Re: [Qemu-devel] [PATCH v2 15/17] target/riscv: convert to DisasJumpType

[Richard Henderson]

> Cc: Michael Clark 
> Cc: Palmer Dabbelt 
> Cc: Sagar Karandikar 
> Cc: Bastian Koppelmann 
> 
> Signed-off-by: Emilio G. Cota 
> ---
>  target/riscv/translate.c | 72 
> +++-
>  1 file changed, 28 insertions(+), 44 deletions(-)

Reviewed-by: Richard Henderson 


> @@ -1345,12 +1339,12 @@ static void gen_system(CPURISCVState *env, 
> DisasContext *ctx, uint32_t opc,
>  /* always generates U-level ECALL, fixed in do_interrupt handler 
> */
>  generate_exception(ctx, RISCV_EXCP_U_ECALL);
>  tcg_gen_exit_tb(0); /* no chaining */
> -ctx->bstate = BS_BRANCH;
> +ctx->is_jmp = DISAS_NORETURN;
>  break;
>  case 0x1: /* EBREAK */
>  generate_exception(ctx, RISCV_EXCP_BREAKPOINT);
>  tcg_gen_exit_tb(0); /* no chaining */
> -ctx->bstate = BS_BRANCH;
> +ctx->is_jmp = DISAS_NORETURN;
>  break;

Not for Emilio, but for the RISCV guys as a follow-up, exit_tb after
generate_exception is dead code -- we have already exited via longjmp.  There
are more than these two instances.


r~

Re: [Qemu-devel] [PATCH v2 15/17] target/riscv: convert to DisasJumpType

[Bastian Koppelmann]

On 04/06/2018 08:19 PM, Emilio G. Cota wrote:
> Cc: Michael Clark 
> Cc: Palmer Dabbelt 
> Cc: Sagar Karandikar 
> Cc: Bastian Koppelmann 
> 
> Signed-off-by: Emilio G. Cota 
> ---
>  target/riscv/translate.c | 72 
> +++-
>  1 file changed, 28 insertions(+), 44 deletions(-)
> 

Reviewed-by: Bastian Koppelmann 

Cheers,
Bastian

[Qemu-devel] [PATCH v2 15/17] target/riscv: convert to DisasJumpType

[Emilio G. Cota]

Cc: Michael Clark 
Cc: Palmer Dabbelt 
Cc: Sagar Karandikar 
Cc: Bastian Koppelmann 

Signed-off-by: Emilio G. Cota 
---
 target/riscv/translate.c | 72 +++-
 1 file changed, 28 insertions(+), 44 deletions(-)

diff --git a/target/riscv/translate.c b/target/riscv/translate.c
index 808eab7..a5c25ab 100644
--- a/target/riscv/translate.c
+++ b/target/riscv/translate.c
@@ -26,6 +26,7 @@
 #include "exec/helper-proto.h"
 #include "exec/helper-gen.h"
 
+#include "exec/translator.h"
 #include "exec/log.h"
 
 #include "instmap.h"
@@ -46,7 +47,7 @@ typedef struct DisasContext {
 uint32_t flags;
 uint32_t mem_idx;
 int singlestep_enabled;
-int bstate;
+DisasJumpType is_jmp;
 /* Remember the rounding mode encoded in the previous fp instruction,
which we have already installed into env->fp_status.  Or -1 for
no previous fp instruction.  Note that we exit the TB when writing
@@ -55,13 +56,6 @@ typedef struct DisasContext {
 int frm;
 } DisasContext;
 
-enum {
-BS_NONE = 0, /* When seen outside of translation while loop, indicates
- need to exit tb due to end of page. */
-BS_STOP = 1, /* Need to exit tb for syscall, sret, etc. */
-BS_BRANCH   = 2, /* Need to exit tb for branch, jal, etc. */
-};
-
 /* convert riscv funct3 to qemu memop for load/store */
 static const int tcg_memop_lookup[8] = {
 [0 ... 7] = -1,
@@ -88,7 +82,7 @@ static void generate_exception(DisasContext *ctx, int excp)
 TCGv_i32 helper_tmp = tcg_const_i32(excp);
 gen_helper_raise_exception(cpu_env, helper_tmp);
 tcg_temp_free_i32(helper_tmp);
-ctx->bstate = BS_BRANCH;
+ctx->is_jmp = DISAS_NORETURN;
 }
 
