From 1e26ff7391c54c6d30760aea427b6bc2bdb46124 Mon Sep 17 00:00:00 2001 From: Richard Sandiford Date: Wed, 22 Jan 2020 18:21:05 +0000 Subject: [PATCH] vect: Pattern-matched calls in reduction chains gcc.dg/pr56350.c started ICEing for SVE in GCC 10 because we pattern-matched a division reduction: a /= 8; into a signed shift with division semantics: ... = IFN_SDIV_POW2 (..., 3); whereas the reduction code expected it still to be a gassign. One fix would be to check for a reduction in the pattern matcher (but current patterns don't generally do that). Another would be to fail gracefully for reductions involving calls. Since we can't vectorise the reduction either way, and probably have a better shot with the shift form, this patch goes for the "fail gracefully" approach. 2020-01-28 Richard Sandiford gcc/ * tree-vect-loop.c (vectorizable_reduction): Fail gracefully for reduction chains that (now) include a call. --- gcc/ChangeLog | 5 +++++ gcc/tree-vect-loop.c | 14 +++++++++++--- 2 files changed, 16 insertions(+), 3 deletions(-) diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 8f5ec7086fc..4d6ceb69258 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,8 @@ +2020-01-28 Richard Sandiford + + * tree-vect-loop.c (vectorizable_reduction): Fail gracefully + for reduction chains that (now) include a call. + 2020-01-28 Richard Sandiford PR tree-optimization/92822 diff --git a/gcc/tree-vect-loop.c b/gcc/tree-vect-loop.c index b4cfad875ab..53fccb715ef 100644 --- a/gcc/tree-vect-loop.c +++ b/gcc/tree-vect-loop.c @@ -6026,10 +6026,18 @@ vectorizable_reduction (stmt_vec_info stmt_info, slp_tree slp_node, info_for_reduction to work. */ if (STMT_VINFO_LIVE_P (vdef)) STMT_VINFO_REDUC_DEF (def) = phi_info; - if (CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (vdef->stmt))) + gassign *assign = dyn_cast (vdef->stmt); + if (!assign) { - if (!tree_nop_conversion_p (TREE_TYPE (gimple_assign_lhs (vdef->stmt)), - TREE_TYPE (gimple_assign_rhs1 (vdef->stmt)))) + if (dump_enabled_p ()) + dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, + "reduction chain includes calls.\n"); + return false; + } + if (CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (assign))) + { + if (!tree_nop_conversion_p (TREE_TYPE (gimple_assign_lhs (assign)), + TREE_TYPE (gimple_assign_rhs1 (assign)))) { if (dump_enabled_p ()) dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,