The following tries to avoid eating into the SLP discovery limit
when we can do cheaper checks first. Together with the previous
patch this allows to use two-lane SLP discovery for mult_su3_an
in 433.milc.
Bootstrapped and tested on x86_64-unknown-linux-gnu, pushed.
PR tree-optimization/117874
* tree-vect-slp.cc (vect_build_slp_tree_2): Perform early
reassoc checks before eating into discovery limit.
---
gcc/tree-vect-slp.cc | 39 +++++++++++++++++++++++++++++----------
1 file changed, 29 insertions(+), 10 deletions(-)
diff --git a/gcc/tree-vect-slp.cc b/gcc/tree-vect-slp.cc
index 1799d5a619b..425135a9ee0 100644
--- a/gcc/tree-vect-slp.cc
+++ b/gcc/tree-vect-slp.cc
@@ -2292,6 +2292,9 @@ vect_build_slp_tree_2 (vec_info *vinfo, slp_tree node,
}
}
/* 2. try to build children nodes, associating as necessary. */
+ /* 2a. prepare and perform early checks to avoid eating into
+ discovery limit unnecessarily. */
+ vect_def_type *dts = XALLOCAVEC (vect_def_type, chain_len);
for (unsigned n = 0; n < chain_len; ++n)
{
vect_def_type dt = chains[0][n].dt;
@@ -2319,6 +2322,7 @@ vect_build_slp_tree_2 (vec_info *vinfo, slp_tree node,
matches[0] = false;
goto out;
}
+ dts[n] = dt;
if (dt == vect_constant_def
|| dt == vect_external_def)
{
@@ -2333,16 +2337,6 @@ vect_build_slp_tree_2 (vec_info *vinfo, slp_tree node,
matches[0] = false;
goto out;
}
- vec<tree> ops;
- ops.create (group_size);
- for (lane = 0; lane < group_size; ++lane)
- if (stmts[lane])
- ops.quick_push (chains[lane][n].op);
- else
- ops.quick_push (NULL_TREE);
- slp_tree child = vect_create_new_slp_node (ops);
- SLP_TREE_DEF_TYPE (child) = dt;
- children.safe_push (child);
}
else if (dt != vect_internal_def)
{
@@ -2354,6 +2348,26 @@ vect_build_slp_tree_2 (vec_info *vinfo, slp_tree node,
hard_fail = false;
goto out;
}
+ }
+ /* 2b. do the actual build. */
+ for (unsigned n = 0; n < chain_len; ++n)
+ {
+ vect_def_type dt = dts[n];
+ unsigned lane;
+ if (dt == vect_constant_def
+ || dt == vect_external_def)
+ {
+ vec<tree> ops;
+ ops.create (group_size);
+ for (lane = 0; lane < group_size; ++lane)
+ if (stmts[lane])
+ ops.quick_push (chains[lane][n].op);
+ else
+ ops.quick_push (NULL_TREE);
+ slp_tree child = vect_create_new_slp_node (ops);
+ SLP_TREE_DEF_TYPE (child) = dt;
+ children.safe_push (child);
+ }
else
{
vec<stmt_vec_info> op_stmts;
@@ -2396,6 +2410,11 @@ vect_build_slp_tree_2 (vec_info *vinfo, slp_tree node,
term = true;
break;
}
+ if (dump_enabled_p ())
+ dump_printf_loc (MSG_NOTE, vect_location,
+ "swapping operand %d and %d "
+ "of lane %d\n",
+ n, n + perms[lane] + 1, lane);
std::swap (chains[lane][n],
chains[lane][n + perms[lane] + 1]);
perms[lane]++;
--
2.43.0
