Re: [Qemu-devel] [PATCH][SPARC] Fix handling of conditional branches in delay slot of a conditional branch

[Blue Swirl]

Thanks, applied.

On Sat, Aug 6, 2011 at 3:01 PM, Artyom Tarasenko <address@hidden> wrote:
> Check whether dc->npc is dynamic before using its value for branch.
>
> Signed-off-by: Artyom Tarasenko <address@hidden>
> ---
> Particaluary the patch fixes handling of the constructions like
>
> 0x13e26c0:  brz,pn   %o0, 0x13e26e4
> 0x13e26c4:  brlez,pn   %o1, 0x13e26e4
>
> present in NetBSD-5.1
>
>  target-sparc/translate.c |   30 +++++++++++++++++++++---------
>  1 files changed, 21 insertions(+), 9 deletions(-)
>
> diff --git a/target-sparc/translate.c b/target-sparc/translate.c
> index 958fbc5..dee67b3 100644
> --- a/target-sparc/translate.c
> +++ b/target-sparc/translate.c
> @@ -1286,7 +1286,6 @@ static inline void gen_cond_reg(TCGv r_dst, int cond, 
> TCGv r_src)
>  }
>  #endif
>
> -/* XXX: potentially incorrect if dynamic npc */
>  static void do_branch(DisasContext *dc, int32_t offset, uint32_t insn, int 
> cc,
>                       TCGv r_cond)
>  {
> @@ -1321,13 +1320,17 @@ static void do_branch(DisasContext *dc, int32_t 
> offset, uint32_t insn, int cc,
>         } else {
>             dc->pc = dc->npc;
>             dc->jump_pc[0] = target;
> -            dc->jump_pc[1] = dc->npc + 4;
> -            dc->npc = JUMP_PC;
> +            if (unlikely(dc->npc == DYNAMIC_PC)) {
> +                dc->jump_pc[1] = DYNAMIC_PC;
> +                tcg_gen_addi_tl(cpu_pc, cpu_npc, 4);
> +            } else {
> +                dc->jump_pc[1] = dc->npc + 4;
> +                dc->npc = JUMP_PC;
> +            }
>         }
>     }
>  }
>
> -/* XXX: potentially incorrect if dynamic npc */
>  static void do_fbranch(DisasContext *dc, int32_t offset, uint32_t insn, int 
> cc,
>                       TCGv r_cond)
>  {
> @@ -1362,14 +1365,18 @@ static void do_fbranch(DisasContext *dc, int32_t 
> offset, uint32_t insn, int cc,
>         } else {
>             dc->pc = dc->npc;
>             dc->jump_pc[0] = target;
> -            dc->jump_pc[1] = dc->npc + 4;
> -            dc->npc = JUMP_PC;
> +            if (unlikely(dc->npc == DYNAMIC_PC)) {
> +                dc->jump_pc[1] = DYNAMIC_PC;
> +                tcg_gen_addi_tl(cpu_pc, cpu_npc, 4);
> +            } else {
> +                dc->jump_pc[1] = dc->npc + 4;
> +                dc->npc = JUMP_PC;
> +            }
>         }
>     }
>  }
>
>  #ifdef TARGET_SPARC64
> -/* XXX: potentially incorrect if dynamic npc */
>  static void do_branch_reg(DisasContext *dc, int32_t offset, uint32_t insn,
>                           TCGv r_cond, TCGv r_reg)
>  {
> @@ -1384,8 +1391,13 @@ static void do_branch_reg(DisasContext *dc, int32_t 
> offset, uint32_t insn,
>     } else {
>         dc->pc = dc->npc;
>         dc->jump_pc[0] = target;
> -        dc->jump_pc[1] = dc->npc + 4;
> -        dc->npc = JUMP_PC;
> +        if (unlikely(dc->npc == DYNAMIC_PC)) {
> +            dc->jump_pc[1] = DYNAMIC_PC;
> +            tcg_gen_addi_tl(cpu_pc, cpu_npc, 4);
> +        } else {
> +            dc->jump_pc[1] = dc->npc + 4;
> +            dc->npc = JUMP_PC;
> +        }
>     }
>  }
>
> --
> 1.7.3.4
>
>