Re: [PATCH v2 12/23] target/i386: Remove cur_eip, next_eip arguments to gen_repz*

[Paolo Bonzini]

On Tue, Sep 6, 2022 at 12:09 PM Richard Henderson
<richard.henderson@linaro.org> wrote:
>
> All callers pass s->base.pc_next and s->pc, which we can just
> as well compute within the functions.  Pull out common helpers
> and reduce the amount of code under macros.
>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>


> ---
>  target/i386/tcg/translate.c | 116 ++++++++++++++++++------------------
>  1 file changed, 57 insertions(+), 59 deletions(-)
>
> diff --git a/target/i386/tcg/translate.c b/target/i386/tcg/translate.c
> index 393a1c1075..f3c26a9956 100644
> --- a/target/i386/tcg/translate.c
> +++ b/target/i386/tcg/translate.c
> @@ -736,7 +736,7 @@ static bool gen_check_io(DisasContext *s, MemOp ot, 
> TCGv_i32 port,
>  #endif
>  }
>
> -static inline void gen_movs(DisasContext *s, MemOp ot)
> +static void gen_movs(DisasContext *s, MemOp ot)
>  {
>      gen_string_movl_A0_ESI(s);
>      gen_op_ld_v(s, ot, s->T0, s->A0);
> @@ -1156,18 +1156,18 @@ static inline void gen_jcc1(DisasContext *s, int b, 
> TCGLabel *l1)
>
>  /* XXX: does not work with gdbstub "ice" single step - not a
>     serious problem */
> -static TCGLabel *gen_jz_ecx_string(DisasContext *s, target_ulong next_eip)
> +static TCGLabel *gen_jz_ecx_string(DisasContext *s)
>  {
>      TCGLabel *l1 = gen_new_label();
>      TCGLabel *l2 = gen_new_label();
>      gen_op_jnz_ecx(s, s->aflag, l1);
>      gen_set_label(l2);
> -    gen_jmp_tb(s, next_eip, 1);
> +    gen_jmp_tb(s, s->pc - s->cs_base, 1);
>      gen_set_label(l1);
>      return l2;
>  }
>
> -static inline void gen_stos(DisasContext *s, MemOp ot)
> +static void gen_stos(DisasContext *s, MemOp ot)
>  {
>      gen_op_mov_v_reg(s, MO_32, s->T0, R_EAX);
>      gen_string_movl_A0_EDI(s);
> @@ -1176,7 +1176,7 @@ static inline void gen_stos(DisasContext *s, MemOp ot)
>      gen_op_add_reg_T0(s, s->aflag, R_EDI);
>  }
>
> -static inline void gen_lods(DisasContext *s, MemOp ot)
> +static void gen_lods(DisasContext *s, MemOp ot)
>  {
>      gen_string_movl_A0_ESI(s);
>      gen_op_ld_v(s, ot, s->T0, s->A0);
> @@ -1185,7 +1185,7 @@ static inline void gen_lods(DisasContext *s, MemOp ot)
>      gen_op_add_reg_T0(s, s->aflag, R_ESI);
>  }
>
> -static inline void gen_scas(DisasContext *s, MemOp ot)
> +static void gen_scas(DisasContext *s, MemOp ot)
>  {
>      gen_string_movl_A0_EDI(s);
>      gen_op_ld_v(s, ot, s->T1, s->A0);
> @@ -1194,7 +1194,7 @@ static inline void gen_scas(DisasContext *s, MemOp ot)
>      gen_op_add_reg_T0(s, s->aflag, R_EDI);
>  }
>
> -static inline void gen_cmps(DisasContext *s, MemOp ot)
> +static void gen_cmps(DisasContext *s, MemOp ot)
>  {
>      gen_string_movl_A0_EDI(s);
>      gen_op_ld_v(s, ot, s->T1, s->A0);
> @@ -1222,7 +1222,7 @@ static void gen_bpt_io(DisasContext *s, TCGv_i32 
> t_port, int ot)
>      }
>  }
>
> -static inline void gen_ins(DisasContext *s, MemOp ot)
> +static void gen_ins(DisasContext *s, MemOp ot)
>  {
>      gen_string_movl_A0_EDI(s);
>      /* Note: we must do this dummy write first to be restartable in
> @@ -1238,7 +1238,7 @@ static inline void gen_ins(DisasContext *s, MemOp ot)
>      gen_bpt_io(s, s->tmp2_i32, ot);
>  }
>
> -static inline void gen_outs(DisasContext *s, MemOp ot)
> +static void gen_outs(DisasContext *s, MemOp ot)
>  {
>      gen_string_movl_A0_ESI(s);
>      gen_op_ld_v(s, ot, s->T0, s->A0);
> @@ -1252,42 +1252,49 @@ static inline void gen_outs(DisasContext *s, MemOp ot)
>      gen_bpt_io(s, s->tmp2_i32, ot);
>  }
>
> -/* same method as Valgrind : we generate jumps to current or next
> -   instruction */
