From 8b61d109b130f0e6551803cc30f3c607d4fde81c Mon Sep 17 00:00:00 2001 From: Xi Ruoyao Date: Tue, 12 Dec 2023 04:54:21 +0800 Subject: LoongArch: Replace -mexplicit-relocs=auto simple-used address peephole2 with combine The problem with peephole2 is it uses a naive sliding-window algorithm and misses many cases. For example: float a[10000]; float t() { return a[0] + a[8000]; } is compiled to: la.local $r13,a la.local $r12,a+32768 fld.s $f1,$r13,0 fld.s $f0,$r12,-768 fadd.s $f0,$f1,$f0 by trunk. But as we've explained in r14-4851, the following would be better with -mexplicit-relocs=auto: pcalau12i $r13,%pc_hi20(a) pcalau12i $r12,%pc_hi20(a+32000) fld.s $f1,$r13,%pc_lo12(a) fld.s $f0,$r12,%pc_lo12(a+32000) fadd.s $f0,$f1,$f0 However the sliding-window algorithm just won't detect the pcalau12i/fld pair to be optimized. Use a define_insn_and_rewrite in combine pass will work around the issue. gcc/ChangeLog: * config/loongarch/predicates.md (symbolic_pcrel_offset_operand): New define_predicate. (mem_simple_ldst_operand): Likewise. * config/loongarch/loongarch-protos.h (loongarch_rewrite_mem_for_simple_ldst): Declare. * config/loongarch/loongarch.cc (loongarch_rewrite_mem_for_simple_ldst): Implement. * config/loongarch/loongarch.md (simple_load): New define_insn_and_rewrite. (simple_load_ext): Likewise. (simple_store): Likewise. (define_peephole2): Remove la.local/[f]ld peepholes. gcc/testsuite/ChangeLog: * gcc.target/loongarch/explicit-relocs-auto-single-load-store-2.c: New test. * gcc.target/loongarch/explicit-relocs-auto-single-load-store-3.c: New test. --- gcc/config/loongarch/loongarch-protos.h | 1 + gcc/config/loongarch/loongarch.cc | 16 +++ gcc/config/loongarch/loongarch.md | 114 +++++---------------- gcc/config/loongarch/predicates.md | 13 +++ .../explicit-relocs-auto-single-load-store-2.c | 11 ++ .../explicit-relocs-auto-single-load-store-3.c | 18 ++++ 6 files changed, 86 insertions(+), 87 deletions(-) create mode 100644 gcc/testsuite/gcc.target/loongarch/explicit-relocs-auto-single-load-store-2.c create mode 100644 gcc/testsuite/gcc.target/loongarch/explicit-relocs-auto-single-load-store-3.c (limited to 'gcc') diff --git a/gcc/config/loongarch/loongarch-protos.h b/gcc/config/loongarch/loongarch-protos.h index 7bf21a4..024f311 100644 --- a/gcc/config/loongarch/loongarch-protos.h +++ b/gcc/config/loongarch/loongarch-protos.h @@ -163,6 +163,7 @@ extern bool loongarch_use_ins_ext_p (rtx, HOST_WIDE_INT, HOST_WIDE_INT); extern bool loongarch_check_zero_div_p (void); extern bool loongarch_pre_reload_split (void); extern int loongarch_use_bstrins_for_ior_with_mask (machine_mode, rtx *); +extern rtx loongarch_rewrite_mem_for_simple_ldst (rtx); union loongarch_gen_fn_ptrs { diff --git a/gcc/config/loongarch/loongarch.cc b/gcc/config/loongarch/loongarch.cc index 1d4d8f0..9f2b3e9 100644 --- a/gcc/config/loongarch/loongarch.cc +++ b/gcc/config/loongarch/loongarch.cc @@ -5717,6 +5717,22 @@ loongarch_use_bstrins_for_ior_with_mask (machine_mode mode, rtx *op) return 0; } +/* Rewrite a MEM for simple load/store under -mexplicit-relocs=auto + -mcmodel={normal/medium}. */ +rtx +loongarch_rewrite_mem_for_simple_ldst (rtx mem) +{ + rtx addr = XEXP (mem, 0); + rtx hi = gen_rtx_UNSPEC (Pmode, gen_rtvec (1, addr), + UNSPEC_PCALAU12I_GR); + rtx new_mem; + + addr = gen_rtx_LO_SUM (Pmode, force_reg (Pmode, hi), addr); + new_mem = gen_rtx_MEM (GET_MODE (mem), addr); + MEM_COPY_ATTRIBUTES (new_mem, mem); + return new_mem; +} + /* Print the text for PRINT_OPERAND punctation character CH to FILE. The punctuation characters are: diff --git