From 2008be405c16e8b7ca5399fb9e6fb25aa92f03a3 Mon Sep 17 00:00:00 2001 From: Segher Boessenkool Date: Mon, 15 Aug 2016 18:17:21 +0200 Subject: [PATCH] lra: A multiple_sets is not a simple_move_p (PR73650) In the PR we have a PARALLEL of a move and a compare (a "mr." instruction). The compare is dead, so single_set on it returns just the move. Then, simple_move_p returns true; but the instruction does need reloads in this case. This patch solves this by making simple_move_p return false for every multiple_sets instruction. PR rtl-optimization/73650 * lra-constraints.c (simple_move_p): If the insn is multiple_sets it is not a simple move. From-SVN: r239483 --- gcc/ChangeLog | 6 ++++++ gcc/lra-constraints.c | 7 +++++++ 2 files changed, 13 insertions(+) diff --git a/gcc/ChangeLog b/gcc/ChangeLog index dc7e8cbc451..fa52700c953 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2016-08-15 Segher Boessenkool + + PR rtl-optimization/73650 + * lra-constraints.c (simple_move_p): If the insn is multiple_sets + it is not a simple move. + 2016-08-15 Martin Liska PR driver/72765 diff --git a/gcc/lra-constraints.c b/gcc/lra-constraints.c index 213e408c08b..053a65aa404 100644 --- a/gcc/lra-constraints.c +++ b/gcc/lra-constraints.c @@ -3493,6 +3493,13 @@ simple_move_p (void) lra_assert (curr_insn_set != NULL_RTX); dest = SET_DEST (curr_insn_set); src = SET_SRC (curr_insn_set); + + /* If the instruction has multiple sets we need to process it even if it + is single_set. This can happen if one or more of the SETs are dead. + See PR73650. */ + if (multiple_sets (curr_insn)) + return false; + return ((dclass = get_op_class (dest)) != NO_REGS && (sclass = get_op_class (src)) != NO_REGS /* The backend guarantees that register moves of cost 2 -- 2.30.2