> -#define GEN_REPZ(op)                                                         
>  \
> -static inline void gen_repz_ ## op(DisasContext *s, MemOp ot,              \
> -                                 target_ulong cur_eip, target_ulong 
> next_eip) \
> -{                                                                            
>  \
> -    TCGLabel *l2;                                                            
>  \
> -    gen_update_cc_op(s);                                                     
>  \
> -    l2 = gen_jz_ecx_string(s, next_eip);                                     
>  \
> -    gen_ ## op(s, ot);                                                       
>  \
> -    gen_op_add_reg_im(s, s->aflag, R_ECX, -1);                               
>  \
> -    /* a loop would cause two single step exceptions if ECX = 1              
>  \
> -       before rep string_insn */                                             
>  \
> -    if (s->repz_opt)                                                         
>  \
> -        gen_op_jz_ecx(s, s->aflag, l2);                                      
>  \
> -    gen_jmp(s, cur_eip);                                                     
>  \
> +/* Generate jumps to current or next instruction */
> +static void gen_repz(DisasContext *s, MemOp ot,
> +                     void (*fn)(DisasContext *s, MemOp ot))
> +{
> +    TCGLabel *l2;
> +    gen_update_cc_op(s);
> +    l2 = gen_jz_ecx_string(s);
> +    fn(s, ot);
> +    gen_op_add_reg_im(s, s->aflag, R_ECX, -1);
> +    /*
> +     * A loop would cause two single step exceptions if ECX = 1
> +     * before rep string_insn
> +     */
> +    if (s->repz_opt) {
> +        gen_op_jz_ecx(s, s->aflag, l2);
> +    }
> +    gen_jmp(s, s->base.pc_next - s->cs_base);
>  }
>
> -#define GEN_REPZ2(op)                                                        
>  \
> -static inline void gen_repz_ ## op(DisasContext *s, MemOp ot,              \
> -                                   target_ulong cur_eip,                     
>  \
> -                                   target_ulong next_eip,                    
>  \
> -                                   int nz)                                   
>  \
> -{                                                                            
>  \
> -    TCGLabel *l2;                                                            
>  \
> -    gen_update_cc_op(s);                                                     
>  \
> -    l2 = gen_jz_ecx_string(s, next_eip);                                     
>  \
> -    gen_ ## op(s, ot);                                                       
>  \
> -    gen_op_add_reg_im(s, s->aflag, R_ECX, -1);                               
>  \
> -    gen_update_cc_op(s);                                                     
>  \
> -    gen_jcc1(s, (JCC_Z << 1) | (nz ^ 1), l2);                                
>  \
> -    if (s->repz_opt)                                                         
>  \
> -        gen_op_jz_ecx(s, s->aflag, l2);                                      
>  \
> -    gen_jmp(s, cur_eip);                                                     
>  \
> +#define GEN_REPZ(op) \
> +    static inline void gen_repz_ ## op(DisasContext *s, MemOp ot) \
> +    { gen_repz(s, ot, gen_##op); }
> +
> +static void gen_repz2(DisasContext *s, MemOp ot, int nz,
> +                      void (*fn)(DisasContext *s, MemOp ot))
> +{
> +    TCGLabel *l2;
> +    gen_update_cc_op(s);
> +    l2 = gen_jz_ecx_string(s);
> +    fn(s, ot);
> +    gen_op_add_reg_im(s, s->aflag, R_ECX, -1);
> +    gen_update_cc_op(s);
> +    gen_jcc1(s, (JCC_Z << 1) | (nz ^ 1), l2);
