Re: [Qemu-devel] [PATCH 01/18] translator: merge max_insns into DisasContextBase

[Michael Clark <mjc@sifive.com>]

On Sat, Apr 21, 2018 at 6:55 AM, Emilio G. Cota <cota@braap.org> wrote:

> While at it, use int for both num_insns and max_insns to make
> sure we have same-type comparisons.
>
> Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
> Signed-off-by: Emilio G. Cota <cota@braap.org>
>

Reviewed-by: Michael Clark <mjc@sifive.com>


> ---
>  accel/tcg/translator.c     | 21 ++++++++++-----------
>  include/exec/translator.h  |  8 ++++----
>  target/alpha/translate.c   |  6 ++----
>  target/arm/translate-a64.c |  8 +++-----
>  target/arm/translate.c     |  9 +++------
>  target/hppa/translate.c    |  7 ++-----
>  target/i386/translate.c    |  5 +----
>  target/ppc/translate.c     |  5 ++---
>  8 files changed, 27 insertions(+), 42 deletions(-)
>
> diff --git a/accel/tcg/translator.c b/accel/tcg/translator.c
> index 23c6602..0f9dca9 100644
> --- a/accel/tcg/translator.c
> +++ b/accel/tcg/translator.c
> @@ -34,8 +34,6 @@ void translator_loop_temp_check(DisasContextBase *db)
>  void translator_loop(const TranslatorOps *ops, DisasContextBase *db,
>                       CPUState *cpu, TranslationBlock *tb)
>  {
> -    int max_insns;
> -
>      /* Initialize DisasContext */
>      db->tb = tb;
>      db->pc_first = tb->pc;
> @@ -45,18 +43,18 @@ void translator_loop(const TranslatorOps *ops,
> DisasContextBase *db,
>      db->singlestep_enabled = cpu->singlestep_enabled;
>
>      /* Instruction counting */
> -    max_insns = tb_cflags(db->tb) & CF_COUNT_MASK;
> -    if (max_insns == 0) {
> -        max_insns = CF_COUNT_MASK;
> +    db->max_insns = tb_cflags(db->tb) & CF_COUNT_MASK;
> +    if (db->max_insns == 0) {
> +        db->max_insns = CF_COUNT_MASK;
>      }
> -    if (max_insns > TCG_MAX_INSNS) {
> -        max_insns = TCG_MAX_INSNS;
> +    if (db->max_insns > TCG_MAX_INSNS) {
> +        db->max_insns = TCG_MAX_INSNS;
>      }
>      if (db->singlestep_enabled || singlestep) {
> -        max_insns = 1;
> +        db->max_insns = 1;
>      }
>
> -    max_insns = ops->init_disas_context(db, cpu, max_insns);
> +    ops->init_disas_context(db, cpu);
>      tcg_debug_assert(db->is_jmp == DISAS_NEXT);  /* no early exit */
>
>      /* Reset the temp count so that we can identify leaks */
> @@ -95,7 +93,8 @@ void translator_loop(const TranslatorOps *ops,
> DisasContextBase *db,
>             update db->pc_next and db->is_jmp to indicate what should be
>             done next -- either exiting this loop or locate the start of
>             the next instruction.  */
> -        if (db->num_insns == max_insns && (tb_cflags(db->tb) &
> CF_LAST_IO)) {
> +        if (db->num_insns == db->max_insns
> +            && (tb_cflags(db->tb) & CF_LAST_IO)) {
>              /* Accept I/O on the last instruction.  */
>              gen_io_start();
>              ops->translate_insn(db, cpu);
> @@ -111,7 +110,7 @@ void translator_loop(const TranslatorOps *ops,
> DisasContextBase *db,
>
>          /* Stop translation if the output buffer is full,
>             or we have executed all of the allowed instructions.  */
> -        if (tcg_op_buf_full() || db->num_insns >= max_insns) {
> +        if (tcg_op_buf_full() || db->num_insns >= db->max_insns) {
>              db->is_jmp = DISAS_TOO_MANY;
>              break;
>          }
> diff --git a/include/exec/translator.h b/include/exec/translator.h
> index e2dc2a0..71e7b2c 100644
> --- a/include/exec/translator.h
> +++ b/include/exec/translator.h
> @@ -58,6 +58,7 @@ typedef enum DisasJumpType {
>   *           disassembly).
>   * @is_jmp: What instruction to disassemble next.
>   * @num_insns: Number of translated instructions (including current).
> + * @max_insns: Maximum number of instructions to be translated in this TB.
>   * @singlestep_enabled: "Hardware" single stepping enabled.
>   *
>   * Architecture-agnostic disassembly context.
