TREE, loop, &gsi, bump_in_latch, &var_before, NULL); > > rewrite_all_phi_nodes_with_iv (loop, var_before); > > diff --git a/gcc/tree-ssa-loop-manip.h b/gcc/tree-ssa-loop-manip.h > index d49273a3987..bda09f51d56 100644 > --- a/gcc/tree-ssa-loop-manip.h > +++ b/gcc/tree-ssa-loop-manip.h > @@ -22,8 +22,8 @@ along with GCC; see the file COPYING3. If not see > > typedef void (*transform_callback)(class loop *, void *); > > -extern void create_iv (tree, tree, tree, class loop *, gimple_stmt_iterator *, > - bool, tree *, tree *); > +extern void create_iv (tree, tree_code, tree, tree, class loop *, > + gimple_stmt_iterator *, bool, tree *, tree *); > extern void rewrite_into_loop_closed_ssa (bitmap, unsigned); > extern void verify_loop_closed_ssa (bool, class loop * = NULL); > > diff --git a/gcc/tree-vect-data-refs.cc b/gcc/tree-vect-data-refs.cc > index c03ffb3aaf1..355ede5c0d9 100644 > --- a/gcc/tree-vect-data-refs.cc > +++ b/gcc/tree-vect-data-refs.cc > @@ -5101,7 +5101,7 @@ vect_create_data_ref_ptr (vec_info *vinfo, stmt_vec_info stmt_info, > > standard_iv_increment_position (loop, &incr_gsi, &insert_after); > > - create_iv (aggr_ptr_init, > + create_iv (aggr_ptr_init, PLUS_EXPR, > fold_convert (aggr_ptr_type, iv_step), > aggr_ptr, loop, &incr_gsi, insert_after, > &indx_before_incr, &indx_after_incr); > @@ -5131,9 +5131,9 @@ vect_create_data_ref_ptr (vec_info *vinfo, stmt_vec_info stmt_info, > { > standard_iv_increment_position (containing_loop, &incr_gsi, > &insert_after); > - create_iv (aptr, fold_convert (aggr_ptr_type, DR_STEP (dr)), aggr_ptr, > - containing_loop, &incr_gsi, insert_after, &indx_before_incr, > - &indx_after_incr); > + create_iv (aptr, PLUS_EXPR, fold_convert (aggr_ptr_type, DR_STEP (dr)), > + aggr_ptr, containing_loop, &incr_gsi, insert_after, > + &indx_before_incr, &indx_after_incr); > incr = gsi_stmt (incr_gsi); > > /* Copy the points-to information if it exists. */ > diff --git a/gcc/tree-vect-loop-manip.cc b/gcc/tree-vect-loop-manip.cc > index f60fa50e8f4..6973314adb5 100644 > --- a/gcc/tree-vect-loop-manip.cc > +++ b/gcc/tree-vect-loop-manip.cc > @@ -468,8 +468,9 @@ vect_set_loop_controls_directly (class loop *loop, loop_vec_info loop_vinfo, > gimple_stmt_iterator incr_gsi; > bool insert_after; > standard_iv_increment_position (loop, &incr_gsi, &insert_after); > - create_iv (build_int_cst (iv_type, 0), nitems_step, NULL_TREE, loop, > - &incr_gsi, insert_after, &index_before_incr, &index_after_incr); > + create_iv (build_int_cst (iv_type, 0), PLUS_EXPR, nitems_step, NULL_TREE, > + loop, &incr_gsi, insert_after, &index_before_incr, > + &index_after_incr); > > tree zero_index = build_int_cst (compare_type, 0); > tree test_index, test_limit, first_limit; > @@ -682,6 +683,260 @@ vect_set_loop_controls_directly (class loop *loop, loop_vec_info loop_vinfo, > return next_ctrl; > } > > +/* Helper for vect_set_loop_condition_partial_vectors. Generate definitions > + for all the rgroup controls in RGC and return a control that is nonzero > + when the loop needs to iterate. Add any new preheader statements to > + PREHEADER_SEQ. Use