Re: [Qemu-devel] [PATCH 12/35] tcg-s390: Define TCG_TMP0.

[Aurelien Jarno <aurelien@aurel32.net>]

On Fri, Jun 04, 2010 at 12:14:20PM -0700, Richard Henderson wrote:
> Use a define for the temp register instead of hard-coding it.
> 
> Signed-off-by: Richard Henderson <rth@twiddle.net>
> ---
>  tcg/s390/tcg-target.c |   54 ++++++++++++++++++++++++++----------------------
>  1 files changed, 29 insertions(+), 25 deletions(-)

This patch looks ok.

> diff --git a/tcg/s390/tcg-target.c b/tcg/s390/tcg-target.c
> index 5b2134b..2b80c02 100644
> --- a/tcg/s390/tcg-target.c
> +++ b/tcg/s390/tcg-target.c
> @@ -40,6 +40,10 @@
>     rather than TCG_REG_R0.  */
>  #define TCG_REG_NONE    0
>  
> +/* A scratch register that may be be used throughout the backend.  */
> +#define TCG_TMP0        TCG_REG_R13
> +
> +
>  /* All of the following instructions are prefixed with their instruction
>     format, and are defined as 8- or 16-bit quantities, even when the two
>     halves of the 16-bit quantity may appear 32 bits apart in the insn.
> @@ -376,12 +380,12 @@ static inline void tcg_out_movi(TCGContext *s, TCGType type,
>          tcg_out_insn(s, RI, IILH, ret, arg >> 16);
>      } else {
>          /* branch over constant and store its address in R13 */
> -        tcg_out_insn(s, RIL, BRASL, TCG_REG_R13, (6 + 8) >> 1);
> +        tcg_out_insn(s, RIL, BRASL, TCG_TMP0, (6 + 8) >> 1);
>          /* 64-bit constant */
>          tcg_out32(s, arg >> 32);
>          tcg_out32(s, arg);
>          /* load constant to ret */
> -        tcg_out_insn(s, RXY, LG, ret, TCG_REG_R13, 0, 0);
> +        tcg_out_insn(s, RXY, LG, ret, TCG_TMP0, 0, 0);
>      }
>  }
>  
> @@ -399,14 +403,14 @@ static void tcg_out_mem(TCGContext *s, S390Opcode opc_rx, S390Opcode opc_rxy,
>      if (ofs < -0x80000 || ofs >= 0x80000) {
>          /* Combine the low 16 bits of the offset with the actual load insn;
>             the high 48 bits must come from an immediate load.  */
> -        tcg_out_movi(s, TCG_TYPE_PTR, TCG_REG_R13, ofs & ~0xffff);
> +        tcg_out_movi(s, TCG_TYPE_PTR, TCG_TMP0, ofs & ~0xffff);
>          ofs &= 0xffff;
>  
>          /* If we were already given an index register, add it in.  */
>          if (index != TCG_REG_NONE) {
> -            tcg_out_insn(s, RRE, AGR, TCG_REG_R13, index);
> +            tcg_out_insn(s, RRE, AGR, TCG_TMP0, index);
>          }
> -        index = TCG_REG_R13;
> +        index = TCG_TMP0;
>      }
>  
>      if (opc_rx && ofs >= 0 && ofs < 0x1000) {
> @@ -482,8 +486,8 @@ static void tgen_gotoi(TCGContext *s, int cc, tcg_target_long dest)
>      } else if (off == (int32_t)off) {
>          tcg_out_insn(s, RIL, BRCL, cc, off);
>      } else {
> -        tcg_out_movi(s, TCG_TYPE_PTR, TCG_REG_R13, dest);
> -        tcg_out_insn(s, RR, BCR, cc, TCG_REG_R13);
> +        tcg_out_movi(s, TCG_TYPE_PTR, TCG_TMP0, dest);
> +        tcg_out_insn(s, RR, BCR, cc, TCG_TMP0);
>      }
>  }
>  
> @@ -505,8 +509,8 @@ static void tgen_calli(TCGContext *s, tcg_target_long dest)
>      if (off == (int32_t)off) {
>          tcg_out_insn(s, RIL, BRASL, TCG_REG_R14, off);
>      } else {
> -        tcg_out_movi(s, TCG_TYPE_PTR, TCG_REG_R13, dest);
> -        tcg_out_insn(s, RR, BASR, TCG_REG_R14, TCG_REG_R13);
> +        tcg_out_movi(s, TCG_TYPE_PTR, TCG_TMP0, dest);
> +        tcg_out_insn(s, RR, BASR, TCG_REG_R14, TCG_TMP0);
>      }
>  }
>  
> @@ -538,22 +542,22 @@ static void tcg_prepare_qemu_ldst(TCGContext* s, int data_reg, int addr_reg,
>      tcg_out_sh64(s, RSY_SRLG, arg1, addr_reg, TCG_REG_NONE,
>                   TARGET_PAGE_BITS - CPU_TLB_ENTRY_BITS);
>  
> -    tcg_out_movi(s, TCG_TYPE_PTR, TCG_REG_R13,
> +    tcg_out_movi(s, TCG_TYPE_PTR, TCG_TMP0,
