https://gcc.gnu.org/g:3858dcd7a05e7a1143c9ac74a42c30c2fb1dbe4c
commit r16-3342-g3858dcd7a05e7a1143c9ac74a42c30c2fb1dbe4c
Author: Richard Biener <rguent...@suse.de>
Date: Fri Aug 22 10:39:33 2025 +0200
Decouple parloops from vect reduction infra some more
The following removes the use of STMT_VINFO_REDUC_* from parloops,
also fixing a mistake with analyzing double reductions which rely
on the outer loop vinfo so the inner loop is properly detected as
nested.
* tree-parloops.cc (parloops_is_simple_reduction): Pass
in double reduction inner loop LC phis and query that.
(parloops_force_simple_reduction): Similar, but set it.
Check for valid reduction types here.
(valid_reduction_p): Remove.
(gather_scalar_reductions): Adjust, fixup double
reduction inner loop processing.
Diff:
---
gcc/tree-parloops.cc | 114 ++++++++++++++++++++++-----------------------------
1 file changed, 48 insertions(+), 66 deletions(-)
diff --git a/gcc/tree-parloops.cc b/gcc/tree-parloops.cc
index 388f903a942a..666c6a1f3760 100644
--- a/gcc/tree-parloops.cc
+++ b/gcc/tree-parloops.cc
@@ -291,7 +291,8 @@ static stmt_vec_info
parloops_is_simple_reduction (loop_vec_info loop_info, stmt_vec_info phi_info,
bool *double_reduc,
bool need_wrapping_integral_overflow,
- enum vect_reduction_type *v_reduc_type)
+ enum vect_reduction_type *v_reduc_type,
+ hash_set<gphi *> &double_reduc_inner_lc_phis)
{
gphi *phi = as_a <gphi *> (phi_info->stmt);
class loop *loop = (gimple_bb (phi))->loop_father;
@@ -385,8 +386,7 @@ parloops_is_simple_reduction (loop_vec_info loop_info,
stmt_vec_info phi_info,
/* We can have more than one loop-closed PHI. */
lcphis.safe_push (as_a <gphi *> (use_stmt));
if (nested_in_vect_loop
- && (STMT_VINFO_DEF_TYPE (loop_info->lookup_stmt (use_stmt))
- == vect_double_reduction_def))
+ && double_reduc_inner_lc_phis.contains (as_a <gphi *> (use_stmt)))
inner_loop_of_double_reduc = true;
}
}
@@ -692,20 +692,20 @@ parloops_is_simple_reduction (loop_vec_info loop_info,
stmt_vec_info phi_info,
stmt_vec_info
parloops_force_simple_reduction (loop_vec_info loop_info, stmt_vec_info
phi_info,
bool *double_reduc,
- bool need_wrapping_integral_overflow)
+ bool need_wrapping_integral_overflow,
+ hash_set<gphi *> &double_reduc_inner_lc_phis)
{
enum vect_reduction_type v_reduc_type;
stmt_vec_info def_info
= parloops_is_simple_reduction (loop_info, phi_info, double_reduc,
need_wrapping_integral_overflow,
- &v_reduc_type);
- if (def_info)
- {
- STMT_VINFO_REDUC_TYPE (phi_info) = v_reduc_type;
- STMT_VINFO_REDUC_DEF (phi_info) = def_info;
- STMT_VINFO_REDUC_TYPE (def_info) = v_reduc_type;
- STMT_VINFO_REDUC_DEF (def_info) = phi_info;
- }
+ &v_reduc_type, double_reduc_inner_lc_phis);
+ /* Parallelization would reassociate the operation, which isn't
+ allowed for in-order reductions. */
+ if (v_reduc_type == FOLD_LEFT_REDUCTION)
+ return NULL;
+ if (def_info && *double_reduc)
+ double_reduc_inner_lc_phis.add (as_a <gphi *> (def_info->stmt));
return def_info;
}
@@ -3113,18 +3113,6 @@ set_reduc_phi_uids (reduction_info **slot, void *data
ATTRIBUTE_UNUSED)
return 1;
}
-/* Return true if the type of reduction performed by STMT_INFO is suitable
- for this pass. */
-
-static bool
-valid_reduction_p (stmt_vec_info stmt_info)
-{
- /* Parallelization would reassociate the operation, which isn't
- allowed for in-order reductions. */
- vect_reduction_type reduc_type = STMT_VINFO_REDUC_TYPE (stmt_info);
