From: Matthew Fortune Date: Mon, 20 Feb 2017 12:07:06 +0000 (+0000) Subject: Tighten condition for converting SUBREG reloads from OP_OUT to OP_INOUT X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=62cdb862640710f991b9e61a5ab4b7a0456a8043;p=gcc.git 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 --- diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 9dc6b58a0ad..1823049df77 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +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 diff --git a/gcc/lra-constraints.c b/gcc/lra-constraints.c index 62947e36c97..18b309658bd 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);