> +    if (s->repz_opt) {
> +        gen_op_jz_ecx(s, s->aflag, l2);
> +    }
> +    gen_jmp(s, s->base.pc_next - s->cs_base);
>  }
>
> +#define GEN_REPZ2(op) \
> +    static inline void gen_repz_ ## op(DisasContext *s, MemOp ot, int nz) \
> +    { gen_repz2(s, ot, nz, gen_##op); }
> +
>  GEN_REPZ(movs)
>  GEN_REPZ(stos)
>  GEN_REPZ(lods)
> @@ -6588,8 +6595,7 @@ static bool disas_insn(DisasContext *s, CPUState *cpu)
>      case 0xa5:
>          ot = mo_b_d(b, dflag);
>          if (prefixes & (PREFIX_REPZ | PREFIX_REPNZ)) {
> -            gen_repz_movs(s, ot, s->base.pc_next - s->cs_base,
> -                          s->pc - s->cs_base);
> +            gen_repz_movs(s, ot);
>          } else {
>              gen_movs(s, ot);
>          }
> @@ -6599,8 +6605,7 @@ static bool disas_insn(DisasContext *s, CPUState *cpu)
>      case 0xab:
>          ot = mo_b_d(b, dflag);
>          if (prefixes & (PREFIX_REPZ | PREFIX_REPNZ)) {
> -            gen_repz_stos(s, ot, s->base.pc_next - s->cs_base,
> -                          s->pc - s->cs_base);
> +            gen_repz_stos(s, ot);
>          } else {
>              gen_stos(s, ot);
>          }
> @@ -6609,8 +6614,7 @@ static bool disas_insn(DisasContext *s, CPUState *cpu)
>      case 0xad:
>          ot = mo_b_d(b, dflag);
>          if (prefixes & (PREFIX_REPZ | PREFIX_REPNZ)) {
> -            gen_repz_lods(s, ot, s->base.pc_next - s->cs_base,
> -                          s->pc - s->cs_base);
> +            gen_repz_lods(s, ot);
>          } else {
>              gen_lods(s, ot);
>          }
> @@ -6619,11 +6623,9 @@ static bool disas_insn(DisasContext *s, CPUState *cpu)
>      case 0xaf:
>          ot = mo_b_d(b, dflag);
>          if (prefixes & PREFIX_REPNZ) {
> -            gen_repz_scas(s, ot, s->base.pc_next - s->cs_base,
> -                          s->pc - s->cs_base, 1);
> +            gen_repz_scas(s, ot, 1);
>          } else if (prefixes & PREFIX_REPZ) {
> -            gen_repz_scas(s, ot, s->base.pc_next - s->cs_base,
> -                          s->pc - s->cs_base, 0);
> +            gen_repz_scas(s, ot, 0);
>          } else {
>              gen_scas(s, ot);
>          }
> @@ -6633,11 +6635,9 @@ static bool disas_insn(DisasContext *s, CPUState *cpu)
>      case 0xa7:
>          ot = mo_b_d(b, dflag);
>          if (prefixes & PREFIX_REPNZ) {
> -            gen_repz_cmps(s, ot, s->base.pc_next - s->cs_base,
> -                          s->pc - s->cs_base, 1);
> +            gen_repz_cmps(s, ot, 1);
>          } else if (prefixes & PREFIX_REPZ) {
> -            gen_repz_cmps(s, ot, s->base.pc_next - s->cs_base,
> -                          s->pc - s->cs_base, 0);
> +            gen_repz_cmps(s, ot, 0);
>          } else {
>              gen_cmps(s, ot);
>          }
> @@ -6655,8 +6655,7 @@ static bool disas_insn(DisasContext *s, CPUState *cpu)
>              gen_io_start();
>          }
>          if (prefixes & (PREFIX_REPZ | PREFIX_REPNZ)) {
> -            gen_repz_ins(s, ot, s->base.pc_next - s->cs_base,
> -                         s->pc - s->cs_base);
> +            gen_repz_ins(s, ot);
>              /* jump generated by gen_repz_ins */
>          } else {
>              gen_ins(s, ot);
> @@ -6677,8 +6676,7 @@ static bool disas_insn(DisasContext *s, CPUState *cpu)
>              gen_io_start();
>          }
>          if (prefixes & (PREFIX_REPZ | PREFIX_REPNZ)) {
> -            gen_repz_outs(s, ot, s->base.pc_next - s->cs_base,
> -                          s->pc - s->cs_base);
> +            gen_repz_outs(s, ot);
>              /* jump generated by gen_repz_outs */
>          } else {
>              gen_outs(s, ot);
> --
> 2.34.1
>