On Fri, 28 Jul 2023, Juzhe-Zhong wrote:
> Hi, Richard and Richi.
>
> Base on the suggestions from Richard:
> https://gcc.gnu.org/pipermail/gcc-patches/2023-July/625396.html
>
> This patch choose (1) approach that Richard provided, meaning:
>
> RVV implements cond_* optabs as expanders. RVV therefore supports
> both IFN_COND_ADD and IFN_COND_LEN_ADD. No dummy length arguments
> are needed at the gimple level.
>
> Such approach can make codes much cleaner and reasonable.
>
> Consider this following case:
> void foo (float * __restrict a, float * __restrict b, int * __restrict cond,
> int n)
> {
> for (int i = 0; i < n; i++)
> if (cond[i])
> a[i] = b[i] + a[i];
> }
>
>
> Output of RISC-V (32-bits) gcc (trunk) (Compiler #3)
> <source>:5:21: missed: couldn't vectorize loop
> <source>:5:21: missed: not vectorized: control flow in loop.
>
> ARM SVE:
>
> ...
> mask__27.10_51 = vect__4.9_49 != { 0, ... };
> ...
> vec_mask_and_55 = loop_mask_49 & mask__27.10_51;
> ...
> vect__9.17_62 = .COND_ADD (vec_mask_and_55, vect__6.13_56, vect__8.16_60,
> vect__6.13_56);
>
> For RVV, we want IR as follows:
>
> ...
> _68 = .SELECT_VL (ivtmp_66, POLY_INT_CST [4, 4]);
> ...
> mask__27.10_51 = vect__4.9_49 != { 0, ... };
> ...
> vect__9.17_60 = .COND_LEN_ADD (mask__27.10_51, vect__6.13_55, vect__8.16_59,
> vect__6.13_55, _68, 0);
> ...
>
> Both len and mask of COND_LEN_ADD are real not dummy.
>
> This patch has been fully tested in RISC-V port with supporting both COND_*
> and COND_LEN_*.
>
> And also, Bootstrap and Regression on X86 passed.
>
> OK for trunk?
>
> gcc/ChangeLog:
>
> * internal-fn.cc (FOR_EACH_LEN_FN_PAIR): New macro.
> (get_len_internal_fn): New function.
> (CASE): Ditto.
> * internal-fn.h (get_len_internal_fn): Ditto.
> * tree-vect-stmts.cc (vectorizable_call): Support CALL vectorization
> with COND_LEN_*.
>
> ---
> gcc/internal-fn.cc | 46 ++++++++++++++++++++++
> gcc/internal-fn.h | 1 +
> gcc/tree-vect-stmts.cc | 87 +++++++++++++++++++++++++++++++++++++-----
> 3 files changed, 125 insertions(+), 9 deletions(-)
>
> diff --git a/gcc/internal-fn.cc b/gcc/internal-fn.cc
> index 8e294286388..379220bebc7 100644
> --- a/gcc/internal-fn.cc
> +++ b/gcc/internal-fn.cc
> @@ -4443,6 +4443,52 @@ get_conditional_internal_fn (internal_fn fn)
> }
> }
>
> +/* Invoke T(IFN) for each internal function IFN that also has an
> + IFN_COND_LEN_* or IFN_MASK_LEN_* form. */
> +#define FOR_EACH_LEN_FN_PAIR(T)
> \
> + T (MASK_LOAD, MASK_LEN_LOAD)
> \
> + T (MASK_STORE, MASK_LEN_STORE)
> \
> + T (MASK_GATHER_LOAD, MASK_LEN_GATHER_LOAD)
> \
> + T (MASK_SCATTER_STORE, MASK_LEN_SCATTER_STORE)
> \
> + T (COND_ADD, COND_LEN_ADD)
> \
> + T (COND_SUB, COND_LEN_SUB)
> \
> + T (COND_MUL, COND_LEN_MUL)
> \
> + T (COND_DIV, COND_LEN_DIV)
> \
> + T (COND_MOD, COND_LEN_MOD)
> \
> + T (COND_RDIV, COND_LEN_RDIV)
> \
> + T (COND_FMIN, COND_LEN_FMIN)
> \
> + T (COND_FMAX, COND_LEN_FMAX)
> \
> + T (COND_MIN, COND_LEN_MIN)
> \
> + T (COND_MAX, COND_LEN_MAX)
> \
> + T (COND_AND, COND_LEN_AND)
> \
> + T (COND_IOR, COND_LEN_IOR)
> \
> + T (COND_XOR, COND_LEN_XOR)
> \
> + T (COND_SHL, COND_LEN_SHL)
> \
> + T (COND_SHR, COND_LEN_SHR)
> \
> + T (COND_NEG, COND_LEN_NEG)
> \
> + T (COND_FMA, COND_LEN_FMA)
> \
> + T (COND_FMS, COND_LEN_FMS)
> \
> + T (COND_FNMA, COND_LEN_FNMA)
> \
> + T (COND_FNMS, COND_LEN_FNMS)
> +
> +/* If there exists an internal function like IFN that operates on vectors,
> + but with additional length and bias parameters, return the internal_fn
> + for that function, otherwise return IFN_LAST. */
> +internal_fn
> +get_len_internal_fn (internal_fn fn)
> +{
> + switch (fn)
> + {
> +#define CASE(NAME, LEN_NAME)
> \
> + case IFN_##NAME:
> \
> + return IFN_##LEN_NAME;
> + FOR_EACH_LEN_FN_PAIR (CASE)
> +#undef CASE
> + default:
> + return IFN_LAST;
> + }
> +}
> +
> /* If IFN implements the conditional form of an unconditional internal
> function, return that unconditional function, otherwise return IFN_LAST.
