On Wed, 12 Apr 2023, juzhe.zh...@rivai.ai wrote: > Thank you very much for reply. > > WHILE_LEN is the pattern that calculates the number of the elements of the > vector will be updated in each iteration. > For RVV, we use vsetvl instruction to calculate the number of the elements of > the vector. > > WHILE_ULT can not work for RVV since WHILE_ULT is generating mask to > predicate vector operation, but RVV do not > use mask to do the loop strip mining (RVV only use mask for control flow > inside the loop). > > Here is the example WHILE_ULT working in ARM SVE: > https://godbolt.org/z/jKsT8E1hP > > The first example is: > void foo (int32_t * __restrict a, int32_t * __restrict b, int n) > { > for (int i = 0; i < n; i++) > a[i] = a[i] + b[i]; > } > > ARM SVE: > foo: > cmp w2, 0 > ble .L1 > mov x3, 0 > cntw x4 > whilelo p0.s, wzr, w2 > .L3: > ld1w z1.s, p0/z, [x0, x3, lsl 2] > ld1w z0.s, p0/z, [x1, x3, lsl 2] > add z0.s, z0.s, z1.s > st1w z0.s, p0, [x0, x3, lsl 2] > add x3, x3, x4 > whilelo p0.s, w3, w2 > b.any .L3 > .L1: > ret > > Here, whilelo will generate the mask according to w3 to w2. > So for example, if w3 = 0, and w2 = 3 (Suppose machine vector length > 3). > Then it will generate a mask with 0b111 mask to predicate loads and stores. > > For RVV, we can't do that since RVV doesn't have whilelo instructions to > generate predicate mask. > Also, we can't use mask as the predicate to do loop strip mining since RVV > only has 1 single mask > to handle flow control inside the loop. > > Instead, we use vsetvl to do the strip mining, so base on this, the same C > code, RVV ideal asm according RVV ISA should be: > > preheader: > a0 = n (the total number of the scalar should be calculated). > ..... > .L3: > vsetvli a5,a0,e32,m1,ta,ma ====> WHILE_LEN pattern generate this > instruction, calculate the number of the elements should be updated > vle32.v v1,0(a4) > sub a0,a0,a5 ============> Decrement the induction variable > by the a5 (generated by WHILE_LEN) > .... > > vadd.vv.... > vse32.v v1,0(a3) > add a4,a4,a2 > add a3,a3,a2 > bne a0,zero,.L3 > .L1: > ret > > So you will see, if n = 3 like I said for ARM SVE (Suppose machine vector > length > 3), then vsetvli a5,a0,e32,m1,ta,ma will > generate a5 = 3, then the vle32.v/vadd.vv/vse32.v are all doing the operation > only on the element 0, element 1, element 2. > > Besides, WHILE_LEN is defined to make sure to be never overflow the input > operand which is "a0". > That means sub a0,a0,a5 will make a0 never underflow 0. > > I have tried to return Pmode in TARGET_VECTORIZE_GET_MASK_MODE > target hook and then use WHILE_ULT. > > But there are 2 issues: > One is that current GCC is doing the flow from 0-based until the TEST_LIMIT. > Wheras the optimal flow of RVV I showed above > is from "n" keep decreasing n until 0. Trying to fit the current flow of > GCC, RVV needs more instructions to do the loop strip mining. > > Second is that if we return a Pmode in TARGET_VECTORIZE_GET_MASK_MODE > which not only specify the dest mode for WHILE_ULT but also the mask mode of > flow control. > If we return Pmode which is used as the length for RVV. We can't use mask > mode like VNx2BI mode to do the flow control predicate. > This another example: > void foo2 (int32_t * __restrict a, int32_t * __restrict b, int32_t * restrict > cond, int n) > { > for (int i = 0; i < n; i++) > if (cond[i]) > a[i] = a[i] + b[i]; > } > > ARM SVE: > ld1w z0.s, p0/z, [x2, x4, lsl 2] > cmpne p0.s, p0/z, z0.s, #0 > ld1w z0.s, p0/z, [x0, x4, lsl 