Unlike most vector ops, extract-last reductions replace the original
scalar code in-situ rather than adding an adjacent vector implementation.
I.e.:
dest_1 = COND_EXPR <...>;
becomes:
dest_1 = .EXTRACT_LAST (...);
gcc.dg/vect/vect-cond-reduc-4.c was ICEing for SVE because we tried
to replace the pattern statement in this way, rather than replacing
the original scalar statement.
Tested on aarch64-linux-gnu and x86_64-linux-gnu. OK to install?
Richard
2019-12-10 Richard Sandiford <richard.sandif...@arm.com>
gcc/
* tree-vect-stmts.c (vect_finish_replace_stmt): Always use the
original scalar statement rather than a pattern statement.
(vectorizable_condition): Likewise, in the handling of extract-last
reductions.
Index: gcc/tree-vect-stmts.c
===================================================================
--- gcc/tree-vect-stmts.c 2019-12-10 09:17:18.768002919 +0000
+++ gcc/tree-vect-stmts.c 2019-12-10 11:27:23.619355131 +0000
@@ -1779,9 +1779,10 @@ vect_finish_stmt_generation_1 (stmt_vec_
stmt_vec_info
vect_finish_replace_stmt (stmt_vec_info stmt_info, gimple *vec_stmt)
{
- gcc_assert (gimple_get_lhs (stmt_info->stmt) == gimple_get_lhs (vec_stmt));
+ gimple *scalar_stmt = vect_orig_stmt (stmt_info)->stmt;
+ gcc_assert (gimple_get_lhs (scalar_stmt) == gimple_get_lhs (vec_stmt));
- gimple_stmt_iterator gsi = gsi_for_stmt (stmt_info->stmt);
+ gimple_stmt_iterator gsi = gsi_for_stmt (scalar_stmt);
gsi_replace (&gsi, vec_stmt, true);
return vect_finish_stmt_generation_1 (stmt_info, vec_stmt);
@@ -10324,20 +10325,21 @@ vectorizable_condition (stmt_vec_info st
if (reduction_type == EXTRACT_LAST_REDUCTION)
{
+ gimple *old_stmt = vect_orig_stmt (stmt_info)->stmt;
+ tree lhs = gimple_get_lhs (old_stmt);
gcall *new_stmt = gimple_build_call_internal
(IFN_FOLD_EXTRACT_LAST, 3, else_clause, vec_compare,
vec_then_clause);
- gimple_call_set_lhs (new_stmt, scalar_dest);
- SSA_NAME_DEF_STMT (scalar_dest) = new_stmt;
- if (stmt_info->stmt == gsi_stmt (*gsi))
+ gimple_call_set_lhs (new_stmt, lhs);
+ SSA_NAME_DEF_STMT (lhs) = new_stmt;
+ if (old_stmt == gsi_stmt (*gsi))
new_stmt_info = vect_finish_replace_stmt (stmt_info, new_stmt);
else
{
/* In this case we're moving the definition to later in the
block. That doesn't matter because the only uses of the
lhs are in phi statements. */
- gimple_stmt_iterator old_gsi
- = gsi_for_stmt (stmt_info->stmt);
+ gimple_stmt_iterator old_gsi = gsi_for_stmt (old_stmt);
gsi_remove (&old_gsi, true);
new_stmt_info
= vect_finish_stmt_generation (stmt_info, new_stmt, gsi);
