On Wed, 18 Sep 2019 at 20:11, Richard Biener <rguent...@suse.de> wrote:
>
>
> It shouldn't be neccessary.
>
> Bootstrapped and tested on x86_64-unknown-linux-gnu, applied to trunk.
> (SLP part testing separately)
>
> Richard.
>
> 2019-09-18 Richard Biener <rguent...@suse.de>
>
> * tree-vect-loop.c (vect_is_simple_reduction): Remove operand
> swapping.
> (vectorize_fold_left_reduction): Remove assert.
> (vectorizable_reduction): Also expect COND_EXPR non-reduction
> operand in position 2. Remove assert.
>
Hi,
Since this was committed (r275898), I've noticed a regression on armeb:
FAIL: gcc.dg/vect/vect-cond-4.c execution test
I'm seeing this with qemu, but I do not have the execution traces yet.
Christophe
> Index: gcc/tree-vect-loop.c
> ===================================================================
> --- gcc/tree-vect-loop.c (revision 275872)
> +++ gcc/tree-vect-loop.c (working copy)
> @@ -3278,56 +3278,8 @@ vect_is_simple_reduction (loop_vec_info
> || !flow_bb_inside_loop_p (loop, gimple_bb (def2_info->stmt))
> || vect_valid_reduction_input_p (def2_info)))
> {
> - if (! nested_in_vect_loop && orig_code != MINUS_EXPR)
> - {
> - /* Check if we can swap operands (just for simplicity - so that
> - the rest of the code can assume that the reduction variable
> - is always the last (second) argument). */
> - if (code == COND_EXPR)
> - {
> - /* Swap cond_expr by inverting the condition. */
> - tree cond_expr = gimple_assign_rhs1 (def_stmt);
> - enum tree_code invert_code = ERROR_MARK;
> - enum tree_code cond_code = TREE_CODE (cond_expr);
> -
> - if (TREE_CODE_CLASS (cond_code) == tcc_comparison)
> - {
> - bool honor_nans = HONOR_NANS (TREE_OPERAND (cond_expr, 0));
> - invert_code = invert_tree_comparison (cond_code,
> honor_nans);
> - }
> - if (invert_code != ERROR_MARK)
> - {
> - TREE_SET_CODE (cond_expr, invert_code);
> - swap_ssa_operands (def_stmt,
> - gimple_assign_rhs2_ptr (def_stmt),
> - gimple_assign_rhs3_ptr (def_stmt));
> - }
> - else
> - {
> - if (dump_enabled_p ())
> - report_vect_op (MSG_NOTE, def_stmt,
> - "detected reduction: cannot swap operands
> "
> - "for cond_expr");
> - return NULL;
> - }
> - }
> - else
> - swap_ssa_operands (def_stmt, gimple_assign_rhs1_ptr (def_stmt),
> - gimple_assign_rhs2_ptr (def_stmt));
> -
> - if (dump_enabled_p ())
> - report_vect_op (MSG_NOTE, def_stmt,
> - "detected reduction: need to swap operands: ");
> -
> - if (CONSTANT_CLASS_P (gimple_assign_rhs1 (def_stmt)))
> - LOOP_VINFO_OPERANDS_SWAPPED (loop_info) = true;
> - }
> - else
> - {
> - if (dump_enabled_p ())
> - report_vect_op (MSG_NOTE, def_stmt, "detected reduction: ");
> - }
> -
> + if (dump_enabled_p ())
> + report_vect_op (MSG_NOTE, def_stmt, "detected reduction: ");
> return def_stmt_info;
> }
>
> @@ -5969,7 +5921,6 @@ vectorize_fold_left_reduction (stmt_vec_
> gcc_assert (!nested_in_vect_loop_p (loop, stmt_info));
> gcc_assert (ncopies == 1);
> gcc_assert (TREE_CODE_LENGTH (code) == binary_op);
> - gcc_assert (reduc_index == (code == MINUS_EXPR ? 0 : 1));
> gcc_assert (STMT_VINFO_VEC_REDUCTION_TYPE (stmt_info)
> == FOLD_LEFT_REDUCTION);
>
> @@ -6542,9 +6493,9 @@ vectorizable_reduction (stmt_vec_info st
> reduc_index = i;
> }
>
> - if (i == 1 && code == COND_EXPR)
> + if (code == COND_EXPR)
> {
> - /* Record how value of COND_EXPR is defined. */
> + /* Record how the non-reduction-def value of COND_EXPR is defined.
> */
> if (dt == vect_constant_def)
> {
> cond_reduc_dt = dt;
> @@ -6622,10 +6573,6 @@ vectorizable_reduction (stmt_vec_info st
> return false;
> }
>
> - /* vect_is_simple_reduction ensured that operand 2 is the
> - loop-carried operand. */
> - gcc_assert (reduc_index == 2);
> -
> /* Loop peeling modifies initial value of reduction PHI, which
> makes the reduction stmt to be transformed different to the
> original stmt analyzed. We need to record reduction code for