LOOP_COND_GSI to insert code before the exit gcond. > + > + RGC belongs to loop LOOP. The loop originally iterated NITERS > + times and has been vectorized according to LOOP_VINFO. > + > + Unlike vect_set_loop_controls_directly which is iterating from 0-based IV > + to TEST_LIMIT - bias. > + > + In vect_set_loop_controls_by_while_len, we are iterating from start at > + IV = TEST_LIMIT - bias and keep subtract IV by the length calculated by > + IFN_WHILE_LEN pattern. > + > + 1. Single rgroup, the Gimple IR should be: > + > + # vectp_B.6_8 = PHI > + # vectp_B.8_16 = PHI > + # vectp_A.11_19 = PHI > + # vectp_A.13_22 = PHI > + # ivtmp_26 = PHI > + _28 = .WHILE_LEN (ivtmp_26, POLY_INT_CST [4, 4]); > + ivtmp_15 = _28 * 4; > + vect__1.10_18 = .LEN_LOAD (vectp_B.8_16, 128B, _28, 0); > + _1 = B[i_10]; > + .LEN_STORE (vectp_A.13_22, 128B, _28, vect__1.10_18, 0); > + i_7 = i_10 + 1; > + vectp_B.8_17 = vectp_B.8_16 + ivtmp_15; > + vectp_A.13_23 = vectp_A.13_22 + ivtmp_15; > + ivtmp_27 = ivtmp_26 - _28; > + if (ivtmp_27 != 0) > + goto ; [83.33%] > + else > + goto ; [16.67%] > + > + Note: We use the outcome of .WHILE_LEN to adjust both loop control IV and > + data reference pointer IV. > + > + 1). The result of .WHILE_LEN: > + _28 = .WHILE_LEN (ivtmp_26, POLY_INT_CST [4, 4]); > + The _28 is not necessary to be VF in any iteration, instead, we allow > + _28 to be any value as long as it it <= VF. Such flexible WHILE_LEN "it is", but I don't really understand what you are trying to say? Is it that loop control cannot be implemented as if (_28 != POLY_INT_CST [4, 4]) next iteration will be the last; but the result can only be used to decrement the remaining scalar iterations? That is, .WHILE_LEN (a, b) doesn't actually subtract 'b' but may choose to subtract any value in [1, b]? How can this work when the vectorizer "knows" that 'b' covers two vectors and thus it emits two vector stmts? > + pattern allows target have various flexible optimizations in vector > + loop iterations. Target like RISC-V has special application vector > + length calculation instruction which will distribute even workload > + in the last 2 iterations. > + > + Other example is that we can allow even generate _28 <= VF / 2 so > + that some machine can run vector codes in low power mode. > + > + 2). Loop control IV: > + ivtmp_27 = ivtmp_26 - _28; > + if (ivtmp_27 != 0) > + goto ; [83.33%] > + else > + goto ; [16.67%] > + > + This is the saturating-subtraction towards zero, the outcome of > + .WHILE_LEN wil make ivtmp_27 never underflow zero. So it's not actually saturating. The saturating operation is done by .WHILE_LEN? > + 3). Data reference pointer IV: > + ivtmp_15 = _28 * 4; > + vectp_B.8_17 = vectp_B.8_16 + ivtmp_15; > + vectp_A.13_23 = vectp_A.13_22 + ivtmp_15; > + > + The pointer IV is adjusted accurately according to the .WHILE_LEN. Note that this will be bad for IVOPTs, it would be _way_ better if the increment were (poly-)constant. For powerpc this would mean complex addressing modes cannot be used (not sure if they have those). > + 2. Multiple rgroup, the Gimple IR should be: > + > + # i_23 = PHI > + # vectp_f.8_51 = PHI > + # vectp_d.10_59 = PHI > + # ivtmp_70 = PHI > + # ivtmp_73 = PHI > + _72 = MIN_EXPR ; > + _75 = MIN_EXPR ; > + _1 = i_23 * 2; > + _2 = (long unsigned int) _1; > + _3 = _2 * 2; > + _4 = f_15(D) + _3; > + _5 = _2 + 1; > + _6 = _5 * 2; > + _7 = f_15(D) + _6; > + .LEN_STORE (vectp_f.8_51, 128B, _75, { 1, 2, 1, 2, 1, 2, 1, 2 }, 0); > + vectp_f.8_56 = vectp_f.8_51 + 16; > + .LEN_STORE (vectp_f.8_56, 128B, _72, { 1, 2, 1, 2, 1, 2, 1, 2 }, 0); > + _8 = (long unsigned int) i_23; > + _9 = _8 * 4; > + _10 = d_18(D) + _9; > + _61 = _75 / 2; > + .LEN_STORE (vectp_d.10_59, 128B, _61, { 3, 3, 3, 3 }, 0); > + vectp_d.10_63 = vectp_d.10_59 + 16; > + _64 = _72 / 2; > + .LEN_STORE (vectp_d.10_63, 128B, _64, { 3, 3, 3, 3 }, 0); > + i_20 = i_23 + 1; > + vectp_f.8_52 = vectp_f.8_56 + 16; > + vectp_d.10_60 = vectp_d.10_63 + 16; > + ivtmp_74 = ivtmp_73 - _75; > + ivtmp_71 = ivtmp_70 - _72; > + if (ivtmp_74 != 0) > + goto ; [83.33%] > + else > + goto ; [16.67%] > + > + Note: We DO NOT use .WHILE_LEN in SLP auto-vectorization for multiple > + rgroups. Instead, we use MIN_EXPR to guarantee we always use VF as the > + iteration amount for mutiple rgroups. I see. I wonder if it makes sense to leave .WHILE_LEN aside for a start, the above scheme should also work for single rgroups, no? > + The analysis of the flow of multiple rgroups: > + _72 = MIN_EXPR ; > + _75 = MIN_EXPR ; > + ... > + .LEN_STORE (vectp_f.8_51, 128B, _75, { 1, 2, 1, 2, 1, 2, 1, 2 }, 0); > + vectp_f.8_56 = vectp_f.8_51 + 16; > + .LEN_STORE (vectp_f.8_56, 128B, _72, { 1, 2, 1, 2, 1, 2, 1, 2 }, 0); > + ... > + _61 = _75 / 2; > + .LEN_STORE (vectp_d.10_59, 128B, _61, { 3, 3, 3, 3 }, 0); > + vectp_d.10_63 = vectp_d.10_59 + 16; > + _64 = _72 / 2; > + .LEN_STORE (vectp_d.10_63, 128B, _64, { 3, 3, 3, 3 }, 0); > + > + We use _72 = MIN_EXPR ; to generate the number of the elements > + to be processed in each iteration. > + > + The related STOREs: > + _72 = MIN_EXPR ; > + .LEN_STORE (vectp_f.8_56, 128B, _72, { 1, 2, 1, 2, 1, 2, 1, 2 }, 0); > + _64 = _72 / 2; > + .LEN_STORE (vectp_d.10_63, 128B, _64, { 3, 3, 3, 3 }, 0); > + Since these 2 STOREs store 2 vectors that the second vector is half elements > + of the first vector. So the length of second STORE will be _64 = _72 / 2; > + It's similar to the VIEW_CONVERT of handling masks in SLP. > +*/ > + > +static tree > +vect_set_loop_controls_by_while_len (class loop *loop, loop_vec_info loop_vinfo, > + gimple_seq *preheader_seq, > + gimple_seq *header_seq, > + rgroup_controls *rgc, tree niters) > +{ > + tree compare_type = LOOP_VINFO_RGROUP_COMPARE_TYPE (loop_vinfo); > + tree iv_type = LOOP_VINFO_RGROUP_IV_TYPE (loop_vinfo); > + /* We are not allowing masked approach in WHILE_LEN. */ > + gcc_assert (!LOOP_VINFO_FULLY_MASKED_P (loop_vinfo)); > + > + tree ctrl_type = rgc->type; > + unsigned int nitems_per_iter = rgc->max_nscalars_per_iter * rgc->factor; > + poly_uint64 nitems_per_ctrl = TYPE_VECTOR_SUBPARTS (ctrl_type) * rgc->factor; > + poly_uint64 vf = LOOP_VINFO_VECT_FACTOR (loop_vinfo); > + > + /* Calculate the maximum number of