On Fri, Oct 4, 2019 at 11:03 AM H.J. Lu <hjl.to...@gmail.com> wrote: > > On Wed, Sep 11, 2019 at 12:14 PM Richard Sandiford > <richard.sandif...@arm.com> wrote: > > > > lra_reg has an actual_call_used_reg_set field that is only used during > > inheritance. This in turn required a special lra_create_live_ranges > > pass for flag_ipa_ra to set up this field. This patch instead makes > > the inheritance code do its own live register tracking, using the > > same ABI-mask-and-clobber-set pair as for IRA. > > > > Tracking ABIs simplifies (and cheapens) the logic in lra-lives.c and > > means we no longer need a separate path for -fipa-ra. It also means > > we can remove TARGET_RETURN_CALL_WITH_MAX_CLOBBERS. > > > > The patch also strengthens the sanity check in lra_assigns so that > > we check that reg_renumber is consistent with the whole conflict set, > > not just the call-clobbered registers. > > > > > > 2019-09-11 Richard Sandiford <richard.sandif...@arm.com> > > > > gcc/ > > * target.def (return_call_with_max_clobbers): Delete. > > * doc/tm.texi.in (TARGET_RETURN_CALL_WITH_MAX_CLOBBERS): Delete. > > * doc/tm.texi: Regenerate. > > * config/aarch64/aarch64.c (aarch64_return_call_with_max_clobbers) > > (TARGET_RETURN_CALL_WITH_MAX_CLOBBERS): Delete. > > * lra-int.h (lra_reg::actual_call_used_reg_set): Delete. > > (lra_reg::call_insn): Delete. > > * lra.c: Include function-abi.h. > > (initialize_lra_reg_info_element): Don't initialize the fields > > above. > > (lra): Use crtl->abi to test whether the current function needs to > > save a register in the prologue. Remove special pre-inheritance > > lra_create_live_ranges pass for flag_ipa_ra. > > * lra-assigns.c: Include function-abi.h > > (find_hard_regno_for_1): Use crtl->abi to test whether the current > > function needs to save a register in the prologue. > > (lra_assign): Assert that registers aren't allocated to a > > conflicting register, rather than checking only for overlaps > > with call_used_or_fixed_regs. Do this even for flag_ipa_ra, > > and for registers that are not live across a call. > > * lra-constraints.c (last_call_for_abi): New variable. > > (full_and_partial_call_clobbers): Likewise. > > (setup_next_usage_insn): Remove the register from > > full_and_partial_call_clobbers. > > (need_for_call_save_p): Use call_clobbered_in_region_p to test > > whether the register needs a caller save. > > (need_for_split_p): Use full_and_partial_reg_clobbers instead > > of call_used_or_fixed_regs. > > (inherit_in_ebb): Initialize and maintain last_call_for_abi and > > full_and_partial_call_clobbers. > > * lra-lives.c (check_pseudos_live_through_calls): Replace > > last_call_used_reg_set and call_insn arguments with an abi argument. > > Remove handling of lra_reg::call_insn. Use > > function_abi::mode_clobbers > > as the set of conflicting registers. > > (calls_have_same_clobbers_p): Delete. > > (process_bb_lives): Track the ABI of the last call instead of an > > insn/HARD_REG_SET pair. Update calls to > > check_pseudos_live_through_calls. Use eh_edge_abi to calculate > > the set of registers that could be clobbered by an EH edge. > > Include partially-clobbered as well as fully-clobbered registers. > > (lra_create_live_ranges_1): Don't initialize lra_reg::call_insn. > > * lra-remat.c: Include function-abi.h. > > (call_used_regs_arr_len, call_used_regs_arr): Delete. > > (set_bb_regs): Use call_insn_abi to get the set of call-clobbered > > registers and bitmap_view to combine them into dead_regs. > > (call_used_input_regno_present_p): Take a function_abi argument > > and use it to test whether a register is call-clobbered. > > (calculate_gen_cands): Use call_insn_abi to get the ABI of the > > call insn target. Update tje call to > > call_used_input_regno_present_p. > > (do_remat): Likewise. > > (lra_remat): Remove the initialization of call_used_regs_arr_len > > and call_used_regs_arr. > > This caused: > > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91994 >
This change doesn't work with -mzeroupper. When -mzeroupper is used, upper bits of vector registers are clobbered upon callee return if any MM/ZMM registers are used in callee. Even if YMM7 isn't used, upper bits of YMM7 can still be clobbered by vzeroupper when YMM1 is used. -- H.J.