2] > ld1w z1.s, p0/z, [x1, x4, lsl 2] > add z0.s, z0.s, z1.s > st1w z0.s, p0, [x0, x4, lsl 2] > add x4, x4, x5 > whilelo p0.s, w4, w3 > b.any .L8 > > Here we can see ARM use mask mode for both loop strip minning and flow > control. > > Wheras, RVV use length generated by vsetvl (WHILE_LEN) to do the loop strip > minning and mask generated by comparison to do the flow control. > > So the ASM generated by my downstream LLVM/GCC: > .L3: > vsetvli a6,a3,e32,m1,ta,mu ==========> generate length to predicate > RVV operation. > vle32.v v0,(a2) > sub a3,a3,a6 ==========> decrease the induction variable > until 0. > vmsne.vi v0,v0,0 ==========> generate mask to predicate RVV > operation. > vle32.v v24,(a0),v0.t ===========> here using v0.t is the only mask > register to predicate RVV operation > vle32.v v25,(a1),v0.t > vadd.vv v24,v24,v25 > vse32.v v24,(a0),v0.t > add a2,a2,a4 > add a0,a0,a4 > add a1,a1,a4 > bne a3,zero,.L3 > .L1: > ret > > > This is the how RVV works. > Feel free to comment if you have any questions.
Thanks for the detailed explanation. Just to clarify - with RVV there's only a single mask register, v0.t, or did you want to say an instruction can only specify a single mask register? ARM SVE would have a loop control mask and a separate mask for the if (cond[i]) which would be combined with a mask-and instruction to a third mask which is then used on the predicated instructions. For AVX512 WHILE_ULT is a better match since we need a mask in the end (but WHILE_ULT isn't a very good match either, so I'm still working on masked loop support there). PowerPC and s390x might be able to use WHILE_LEN as well (though they only have LEN variants of loads and stores) - of course only "simulating it". For the fixed-vector-length ISAs the predicated vector loop IMHO makes most sense for the epilogue to handle low-trip loops better. Richard. > Thanks. > > > juzhe.zh...@rivai.ai > > From: Richard Biener > Date: 2023-04-12 15:00 > To: Richard Sandiford > CC: juzhe.zh...@rivai.ai; gcc-patches; jeffreyalaw > Subject: Re: [PATCH] VECT: Add WHILE_LEN pattern for decrement IV support for > auto-vectorization > On Tue, 11 Apr 2023, Richard Sandiford wrote: > > > "juzhe.zh...@rivai.ai" <juzhe.zh...@rivai.ai> writes: > > > Hi, Richards. > > > Kindly Ping this patch. > > > This is the most important patch for RVV auto-vectorization support. > > > Bootstraped on X86 has passed. > > > > Can it wait for GCC 14? It doesn't seem like stage 4 material. > > > > Also, pinging after 5 days seems a bit soon. It's been a 4-day > > holiday weekend for much of Europe. > > Also can you explain why using WHILE_ULT is not possible? (I've > successfully - to some extent - done that for AVX512 for example) > > The patch lacks the description of what WHILE_LEN actually is. > > Richard. > > > Thanks, > > Richard > > > > > Feel free to comments. > > > > > > Thanks. > > > > > > > > > juzhe.zh...@rivai.ai > > > > > > From: juzhe.zhong > > > Date: 2023-04-07 09:47 > > > To: gcc-patches > > > CC: richard.sandiford; rguenther; jeffreyalaw; Juzhe-Zhong > > > Subject: [PATCH] VECT: Add WHILE_LEN pattern for decrement IV support for > > > auto-vectorization > > > From: Juzhe-Zhong <juzhe.zh...