item values that the rgroup > + handles in total, the number that it handles for each iteration > + of the vector loop. */ > + tree nitems_total = niters; > + if (nitems_per_iter != 1) > + { > + /* We checked before setting LOOP_VINFO_USING_PARTIAL_VECTORS_P that > + these multiplications don't overflow. */ > + tree compare_factor = build_int_cst (compare_type, nitems_per_iter); > + nitems_total = gimple_build (preheader_seq, MULT_EXPR, compare_type, > + nitems_total, compare_factor); > + } > + > + /* Convert the comparison value to the IV type (either a no-op or > + a promotion). */ > + nitems_total = gimple_convert (preheader_seq, iv_type, nitems_total); > + > + /* Create an induction variable that counts the number of items > + processed. */ > + tree index_before_incr, index_after_incr; > + gimple_stmt_iterator incr_gsi; > + bool insert_after; > + standard_iv_increment_position (loop, &incr_gsi, &insert_after); > + > + /* Test the decremented IV, which will never underflow 0 since we have > + IFN_WHILE_LEN to gurantee that. */ > + tree test_limit = nitems_total; > + > + /* Provide a definition of each control in the group. */ > + tree ctrl; > + unsigned int i; > + FOR_EACH_VEC_ELT_REVERSE (rgc->controls, i, ctrl) > + { > + /* Previous controls will cover BIAS items. This control covers the > + next batch. */ > + poly_uint64 bias = nitems_per_ctrl * i; > + tree bias_tree = build_int_cst (iv_type, bias); > + > + /* Rather than have a new IV that starts at TEST_LIMIT and goes down to > + BIAS, prefer to use the same TEST_LIMIT - BIAS based IV for each > + control and adjust the bound down by BIAS. */ > + tree this_test_limit = test_limit; > + if (i != 0) > + { > + this_test_limit = gimple_build (preheader_seq, MAX_EXPR, iv_type, > + this_test_limit, bias_tree); > + this_test_limit = gimple_build (preheader_seq, MINUS_EXPR, iv_type, > + this_test_limit, bias_tree); > + } > + > + /* Create decrement IV. */ > + create_iv (this_test_limit, MINUS_EXPR, ctrl, NULL_TREE, loop, &incr_gsi, > + insert_after, &index_before_incr, &index_after_incr); > + > + poly_uint64 final_vf = vf * nitems_per_iter; > + tree vf_step = build_int_cst (iv_type, final_vf); > + tree res_len; > + if (nitems_per_iter != 1) > + { > + /* For SLP, we can't allow non-VF number of elements to be processed > + in non-final iteration. We force the number of elements to be > + processed in each non-final iteration is VF elements. If we allow > + non-VF elements processing in non-final iteration will make SLP too > + complicated and produce inferior codegen. > + > + For example: > + > + If non-final iteration process VF elements. > + > + ... > + .LEN_STORE (vectp_f.8_51, 128B, _71, { 1, 2, 1, 2 }, 0); > + .LEN_STORE (vectp_f.8_56, 128B, _72, { 1, 2, 1, 2 }, 0); > + ... > + > + If non-final iteration process non-VF elements. > + > + ... > + .LEN_STORE (vectp_f.8_51, 128B, _71, { 1, 2, 1, 2 }, 0); > + if (_71 % 2 == 0) > + .LEN_STORE (vectp_f.8_56, 128B, _72, { 1, 2, 1, 2 }, 0); > + else > + .LEN_STORE (vectp_f.8_56, 128B, _72, { 2, 1, 2, 1 }, 0); > + ... > + > + This is the simple case of 