This patch adds a partial_subreg_p predicate to go alongside
paradoxical_subreg_p.
Like the paradoxical_subreg_p patch, this one replaces some tests that
were based on GET_MODE_SIZE rather than GET_MODE_PRECISION. In each
case the change should be a no-op or an improvement.
The regcprop.c patch prevents some replacements of the 82-bit RFmode
with the 80-bit XFmode on ia64. I don't understand the target details
here particularly well, but from the way the modes are described in
ia64-modes.def, it isn't valid to assume that an XFmode can carry an
RFmode payload. A comparison of the testsuite assembly output for one
target per CPU showed no other differences.
Some of the places changed here are tracking the widest access mode
found for a register. The series tries to standardise on:
if (partial_subreg_p (widest_seen, new_mode))
widest_seen = new_mode;
rather than:
if (paradoxical_subreg_p (new_mode, widest_seen))
widest_seen = new_mode;
Either would have been OK.
2017-08-30 Richard Sandiford <richard.sandiford@linaro.org>
Alan Hayward <alan.hayward@arm.com>
David Sherwood <david.sherwood@arm.com>
gcc/
* rtl.h (partial_subreg_p): New function.
* caller-save.c (save_call_clobbered_regs): Use it.
* calls.c (expand_call): Likewise.
* combine.c (combinable_i3pat): Likewise.
(simplify_set): Likewise.
(make_extraction): Likewise.
(make_compound_operation_int): Likewise.
(gen_lowpart_or_truncate): Likewise.
(force_to_mode): Likewise.
(make_field_assignment): Likewise.
(reg_truncated_to_mode): Likewise.
(record_truncated_value): Likewise.
(move_deaths): Likewise.
* cse.c (record_jump_cond): Likewise.
(cse_insn): Likewise.
* cselib.c (cselib_lookup_1): Likewise.
* expmed.c (extract_bit_field_using_extv): Likewise.
* function.c (assign_parm_setup_reg): Likewise.
* ifcvt.c (noce_convert_multiple_sets): Likewise.
* ira-build.c (create_insn_allocnos): Likewise.
* lra-coalesce.c (merge_pseudos): Likewise.
* lra-constraints.c (match_reload): Likewise.
(simplify_operand_subreg): Likewise.
(curr_insn_transform): Likewise.
* lra-lives.c (process_bb_lives): Likewise.
* lra.c (new_insn_reg): Likewise.
(lra_substitute_pseudo): Likewise.
* regcprop.c (mode_change_ok): Likewise.
(maybe_mode_change): Likewise.
(copyprop_hardreg_forward_1): Likewise.
* reload.c (push_reload): Likewise.
(find_reloads): Likewise.
(find_reloads_subreg_address): Likewise.
* reload1.c (alter_reg): Likewise.
(eliminate_regs_1): Likewise.
* simplify-rtx.c (simplify_unary_operation_1): Likewise.
Co-Authored-By: Alan Hayward <alan.hayward@arm.com>
Co-Authored-By: David Sherwood <david.sherwood@arm.com>
From-SVN: r251536
