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| author | Richard Sandiford <richard.sandiford@linaro.org> | 2017-10-26 16:12:09 +0000 |
|---|---|---|
| committer | Richard Sandiford <rsandifo@gcc.gnu.org> | 2017-10-26 16:12:09 +0000 |
| commit | 9eaf97d6d7f1511638fb9209b7acf30e8f26a060 (patch) | |
| tree | 16674acba1f8fe4ba22347b1846ccdecf4c4d541 /gcc/lra-constraints.c | |
| parent | 7984457f8295811880c37e7861aa7c0454ce9845 (diff) | |
| download | gcc-9eaf97d6d7f1511638fb9209b7acf30e8f26a060.zip gcc-9eaf97d6d7f1511638fb9209b7acf30e8f26a060.tar.gz gcc-9eaf97d6d7f1511638fb9209b7acf30e8f26a060.tar.bz2 | |
Make more use of df_read_modify_subreg_p
This patch uses df_read_modify_subreg_p to check whether writing
to a subreg would preserve some of the existing contents.
This has the effect of putting more emphasis on the
REGMODE_NATURAL_SIZE-based definition of whether something can be
partially modified, instead of using UNITS_PER_WORD unconditionally.
This becomes important for SVE, where UNITS_PER_WORD has no
significance for subregs of multi-register LD2/ST2, LD3/ST3 and
LD4/ST4 tuples.
2017-10-26 Richard Sandiford <richard.sandiford@linaro.org>
Alan Hayward <alan.hayward@arm.com>
David Sherwood <david.sherwood@arm.com>
gcc/
* caller-save.c (mark_referenced_regs): Use read_modify_subreg_p.
* combine.c (find_single_use_1): Likewise.
(expand_field_assignment): Likewise.
(move_deaths): Likewise.
* lra-constraints.c (simplify_operand_subreg): Likewise.
(curr_insn_transform): Likewise.
* lra.c (collect_non_operand_hard_regs): Likewise.
(add_regs_to_insn_regno_info): Likewise.
* rtlanal.c (reg_referenced_p): Likewise.
(covers_regno_no_parallel_p): Likewise.
Co-Authored-By: Alan Hayward <alan.hayward@arm.com>
Co-Authored-By: David Sherwood <david.sherwood@arm.com>
From-SVN: r254110
Diffstat (limited to 'gcc/lra-constraints.c')
| -rw-r--r-- | gcc/lra-constraints.c | 6 |
1 files changed, 2 insertions, 4 deletions
diff --git a/gcc/lra-constraints.c b/gcc/lra-constraints.c index 6163d7d..c3bbfd7 100644 --- a/gcc/lra-constraints.c +++ b/gcc/lra-constraints.c @@ -1679,7 +1679,7 @@ simplify_operand_subreg (int nop, machine_mode reg_mode) bitmap_set_bit (&lra_subreg_reload_pseudos, REGNO (new_reg)); insert_before = (type != OP_OUT - || GET_MODE_SIZE (innermode) > GET_MODE_SIZE (mode)); + || read_modify_subreg_p (operand)); insert_after = (type != OP_IN); insert_move_for_subreg (insert_before ? &before : NULL, insert_after ? &after : NULL, @@ -4232,9 +4232,7 @@ curr_insn_transform (bool check_only_p) 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)))))) + || read_modify_subreg_p (*loc))) type = OP_INOUT; loc = &SUBREG_REG (*loc); mode = GET_MODE (*loc); |