a/gcc/config/loongarch/loongarch.md b/gcc/config/loongarch/loongarch.md index e56ea71..d705717 100644 --- a/gcc/config/loongarch/loongarch.md +++ b/gcc/config/loongarch/loongarch.md @@ -4135,101 +4135,41 @@ ;; ;; And if the pseudo op cannot be relaxed, we'll get a worse result (with ;; 3 instructions). -(define_peephole2 - [(set (match_operand:P 0 "register_operand") - (match_operand:P 1 "symbolic_pcrel_operand")) - (set (match_operand:LD_AT_LEAST_32_BIT 2 "register_operand") - (mem:LD_AT_LEAST_32_BIT (match_dup 0)))] - "la_opt_explicit_relocs == EXPLICIT_RELOCS_AUTO \ - && (TARGET_CMODEL_NORMAL || TARGET_CMODEL_MEDIUM) \ - && (peep2_reg_dead_p (2, operands[0]) \ - || REGNO (operands[0]) == REGNO (operands[2]))" - [(set (match_dup 2) - (mem:LD_AT_LEAST_32_BIT (lo_sum:P (match_dup 0) (match_dup 1))))] - { - emit_insn (gen_pcalau12i_gr (operands[0], operands[1])); - }) - -(define_peephole2 - [(set (match_operand:P 0 "register_operand") - (match_operand:P 1 "symbolic_pcrel_operand")) - (set (match_operand:LD_AT_LEAST_32_BIT 2 "register_operand") - (mem:LD_AT_LEAST_32_BIT (plus (match_dup 0) - (match_operand 3 "const_int_operand"))))] - "la_opt_explicit_relocs == EXPLICIT_RELOCS_AUTO \ - && (TARGET_CMODEL_NORMAL || TARGET_CMODEL_MEDIUM) \ - && (peep2_reg_dead_p (2, operands[0]) \ - || REGNO (operands[0]) == REGNO (operands[2]))" - [(set (match_dup 2) - (mem:LD_AT_LEAST_32_BIT (lo_sum:P (match_dup 0) (match_dup 1))))] - { - operands[1] = plus_constant (Pmode, operands[1], INTVAL (operands[3])); - emit_insn (gen_pcalau12i_gr (operands[0], operands[1])); - }) - -(define_peephole2 - [(set (match_operand:P 0 "register_operand") - (match_operand:P 1 "symbolic_pcrel_operand")) - (set (match_operand:GPR 2 "register_operand") - (any_extend:GPR (mem:SUBDI (match_dup 0))))] - "la_opt_explicit_relocs == EXPLICIT_RELOCS_AUTO \ - && (TARGET_CMODEL_NORMAL || TARGET_CMODEL_MEDIUM) \ - && (peep2_reg_dead_p (2, operands[0]) \ - || REGNO (operands[0]) == REGNO (operands[2]))" - [(set (match_dup 2) - (any_extend:GPR (mem:SUBDI (lo_sum:P (match_dup 0) - (match_dup 1)))))] +(define_insn_and_rewrite "simple_load" + [(set (match_operand:LD_AT_LEAST_32_BIT 0 "register_operand" "=r,f") + (match_operand:LD_AT_LEAST_32_BIT 1 "mem_simple_ldst_operand" ""))] + "loongarch_pre_reload_split () + && la_opt_explicit_relocs == EXPLICIT_RELOCS_AUTO + && (TARGET_CMODEL_NORMAL || TARGET_CMODEL_MEDIUM)" + "#" + "&& true" { - emit_insn (gen_pcalau12i_gr (operands[0], operands[1])); + operands[1] = loongarch_rewrite_mem_for_simple_ldst (operands[1]); }) -(define_peephole2 - [(set (match_operand:P 0 "register_operand") - (match_operand:P 1 "symbolic_pcrel_operand")) - (set (match_operand:GPR 2 "register_operand") +(define_insn_and_rewrite "simple_load_ext" + [(set (match_operand:GPR 0 "register_operand" "=r") (any_extend:GPR - (mem:SUBDI (plus (match_dup 0) - (match_operand 3 "const_int_operand")))))] - "la_opt_explicit_relocs == EXPLICIT_RELOCS_AUTO \ - && (TARGET_CMODEL_NORMAL || TARGET_CMODEL_MEDIUM) \ - && (peep2_reg_dead_p (2, operands[0]) \ - || REGNO (operands[0]) == REGNO (operands[2]))" - [(set (match_dup 2) - (any_extend:GPR (mem:SUBDI (lo_sum:P (match_dup 0) - (match_dup 1)))))] - { - operands[1] = plus_constant (Pmode, operands[1], INTVAL (operands[3])); - emit_insn (gen_pcalau12i_gr (operands[0], operands[1])); - }) - -(define_peephole2 - [(set (match_operand:P 0 "register_operand") - (match_operand:P 1 "symbolic_pcrel_operand")) - (set (mem:ST_ANY (match_dup 0)) - (match_operand:ST_ANY 2 "register_operand"))] - "la_opt_explicit_relocs == EXPLICIT_RELOCS_AUTO \ - && (TARGET_CMODEL_NORMAL || TARGET_CMODEL_MEDIUM) \ - && (peep2_reg_dead_p (2, operands[0])) \ - && REGNO (operands[0]) != REGNO (operands[2])" - [(set (mem:ST_ANY (lo_sum:P (match_dup 0) (match_dup 1))) (match_dup 2))] + (match_operand:SUBDI 1 "mem_simple_ldst_operand" "")))] + "loongarch_pre_reload_split () + && la_opt_explicit_relocs == EXPLICIT_RELOCS_AUTO + && (TARGET_CMODEL_NORMAL || TARGET_CMODEL_MEDIUM)" + "#" + "&& true" { - emit_insn (gen_pcalau12i_gr (operands[0], operands[1])); + operands[1] = loongarch_rewrite_mem_for_simple_ldst (operands[1]); }) -(define_peephole2 - [(set (match_operand:P 0 "register_operand") - (match_operand:P 1 "symbolic_pcrel_operand")) - (set (mem:ST_ANY (plus (match_dup 0) - (match_operand 3 "const_int_operand"))) - (match_operand:ST_ANY 2 "register_operand"))] - "la_opt_explicit_relocs == EXPLICIT_RELOCS_AUTO \ - && (TARGET_CMODEL_NORMAL || TARGET_CMODEL_MEDIUM) \ - && (peep2_reg_dead_p (2, operands[0])) \ - && REGNO (operands[0]) != REGNO (operands[2])" - [(set (mem:ST_ANY (lo_sum:P (match_dup 0) (match_dup 1))) (match_dup 2))] +(define_insn_and_rewrite "simple_store" + [(set (match_operand:ST_ANY 0 "mem_simple_ldst_operand" "") + (match_operand:ST_ANY 1 "reg_or_0_operand" "r,f"))] + "loongarch_pre_reload_split () + && la_opt_explicit_relocs == EXPLICIT_RELOCS_AUTO + && (TARGET_CMODEL_NORMAL || TARGET_CMODEL_MEDIUM)" + "#" + "&& true" { - operands[1] = plus_constant (Pmode, operands[1], INTVAL (operands[3])); - emit_insn (gen_pcalau12i_gr (operands[0], operands[1])); + operands[0] = loongarch_rewrite_mem_for_simple_ldst (operands[0]); }) ;; Synchronization instructions. diff --git a/gcc/config/loongarch/predicates.md b/gcc/config/loongarch/predicates.md index 83fea08..4db4442 100644 --- a/gcc/config/loongarch/predicates.md +++ b/gcc/config/loongarch/predicates.md @@ -579,6 +579,19 @@ return loongarch_symbolic_constant_p (op, &type) && type == SYMBOL_PCREL; }) +(define_predicate "symbolic_pcrel_offset_operand" + (and (match_code "plus") + (match_operand 0 "symbolic_pcrel_operand") + (match_operand 1 "const_int_operand"))) + +(define_predicate "mem_simple_ldst_operand" + (match_code "mem") +{ + op = XEXP (op, 0); + return (symbolic_pcrel_operand (op, Pmode) + || symbolic_pcrel_offset_operand (op, Pmode)); +}) + (define_predicate "equality_operator" (match_code "eq,ne")) diff --git a/gcc/testsuite/gcc.target/loongarch/explicit-relocs-auto-single-load-store-2.c b/gcc/testsuite/gcc.target/loongarch/explicit-relocs-auto-single-load-store-2.c new file mode 100644 index 0000000..42cb966 --- /dev/null +++ b/gcc/testsuite/gcc.target/loongarch/explicit-relocs-auto-single-load-store-2.c @@ -0,0 +1,11 @@ +/* { dg-do compile } */ +/* { dg-options "-O2 -march=loongarch64 -mabi=lp64d -mexplicit-relocs=auto" } */ + +float a[8001]; +float +t (void) +{ + return a[0] + a[8000]; +} + +/* { dg-final { scan-assembler-not "la.local" } } */ diff --git a/gcc/testsuite/gcc.target/loongarch/explicit-relocs-auto-single-load-store-3.c b/gcc/testsuite/gcc.target/loongarch/explicit-relocs-auto-single-load-store-3.c new file mode 100644 index 0000000..32aa538 --- /dev/null +++ b/gcc/testsuite/gcc.target/loongarch/explicit-relocs-auto-single-load-store-3.c @@ -0,0 +1,18 @@ +/* { dg-do compile } */ +/* { dg-options "-O2 -mexplicit-relocs=auto -fdump-rtl-final" } */ +/* { dg-final { scan-rtl-dump-times "mem/v/c" 2 "final" } } */ +/* { dg-final { scan-assembler-not "la\\.local" } } */ + +volatile unsigned long counter; + +unsigned long +read (void) +{ + return counter; +} + +void +clear (void) +{ + counter = 0; +} -- cgit v1.1