When making the SLP tree a graph I messed up and in some cases we can
fail to propagate a higher max_nunits upwards when re-using a subtree.
For the testcase, but only on the gcc-9-branch, this causes us to
miss a higher value of 4 completely since it comes from a
single widening stmt which we remember but throw out of the window
due to an early mismatch fixable by commutating.
I hope TYPE_VECTOR_SUBPARTS are all ordered, at least aarch64-sve.exp
is clean as it gets with a cc1 cross (it doesn't seem to find
gcc/include/stdint.h so has more compile-time errors than necessary...).
Richard, is that an OK-ish assumption?
For dumping I simply use estimated_poly_value (didn't find a
format for dump_printf_loc suitable for poly_uint64).
Bootstrapped on x86_64-unknown-linux-gnu, testing in progress.
Will apply unless you find issues with the patch.
Thanks,
Richard.
2019-08-28 Richard Biener <rguent...@suse.de>
PR tree-optimization/91568
* tree-vectorizer.h (_slp_tree::max_nunits): Add.
* tree-vect-slp.c (vect_create_new_slp_node): Initialize it.
(vect_build_slp_tree): Record max_nunits into the subtree
and merge it upwards.
(vect_print_slp_tree): Print max_nunits.
* gfortran.dg/pr91568.f: New testcase.
Index: gcc/testsuite/gfortran.dg/pr91568.f
===================================================================
--- gcc/testsuite/gfortran.dg/pr91568.f (nonexistent)
+++ gcc/testsuite/gfortran.dg/pr91568.f (working copy)
@@ -0,0 +1,11 @@
+! { dg-do compile }
+! { dg-options "-Ofast" }
+ subroutine h3dall(z,hvec,hder,nterms)
+ complex *16 hvec(0:1),hder(0:1)
+ complex *16 z,zinv,ztmp/1.0/
+ zinv=1.0/z
+ do i=1,nterms
+ ztmp=zinv*i
+ hder(i)=hvec(i-1)-ztmp*hvec(i)
+ enddo
+ end
Index: gcc/tree-vect-slp.c
===================================================================
--- gcc/tree-vect-slp.c (revision 274983)
+++ gcc/tree-vect-slp.c (working copy)
@@ -129,6 +129,7 @@ vect_create_new_slp_node (vec<stmt_vec_i
SLP_TREE_TWO_OPERATORS (node) = false;
SLP_TREE_DEF_TYPE (node) = vect_internal_def;
node->refcnt = 1;
+ node->max_nunits = 1;
unsigned i;
FOR_EACH_VEC_ELT (scalar_stmts, i, stmt_info)
@@ -1051,15 +1052,24 @@ vect_build_slp_tree (vec_info *vinfo,
dump_printf_loc (MSG_NOTE, vect_location, "re-using %sSLP tree %p\n",
*leader ? "" : "failed ", *leader);
if (*leader)
- (*leader)->refcnt++;
+ {
+ (*leader)->refcnt++;
+ *max_nunits = ordered_max ((*leader)->max_nunits, *max_nunits);
+ }
return *leader;
}
- slp_tree res = vect_build_slp_tree_2 (vinfo, stmts, group_size, max_nunits,
+ poly_uint64 this_max_nunits = 1;
+ slp_tree res = vect_build_slp_tree_2 (vinfo, stmts, group_size,
+ &this_max_nunits,
matches, npermutes, tree_size,
max_tree_size, bst_map);
- /* Keep a reference for the bst_map use. */
if (res)
- res->refcnt++;
+ {
+ res->max_nunits = this_max_nunits;
+ *max_nunits = ordered_max (this_max_nunits, *max_nunits);
+ /* Keep a reference for the bst_map use. */
+ res->refcnt++;
+ }
bst_map->put (stmts.copy (), res);
return res;
}
@@ -1463,9 +1473,10 @@ vect_print_slp_tree (dump_flags_t dump_k
dump_metadata_t metadata (dump_kind, loc.get_impl_location ());
dump_user_location_t user_loc = loc.get_user_location ();
- dump_printf_loc (metadata, user_loc, "node%s %p\n",
+ dump_printf_loc (metadata, user_loc, "node%s %p (max_nunits=%u)\n",
SLP_TREE_DEF_TYPE (node) != vect_internal_def
- ? " (external)" : "", node);
+ ? " (external)" : "", node,
+ estimated_poly_value (node->max_nunits));
FOR_EACH_VEC_ELT (SLP_TREE_SCALAR_STMTS (node), i, stmt_info)
dump_printf_loc (metadata, user_loc, "\tstmt %d %G", i, stmt_info->stmt);
if (SLP_TREE_CHILDREN (node).is_empty ())
Index: gcc/tree-vectorizer.h
===================================================================
--- gcc/tree-vectorizer.h (revision 274983)
+++ gcc/tree-vectorizer.h (working copy)
@@ -132,6 +132,9 @@ struct _slp_tree {
unsigned int vec_stmts_size;
/* Reference count in the SLP graph. */
unsigned int refcnt;
+ /* The maximum number of vector elements for the subtree rooted
+ at this node. */
+ poly_uint64 max_nunits;
/* Whether the scalar computations use two different operators. */
bool two_operators;
/* The DEF type of this node. */