> */
>
> diff --git a/gcc/internal-fn.h b/gcc/internal-fn.h
> index a5c3f4765ff..410c1b623d6 100644
> --- a/gcc/internal-fn.h
> +++ b/gcc/internal-fn.h
> @@ -224,6 +224,7 @@ extern bool set_edom_supported_p (void);
>
> extern internal_fn get_conditional_internal_fn (tree_code);
> extern internal_fn get_conditional_internal_fn (internal_fn);
> +extern internal_fn get_len_internal_fn (internal_fn);
> extern internal_fn get_conditional_len_internal_fn (tree_code);
> extern tree_code conditional_internal_fn_code (internal_fn);
> extern internal_fn get_unconditional_internal_fn (internal_fn);
> diff --git a/gcc/tree-vect-stmts.cc b/gcc/tree-vect-stmts.cc
> index 6a4e8fce126..ae5b0b09c08 100644
> --- a/gcc/tree-vect-stmts.cc
> +++ b/gcc/tree-vect-stmts.cc
> @@ -3540,7 +3540,10 @@ vectorizable_call (vec_info *vinfo,
>
> int reduc_idx = STMT_VINFO_REDUC_IDX (stmt_info);
> internal_fn cond_fn = get_conditional_internal_fn (ifn);
> + internal_fn cond_len_fn = get_len_internal_fn (ifn);
> + int len_opno = internal_fn_len_index (cond_len_fn);
> vec_loop_masks *masks = (loop_vinfo ? &LOOP_VINFO_MASKS (loop_vinfo) :
> NULL);
> + vec_loop_lens *lens = (loop_vinfo ? &LOOP_VINFO_LENS (loop_vinfo) : NULL);
> if (!vec_stmt) /* transformation not required. */
> {
> if (slp_node)
> @@ -3586,8 +3589,14 @@ vectorizable_call (vec_info *vinfo,
Above for reduc_idx >= 0 there's a check whether cond_fn is supported,
don't you need to amend that with a check for cond_len_fn?
> tree scalar_mask = NULL_TREE;
> if (mask_opno >= 0)
> scalar_mask = gimple_call_arg (stmt_info->stmt, mask_opno);
> - vect_record_loop_mask (loop_vinfo, masks, nvectors,
> - vectype_out, scalar_mask);
> + if (cond_len_fn != IFN_LAST
> + && direct_internal_fn_supported_p (cond_len_fn, vectype_out,
> + OPTIMIZE_FOR_SPEED))
> + vect_record_loop_len (loop_vinfo, lens, nvectors, vectype_out,
> + 1);
> + else
> + vect_record_loop_mask (loop_vinfo, masks, nvectors, vectype_out,
> + scalar_mask);
> }
> }
> return true;
> @@ -3603,8 +3612,24 @@ vectorizable_call (vec_info *vinfo,
> vec_dest = vect_create_destination_var (scalar_dest, vectype_out);
>
> bool masked_loop_p = loop_vinfo && LOOP_VINFO_FULLY_MASKED_P (loop_vinfo);
> + bool len_loop_p = loop_vinfo && LOOP_VINFO_FULLY_WITH_LENGTH_P
> (loop_vinfo);
> unsigned int vect_nargs = nargs;
> - if (masked_loop_p && reduc_idx >= 0)
> + if (len_loop_p)
> + {
> + if (len_opno >= 0)
> + {
> + ifn = cond_len_fn;
> + /* COND_* -> COND_LEN_* takes 2 extra arguments:LEN,BIAS. */
> + vect_nargs += 2;
> + }
> + else if (reduc_idx >= 0)
> + {
> + /* FMA -> COND_LEN_FMA takes 4 extra arguments:MASK,ELSE,LEN,BIAS. */
> + ifn = get_len_internal_fn (cond_fn);
> + vect_nargs += 4;
I'm a bit confused (but also by the existing mask code), whether
vect_nargs needs adjustment depends on the IFN in the IL we analyze.
If if-conversion recognizes a .COND_ADD then we need to add nothing
for masking (that is, ifn == cond_fn already). In your code above
you either use cond_len_fn or get_len_internal_fn (cond_fn) but
isn't that the very same?! So how come you in one case add two
and in the other add four args?
