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From: Peter Maydell <peter.maydell@linaro.org>
To: qemu-devel@nongnu.org
Cc: Richard Henderson <richard.henderson@linaro.org>,
	Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>,
	Artyom Tarasenko <atar4qemu@gmail.com>
Subject: [PATCH for-6.2 1/2] target/sparc: Drop use of gen_io_end()
Date: Sat, 24 Jul 2021 14:49:01 +0100	[thread overview]
Message-ID: <20210724134902.7785-2-peter.maydell@linaro.org> (raw)
In-Reply-To: <20210724134902.7785-1-peter.maydell@linaro.org>

The gen_io_end() function is obsolete (as documented in
docs/devel/tcg-icount.rst). Where an instruction is an I/O
operation, the translator frontend should call gen_io_start()
before generating the code which does the I/O, and then
end the TB immediately after this insn.

Remove the calls to gen_io_end() in the SPARC frontend,
and ensure that the insns which were calling it end the
TB if they didn't do so already.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 target/sparc/translate.c | 25 ++++++++++---------------
 1 file changed, 10 insertions(+), 15 deletions(-)

diff --git a/target/sparc/translate.c b/target/sparc/translate.c
index 11de5a49631..bb70ba17deb 100644
--- a/target/sparc/translate.c
+++ b/target/sparc/translate.c
@@ -3401,7 +3401,8 @@ static void disas_sparc_insn(DisasContext * dc, unsigned int insn)
                         tcg_temp_free_i32(r_const);
                         gen_store_gpr(dc, rd, cpu_dst);
                         if (tb_cflags(dc->base.tb) & CF_USE_ICOUNT) {
-                            gen_io_end();
+                            /* I/O operations in icount mode must end the TB */
+                            dc->base.is_jmp = DISAS_EXIT;
                         }
                     }
                     break;
@@ -3454,7 +3455,8 @@ static void disas_sparc_insn(DisasContext * dc, unsigned int insn)
                         tcg_temp_free_i32(r_const);
                         gen_store_gpr(dc, rd, cpu_dst);
                         if (tb_cflags(dc->base.tb) & CF_USE_ICOUNT) {
-                            gen_io_end();
+                            /* I/O operations in icount mode must end the TB */
+                            dc->base.is_jmp = DISAS_EXIT;
                         }
                     }
                     break;
@@ -3588,7 +3590,8 @@ static void disas_sparc_insn(DisasContext * dc, unsigned int insn)
                         tcg_temp_free_ptr(r_tickptr);
                         tcg_temp_free_i32(r_const);
                         if (tb_cflags(dc->base.tb) & CF_USE_ICOUNT) {
-                            gen_io_end();
+                            /* I/O operations in icount mode must end the TB */
+                            dc->base.is_jmp = DISAS_EXIT;
                         }
                     }
                     break;
@@ -4582,7 +4585,8 @@ static void disas_sparc_insn(DisasContext * dc, unsigned int insn)
                                 }
                                 gen_helper_wrpstate(cpu_env, cpu_tmp0);
                                 if (tb_cflags(dc->base.tb) & CF_USE_ICOUNT) {
-                                    gen_io_end();
+                                    /* I/O ops in icount mode must end the TB */
+                                    dc->base.is_jmp = DISAS_EXIT;
                                 }
                                 dc->npc = DYNAMIC_PC;
                                 break;
@@ -4598,7 +4602,8 @@ static void disas_sparc_insn(DisasContext * dc, unsigned int insn)
                                 }
                                 gen_helper_wrpil(cpu_env, cpu_tmp0);
                                 if (tb_cflags(dc->base.tb) & CF_USE_ICOUNT) {
-                                    gen_io_end();
+                                    /* I/O ops in icount mode must end the TB */
+                                    dc->base.is_jmp = DISAS_EXIT;
                                 }
                                 break;
                             case 9: // cwp
@@ -4697,10 +4702,6 @@ static void disas_sparc_insn(DisasContext * dc, unsigned int insn)
                                     gen_helper_tick_set_limit(r_tickptr,
                                                               cpu_hstick_cmpr);
                                     tcg_temp_free_ptr(r_tickptr);
-                                    if (tb_cflags(dc->base.tb) &
-                                           CF_USE_ICOUNT) {
-                                        gen_io_end();
-                                    }
                                     /* End TB to handle timer interrupt */
                                     dc->base.is_jmp = DISAS_EXIT;
                                 }
@@ -5327,9 +5328,6 @@ static void disas_sparc_insn(DisasContext * dc, unsigned int insn)
                                 gen_io_start();
                             }
                             gen_helper_done(cpu_env);
-                            if (tb_cflags(dc->base.tb) & CF_USE_ICOUNT) {
-                                gen_io_end();
-                            }
                             goto jmp_insn;
                         case 1:
                             if (!supervisor(dc))
@@ -5340,9 +5338,6 @@ static void disas_sparc_insn(DisasContext * dc, unsigned int insn)
                                 gen_io_start();
                             }
                             gen_helper_retry(cpu_env);
-                            if (tb_cflags(dc->base.tb) & CF_USE_ICOUNT) {
-                                gen_io_end();
-                            }
                             goto jmp_insn;
                         default:
                             goto illegal_insn;
-- 
2.20.1



  reply	other threads:[~2021-07-24 13:51 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-07-24 13:49 [PATCH for-6.2 0/2] target/sparc: Drop use of gen_io_end() Peter Maydell
2021-07-24 13:49 ` Peter Maydell [this message]
2021-07-25  9:00   ` [PATCH for-6.2 1/2] " Mark Cave-Ayland
2021-07-24 13:49 ` [PATCH for-6.2 2/2] tcg: Drop gen_io_end() Peter Maydell
2021-07-24 19:07 ` [PATCH for-6.2 0/2] target/sparc: Drop use of gen_io_end() Richard Henderson
2021-07-24 20:27 ` Peter Maydell
2021-07-24 20:47   ` Richard Henderson
2021-07-25 15:00     ` Peter Maydell
2021-09-01  7:58 ` Peter Maydell
2021-09-01  8:12   ` Mark Cave-Ayland

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