On 16/08/2026 20:51, Andrea Pinski wrote: > On Sun, Aug 16, 2026 at 8:17 PM huzife <[email protected]> wrote: > > > > A load pair that partially overlaps a recent scalar store can prevent the > > load from using store-to-load forwarding. Splitting the pair lets the > > overlapping half use the forwarding path. > > > > Add a late AArch64 RTL pass that handles non-writeback SI and DI GPR load > > pairs. Search a bounded part of the containing basic block for a scalar > > store to either half, and replace the pair only when both scalar loads are > > recognized. Reject volatile, frame-related and exception-sensitive forms, > > and disable the transformation for size optimization. Keep the pass off by > > default behind a target parameter while its profitability is evaluated. > > > I am not sure we want this. Is this dependent on the micro-arch? Can > you expand on which micro-arch where this helps out? > Also shouldn't instead of a separate pass which undoes what an earlier > pass. Won't it be better to improve the heuristics of ldp_fusion pass > to reject this from happening in the first place for these cases?
I agree with everything Andrea said here, it would be good to know which u-arches are expected to benefit, and potentially which workloads show a benefit with this transformation. If we do decide to to do this, I agree that it would be better to try and prevent the pairs from being formed in the first place (i.e. in pair-fusion) if possible. Thanks, Alex > > > > > gcc/ChangeLog: > > > > * config.gcc (aarch64*-*-*): Add aarch64-ldp-split.o. > > * config/aarch64/aarch64-ldp-split.cc: New file. > > * config/aarch64/aarch64-passes.def: Insert pass_split_ldp_stlf > > before > > pass_sched2. > > * config/aarch64/aarch64-protos.h (make_pass_split_ldp_stlf): > > Declare. > > * config/aarch64/aarch64.opt: Add aarch64-split-ldp-stlf parameter. > > * config/aarch64/t-aarch64 (aarch64-ldp-split.o): New rule. > > * doc/params.texi (aarch64-split-ldp-stlf): Document. > > > > gcc/testsuite/ChangeLog: > > > > * gcc.target/aarch64/split-ldp-stlf-1.c: New test. > > * gcc.target/aarch64/split-ldp-stlf-2.c: New test. > > * gcc.target/aarch64/split-ldp-stlf-3.c: New test. > > * gcc.target/aarch64/split-ldp-stlf-4.c: New test. > > * gcc.target/aarch64/split-ldp-stlf-5.c: New test. > > * gcc.target/aarch64/split-ldp-stlf-6.c: New test. > > > > Signed-off-by: huzife <[email protected]> > > --- > > gcc/config.gcc | 1 + > > gcc/config/aarch64/aarch64-ldp-split.cc | 316 ++++++++++++++++++ > > gcc/config/aarch64/aarch64-passes.def | 1 + > > gcc/config/aarch64/aarch64-protos.h | 1 + > > gcc/config/aarch64/aarch64.opt | 5 + > > gcc/config/aarch64/t-aarch64 | 6 + > > gcc/doc/params.texi | 8 + > > .../gcc.target/aarch64/split-ldp-stlf-1.c | 43 +++ > > .../gcc.target/aarch64/split-ldp-stlf-2.c | 13 + > > .../gcc.target/aarch64/split-ldp-stlf-3.c | 22 ++ > > .../gcc.target/aarch64/split-ldp-stlf-4.c | 14 + > > .../gcc.target/aarch64/split-ldp-stlf-5.c | 13 + > > .../gcc.target/aarch64/split-ldp-stlf-6.c | 13 + > > 13 files changed, 456 insertions(+) > > create mode 100644 gcc/config/aarch64/aarch64-ldp-split.cc > > create mode 100644 gcc/testsuite/gcc.target/aarch64/split-ldp-stlf-1.c > > create mode 100644 gcc/testsuite/gcc.target/aarch64/split-ldp-stlf-2.c > > create mode 100644 gcc/testsuite/gcc.target/aarch64/split-ldp-stlf-3.c > > create mode 100644 gcc/testsuite/gcc.target/aarch64/split-ldp-stlf-4.c > > create mode 100644 gcc/testsuite/gcc.target/aarch64/split-ldp-stlf-5.c > > create mode 100644 gcc/testsuite/gcc.target/aarch64/split-ldp-stlf-6.c > > > > diff --git a/gcc/config.gcc b/gcc/config.gcc > > index 0477bf22c8a..00aa965f162 100644 > > --- a/gcc/config.gcc > > +++ b/gcc/config.gcc > > @@ -362,6 +362,7 @@ aarch64*-*-*) > > extra_objs="${extra_objs} aarch-bti-insert.o" > > extra_objs="${extra_objs} aarch64-early-ra.o" > > extra_objs="${extra_objs} aarch64-ldp-fusion.o" > > + extra_objs="${extra_objs} aarch64-ldp-split.o" > > extra_objs="${extra_objs} aarch64-sched-dispatch.o" > > extra_objs="${extra_objs} aarch64-json-tunings-printer.o" > > extra_objs="${extra_objs} aarch64-json-tunings-parser.o" > > diff --git a/gcc/config/aarch64/aarch64-ldp-split.cc > > b/gcc/config/aarch64/aarch64-ldp-split.cc > > new file mode 100644 > > index 00000000000..a4c2c159529 > > --- /dev/null > > +++ b/gcc/config/aarch64/aarch64-ldp-split.cc > > @@ -0,0 +1,316 @@ > > +/* Split selected load pairs to improve store-to-load forwarding on > > AArch64. > > + Copyright (C) 2026 Free Software Foundation, Inc. > > + > > + This file is part of GCC. > > + > > + GCC is free software; you can redistribute it and/or modify it under > > + the terms of the GNU General Public License as published by the Free > > + Software Foundation; either version 3, or (at your option) any later > > + version. > > + > > + GCC is distributed in the hope that it will be useful, but WITHOUT ANY > > + WARRANTY; without even the implied warranty of MERCHANTABILITY or > > + FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License > > + for more details. > > + > > + You should have received a copy of the GNU General Public License > > + along with GCC; see the file COPYING3. If not see > > + <http://www.gnu.org/licenses/>. */ > > + > > +#define IN_TARGET_CODE 1 > > + > > +#include "config.h" > > +#include "system.h" > > +#include "coretypes.h" > > +#include "backend.h" > > +#include "rtl.h" > > +#include "df.h" > > +#include "memmodel.h" > > +#include "emit-rtl.h" > > +#include "tree-pass.h" > > +#include "insn-attr.h" > > +#include "insn-constants.h" > > +#include "insn-config.h" > > +#include "recog.h" > > +#include "cfgrtl.h" > > +#include "predict.h" > > + > > +namespace { > > + > > +/* A non-writeback GPR load pair that is safe for this pass to split. */ > > +struct ldp_info > > +{ > > + rtx dests[2]; > > + rtx mem; > > + rtx base; > > + machine_mode mode; > > + HOST_WIDE_INT offset; > > + HOST_WIDE_INT access_size; > > +}; > > + > > +/* Return true if REG is a hard general-purpose register in MODE. */ > > + > > +static bool > > +gpr_operand_p (rtx reg, machine_mode mode) > > +{ > > + return (REG_P (reg) > > + && HARD_REGISTER_P (reg) > > + && GP_REGNUM_P (REGNO (reg)) > > + && GET_MODE (reg) == mode); > > +} > > + > > +/* Extract the MEM from one half of an AArch64 load pair. */ > > + > > +static rtx > > +extract_ldp_mem (rtx set, rtx dest, int unspec_code) > > +{ > > + if (GET_CODE (set) != SET || !rtx_equal_p (SET_DEST (set), dest)) > > + return NULL_RTX; > > + > > + rtx src = SET_SRC (set); > > + if (GET_CODE (src) != UNSPEC > > + || XINT (src, 1) != unspec_code > > + || XVECLEN (src, 0) != 1) > > + return NULL_RTX; > > + > > + rtx mem = XVECEXP (src, 