- return reduc_type != FOLD_LEFT_REDUCTION;
-}
-
/* Detect all reductions in the LOOP, insert them into REDUCTION_LIST. */
static void
@@ -3134,6 +3122,7 @@ gather_scalar_reductions (loop_p loop,
reduction_info_table_type *reduction_list
loop_vec_info simple_loop_info;
auto_vec<gphi *, 4> double_reduc_phis;
auto_vec<gimple *, 4> double_reduc_stmts;
+ hash_set<gphi *> double_reduc_inner_lc_phis;
vec_info_shared shared;
vect_loop_form_info info;
@@ -3157,14 +3146,15 @@ gather_scalar_reductions (loop_p loop,
reduction_info_table_type *reduction_list
stmt_vec_info reduc_stmt_info
= parloops_force_simple_reduction (simple_loop_info,
simple_loop_info->lookup_stmt (phi),
- &double_reduc, true);
- if (!reduc_stmt_info || !valid_reduction_p (reduc_stmt_info))
+ &double_reduc, true,
+ double_reduc_inner_lc_phis);
+ if (!reduc_stmt_info)
continue;
if (double_reduc)
{
- if (loop->inner->inner != NULL)
- continue;
+ /* vect_analyze_loop_form guarantees this. */
+ gcc_assert (loop->inner->inner == NULL);
double_reduc_phis.safe_push (phi);
double_reduc_stmts.safe_push (reduc_stmt_info->stmt);
@@ -3173,52 +3163,44 @@ gather_scalar_reductions (loop_p loop,
reduction_info_table_type *reduction_list
build_new_reduction (reduction_list, reduc_stmt_info->stmt, phi);
}
- delete simple_loop_info;
if (!double_reduc_phis.is_empty ())
{
- vec_info_shared shared;
- vect_loop_form_info info;
- if (vect_analyze_loop_form (loop->inner, NULL, &info))
- {
- simple_loop_info
- = vect_create_loop_vinfo (loop->inner, &shared, &info);
- gphi *phi;
- unsigned int i;
+ gphi *phi;
+ unsigned int i;
- FOR_EACH_VEC_ELT (double_reduc_phis, i, phi)
- {
- affine_iv iv;
- tree res = PHI_RESULT (phi);
- bool double_reduc;
-
- use_operand_p use_p;
- gimple *inner_stmt;
- bool single_use_p = single_imm_use (res, &use_p, &inner_stmt);
- gcc_assert (single_use_p);
- if (gimple_code (inner_stmt) != GIMPLE_PHI)
- continue;
- gphi *inner_phi = as_a <gphi *> (inner_stmt);
- if (simple_iv (loop->inner, loop->inner, PHI_RESULT (inner_phi),
- &iv, true))
- continue;
+ FOR_EACH_VEC_ELT (double_reduc_phis, i, phi)
+ {
+ affine_iv iv;
+ tree res = PHI_RESULT (phi);
+ bool double_reduc;
+
+ use_operand_p use_p;
+ gimple *inner_stmt;
+ bool single_use_p = single_imm_use (res, &use_p, &inner_stmt);
+ gcc_assert (single_use_p);
+ if (gimple_code (inner_stmt) != GIMPLE_PHI)
+ continue;
+ gphi *inner_phi = as_a <gphi *> (inner_stmt);
+ if (simple_iv (loop->inner, loop->inner, PHI_RESULT (inner_phi),
+ &iv, true))
+ continue;
- stmt_vec_info inner_phi_info
- = simple_loop_info->lookup_stmt (inner_phi);
- stmt_vec_info inner_reduc_stmt_info
- = parloops_force_simple_reduction (simple_loop_info,
- inner_phi_info,
- &double_reduc, true);
- gcc_assert (!double_reduc);
- if (!inner_reduc_stmt_info
- || !valid_reduction_p (inner_reduc_stmt_info))
- continue;
+ stmt_vec_info inner_phi_info
+ = simple_loop_info->lookup_stmt (inner_phi);
+ stmt_vec_info inner_reduc_stmt_info
+ = parloops_force_simple_reduction (simple_loop_info,
+ inner_phi_info,
+ &double_reduc, true,
+ double_reduc_inner_lc_phis);
+ gcc_assert (!double_reduc);
+ if (!inner_reduc_stmt_info)
+ continue;
- build_new_reduction (reduction_list, double_reduc_stmts[i], phi);
- }
- delete simple_loop_info;
+ build_new_reduction (reduction_list, double_reduc_stmts[i], phi);
}
}
+ delete simple_loop_info;
gather_done:
if (reduction_list->is_empty ())