>                   TARGET_PAGE_MASK | ((1 << s_bits) - 1));
> -    tcg_out_insn(s, RRE, NGR, arg0, TCG_REG_R13);
> +    tcg_out_insn(s, RRE, NGR, arg0, TCG_TMP0);
>  
> -    tcg_out_movi(s, TCG_TYPE_PTR, TCG_REG_R13,
> +    tcg_out_movi(s, TCG_TYPE_PTR, TCG_TMP0,
>                   (CPU_TLB_SIZE - 1) << CPU_TLB_ENTRY_BITS);
> -    tcg_out_insn(s, RRE, NGR, arg1, TCG_REG_R13);
> +    tcg_out_insn(s, RRE, NGR, arg1, TCG_TMP0);
>  
>      if (is_store) {
> -        tcg_out_movi(s, TCG_TYPE_PTR, TCG_REG_R13,
> +        tcg_out_movi(s, TCG_TYPE_PTR, TCG_TMP0,
>                       offsetof(CPUState, tlb_table[mem_index][0].addr_write));
>      } else {
> -        tcg_out_movi(s, TCG_TYPE_PTR, TCG_REG_R13,
> +        tcg_out_movi(s, TCG_TYPE_PTR, TCG_TMP0,
>                       offsetof(CPUState, tlb_table[mem_index][0].addr_read));
>      }
> -    tcg_out_insn(s, RRE, AGR, arg1, TCG_REG_R13);
> +    tcg_out_insn(s, RRE, AGR, arg1, TCG_TMP0);
>  
>      tcg_out_insn(s, RRE, AGR, arg1, TCG_AREG0);
>  
> @@ -688,8 +692,8 @@ static void tcg_out_qemu_ld(TCGContext* s, const TCGArg* args, int opc)
>  #else
>          /* swapped unsigned halfword load with upper bits zeroed */
>          tcg_out_insn(s, RXY, LRVH, data_reg, arg0, 0, 0);
> -        tcg_out_movi(s, TCG_TYPE_PTR, TCG_REG_R13, 0xffffL);
> -        tcg_out_insn(s, RRE, NGR, data_reg, 13);
> +        tcg_out_movi(s, TCG_TYPE_PTR, TCG_TMP0, 0xffffL);
> +        tcg_out_insn(s, RRE, NGR, data_reg, TCG_TMP0);
>  #endif
>          break;
>      case LD_INT16:
> @@ -802,16 +806,16 @@ static inline void tcg_out_op(TCGContext *s, TCGOpcode opc,
>                                     (tcg_target_long)s->code_ptr) >> 1;
>              if (off == (int32_t)off) {
>                  /* load address relative to PC */
> -                tcg_out_insn(s, RIL, LARL, TCG_REG_R13, off);
> +                tcg_out_insn(s, RIL, LARL, TCG_TMP0, off);
>              } else {
>                  /* too far for larl */
> -                tcg_out_movi(s, TCG_TYPE_PTR, TCG_REG_R13,
> +                tcg_out_movi(s, TCG_TYPE_PTR, TCG_TMP0,
>                               (tcg_target_long)(s->tb_next + args[0]));
>              }
>              /* load address stored at s->tb_next + args[0] */
> -            tcg_out_ld(s, TCG_TYPE_PTR, TCG_REG_R13, TCG_REG_R13, 0);
> +            tcg_out_ld(s, TCG_TYPE_PTR, TCG_TMP0, TCG_TMP0, 0);
>              /* and go there */
> -            tcg_out_insn(s, RR, BCR, S390_CC_ALWAYS, TCG_REG_R13);
> +            tcg_out_insn(s, RR, BCR, S390_CC_ALWAYS, TCG_TMP0);
>          }
>          s->tb_next_offset[args[0]] = s->code_ptr - s->code_buf;
>          break;
> @@ -934,9 +938,9 @@ static inline void tcg_out_op(TCGContext *s, TCGOpcode opc,
>          break;
>      case INDEX_op_neg_i64:
>          /* FIXME: optimize args[0] != args[1] case */
> -        tcg_out_mov(s, TCG_REG_R13, args[1]);
> +        tcg_out_mov(s, TCG_TMP0, args[1]);
>          tcg_out_movi(s, TCG_TYPE_I64, args[0], 0);
> -        tcg_out_insn(s, RRE, SGR, args[0], TCG_REG_R13);
> +        tcg_out_insn(s, RRE, SGR, args[0], TCG_TMP0);
>          break;
>  
>      case INDEX_op_mul_i32:
> @@ -1192,7 +1196,7 @@ void tcg_target_init(TCGContext *s)
>  
>      tcg_regset_clear(s->reserved_regs);
>      /* frequently used as a temporary */
> -    tcg_regset_set_reg(s->reserved_regs, TCG_REG_R13);
> +    tcg_regset_set_reg(s->reserved_regs, TCG_TMP0);
>      /* another temporary */
>      tcg_regset_set_reg(s->reserved_regs, TCG_REG_R12);
>      /* XXX many insns can't be used with R0, so we better avoid it for now */
> -- 
> 1.7.0.1
> 
> 
> 

-- 
Aurelien Jarno                          GPG: 1024D/F1BCDB73
aurelien@aurel32.net                 http://www.aurel32.net