 static void generate_exception_mbadaddr(DisasContext *ctx, int excp)
@@ -98,7 +92,7 @@ static void generate_exception_mbadaddr(DisasContext *ctx, 
int excp)
 TCGv_i32 helper_tmp = tcg_const_i32(excp);
 gen_helper_raise_exception(cpu_env, helper_tmp);
 tcg_temp_free_i32(helper_tmp);
-ctx->bstate = BS_BRANCH;
+ctx->is_jmp = DISAS_NORETURN;
 }
 
 static void gen_exception_debug(void)
@@ -532,7 +526,7 @@ static void gen_jal(CPURISCVState *env, DisasContext *ctx, 
int rd,
 }
 
 gen_goto_tb(ctx, 0, ctx->pc + imm); /* must use this for safety */
-ctx->bstate = BS_BRANCH;
+ctx->is_jmp = DISAS_NORETURN;
 }
 
 static void gen_jalr(CPURISCVState *env, DisasContext *ctx, uint32_t opc,
@@ -563,7 +557,7 @@ static void gen_jalr(CPURISCVState *env, DisasContext *ctx, 
uint32_t opc,
 gen_set_label(misaligned);
 gen_exception_inst_addr_mis(ctx);
 }
-ctx->bstate = BS_BRANCH;
+ctx->is_jmp = DISAS_NORETURN;
 break;
 
 default:
@@ -617,7 +611,7 @@ static void gen_branch(CPURISCVState *env, DisasContext 
*ctx, uint32_t opc,
 } else {
 gen_goto_tb(ctx, 0, ctx->pc + bimm);
 }
-ctx->bstate = BS_BRANCH;
+ctx->is_jmp = DISAS_NORETURN;
 }
 
 static void gen_load(DisasContext *ctx, uint32_t opc, int rd, int rs1,
@@ -1345,12 +1339,12 @@ static void gen_system(CPURISCVState *env, DisasContext 
*ctx, uint32_t opc,
 /* always generates U-level ECALL, fixed in do_interrupt handler */
 generate_exception(ctx, RISCV_EXCP_U_ECALL);
 tcg_gen_exit_tb(0); /* no chaining */
-ctx->bstate = BS_BRANCH;
+ctx->is_jmp = DISAS_NORETURN;
 break;
 case 0x1: /* EBREAK */
 generate_exception(ctx, RISCV_EXCP_BREAKPOINT);
 tcg_gen_exit_tb(0); /* no chaining */
-ctx->bstate = BS_BRANCH;
+ctx->is_jmp = DISAS_NORETURN;
 break;
 #ifndef CONFIG_USER_ONLY
 case 0x002: /* URET */
@@ -1360,7 +1354,7 @@ static void gen_system(CPURISCVState *env, DisasContext 
*ctx, uint32_t opc,
 if (riscv_has_ext(env, RVS)) {
 gen_helper_sret(cpu_pc, cpu_env, cpu_pc);
 tcg_gen_exit_tb(0); /* no chaining */
-ctx->bstate = BS_BRANCH;
+ctx->is_jmp = DISAS_NORETURN;
 } else {
 gen_exception_illegal(ctx);
 }
@@ -1371,7 +1365,7 @@ static void gen_system(CPURISCVState *env, DisasContext 
*ctx, uint32_t opc,
 case 0x302: /* MRET */
 gen_helper_mret(cpu_pc, cpu_env, cpu_pc);
 tcg_gen_exit_tb(0); /* no chaining */
-ctx->bstate = BS_BRANCH;
+ctx->is_jmp = DISAS_NORETURN;
 break;
 case 0x7b2: /* DRET */
 gen_exception_illegal(ctx);
@@ -1418,7 +1412,7 @@ static void gen_system(CPURISCVState *env, DisasContext 
*ctx, uint32_t opc,
 /* end tb since we may be changing priv modes, to get mmu_index right 
*/
 tcg_gen_movi_tl(cpu_pc, ctx->next_pc);
 tcg_gen_exit_tb(0); /* no chaining */
-ctx->bstate