Re: [PATCH] perf annotate: Fix instruction association and parsing for LoongArch

[Namhyung Kim]

Hello,

On Tue, Jun 20, 2023 at 6:21 AM WANG Rui <wangrui@xxxxxxxxxxx> wrote:
>
> In the perf annotate view for LoongArch, there is no arrowed line
> pointing to the target from the branch instruction. This issue is
> caused by incorrect instruction association and parsing.
>
> $ perf record alloc-6276705c94ad1398 # rust benchmark
> $ perf report
>
>   0.28 │       ori        $a1, $zero, 0x63
>        │       move       $a2, $zero
>  10.55 │       addi.d     $a3, $a2, 1(0x1)
>        │       sltu       $a4, $a3, $s7
>   9.53 │       masknez    $a4, $s7, $a4
>        │       sub.d      $a3, $a3, $a4
>  12.12 │       st.d       $a1, $fp, 24(0x18)
>        │       st.d       $a3, $fp, 16(0x10)
>  16.29 │       slli.d     $a2, $a2, 0x2
>        │       ldx.w      $a2, $s8, $a2
>  12.77 │       st.w       $a2, $sp, 724(0x2d4)
>        │       st.w       $s0, $sp, 720(0x2d0)
>   7.03 │       addi.d     $a2, $sp, 720(0x2d0)
>        │       addi.d     $a1, $a1, -1(0xfff)
>  12.03 │       move       $a2, $a3
>        │     → bne        $a1, $s3, -52(0x3ffcc)  # 82ce8 <test::bench::Bencher::iter+0x3f4>
>   2.50 │       addi.d     $a0, $a0, 1(0x1)
>
> This patch fixes instruction association issues, such as associating
> branch instructions with jump_ops instead of call_ops, and corrects
> false instruction matches. It also implements branch instruction parsing
> specifically for LoongArch. With this patch, we will be able to see the
> arrowed line.
>
>   0.79 │3ec:   ori        $a1, $zero, 0x63
>        │       move       $a2, $zero
>  10.32 │3f4:┌─→addi.d     $a3, $a2, 1(0x1)
>        │    │  sltu       $a4, $a3, $s7
>  10.44 │    │  masknez    $a4, $s7, $a4
>        │    │  sub.d      $a3, $a3, $a4
>  14.17 │    │  st.d       $a1, $fp, 24(0x18)
>        │    │  st.d       $a3, $fp, 16(0x10)
>  13.15 │    │  slli.d     $a2, $a2, 0x2
>        │    │  ldx.w      $a2, $s8, $a2
>  11.00 │    │  st.w       $a2, $sp, 724(0x2d4)
>        │    │  st.w       $s0, $sp, 720(0x2d0)
>   8.00 │    │  addi.d     $a2, $sp, 720(0x2d0)
>        │    │  addi.d     $a1, $a1, -1(0xfff)
>  11.99 │    │  move       $a2, $a3
>        │    └──bne        $a1, $s3, 3f4
>   3.17 │       addi.d     $a0, $a0, 1(0x1)
>
> Signed-off-by: WANG Rui <wangrui@xxxxxxxxxxx>

Just a nitpick.  Otherwise looks good.

> ---
>  .../arch/loongarch/annotate/instructions.c    | 116 ++++++++++++++++--
>  tools/perf/arch/s390/annotate/instructions.c  |   3 -
>  tools/perf/util/annotate.c                    |   8 +-
>  3 files changed, 109 insertions(+), 18 deletions(-)
>
> diff --git a/tools/perf/arch/loongarch/annotate/instructions.c b/tools/perf/arch/loongarch/annotate/instructions.c
> index ab21bf122135..98e19c5366ac 100644
> --- a/tools/perf/arch/loongarch/annotate/instructions.c
> +++ b/tools/perf/arch/loongarch/annotate/instructions.c
> @@ -5,25 +5,115 @@
>   * Copyright (C) 2020-2023 Loongson Technology Corporation Limited
>   */
>
> +static int loongarch_call__parse(struct arch *arch, struct ins_operands *ops, struct map_symbol *ms)
> +{
> +       char *c, *endptr, *tok, *name;
> +       struct map *map = ms->map;
> +       struct addr_map_symbol target = {
> +               .ms = { .map = map, },

Looking here...

> +       };
> +
> +       c = strchr(ops->raw, '#');
> +       if (c++ == NULL)
> +               return -1;
> +
> +       ops->target.addr = strtoull(c, &endptr, 16);
> +
> +       name = strchr(endptr, '<');
> +       name++;
> +
> +       if (arch->objdump.skip_functions_char &&
> +           strchr(name, arch->objdump.skip_functions_char))
> +               return -1;
> +
> +       tok = strchr(name, '>');
> +       if (tok == NULL)
> +               return -1;
> +
> +       *tok = '\0';
> +       ops->target.name = strdup(name);
> +       *tok = '>';
> +
> +       if (ops->target.name == NULL)
> +               return -1;
> +
> +       target.addr = map__objdump_2mem(map, ops->target.addr);
> +
> +       if (maps__find_ams(ms->maps, &target) == 0 &&
> +           map__rip_2objdump(target.ms.map, map__map_ip(target.ms.map, target.addr)) == ops->target.addr)

So the target.ms.map is 'map', right?  Then we can reduce the line.