> @@ -67,7 +68,8 @@ typedef struct DisasContextBase {
>      target_ulong pc_first;
>      target_ulong pc_next;
>      DisasJumpType is_jmp;
> -    unsigned int num_insns;
> +    int num_insns;
> +    int max_insns;
>      bool singlestep_enabled;
>  } DisasContextBase;
>
> @@ -76,7 +78,6 @@ typedef struct DisasContextBase {
>   * @init_disas_context:
>   *      Initialize the target-specific portions of DisasContext struct.
>   *      The generic DisasContextBase has already been initialized.
> - *      Return max_insns, modified as necessary by db->tb->flags.
>   *
>   * @tb_start:
>   *      Emit any code required before the start of the main loop,
> @@ -106,8 +107,7 @@ typedef struct DisasContextBase {
>   *      Print instruction disassembly to log.
>   */
>  typedef struct TranslatorOps {
> -    int (*init_disas_context)(DisasContextBase *db, CPUState *cpu,
> -                              int max_insns);
> +    void (*init_disas_context)(DisasContextBase *db, CPUState *cpu);
>      void (*tb_start)(DisasContextBase *db, CPUState *cpu);
>      void (*insn_start)(DisasContextBase *db, CPUState *cpu);
>      bool (*breakpoint_check)(DisasContextBase *db, CPUState *cpu,
> diff --git a/target/alpha/translate.c b/target/alpha/translate.c
> index 73a1b5e..15eca71 100644
> --- a/target/alpha/translate.c
> +++ b/target/alpha/translate.c
> @@ -2919,8 +2919,7 @@ static DisasJumpType translate_one(DisasContext
> *ctx, uint32_t insn)
>      return ret;
>  }
>
> -static int alpha_tr_init_disas_context(DisasContextBase *dcbase,
> -                                       CPUState *cpu, int max_insns)
> +static void alpha_tr_init_disas_context(DisasContextBase *dcbase,
> CPUState *cpu)
>  {
>      DisasContext *ctx = container_of(dcbase, DisasContext, base);
>      CPUAlphaState *env = cpu->env_ptr;
> @@ -2959,8 +2958,7 @@ static int alpha_tr_init_disas_context(DisasContextBase
> *dcbase,
>          mask = TARGET_PAGE_MASK;
>      }
>      bound = -(ctx->base.pc_first | mask) / 4;
> -
> -    return MIN(max_insns, bound);
> +    ctx->base.max_insns = MIN(ctx->base.max_insns, bound);
>  }
>
>  static void alpha_tr_tb_start(DisasContextBase *db, CPUState *cpu)
> diff --git a/target/arm/translate-a64.c b/target/arm/translate-a64.c
> index c913292..1bf16ff 100644
> --- a/target/arm/translate-a64.c
> +++ b/target/arm/translate-a64.c
> @@ -13218,8 +13218,8 @@ static void disas_a64_insn(CPUARMState *env,
> DisasContext *s)
>      free_tmp_a64(s);
>  }
>
> -static int aarch64_tr_init_disas_context(DisasContextBase *dcbase,
> -                                         CPUState *cpu, int max_insns)
> +static void aarch64_tr_init_disas_context(DisasContextBase *dcbase,
> +                                          CPUState *cpu)
>  {
>      DisasContext *dc = container_of(dcbase, DisasContext, base);
>      CPUARMState *env = cpu->env_ptr;
> @@ -13282,11 +13282,9 @@ static int aarch64_tr_init_disas_context(DisasContextBase
> *dcbase,
>      if (dc->ss_active) {
>          bound = 1;
>      }
> -    max_insns = MIN(max_insns, bound);
> +    dc->base.max_insns = MIN(dc->base.max_insns, bound);
>
>      init_tmp_a64_array(dc);
> -
> -    return max_insns;
>  }
>
>  static void aarch64_tr_tb_start(DisasContextBase *db, CPUState *cpu)
> diff --git a/target/arm/translate.c b/target/arm/translate.c
> index d80c0c4..acf539f 100644
> --- a/target/arm/translate.c
> +++ b/target/arm/translate.c
> @@ -12216,8 +12216,7 @@ static bool insn_crosses_page(CPUARMState *env,
> DisasContext *s)
>      return !thumb_insn_is_16bit(s, insn);
>  }
>
> -static int arm_tr_init_disas_context(DisasContextBase *dcbase,
> -                                     CPUState *cs, int max_insns)
> +static void arm_tr_init_disas_context(DisasContextBase *dcbase, CPUState
> *cs)
>  {
>      DisasContext *dc = container_of(dcbase, DisasContext, base);
>      CPUARMState *env = cs->env_ptr;