2-elements interleaved vector SLP. We > + consider other interleave vector, the situation will become more > + complicated. */ > + res_len = gimple_build (header_seq, MIN_EXPR, iv_type, > + index_before_incr, vf_step); > + } > + else > + { > + res_len = gimple_build (header_seq, IFN_WHILE_LEN, iv_type, > + index_before_incr, vf_step); > + } > + gassign *assign = gimple_build_assign (ctrl, res_len); > + gimple_seq_add_stmt (header_seq, assign); > + } > + > + return index_after_incr; > +} > + > /* Set up the iteration condition and rgroup controls for LOOP, given > that LOOP_VINFO_USING_PARTIAL_VECTORS_P is true for the vectorized > loop. LOOP_VINFO describes the vectorization of LOOP. NITERS is > @@ -703,6 +958,7 @@ vect_set_loop_condition_partial_vectors (class loop *loop, > > bool use_masks_p = LOOP_VINFO_FULLY_MASKED_P (loop_vinfo); > tree compare_type = LOOP_VINFO_RGROUP_COMPARE_TYPE (loop_vinfo); > + tree iv_type = LOOP_VINFO_RGROUP_IV_TYPE (loop_vinfo); > unsigned int compare_precision = TYPE_PRECISION (compare_type); > tree orig_niters = niters; > > @@ -757,12 +1013,18 @@ vect_set_loop_condition_partial_vectors (class loop *loop, > bool might_wrap_p = vect_rgroup_iv_might_wrap_p (loop_vinfo, rgc); > > /* Set up all controls for this group. */ > - test_ctrl = vect_set_loop_controls_directly (loop, loop_vinfo, > - &preheader_seq, > - &header_seq, > - loop_cond_gsi, rgc, > - niters, niters_skip, > - might_wrap_p); > + if (direct_internal_fn_supported_p (IFN_WHILE_LEN, iv_type, > + OPTIMIZE_FOR_SPEED)) > + test_ctrl > + = vect_set_loop_controls_by_while_len (loop, loop_vinfo, > + &preheader_seq, &header_seq, > + rgc, niters); > + else > + test_ctrl > + = vect_set_loop_controls_directly (loop, loop_vinfo, &preheader_seq, > + &header_seq, loop_cond_gsi, rgc, > + niters, niters_skip, > + might_wrap_p); > } > > /* Emit all accumulated statements. */ > @@ -893,7 +1155,7 @@ vect_set_loop_condition_normal (class loop *loop, tree niters, tree step, > } > > standard_iv_increment_position (loop, &incr_gsi, &insert_after); > - create_iv (init, step, NULL_TREE, loop, > + create_iv (init, PLUS_EXPR, step, NULL_TREE, loop, > &incr_gsi, insert_after, &indx_before_incr, &indx_after_incr); > indx_after_incr = force_gimple_operand_gsi (&loop_cond_gsi, indx_after_incr, > true, NULL_TREE, true, > diff --git a/gcc/tree-vect-loop.cc b/gcc/tree-vect-loop.cc > index 6ea0f21fd13..d6e90ed93cd 100644 > --- a/gcc/tree-vect-loop.cc > +++ b/gcc/tree-vect-loop.cc > @@ -5567,7 +5567,7 @@ vect_create_epilog_for_reduction (loop_vec_info loop_vinfo, > gimple_stmt_iterator incr_gsi; > bool insert_after; > standard_iv_increment_position (loop, &incr_gsi, &insert_after); > - create_iv (series_vect, vec_step, NULL_TREE, loop, &incr_gsi, > + create_iv (series_vect, PLUS_EXPR, vec_step, NULL_TREE, loop, &incr_gsi, > insert_after, &indx_before_incr, &indx_after_incr); > > /* Next create a new phi node vector (NEW_PHI_TREE) which starts > @@ -10364,12 +10364,14 @@ vect_record_loop_len (loop_vec_info loop_vinfo, vec_loop_lens *lens, > rgroup that operates on NVECTORS vectors, where 0 <= INDEX < NVECTORS. */ > > tree > -vect_get_loop_len (loop_vec_info loop_vinfo, vec_loop_lens *lens, > - unsigned int nvectors, unsigned int index) > +vect_get_loop_len (gimple_stmt_iterator *gsi, loop_vec_info loop_vinfo, please keep loop_vinfo as first parameter and update the comment for the new. > + vec_loop_lens *lens, unsigned int nvectors, tree vectype, > + unsigned int index) > { > rgroup_controls *rgl = &(*lens)[nvectors - 1]; > bool use_bias_adjusted_len = > LOOP_VINFO_PARTIAL_LOAD_STORE_BIAS (loop_vinfo) != 0; > + tree iv_type = LOOP_VINFO_RGROUP_IV_TYPE (loop_vinfo); > > /* Populate the rgroup's len array, if this is the first time we've > used it. */ > @@ -10400,6 +10402,27 @@ vect_get_loop_len (loop_vec_info loop_vinfo, vec_loop_lens *lens, > > if (use_bias_adjusted_len) > return rgl->bias_adjusted_ctrl; > + else if (direct_internal_fn_supported_p (IFN_WHILE_LEN, iv_type, > + OPTIMIZE_FOR_SPEED)) It's odd to see this test here - why's the .WHILE_LEN sufficiently different from "other" loop_len cases? > + { > + tree loop_len = rgl->controls[index]; > + poly_int64 nunits1 = TYPE_VECTOR_SUBPARTS (rgl->type); > + poly_int64 nunits2 = TYPE_VECTOR_SUBPARTS (vectype); > + if (maybe_ne (nunits1, nunits2)) > + { > + /* A loop len for data type X can be reused for data type Y > + if X has N times more elements than Y and if Y's elements > + are N times bigger than X's. */ > + gcc_assert (multiple_p (nunits1, nunits2)); > + unsigned int factor = exact_div (nunits1, nunits2).to_constant (); > + gimple_seq seq = NULL; > + loop_len = gimple_build (&seq, RDIV_EXPR, iv_type, loop_len, > + build_int_cst (iv_type, factor)); > + if (seq) > + gsi_insert_seq_before (gsi, seq, GSI_SAME_STMT); > + } > + return loop_len; You are going to re-emit this division for each load/store, shouldn't this be integrated in the loop populating controls[] at the first call? > + } > else > return rgl->controls[index]; > } > diff --git a/gcc/tree-vect-stmts.cc b/gcc/tree-vect-stmts.cc > index 6b7dbfd4a23..98bef8f4fc9 100644 > --- a/gcc/tree-vect-stmts.cc > +++ b/gcc/tree-vect-stmts.cc > @@ -3144,6 +3144,70 @@ vect_get_data_ptr_increment (vec_info *vinfo, > return iv_step; > } > > +/* Prepare the pointer IVs which needs to be updated by a variable amount. > + Such variable amount is the outcome of .WHILE_LEN. In this case, we can > + allow each iteration process the flexible number of elements as long as > + the number <= vf elments. > + > + Return data reference according to WHILE_LEN. > + If new statements are needed, insert them before GSI. */ > + > +static tree > +get_while_len_data_ref_ptr (vec_info *vinfo, stmt_vec_info stmt_info, > + tree aggr_type, class loop *at_loop, tree offset, > + tree *dummy, gimple_stmt_iterator *gsi, > + bool simd_lane_access_p, vec_loop_lens *loop_lens, > + dr_vec_info *dr_info, > + vect_memory_access_type memory_access_type) > +{ > + if (!loop_lens || loop_lens->length () != 1) > + return NULL_TREE; > + loop_vec_info loop_vinfo = dyn_cast (vinfo); > + tree iv_type = LOOP_VINFO_RGROUP_IV_TYPE (loop_vinfo); > + tree step = vect_dr_behavior (vinfo, dr_info)->step; > + if (!direct_internal_fn_supported_p (IFN_WHILE_LEN, iv_type, > + OPTIMIZE_FOR_SPEED)) > + return NULL_TREE; > + > + if (memory_access_type == VMAT_INVARIANT) > + return NULL_TREE; > + > + /* TODO: We don't support gather/scatter or load_lanes/store_lanes for pointer > + IVs are updated by variable amount but we will support them in the future. > + */ > + gcc_assert (memory_access_type != VMAT_GATHER_SCATTER > + && memory_access_type != VMAT_LOAD_STORE_LANES); All this should be gated at the caller site. Quoting one: @@ -9798,6 +9872,15 @@ vectorizable_load (vec_info *vinfo, at_loop, offset, &dummy, gsi, &ptr_incr, simd_lane_access_p, bump); + + tree while_len_data_ref_ptr + = get_while_len_data_ref_ptr (vinfo, stmt_info, aggr_type, at_loop, + offset, &dummy, gsi, + simd_lane_access_p, loop_lens, + dr_info, memory_access_type); + if (while_len_data_ref_ptr) + dataref_ptr = while_len_data_ref_ptr; you call this after other methods have computed a dataref_ptr, that's very ugly. Instead you should compute the "update method" during load/store _analysis_ and then conciously decide on using this function (which then better should succeed). That will also be required to properly apply costing during analysis. I also wonder how you can get away without touching the j == 1 case. I suppose we'll ever use the .WHILE_LEN path then. > + /* When we support WHILE_LEN pattern, we dynamic adjust > + the memory address by .WHILE_LEN result. > + > + The result of .WHILE_LEN is the number of elements to > + be processed of each iteration. So the memory address > + adjustment operation should be: > + > + bytesize = GET_MODE_SIZE (element_mode (aggr_type)); > + addr = addr + .WHILE_LEN (ARG..) * bytesize; > + */ > + gimple *ptr_incr; > + tree loop_len > + = vect_get_loop_len (gsi, loop_vinfo, loop_lens, 1, aggr_type, 0); > + tree len_type = TREE_TYPE (loop_len); > + poly_uint64 bytesize = GET_MODE_SIZE (element_mode (aggr_type)); > + /* Since the outcome of .WHILE_LEN is element size, we should adjust > + it into bytesize so that it can be used in address pointer variable > + amount IVs adjustment. */ > + tree tmp = fold_build2 (MULT_EXPR, len_type, loop_len, > + build_int_cst (len_type, bytesize)); > + if (tree_int_cst_sgn (step) == -1) > + tmp = fold_build1 (NEGATE_EXPR, len_type, tmp); > + tree bump = make_temp_ssa_name (len_type, NULL, "ivtmp"); > + gassign *assign = gimple_build_assign (bump, tmp); > + gsi_insert_before (gsi, assign, GSI_SAME_STMT); > + return vect_create_data_ref_ptr (vinfo, stmt_info, aggr_type, at_loop, offset, > + dummy, gsi, &ptr_incr, simd_lane_access_p, > + bump); > +} > + > /* Check and perform vectorization of BUILT_IN_BSWAP{16,32,64,128}. */ > > static bool > @@ -8195,7 +8259,7 @@ vectorizable_store (vec_info *vinfo, > > stride_base = cse_and_gimplify_to_preheader (loop_vinfo, stride_base); > ivstep = cse_and_gimplify_to_preheader (loop_vinfo, ivstep); > - create_iv (stride_base, ivstep, NULL, > + create_iv (stride_base, PLUS_EXPR, ivstep, NULL, > loop, &incr_gsi, insert_after, > &offvar, NULL); > incr = gsi_stmt (incr_gsi); > @@ -8465,6 +8529,15 @@ vectorizable_store (vec_info *vinfo, > simd_lane_access_p ? loop : NULL, > offset, &dummy, gsi, &ptr_incr, > simd_lane_access_p, bump); > + > + tree while_len_data_ref_ptr > + = get_while_len_data_ref_ptr (vinfo, stmt_info, aggr_type, > + simd_lane_access_p ? loop : NULL, > + offset, &dummy, gsi, > + simd_lane_access_p, loop_lens, > + dr_info, memory_access_type); > + if (while_len_data_ref_ptr) > + dataref_ptr = while_len_data_ref_ptr; > } > else > { > @@ -8652,8 +8725,9 @@ vectorizable_store (vec_info *vinfo, > else if (loop_lens) > { > tree final_len > - = vect_get_loop_len (loop_vinfo, loop_lens, > - vec_num * ncopies, vec_num * j + i); > + = vect_get_loop_len (gsi, loop_vinfo, loop_lens, > + vec_num * ncopies, vectype, > + vec_num * j + i); > tree ptr = build_int_cst (ref_type, align * BITS_PER_UNIT); > machine_mode vmode = TYPE_MODE (vectype); > opt_machine_mode new_ovmode > @@ -9314,7 +9388,7 @@ vectorizable_load (vec_info *vinfo, > > stride_base = cse_and_gimplify_to_preheader (loop_vinfo, stride_base); > ivstep = cse_and_gimplify_to_preheader (loop_vinfo, ivstep); > - create_iv (stride_base, ivstep, NULL, > + create_iv (stride_base, PLUS_EXPR, ivstep, NULL, > loop, &incr_gsi, insert_after, > &offvar, NULL); > > @@ -9798,6 +9872,15 @@ vectorizable_load (vec_info *vinfo, > at_loop, > offset, &dummy, gsi, &ptr_incr, > simd_lane_access_p, bump); > + > + tree while_len_data_ref_ptr > + = get_while_len_data_ref_ptr (vinfo, stmt_info, aggr_type, at_loop, > + offset, &dummy, gsi, > + simd_lane_access_p, loop_lens, > + dr_info, memory_access_type); > + if (while_len_data_ref_ptr) > + dataref_ptr = while_len_data_ref_ptr; > + > if (mask) > vec_mask = vec_masks[0]; > } > @@ -10008,8 +10091,8 @@ vectorizable_load (vec_info *vinfo, > else if (loop_lens && memory_access_type != VMAT_INVARIANT) > { > tree final_len > - = vect_get_loop_len (loop_vinfo, loop_lens, > - vec_num * ncopies, > + = vect_get_loop_len (gsi, loop_vinfo, loop_lens, > + vec_num * ncopies, vectype, > vec_num * j + i); > tree ptr = build_int_cst (ref_type, > align * BITS_PER_UNIT); > diff --git a/gcc/tree-vectorizer.h b/gcc/tree-vectorizer.h > index 9cf2fb23fe3..811c17e1d3d 100644 > --- a/gcc/tree-vectorizer.h > +++ b/gcc/tree-vectorizer.h > @@ -2293,8 +2293,8 @@ extern tree vect_get_loop_mask (gimple_stmt_iterator *, vec_loop_masks *, > unsigned int, tree, unsigned int); > extern void vect_record_loop_len (loop_vec_info, vec_loop_lens *, unsigned int, > tree, unsigned int); > -extern tree vect_get_loop_len (loop_vec_info, vec_loop_lens *, unsigned int, > - unsigned int); > +extern tree vect_get_loop_len (gimple_stmt_iterator *, loop_vec_info, vec_loop_lens *, > + unsigned int, tree, unsigned int); > extern gimple_seq vect_gen_len (tree, tree, tree, tree); > extern stmt_vec_info info_for_reduction (vec_info *, stmt_vec_info); > extern bool reduction_fn_for_scalar_code (code_helper, internal_fn *); Otherwise looks reasonable. As said, it _looks_ like you can progress without .WHILE_LEN and using .WHILE_LEN is a pure optimization? Thanks, Richard.