On 4/25/10, Richard Henderson <r...@twiddle.net> wrote:
> Single-stepping was not properly updating npc, resulting in some
> instructions being executed twice. In addition, we were emitting
> dead code at the end of the TB.
>
> Fix both by teaching gen_goto_tb to avoid goto_tb for single-step
> and removing the special-case code in gen_intermediate_code_internal.
Nice work!
> Signed-off-by: Richard Henderson <r...@twiddle.net>
> ---
> target-sparc/translate.c | 7 ++++---
> 1 files changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/target-sparc/translate.c b/target-sparc/translate.c
> index b54c520..5162b87 100644
> --- a/target-sparc/translate.c
> +++ b/target-sparc/translate.c
> @@ -81,6 +81,7 @@ typedef struct DisasContext {
> int address_mask_32bit;
> uint32_t cc_op; /* current CC operation */
> struct TranslationBlock *tb;
> + CPUState *env;
Instead of CPUState pointer, please create a flag which combines
env->singlestep_enabled || singlestep.
> sparc_def_t *def;
> } DisasContext;
>
> @@ -234,7 +235,8 @@ static inline void gen_goto_tb(DisasContext *s, int
> tb_num,
>
> tb = s->tb;
> if ((pc & TARGET_PAGE_MASK) == (tb->pc & TARGET_PAGE_MASK) &&
> - (npc & TARGET_PAGE_MASK) == (tb->pc & TARGET_PAGE_MASK)) {
> + (npc & TARGET_PAGE_MASK) == (tb->pc & TARGET_PAGE_MASK) &&
> + !(s->env->singlestep_enabled || singlestep)) {
> /* jump to same page: we can use a direct jump */
> tcg_gen_goto_tb(tb_num);
> tcg_gen_movi_tl(cpu_pc, pc);
> @@ -4680,6 +4682,7 @@ static inline void
> gen_intermediate_code_internal(TranslationBlock * tb,
>
> memset(dc, 0, sizeof(DisasContext));
> dc->tb = tb;
> + dc->env = env;
> pc_start = tb->pc;
> dc->pc = pc_start;
> last_pc = dc->pc;
> @@ -4755,8 +4758,6 @@ static inline void
> gen_intermediate_code_internal(TranslationBlock * tb,
> /* if single step mode, we generate only one instruction and
> generate an exception */
> if (env->singlestep_enabled || singlestep) {
> - tcg_gen_movi_tl(cpu_pc, dc->pc);
> - tcg_gen_exit_tb(0);
> break;
> }
> } while ((gen_opc_ptr < gen_opc_end) &&
>
> --
> 1.6.6.1
>
>