> @@ -12278,14 +12277,14 @@ static int arm_tr_init_disas_context(DisasContextBase
> *dcbase,
>
>      /* If architectural single step active, limit to 1.  */
>      if (is_singlestepping(dc)) {
> -        max_insns = 1;
> +        dc->base.max_insns = 1;
>      }
>
>      /* ARM is a fixed-length ISA.  Bound the number of insns to execute
>         to those left on the page.  */
>      if (!dc->thumb) {
>          int bound = -(dc->base.pc_first | TARGET_PAGE_MASK) / 4;
> -        max_insns = MIN(max_insns, bound);
> +        dc->base.max_insns = MIN(dc->base.max_insns, bound);
>      }
>
>      cpu_F0s = tcg_temp_new_i32();
> @@ -12296,8 +12295,6 @@ static int arm_tr_init_disas_context(DisasContextBase
> *dcbase,
>      cpu_V1 = cpu_F1d;
>      /* FIXME: cpu_M0 can probably be the same as cpu_V0.  */
>      cpu_M0 = tcg_temp_new_i64();
> -
> -    return max_insns;
>  }
>
>  static void arm_tr_tb_start(DisasContextBase *dcbase, CPUState *cpu)
> diff --git a/target/hppa/translate.c b/target/hppa/translate.c
> index c532889..424991f 100644
> --- a/target/hppa/translate.c
> +++ b/target/hppa/translate.c
> @@ -4681,8 +4681,7 @@ static DisasJumpType translate_one(DisasContext
> *ctx, uint32_t insn)
>      return gen_illegal(ctx);
>  }
>
> -static int hppa_tr_init_disas_context(DisasContextBase *dcbase,
> -                                      CPUState *cs, int max_insns)
> +static void hppa_tr_init_disas_context(DisasContextBase *dcbase,
> CPUState *cs)
>  {
>      DisasContext *ctx = container_of(dcbase, DisasContext, base);
>      int bound;
> @@ -4712,14 +4711,12 @@ static int hppa_tr_init_disas_context(DisasContextBase
> *dcbase,
>
>      /* Bound the number of instructions by those left on the page.  */
>      bound = -(ctx->base.pc_first | TARGET_PAGE_MASK) / 4;
> -    bound = MIN(max_insns, bound);
> +    ctx->base.max_insns = MIN(ctx->base.max_insns, bound);
>
>      ctx->ntempr = 0;
>      ctx->ntempl = 0;
>      memset(ctx->tempr, 0, sizeof(ctx->tempr));
>      memset(ctx->templ, 0, sizeof(ctx->templ));
> -
> -    return bound;
>  }
>
>  static void hppa_tr_tb_start(DisasContextBase *dcbase, CPUState *cs)
> diff --git a/target/i386/translate.c b/target/i386/translate.c
> index c9ed8dc..b0f6983 100644
> --- a/target/i386/translate.c
> +++ b/target/i386/translate.c
> @@ -8402,8 +8402,7 @@ void tcg_x86_init(void)
>      }
>  }
>
> -static int i386_tr_init_disas_context(DisasContextBase *dcbase, CPUState
> *cpu,
> -                                      int max_insns)
> +static void i386_tr_init_disas_context(DisasContextBase *dcbase,
> CPUState *cpu)
>  {
>      DisasContext *dc = container_of(dcbase, DisasContext, base);
>      CPUX86State *env = cpu->env_ptr;
> @@ -8470,8 +8469,6 @@ static int i386_tr_init_disas_context(DisasContextBase
> *dcbase, CPUState *cpu,
>      cpu_ptr0 = tcg_temp_new_ptr();
>      cpu_ptr1 = tcg_temp_new_ptr();
>      cpu_cc_srcT = tcg_temp_local_new();
> -
> -    return max_insns;
>  }
>
>  static void i386_tr_tb_start(DisasContextBase *db, CPUState *cpu)
> diff --git a/target/ppc/translate.c b/target/ppc/translate.c
> index 3457d29..019489b 100644
> --- a/target/ppc/translate.c
> +++ b/target/ppc/translate.c
> @@ -7212,8 +7212,7 @@ void ppc_cpu_dump_statistics(CPUState *cs, FILE*f,
>  #endif
>  }
>
> -static int ppc_tr_init_disas_context(DisasContextBase *dcbase,
> -                                     CPUState *cs, int max_insns)
> +static void ppc_tr_init_disas_context(DisasContextBase *dcbase, CPUState
> *cs)
>  {
>      DisasContext *ctx = container_of(dcbase, DisasContext, base);
>      CPUPPCState *env = cs->env_ptr;
> @@ -7278,7 +7277,7 @@ static int ppc_tr_init_disas_context(DisasContextBase
> *dcbase,
>  #endif
>
>      bound = -(ctx->base.pc_first | TARGET_PAGE_MASK) / 4;
> -    return MIN(max_insns, bound);
> +    ctx->base.max_insns = MIN(ctx->base.max_insns, bound);
>  }
>
>  static void ppc_tr_tb_start(DisasContextBase *db, CPUState *cs)
> --
> 2.7.4
>
>
>