Re: [Qemu-devel] [PATCH] target-xtensa: make sar_m32 global instead of local temp

[Aurelien Jarno]

On Sat, Nov 24, 2012 at 04:51:36AM +0400, Max Filippov wrote:
> This fixes the following assertion caused by local temp reaching the end
> of TB in discarded state:
> 
>   qemu-system-xtensa: tcg/tcg.c:1665: temp_save: Assertion 
> `s->temps[temp].val_type == 2 || s->temps[temp].fixed_reg' failed.
>   Aborted
> 
> Signed-off-by: Max Filippov <address@hidden>
> ---
>  target-xtensa/cpu.h       |    1 +
>  target-xtensa/translate.c |   28 ++++++++--------------------
>  2 files changed, 9 insertions(+), 20 deletions(-)

I have just send a patch to fix the issue in the TCG code instead (sorry
for being so long, the last weeks have been quite busy). I think it is
better than fixing the issue in target-xtensa.

If it works for you, I'll commit it.

> diff --git a/target-xtensa/cpu.h b/target-xtensa/cpu.h
> index 74e9888..f021a9a 100644
> --- a/target-xtensa/cpu.h
> +++ b/target-xtensa/cpu.h
> @@ -323,6 +323,7 @@ typedef struct CPUXtensaState {
>      const XtensaConfig *config;
>      uint32_t regs[16];
>      uint32_t pc;
> +    uint32_t sar_m32;
>      uint32_t sregs[256];
>      uint32_t uregs[256];
>      uint32_t phys_regs[MAX_NAREG];
> diff --git a/target-xtensa/translate.c b/target-xtensa/translate.c
> index e5a3f49..4f3cf32 100644
> --- a/target-xtensa/translate.c
> +++ b/target-xtensa/translate.c
> @@ -56,8 +56,6 @@ typedef struct DisasContext {
>  
>      bool sar_5bit;
>      bool sar_m32_5bit;
> -    bool sar_m32_allocated;
> -    TCGv_i32 sar_m32;
>  
>      uint32_t ccount_delta;
>      unsigned used_window;
> @@ -71,6 +69,7 @@ typedef struct DisasContext {
>  
>  static TCGv_ptr cpu_env;
>  static TCGv_i32 cpu_pc;
> +static TCGv_i32 cpu_sar_m32;
>  static TCGv_i32 cpu_R[16];
>  static TCGv_i32 cpu_FR[16];
>  static TCGv_i32 cpu_SR[256];
> @@ -169,6 +168,8 @@ void xtensa_translate_init(void)
>      cpu_env = tcg_global_reg_new_ptr(TCG_AREG0, "env");
>      cpu_pc = tcg_global_mem_new_i32(TCG_AREG0,
>              offsetof(CPUXtensaState, pc), "pc");
> +    cpu_sar_m32 = tcg_global_mem_new_i32(TCG_AREG0,
> +            offsetof(CPUXtensaState, sar_m32), "sar_m32");
>  
>      for (i = 0; i < 16; i++) {
>          cpu_R[i] = tcg_global_mem_new_i32(TCG_AREG0,
> @@ -230,21 +231,13 @@ static void init_sar_tracker(DisasContext *dc)
>  {
>      dc->sar_5bit = false;
>      dc->sar_m32_5bit = false;
> -    dc->sar_m32_allocated = false;
> -}
> -
> -static void reset_sar_tracker(DisasContext *dc)
> -{
> -    if (dc->sar_m32_allocated) {
> -        tcg_temp_free(dc->sar_m32);
> -    }
>  }
>  
>  static void gen_right_shift_sar(DisasContext *dc, TCGv_i32 sa)
>  {
>      tcg_gen_andi_i32(cpu_SR[SAR], sa, 0x1f);
>      if (dc->sar_m32_5bit) {
> -        tcg_gen_discard_i32(dc->sar_m32);
> +        tcg_gen_discard_i32(cpu_sar_m32);
>      }
>      dc->sar_5bit = true;
>      dc->sar_m32_5bit = false;
> @@ -253,12 +246,8 @@ static void gen_right_shift_sar(DisasContext *dc, 
> TCGv_i32 sa)
>  static void gen_left_shift_sar(DisasContext *dc, TCGv_i32 sa)
>  {
>      TCGv_i32 tmp = tcg_const_i32(32);
> -    if (!dc->sar_m32_allocated) {
> -        dc->sar_m32 = tcg_temp_local_new_i32();
> -        dc->sar_m32_allocated = true;
> -    }
> -    tcg_gen_andi_i32(dc->sar_m32, sa, 0x1f);
> -    tcg_gen_sub_i32(cpu_SR[SAR], tmp, dc->sar_m32);
> +    tcg_gen_andi_i32(cpu_sar_m32, sa, 0x1f);
> +    tcg_gen_sub_i32(cpu_SR[SAR], tmp, cpu_sar_m32);
>      dc->sar_5bit = false;
>      dc->sar_m32_5bit = true;
>      tcg_temp_free(tmp);
> @@ -498,7 +487,7 @@ static void gen_wsr_sar(DisasContext *dc, uint32_t sr, 
> TCGv_i32 s)
>  {
>      tcg_gen_andi_i32(cpu_SR[sr], s, 0x3f);
>      if (dc->sar_m32_5bit) {
> -        tcg_gen_discard_i32(dc->sar_m32);
> +        tcg_gen_discard_i32(cpu_sar_m32);
>      }
>      dc->sar_5bit = false;
>      dc->sar_m32_5bit = false;
> @@ -1483,7 +1472,7 @@ static void disas_xtensa_insn(CPUXtensaState *env, 
> DisasContext *dc)
>              case 10: /*SLL*/
>                  gen_window_check2(dc, RRR_R, RRR_S);
>                  if (dc->sar_m32_5bit) {
> -                    tcg_gen_shl_i32(cpu_R[RRR_R], cpu_R[RRR_S], dc->sar_m32);
> +                    tcg_gen_shl_i32(cpu_R[RRR_R], cpu_R[RRR_S], cpu_sar_m32);
>                  } else {
>                      TCGv_i64 v = tcg_temp_new_i64();
>                      TCGv_i32 s = tcg_const_i32(32);
> @@ -2947,7 +2936,6 @@ static void gen_intermediate_code_internal(
>              tcg_ctx.gen_opc_ptr < gen_opc_end);
>  
>      reset_litbase(&dc);
> -    reset_sar_tracker(&dc);
>      if (dc.icount) {
>          tcg_temp_free(dc.next_icount);
>      }
> -- 
> 1.7.7.6
> 
> 

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