@rivai.ai> > > > > > > This patch is to add WHILE_LEN pattern. > > > It's inspired by RVV ISA simple "vvaddint32.s" example: > > > https://github.com/riscv/riscv-v-spec/blob/master/example/vvaddint32.s > > > > > > More details are in "vect_set_loop_controls_by_while_len" implementation > > > and comments. > > > > > > Consider such following case: > > > #define N 16 > > > int src[N]; > > > int dest[N]; > > > > > > void > > > foo (int n) > > > { > > > for (int i = 0; i < n; i++) > > > dest[i] = src[i]; > > > } > > > > > > -march=rv64gcv -O3 --param riscv-autovec-preference=scalable > > > -fno-vect-cost-model -fno-tree-loop-distribute-patterns: > > > > > > foo: > > > ble a0,zero,.L1 > > > lui a4,%hi(.LANCHOR0) > > > addi a4,a4,%lo(.LANCHOR0) > > > addi a3,a4,64 > > > csrr a2,vlenb > > > .L3: > > > vsetvli a5,a0,e32,m1,ta,ma > > > vle32.v v1,0(a4) > > > sub a0,a0,a5 > > > vse32.v v1,0(a3) > > > add a4,a4,a2 > > > add a3,a3,a2 > > > bne a0,zero,.L3 > > > .L1: > > > ret > > > > > > gcc/ChangeLog: > > > > > > * doc/md.texi: Add WHILE_LEN support. > > > * internal-fn.cc (while_len_direct): Ditto. > > > (expand_while_len_optab_fn): Ditto. > > > (direct_while_len_optab_supported_p): Ditto. > > > * internal-fn.def (WHILE_LEN): Ditto. > > > * optabs.def (OPTAB_D): Ditto. > > > * tree-ssa-loop-manip.cc (create_iv): Ditto. > > > * tree-ssa-loop-manip.h (create_iv): Ditto. > > > * tree-vect-loop-manip.cc (vect_set_loop_controls_by_while_len): > > > Ditto. > > > (vect_set_loop_condition_partial_vectors): Ditto. > > > * tree-vect-loop.cc (vect_get_loop_len): Ditto. > > > * tree-vect-stmts.cc (vectorizable_store): Ditto. > > > (vectorizable_load): Ditto. > > > * tree-vectorizer.h (vect_get_loop_len): Ditto. > > > > > > --- > > > gcc/doc/md.texi | 14 +++ > > > gcc/internal-fn.cc | 29 ++++++ > > > gcc/internal-fn.def | 1 + > > > gcc/optabs.def | 1 + > > > gcc/tree-ssa-loop-manip.cc | 4 +- > > > gcc/tree-ssa-loop-manip.h | 2 +- > > > gcc/tree-vect-loop-manip.cc | 186 ++++++++++++++++++++++++++++++++++-- > > > gcc/tree-vect-loop.cc | 35 +++++-- > > > gcc/tree-vect-stmts.cc | 9 +- > > > gcc/tree-vectorizer.h | 4 +- > > > 10 files changed, 264 insertions(+), 21 deletions(-) > > > > > > diff --git a/gcc/doc/md.texi b/gcc/doc/md.texi > > > index 8e3113599fd..72178ab014c 100644 > > > --- a/gcc/doc/md.texi > > > +++ b/gcc/doc/md.texi > > > @@ -4965,6 +4965,20 @@ 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 operation is equivalent to: > > > + > > > +@smallexample > > > +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. > > > +@end smallexample > > > + > > > @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/internal-fn.cc b/gcc/internal-fn.cc > > > index 6e81dc05e0e..5f44def90d3 100644 > > > --- a/gcc/internal-fn.cc > > > +++ b/gcc/internal-fn.cc > > > @@ -127,6 +127,7 @@ init_internal_fns () > > > #define cond_binary_direct { 1, 1, true } > > > #define cond_ternary_direct { 1, 1, true } > > > #define while_direct { 0, 2, false } > > > +#define while_len_direct { 0, 0, false } > > > #define fold_extract_direct { 2, 2, false } > > > #define fold_left_direct { 1, 1, false } > > > #define mask_fold_left_direct { 1, 1, false } > > > @@ -3702,6 +3703,33 @@ expand_while_optab_fn (internal_fn, gcall *stmt, > > > convert_optab optab) > > > emit_move_insn (lhs_rtx, ops[0].value); > > > } > > > +/* Expand WHILE_LEN call STMT using optab OPTAB. */ > > > +static void > > > +expand_while_len_optab_fn (internal_fn, gcall *stmt, convert_optab optab) > > > +{ > > > + expand_operand ops[3]; > > > + tree rhs_type[2]; > > > + > > > + tree lhs = gimple_call_lhs (stmt); > > > + tree lhs_type = TREE_TYPE (lhs); > > > + rtx lhs_rtx = expand_expr (lhs, NULL_RTX, VOIDmode, EXPAND_WRITE); > > > + create_output_operand (&ops[0], lhs_rtx, TYPE_MODE (lhs_type)); > > > + > > > + for (unsigned int i = 0; i < gimple_call_num_args (stmt); ++i) > > > + { > > > + tree rhs = gimple_call_arg (stmt, i); > > > + rhs_type[i] = TREE_TYPE (rhs); > > > + rtx rhs_rtx = expand_normal (rhs); > > > + create_input_operand (&ops[i + 1], rhs_rtx, TYPE_MODE > > > (rhs_type[i])); > > > + } > > > + > > > + insn_code icode = direct_optab_handler (optab, TYPE_MODE > > > (rhs_type[0])); > > > + > > > + expand_insn (icode, 3, ops); > > > + if (!rtx_equal_p (lhs_rtx, ops[0].value)) > > > + emit_move_insn (lhs_rtx, ops[0].value); > > > +} > > > + > > > /* Expand a call to a convert-like optab using the operands in STMT. > > > FN has a single output operand and NARGS input operands. */ > > > @@ -3843,6 +3871,7 @@ multi_vector_optab_supported_p (convert_optab > > > optab, tree_pair types, > > > #define direct_scatter_store_optab_supported_p convert_optab_supported_p > > > #define direct_len_store_optab_supported_p direct_optab_supported_p > > > #define direct_while_optab_supported_p convert_optab_supported_p > > > +#define direct_while_len_optab_supported_p direct_optab_supported_p > > > #define direct_fold_extract_optab_supported_p direct_optab_supported_p > > > #define direct_fold_left_optab_supported_p direct_optab_supported_p > > > #define direct_mask_fold_left_optab_supported_p direct_optab_supported_p > > > diff --git a/gcc/internal-fn.def b/gcc/internal-fn.def > > > index 7fe742c2ae7..3a933abff5d 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, > > > while_len) > > > 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") > > > diff --git a/gcc/tree-ssa-loop-manip.cc b/gcc/tree-ssa-loop-manip.cc > > > index 09acc1c94cc..cdbf280e249 100644 > > > --- a/gcc/tree-ssa-loop-manip.cc > > > +++ b/gcc/tree-ssa-loop-manip.cc > > > @@ -59,14 +59,14 @@ static bitmap_obstack loop_renamer_obstack; > > > void > > > create_iv (tree base, tree step, tree var, class loop *loop, > > > gimple_stmt_iterator *incr_pos, bool after, > > > - tree *var_before, tree *var_after) > > > + tree *var_before, tree *var_after, enum tree_code code) > > > { > > > gassign *stmt; > > > gphi *phi; > > > tree initial, step1; > > > gimple_seq stmts; > > > tree vb, va; > > > - enum tree_code incr_op = PLUS_EXPR; > > > + enum tree_code incr_op = code; > > > edge pe = loop_preheader_edge (loop); > > > if (var != NULL_TREE) > > > diff --git a/gcc/tree-ssa-loop-manip.h b/gcc/tree-ssa-loop-manip.h > > > index d49273a3987..da755320a3a 100644 > > > --- a/gcc/tree-ssa-loop-manip.h > > > +++ b/gcc/tree-ssa-loop-manip.h > > > @@ -23,7 +23,7 @@ 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 *); > > > + bool, tree *, tree *, enum tree_code = PLUS_EXPR); > > > 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-loop-manip.cc b/gcc/tree-vect-loop-manip.cc > > > index f60fa50e8f4..f3cd6c51d2e 100644 > > > --- a/gcc/tree-vect-loop-manip.cc > > > +++ b/gcc/tree-vect-loop-manip.cc > > > @@ -682,6 +682,173 @@ 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. > > > + > > > + Note: the cost of the code generated by this function is modeled > > > + by vect_estimate_min_profitable_iters, so changes here may need > > > + corresponding changes there. > > > + > > > + 1. Single rgroup, the Gimple IR should be: > > > + > > > + <bb 3> > > > + _19 = (unsigned long) n_5(D); > > > + ... > > > + > > > + <bb 4>: > > > + ... > > > + # ivtmp_20 = PHI <ivtmp_21(4), _19(3)> > > > + ... > > > + _22 = .WHILE_LEN (ivtmp_20, vf); > > > + ... > > > + vector statement (use _22); > > > + ... > > > + ivtmp_21 = ivtmp_20 - _22; > > > + ... > > > + if (ivtmp_21 != 0) > > > + goto <bb 4>; [75.00%] > > > + else > > > + goto <bb 5>; [25.00%] > > > + > > > + <bb 5> > > > + return; > > > + > > > + Note: IFN_WHILE_LEN will guarantee "ivtmp_21 = ivtmp_20 - _22" never > > > + underflow 0. > > > + > > > + 2. Multiple rgroup, the Gimple IR should be: > > > + > > > + <bb 3> > > > + _70 = (unsigned long) bnd.7_52; > > > + _71 = _70 * 2; > > > + _72 = MAX_EXPR <_71, 4>; > > > + _73 = _72 + 18446744073709551612; > > > + ... > > > + > > > + <bb 4>: > > > + ... > > > + # ivtmp_74 = PHI <ivtmp_75(6), _73(12)> > > > + # ivtmp_77 = PHI <ivtmp_78(6), _71(12)> > > > + _76 = .WHILE_LEN (ivtmp_74, vf * nitems_per_ctrl); > > > + _79 = .WHILE_LEN (ivtmp_77, vf * nitems_per_ctrl); > > > + ... > > > + vector statement (use _79); > > > + ... > > > + vector statement (use _76); > > > + ... > > > + _65 = _79 / 2; > > > + vector statement (use _65); > > > + ... > > > + _68 = _76 / 2; > > > + vector statement (use _68); > > > + ... > > > + ivtmp_78 = ivtmp_77 - _79; > > > + ivtmp_75 = ivtmp_74 - _76; > > > + ... > > > + if (ivtmp_78 != 0) > > > + goto <bb 4>; [75.00%] > > > + else > > > + goto <bb 5>; [25.00%] > > > + > > > + <bb 5> > > > + return; > > > + > > > +*/ > > > + > > > +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, ctrl, NULL_TREE, loop, &incr_gsi, > > > + insert_after, &index_before_incr, &index_after_incr, > > > + MINUS_EXPR); > > > + > > > + poly_uint64 final_vf = vf * nitems_per_iter; > > > + tree vf_step = build_int_cst (iv_type, final_vf); > > > + tree 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 +870,7 @@ 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 +925,18 @@ 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. */ > > > diff --git a/gcc/tree-vect-loop.cc b/gcc/tree-vect-loop.cc > > > index 1ba9f18d73e..5bffd9a6322 100644 > > > --- a/gcc/tree-vect-loop.cc > > > +++ b/gcc/tree-vect-loop.cc > > > @@ -10360,12 +10360,14 @@ 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, > > > + 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; > > > + 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. */ > > > @@ -10386,8 +10388,8 @@ vect_get_loop_len (loop_vec_info loop_vinfo, > > > vec_loop_lens *lens, > > > if (use_bias_adjusted_len) > > > { > > > gcc_assert (i == 0); > > > - tree adjusted_len = > > > - make_temp_ssa_name (len_type, NULL, "adjusted_loop_len"); > > > + tree adjusted_len > > > + = make_temp_ssa_name (len_type, NULL, "adjusted_loop_len"); > > > SSA_NAME_DEF_STMT (adjusted_len) = gimple_build_nop (); > > > rgl->bias_adjusted_ctrl = adjusted_len; > > > } > > > @@ -10396,6 +10398,27 @@ 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)) > > > + { > > > + 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; > > > + } > > > else > > > return rgl->controls[index]; > > > } > > > diff --git a/gcc/tree-vect-stmts.cc b/gcc/tree-vect-stmts.cc > > > index efa2d0daa52..708c8a1d806 100644 > > > --- a/gcc/tree-vect-stmts.cc > > > +++ b/gcc/tree-vect-stmts.cc > > > @@ -8653,8 +8653,9 @@ 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 > > > @@ -10009,8 +10010,8 @@ 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..e5cf38caf4b 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 *); > > > > -- Richard Biener <rguent...@suse.de> SUSE Software Solutions Germany GmbH, Frankenstrasse 146, 90461 Nuernberg, Germany; GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman; HRB 36809 (AG Nuernberg)