Please make sure to place gcc_unreachable () in each arm and check
you have test coverage. I believe that the else arm is unreachable
but when you vectorize .FMA you will need to add 4 and when you
vectorize .COND_FMA you will need to add two arguments (as said,
no idea why we special case reduc_idx >= 0 at the moment).
Otherwise the patch looks OK to me.
Thanks,
Richard.
> + }
> + }
> + else if (masked_loop_p && reduc_idx >= 0)
> {
> ifn = cond_fn;
> vect_nargs += 2;
> @@ -3629,7 +3654,18 @@ vectorizable_call (vec_info *vinfo,
> FOR_EACH_VEC_ELT (vec_oprnds0, i, vec_oprnd0)
> {
> int varg = 0;
> - if (masked_loop_p && reduc_idx >= 0)
> + if (len_loop_p && reduc_idx >= 0)
> + {
> + /* Always true for SLP. */
> + gcc_assert (ncopies == 1);
> + /* For COND_LEN_* operations used by reduction of
> + CALL vectorization, the LEN argument is the real
> + loop len produced by SELECT_VL or MIN wheras the
> + MASK argument here is the dummy mask. */
> + vargs[varg++]
> + = build_minus_one_cst (truth_type_for (vectype_out));
> + }
> + else if (masked_loop_p && reduc_idx >= 0)
> {
> unsigned int vec_num = vec_oprnds0.length ();
> /* Always true for SLP. */
> @@ -3644,7 +3680,7 @@ vectorizable_call (vec_info *vinfo,
> vec<tree> vec_oprndsk = vec_defs[k];
> vargs[varg++] = vec_oprndsk[i];
> }
> - if (masked_loop_p && reduc_idx >= 0)
> + if ((masked_loop_p || len_loop_p) && reduc_idx >= 0)
> vargs[varg++] = vargs[reduc_idx + 1];
> gimple *new_stmt;
> if (modifier == NARROW)
> @@ -3671,7 +3707,21 @@ vectorizable_call (vec_info *vinfo,
> }
> else
> {
> - if (mask_opno >= 0 && masked_loop_p)
> + if (len_opno >= 0 && len_loop_p)
> + {
> + unsigned int vec_num = vec_oprnds0.length ();
> + /* Always true for SLP. */
> + gcc_assert (ncopies == 1);
> + tree len
> + = vect_get_loop_len (loop_vinfo, gsi, lens, vec_num,
> + vectype_out, i, 1);
> + signed char biasval
> + = LOOP_VINFO_PARTIAL_LOAD_STORE_BIAS (loop_vinfo);
> + tree bias = build_int_cst (intQI_type_node, biasval);
> + vargs[len_opno] = len;
> + vargs[len_opno + 1] = bias;
> + }
> + else if (mask_opno >= 0 && masked_loop_p)
> {
> unsigned int vec_num = vec_oprnds0.length ();
> /* Always true for SLP. */
> @@ -3701,7 +3751,16 @@ vectorizable_call (vec_info *vinfo,
> }
>
> int varg = 0;
> - if (masked_loop_p && reduc_idx >= 0)
> + if (len_loop_p && reduc_idx >= 0)
> + {
> + /* For COND_LEN_* operations used by reduction of
> + CALL vectorization, the LEN argument is the real
> + loop len produced by SELECT_VL or MIN wheras the
> + MASK argument here is the dummy mask. */
> + vargs[varg++]
> + = build_minus_one_cst (truth_type_for (vectype_out));
> + }
> + else if (masked_loop_p && reduc_idx >= 0)
> vargs[varg++] = vect_get_loop_mask (loop_vinfo, gsi, masks, ncopies,
> vectype_out, j);
> for (i = 0; i < nargs; i++)
> @@ -3716,10 +3775,20 @@ vectorizable_call (vec_info *vinfo,
> }
> vargs[varg++] = vec_defs[i][j];
> }
> - if (masked_loop_p && reduc_idx >= 0)
> + if ((masked_loop_p || len_loop_p) && reduc_idx >= 0)
> vargs[varg++] = vargs[reduc_idx + 1];
>
> - if (mask_opno >= 0 && masked_loop_p)
> + if (len_opno >= 0 && len_loop_p)
> + {
> + tree len = vect_get_loop_len (loop_vinfo, gsi, lens, ncopies,
> + vectype_out, j, 1);
> + signed char biasval
> + = LOOP_VINFO_PARTIAL_LOAD_STORE_BIAS (loop_vinfo);
> + tree bias = build_int_cst (intQI_type_node, biasval);
> + vargs[len_opno] = len;
> + vargs[len_opno + 1] = bias;
> + }
> + else if (mask_opno >= 0 && masked_loop_p)
> {
> tree mask = vect_get_loop_mask (loop_vinfo, gsi, masks, ncopies,
> vectype_out, j);
>
--
Richard Biener <rguent...@suse.de>
SUSE Software Solutions Germany GmbH,
Frankenstrasse 146, 90461 Nuernberg, Germany;
GF: Ivo Totev, Andrew McDonald, Werner Knoblich; (HRB 36809, AG Nuernberg)