0, 0); > > + return MEM_P (mem) ? mem : NULL_RTX; > > +} > > + > > +/* If INSN is an ordinary, non-writeback SI or DI GPR LDP, describe it in > > + INFO and return true. Deliberately reject FP/SIMD, TImode, volatile, > > + frame-related, and EH-sensitive forms. */ > > + > > +static bool > > +extract_ldp (rtx_insn *insn, ldp_info *info) > > +{ > > + if (!NONDEBUG_INSN_P (insn) > > + || INSN_CODE (insn) < 0 > > + || get_attr_ldpstp (insn) != LDPSTP_LDP > > + || RTX_FRAME_RELATED_P (insn) > > + || find_reg_note (insn, REG_EH_REGION, NULL_RTX)) > > + return false; > > + > > + rtx pattern = PATTERN (insn); > > + if (GET_CODE (pattern) != PARALLEL || XVECLEN (pattern, 0) != 2) > > + return false; > > + > > + rtx sets[2] = { XVECEXP (pattern, 0, 0), XVECEXP (pattern, 0, 1) }; > > + if (GET_CODE (sets[0]) != SET || GET_CODE (sets[1]) != SET) > > + return false; > > + > > + info->dests[0] = SET_DEST (sets[0]); > > + info->dests[1] = SET_DEST (sets[1]); > > + info->mode = GET_MODE (info->dests[0]); > > + if ((info->mode != SImode && info->mode != DImode) > > + || !gpr_operand_p (info->dests[0], info->mode) > > + || !gpr_operand_p (info->dests[1], info->mode) > > + || reg_overlap_mentioned_p (info->dests[0], info->dests[1])) > > + return false; > > + > > + rtx mem0 = extract_ldp_mem (sets[0], info->dests[0], UNSPEC_LDP_FST); > > + rtx mem1 = extract_ldp_mem (sets[1], info->dests[1], UNSPEC_LDP_SND); > > + if (!mem0 > > + || !mem1 > > + || !rtx_equal_p (mem0, mem1) > > + || MEM_VOLATILE_P (mem0) > > + || side_effects_p (XEXP (mem0, 0)) > > + || !MEM_SIZE_KNOWN_P (mem0) > > + || !MEM_SIZE (mem0).is_constant ()) > > + return false; > > + > > + info->access_size = GET_MODE_SIZE (info->mode).to_constant (); > > + if (!known_eq (MEM_SIZE (mem0), 2 * info->access_size)) > > + return false; > > + > > + poly_int64 offset; > > + info->base = strip_offset (XEXP (mem0, 0), &offset); > > + if (!REG_P (info->base) || !offset.is_constant (&info->offset)) > > + return false; > > + > > + info->mem = mem0; > > + return true; > > +} > > + > > +/* Return true if INSN is a nonvolatile GPR store of one LDP half, using > > the > > + same unmodified base as INFO and writing exactly the low or high half. > > */ > > + > > +static bool > > +forwarding_store_p (rtx_insn *insn, const ldp_info &info) > > +{ > > + if (!NONDEBUG_INSN_P (insn) || RTX_FRAME_RELATED_P (insn)) > > + return false; > > + > > + rtx set = single_set (insn); > > + if (!set || !MEM_P (SET_DEST (set))) > > + return false; > > + > > + rtx mem = SET_DEST (set); > > + rtx value = SET_SRC (set); > > + if (GET_MODE (mem) != info.mode > > + || !gpr_operand_p (value, info.mode) > > + || MEM_VOLATILE_P (mem) > > + || side_effects_p (XEXP (mem, 0)) > > + || !MEM_SIZE_KNOWN_P (mem) > > + || !known_eq (MEM_SIZE (mem), info.access_size)) > > + return false; > > + > > + poly_int64 poly_offset; > > + rtx base = strip_offset (XEXP (mem, 0), &poly_offset); > > + HOST_WIDE_INT offset; > > + if (!REG_P (base) > > + || !rtx_equal_p (base, info.base) > > + || !poly_offset.is_constant (&offset)) > > + return false; > > + > > + return (offset == info.offset > > + || offset == info.offset + info.access_size); > > +} > > + > > +/* Search backwards in the containing basic block for a nearby store that > > + makes splitting PAIR profitable. Stop once the base value changes. */ > > + > > +static