> +               ops->target.sym = target.ms.sym;
> +
> +       return 0;
> +}
> +
> +static struct ins_ops loongarch_call_ops = {
> +       .parse     = loongarch_call__parse,
> +       .scnprintf = call__scnprintf,
> +};
> +
> +static int loongarch_jump__parse(struct arch *arch, struct ins_operands *ops, struct map_symbol *ms)
> +{
> +       struct map *map = ms->map;
> +       struct symbol *sym = ms->sym;
> +       struct addr_map_symbol target = {
> +               .ms = { .map = map, },
> +       };
> +       const char *c = strchr(ops->raw, '#');
> +       u64 start, end;
> +
> +       ops->raw_comment = strchr(ops->raw, arch->objdump.comment_char);
> +       ops->raw_func_start = strchr(ops->raw, '<');
> +
> +       if (ops->raw_func_start && c > ops->raw_func_start)
> +               c = NULL;
> +
> +       if (c++ != NULL)
> +               ops->target.addr = strtoull(c, NULL, 16);
> +       else
> +               ops->target.addr = strtoull(ops->raw, NULL, 16);
> +
> +       target.addr = map__objdump_2mem(map, ops->target.addr);
> +       start = map__unmap_ip(map, sym->start);
> +       end = map__unmap_ip(map, sym->end);
> +
> +       ops->target.outside = target.addr < start || target.addr > end;
> +
> +       if (maps__find_ams(ms->maps, &target) == 0 &&
> +           map__rip_2objdump(target.ms.map, map__map_ip(target.ms.map, target.addr)) == ops->target.addr)

Ditto.

Thanks,
Namhyung


> +               ops->target.sym = target.ms.sym;
> +
> +       if (!ops->target.outside) {
> +               ops->target.offset = target.addr - start;
> +               ops->target.offset_avail = true;
> +       } else {
> +               ops->target.offset_avail = false;
> +       }
> +
> +       return 0;
> +}
> +
> +static struct ins_ops loongarch_jump_ops = {
> +       .parse     = loongarch_jump__parse,
> +       .scnprintf = jump__scnprintf,
> +};
> +
>  static
>  struct ins_ops *loongarch__associate_ins_ops(struct arch *arch, const char *name)
>  {
>         struct ins_ops *ops = NULL;
>
> -       if (!strncmp(name, "beqz", 4) ||
> -           !strncmp(name, "bnez", 4) ||
> -           !strncmp(name, "beq", 3) ||
> -           !strncmp(name, "bne", 3) ||
> -           !strncmp(name, "blt", 3) ||
> -           !strncmp(name, "bge", 3) ||
> -           !strncmp(name, "bltu", 4) ||
> -           !strncmp(name, "bgeu", 4) ||
> -           !strncmp(name, "bl", 2))
> -               ops = &call_ops;
> -       else if (!strncmp(name, "jirl", 4))
> +       if (!strcmp(name, "bl"))
> +               ops = &loongarch_call_ops;
> +       else if (!strcmp(name, "jirl"))
>                 ops = &ret_ops;
> -       else if (name[0] == 'b')
> -               ops = &jump_ops;
> +       else if (!strcmp(name, "b") ||
> +                !strncmp(name, "beq", 3) ||
> +                !strncmp(name, "bne", 3) ||
> +                !strncmp(name, "blt", 3) ||
> +                !strncmp(name, "bge", 3) ||
> +                !strncmp(name, "bltu", 4) ||
> +                !strncmp(name, "bgeu", 4))
> +               ops = &loongarch_jump_ops;
>         else
>                 return NULL;
>
> diff --git a/tools/perf/arch/s390/annotate/instructions.c b/tools/perf/arch/s390/annotate/instructions.c
> index de925b0e35ce..da5aa3e1f04c 100644
> --- a/tools/perf/arch/s390/annotate/instructions.c
> +++ b/tools/perf/arch/s390/annotate/instructions.c
> @@ -45,9 +45,6 @@ static int s390_call__parse(struct arch *arch, struct ins_operands *ops,
>         return 0;
>  }
>
> -static int call__scnprintf(struct ins *ins, char *bf, size_t size,
> -                          struct ins_operands *ops, int max_ins_name);
> -
>  static struct ins_ops s390_call_ops = {
>         .parse     = s390_call__parse,
>         .scnprintf = call__scnprintf,
> diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c
> index cdd1924a4418..ad40adbd8895 100644
> --- a/tools/perf/util/annotate.c
> +++ b/tools/perf/util/annotate.c
> @@ -61,6 +61,10 @@ static regex_t        file_lineno;
>  static struct ins_ops *ins__find(struct arch *arch, const char *name);
>  static void ins__sort(struct arch *arch);
>  static int disasm_line__parse(char *line, const char **namep, char **rawp);
> +static int call__scnprintf(struct ins *ins, char *bf, size_t size,
> +                         struct ins_operands *ops, int max_ins_name);
> +static int jump__scnprintf(struct ins *ins, char *bf, size_t size,
> +                         struct ins_operands *ops, int max_ins_name);
>
>  struct arch {
>         const char      *name;
> @@ -323,7 +327,7 @@ static struct ins_ops call_ops = {
>
>  bool ins__is_call(const struct ins *ins)
>  {
> -       return ins->ops == &call_ops || ins->ops == &s390_call_ops;
> +       return ins->ops == &call_ops || ins->ops == &s390_call_ops || ins->ops == &loongarch_call_ops;
>  }
>
>  /*
> @@ -464,7 +468,7 @@ static struct ins_ops jump_ops = {
>
>  bool ins__is_jump(const struct ins *ins)
>  {
> -       return ins->ops == &jump_ops;
> +       return ins->ops == &jump_ops || ins->ops == &loongarch_jump_ops;
>  }
>
>  static int comment__symbol(char *raw, char *comment, u64 *addrp, char **namep)
> --
> 2.41.0
>