From 62cdb862640710f991b9e61a5ab4b7a0456a8043 Mon Sep 17 00:00:00 2001 From: Matthew Fortune Date: Mon, 20 Feb 2017 12:07:06 +0000 Subject: [PATCH] Tighten condition for converting SUBREG reloads from OP_OUT to OP_INOUT gcc/ PR target/78660 * lra-constraints.c (curr_insn_transform): Tighten condition for converting SUBREG reloads from OP_OUT to OP_INOUT. From-SVN: r245599 --- gcc/ChangeLog | 6 ++++++ gcc/lra-constraints.c | 12 +++++++++++- 2 files changed, 17 insertions(+), 1 deletion(-) diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 9dc6b58..1823049 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,6 +1,12 @@ 2017-02-20 Matthew Fortune PR target/78660 + * lra-constraints.c (curr_insn_transform): Tighten condition + for converting SUBREG reloads from OP_OUT to OP_INOUT. + +2017-02-20 Matthew Fortune + + PR target/78660 * lra-constraints.c (curr_insn_transform): Handle WORD_REGISTER_OPERATIONS requirements when reloading SUBREGs. diff --git a/gcc/lra-constraints.c b/gcc/lra-constraints.c index 62947e3..18b3096 100644 --- a/gcc/lra-constraints.c +++ b/gcc/lra-constraints.c @@ -4140,7 +4140,17 @@ curr_insn_transform (bool check_only_p) < GET_MODE_PRECISION (GET_MODE (reg)) && WORD_REGISTER_OPERATIONS))) { - if (type == OP_OUT) + /* An OP_INOUT is required when reloading a subreg of a + mode wider than a word to ensure that data beyond the + word being reloaded is preserved. Also automatically + ensure that strict_low_part reloads are made into + OP_INOUT which should already be true from the backend + constraints. */ + if (type == OP_OUT + && (curr_static_id->operand[i].strict_low + || (GET_MODE_SIZE (GET_MODE (reg)) > UNITS_PER_WORD + && (GET_MODE_SIZE (mode) + < GET_MODE_SIZE (GET_MODE (reg)))))) type = OP_INOUT; loc = &SUBREG_REG (*loc); mode = GET_MODE (*loc); -- 2.7.4