rtx_insn * > > +find_forwarding_store (rtx_insn *pair, const ldp_info &info) > > +{ > > + basic_block bb = BLOCK_FOR_INSN (pair); > > + unsigned int distance = 0; > > + unsigned int max_distance = (unsigned int) aarch64_split_ldp_stlf; > > + > > + for (rtx_insn *insn = PREV_INSN (pair); > > + insn && BLOCK_FOR_INSN (insn) == bb; > > + insn = PREV_INSN (insn)) > > + { > > + if (!NONDEBUG_INSN_P (insn)) > > + continue; > > + > > + if (++distance > max_distance) > > + break; > > + > > + if (CALL_P (insn) || modified_in_p (info.base, insn)) > > + break; > > + > > + if (forwarding_store_p (insn, info)) > > + return insn; > > + } > > + > > + return NULL; > > +} > > + > > +/* Replace PAIR with two individually-recognized scalar loads. Load the > > + non-base destination first when the low destination overlaps the base. > > */ > > + > > +static bool > > +split_ldp (rtx_insn *pair, const ldp_info &info) > > +{ > > + rtx mems[2] = { > > + adjust_address_nv (info.mem, info.mode, 0), > > + adjust_address_nv (info.mem, info.mode, info.access_size) > > + }; > > + > > + int order[2] = { 0, 1 }; > > + if (reg_overlap_mentioned_p (info.base, info.dests[0])) > > + std::swap (order[0], order[1]); > > + > > + start_sequence (); > > + emit_insn (gen_rtx_SET (info.dests[order[0]], mems[order[0]])); > > + emit_insn (gen_rtx_SET (info.dests[order[1]], mems[order[1]])); > > + rtx_insn *seq = get_insns (); > > + end_sequence (); > > + > > + unshare_all_rtl_in_chain (seq); > > + for (rtx_insn *insn = seq; insn; insn = NEXT_INSN (insn)) > > + if (!NONDEBUG_INSN_P (insn) || recog_memoized (insn) < 0) > > + { > > + if (dump_file) > > + fprintf (dump_file, > > + "Rejecting LDP %d: scalar replacement is not > > recognized\n", > > + INSN_UID (pair)); > > + return false; > > + } > > + > > + if (dump_file) > > + { > > + fprintf (dump_file, "Splitting LDP %d into:\n", INSN_UID (pair)); > > + for (rtx_insn *insn = seq; insn; insn = NEXT_INSN (insn)) > > + print_rtl_single (dump_file, insn); > > + } > > + > > + emit_insn_before_setloc (seq, pair, INSN_LOCATION (pair)); > > + delete_insn (pair); > > + return true; > > +} > > + > > +const pass_data pass_data_split_ldp_stlf = > > +{ > > + RTL_PASS, /* type. */ > > + "split_ldp_stlf", /* name. */ > > + OPTGROUP_NONE, /* optinfo_flags. */ > > + TV_MACH_DEP, /* tv_id. */ > > + 0, /* properties_required. */ > > + 0, /* properties_provided. */ > > + 0, /* properties_destroyed. */ > > + 0, /* todo_flags_start. */ > > + TODO_df_verify | TODO_df_finish, /* todo_flags_finish. */ > > +}; > > + > > +class pass_split_ldp_stlf : public rtl_opt_pass > > +{ > > +public: > > + pass_split_ldp_stlf (gcc::context *ctxt) > > + : rtl_opt_pass (pass_data_split_ldp_stlf, ctxt) > > + {} > > + > > + bool gate (function *fn) final override > > + { > > + return (optimize >= 1 > > + && !optimize_debug > > + && reload_completed > > + && aarch64_split_ldp_stlf > > + && !optimize_function_for_size_p (fn) > > + && !fn->can_throw_non_call_exceptions); > > + } > > + > > + unsigned int execute (function *fn) final override > > + { > > + unsigned int split_count = 0; > > + basic_block bb; > > + > > + FOR_EACH_BB_FN (bb, fn) > > + { > > + rtx_insn *insn; > > + rtx_insn *next; > > + FOR_BB_INSNS_SAFE (bb, insn, next) > > + { > > + ldp_info info; > > + if (!extract_ldp (insn, &info)) > > + continue; > > + > > + rtx_insn *store = find_forwarding_store (insn, info); > > + if (!store) > > + continue; > > + > > + if (dump_file) > > + { > > + fprintf (dump_file, "Found forwarding store for LDP %d:\n", > > + INSN_UID (insn)); > > + print_rtl_single (dump_file, store); > > + } > > + > > + split_count += split_ldp (insn, info); > > + } > > + } > > + > > + if (dump_file) > > + fprintf (dump_file, "Split %u LDP instructions\n", split_count); > > + return 0; > > + } > > +}; > > + > > +} // namespace > > + > > +rtl_opt_pass * > > +make_pass_split_ldp_stlf (gcc::context *ctxt) > > +{ > > + return new pass_split_ldp_stlf (ctxt); > > +} > > diff --git a/gcc/config/aarch64/aarch64-passes.def > > b/gcc/config/aarch64/aarch64-passes.def > > index 2df7459af92..594348a0532 100644 > > --- a/gcc/config/aarch64/aarch64-passes.def > > +++ b/gcc/config/aarch64/aarch64-passes.def > > @@ -26,4 +26,5 @@ INSERT_PASS_BEFORE > > (pass_late_thread_prologue_and_epilogue, 1, pass_late_track_s > > INSERT_PASS_BEFORE (pass_shorten_branches, 1, pass_insert_bti); > > INSERT_PASS_BEFORE (pass_early_remat, 1, pass_ldp_fusion); > > INSERT_PASS_BEFORE (pass_peephole2, 1, pass_ldp_fusion); > > +INSERT_PASS_BEFORE (pass_sched2, 1, pass_split_ldp_stlf); > > INSERT_PASS_BEFORE (pass_free_cfg, 1, pass_narrow_gp_writes); > > diff --git a/gcc/config/aarch64/aarch64-protos.h > > b/gcc/config/aarch64/aarch64-protos.h > > index bcc833cfaa1..ec8be386c29 100644 > > --- a/gcc/config/aarch64/aarch64-protos.h > > +++ b/gcc/config/aarch64/aarch64-protos.h > > @@ -1268,6 +1268,7 @@ rtl_opt_pass *make_pass_late_track_speculation > > (gcc::context *); > > rtl_opt_pass *make_pass_insert_bti (gcc::context *ctxt); > > rtl_opt_pass *make_pass_switch_pstate_sm (gcc::context *ctxt); > > rtl_opt_pass *make_pass_ldp_fusion (gcc::context *); > > +rtl_opt_pass *make_pass_split_ldp_stlf (gcc::context *); > > rtl_opt_pass *make_pass_narrow_gp_writes (gcc::context *); > > > > poly_uint64 aarch64_regmode_natural_size (machine_mode); > > diff --git a/gcc/config/aarch64/aarch64.opt b/gcc/config/aarch64/aarch64.opt > > index deccc6c8887..21e9500996d 100644 > > --- a/gcc/config/aarch64/aarch64.opt > > +++ b/gcc/config/aarch64/aarch64.opt > > @@ -461,6 +461,11 @@ individual writeback accesses where possible. A value > > of two means we > > also try to opportunistically form writeback opportunities by folding in > > trailing destructive updates of the base register used by a pair. > > > > +-param=aarch64-split-ldp-stlf= > > +Target Joined UInteger Var(aarch64_split_ldp_stlf) Init(0) IntegerRange(0, > > 32) Param > > +Maximum number of preceding instructions to search when splitting an LDP > > +to improve store-to-load forwarding. A value of zero disables the pass. > > + > > -param=aarch64-tag-memory-loop-threshold= > > Target Joined UInteger Var(aarch64_tag_memory_loop_threshold) Init(10) > > IntegerRange(0, 65536) Param > > Param to control the threshold in number of granules beyond which an > > diff --git a/gcc/config/aarch64/t-aarch64 b/gcc/config/aarch64/t-aarch64 > > index 3942a1049b9..936540aeb4e 100644 > > --- a/gcc/config/aarch64/t-aarch64 > > +++ b/gcc/config/aarch64/t-aarch64 > > @@ -238,6 +238,12 @@ aarch64-ldp-fusion.o: > > $(srcdir)/config/aarch64/aarch64-ldp-fusion.cc \ > > $(COMPILER) -c $(ALL_COMPILERFLAGS) $(ALL_CPPFLAGS) $(INCLUDES) \ > > $(srcdir)/config/aarch64/aarch64-ldp-fusion.cc > > > > +aarch64-ldp-split.o: $(srcdir)/config/aarch64/aarch64-ldp-split.cc \ > > + $(CONFIG_H) $(SYSTEM_H) $(CORETYPES_H) $(BACKEND_H) $(RTL_H) $(DF_H) \ > > + $(INSN_ATTR_H) insn-config.h $(RECOG_H) tree-pass.h > > + $(COMPILER) -c $(ALL_COMPILERFLAGS) $(ALL_CPPFLAGS) $(INCLUDES) \ > > + $(srcdir)/config/aarch64/aarch64-ldp-split.cc > > + > > aarch64-sched-dispatch.o: > > $(srcdir)/config/aarch64/aarch64-sched-dispatch.cc \ > > $(CONFIG_H) $(SYSTEM_H) $(CORETYPES_H) $(BACKEND_H) $(RTL_H) \ > > $(INSN_ATTR_H) $(REGSET_H) sched-int.h $(DUMPFILE_H) \ > > diff --git a/gcc/doc/params.texi b/gcc/doc/params.texi > > index 26b34a59aa9..1ae93ae6c75 100644 > > --- a/gcc/doc/params.texi > > +++ b/gcc/doc/params.texi > > @@ -2061,6 +2061,14 @@ accesses where possible. A value of two means we > > also try to opportunistically > > form writeback opportunities by folding in trailing destructive updates of > > the > > base register used by a pair. > > > > +@paindex aarch64-split-ldp-stlf > > +@item aarch64-split-ldp-stlf > > +Maximum number of preceding instructions that the AArch64 backend searches > > +for a scalar store that writes one half of a later @code{ldp}. When such a > > +store is found, the backend can split the @code{ldp} into two scalar loads > > to > > +improve store-to-load forwarding. A value of zero, which is the default, > > +disables the transformation. > > + > > @paindex aarch64-loop-vect-issue-rate-niters > > @item aarch64-loop-vect-issue-rate-niters > > The tuning for some AArch64 CPUs tries to take both latencies and issue > > diff --git a/gcc/testsuite/gcc.target/aarch64/split-ldp-stlf-1.c > > b/gcc/testsuite/gcc.target/aarch64/split-ldp-stlf-1.c > > new file mode 100644 > > index 00000000000..ca4ca4821b1 > > --- /dev/null > > +++ b/gcc/testsuite/gcc.target/aarch64/split-ldp-stlf-1.c > > @@ -0,0 +1,43 @@ > > +/* { dg-options "-O2 --param=aarch64-split-ldp-stlf=16" } */ > > + > > +__attribute__ ((noinline, noclone)) > > +long > > +split_low (long *p, long value) > > +{ > > + p[1] = value; > > + __asm__ __volatile__ ("" ::: "memory"); > > + return p[1] + p[2]; > > +} > > + > > +__attribute__ ((noinline, noclone)) > > +long > > +split_high (long *p, long value) > > +{ > > + p[2] = value; > > + __asm__ __volatile__ ("" ::: "memory"); > > + return p[1] + p[2]; > > +} > > + > > +__attribute__ ((noinline, noclone)) > > +int > > +split_low_si (int *p, int value) > > +{ > > + p[1] = value; > > + __asm__ __volatile__ ("" ::: "memory"); > > + return p[1] + p[2]; > > +} > > + > > +extern void consume (long, long); > > + > > +__attribute__ ((noinline, noclone)) > > +void > > +split_base_dest_overlap (long *p, long value) > > +{ > > + p[1] = value; > > + __asm__ __volatile__ ("" ::: "memory"); > > + consume (p[1], p[2]); > > +} > > + > > +/* { dg-final { scan-assembler-not {\tldp\t} } } */ > > +/* { dg-final { scan-assembler-times {\tldr\t} 8 } } */ > > +/* { dg-final { scan-assembler-times {\tldr\tx1, \[x0, 16\]\n\tldr\tx0, > > \[x0, 8\]} 1 } } */ > > diff --git a/gcc/testsuite/gcc.target/aarch64/split-ldp-stlf-2.c > > b/gcc/testsuite/gcc.target/aarch64/split-ldp-stlf-2.c > > new file mode 100644 > > index 00000000000..2ad7e2d5825 > > --- /dev/null > > +++ b/gcc/testsuite/gcc.target/aarch64/split-ldp-stlf-2.c > > @@ -0,0 +1,13 @@ > > +/* { dg-options "-O2" } */ > > + > > +__attribute__ ((noinline, noclone)) > > +long > > +disabled_by_default (long *p, long value) > > +{ > > + p[1] = value; > > + __asm__ __volatile__ ("" ::: "memory"); > > + return p[1] + p[2]; > > +} > > + > > +/* { dg-final { scan-assembler-times {\tldp\t} 1 } } */ > > +/* { dg-final { scan-assembler-not {\tldr\t} } } */ > > diff --git a/gcc/testsuite/gcc.target/aarch64/split-ldp-stlf-3.c > > b/gcc/testsuite/gcc.target/aarch64/split-ldp-stlf-3.c > > new file mode 100644 > > index 00000000000..930ada6836d > > --- /dev/null > > +++ b/gcc/testsuite/gcc.target/aarch64/split-ldp-stlf-3.c > > @@ -0,0 +1,22 @@ > > +/* { dg-options "-O2 --param=aarch64-split-ldp-stlf=16" } */ > > + > > +__attribute__ ((noinline, noclone)) > > +long > > +no_overlap (long *p, long value) > > +{ > > + p[4] = value; > > + __asm__ __volatile__ ("" ::: "memory"); > > + return p[1] + p[2]; > > +} > > + > > +__attribute__ ((noinline, noclone)) > > +long > > +wrong_store_width (long *p, int value) > > +{ > > + *(int *) ((char *) p + 8) = value; > > + __asm__ __volatile__ ("" ::: "memory"); > > + return p[1] + p[2]; > > +} > > + > > +/* { dg-final { scan-assembler-times {\tldp\t} 2 } } */ > > +/* { dg-final { scan-assembler-not {\tldr\t} } } */ > > diff --git a/gcc/testsuite/gcc.target/aarch64/split-ldp-stlf-4.c > > b/gcc/testsuite/gcc.target/aarch64/split-ldp-stlf-4.c > > new file mode 100644 > > index 00000000000..3e08bcbea05 > > --- /dev/null > > +++ b/gcc/testsuite/gcc.target/aarch64/split-ldp-stlf-4.c > > @@ -0,0 +1,14 @@ > > +/* { dg-options "-O2 --param=aarch64-split-ldp-stlf=16" } */ > > +/* { dg-additional-options "-fnon-call-exceptions" } */ > > + > > +__attribute__ ((noinline, noclone)) > > +long > > +preserve_faulting_pair (long *p, long value) > > +{ > > + p[1] = value; > > + __asm__ __volatile__ ("" ::: "memory"); > > + return p[1] + p[2]; > > +} > > + > > +/* { dg-final { scan-assembler-times {\tldp\t} 1 } } */ > > +/* { dg-final { scan-assembler-not {\tldr\t} } } */ > > diff --git a/gcc/testsuite/gcc.target/aarch64/split-ldp-stlf-5.c > > b/gcc/testsuite/gcc.target/aarch64/split-ldp-stlf-5.c > > new file mode 100644 > > index 00000000000..a19551c4374 > > --- /dev/null > > +++ b/gcc/testsuite/gcc.target/aarch64/split-ldp-stlf-5.c > > @@ -0,0 +1,13 @@ > > +/* { dg-options "-Os --param=aarch64-split-ldp-stlf=16" } */ > > + > > +__attribute__ ((noinline, noclone)) > > +long > > +optimize_for_size (long *p, long value) > > +{ > > + p[1] = value; > > + __asm__ __volatile__ ("" ::: "memory"); > > + return p[1] + p[2]; > > +} > > + > > +/* { dg-final { scan-assembler-times {\tldp\t} 1 } } */ > > +/* { dg-final { scan-assembler-not {\tldr\t} } } */ > > diff --git a/gcc/testsuite/gcc.target/aarch64/split-ldp-stlf-6.c > > b/gcc/testsuite/gcc.target/aarch64/split-ldp-stlf-6.c > > new file mode 100644 > > index 00000000000..bd59fe77b47 > > --- /dev/null > > +++ b/gcc/testsuite/gcc.target/aarch64/split-ldp-stlf-6.c > > @@ -0,0 +1,13 @@ > > +/* { dg-options "-O2 --param=aarch64-split-ldp-stlf=1" } */ > > + > > +__attribute__ ((noinline, noclone)) > > +long > > +outside_search_window (long *p, long value) > > +{ > > + p[1] = value; > > + __asm__ __volatile__ ("" ::: "memory"); > > + return p[1] + p[2]; > > +} > > + > > +/* { dg-final { scan-assembler-times {\tldp\t} 1 } } */ > > +/* { dg-final { scan-assembler-not {\tldr\t} } } */ > > -- > > 2.43.0 > >
