[PATCH v2 04/21] Hexagon (target/hexagon) properly generate TB end for DISAS_NORETURN

From: Taylor Simpson <tsimpson@quicinc.com>
To: qemu-devel@nongnu.org
Cc: ale@rev.ng, philmd@redhat.com, tsimpson@quicinc.com,
	richard.henderson@linaro.org, bcain@quicinc.com
Subject: [PATCH v2 04/21] Hexagon (target/hexagon) properly generate TB end for DISAS_NORETURN
Date: Wed, 31 Mar 2021 22:53:16 -0500	[thread overview]
Message-ID: <1617249213-22667-5-git-send-email-tsimpson@quicinc.com> (raw)
In-Reply-To: <1617249213-22667-1-git-send-email-tsimpson@quicinc.com>

When exiting a TB, generate all the code before returning from
hexagon_tr_translate_packet so that nothing needs to be done in
hexagon_tr_tb_stop.

Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
---
 target/hexagon/translate.c | 62 ++++++++++++++++++++++++----------------------
 target/hexagon/translate.h |  3 ---
 2 files changed, 33 insertions(+), 32 deletions(-)

diff --git a/target/hexagon/translate.c b/target/hexagon/translate.c
index e235fdb..9f2a531 100644
--- a/target/hexagon/translate.c
+++ b/target/hexagon/translate.c
@@ -54,16 +54,40 @@ static const char * const hexagon_prednames[] = {
   "p0", "p1", "p2", "p3"
 };
 
-void gen_exception(int excp)
+static void gen_exception_raw(int excp)
 {
     TCGv_i32 helper_tmp = tcg_const_i32(excp);
     gen_helper_raise_exception(cpu_env, helper_tmp);
     tcg_temp_free_i32(helper_tmp);
 }
 
-void gen_exception_debug(void)
+static void gen_exec_counters(DisasContext *ctx)
+{
+    tcg_gen_addi_tl(hex_gpr[HEX_REG_QEMU_PKT_CNT],
+                    hex_gpr[HEX_REG_QEMU_PKT_CNT], ctx->num_packets);
+    tcg_gen_addi_tl(hex_gpr[HEX_REG_QEMU_INSN_CNT],
+                    hex_gpr[HEX_REG_QEMU_INSN_CNT], ctx->num_insns);
+}
+
+static void gen_end_tb(DisasContext *ctx)
 {
-    gen_exception(EXCP_DEBUG);
+    gen_exec_counters(ctx);
+    tcg_gen_mov_tl(hex_gpr[HEX_REG_PC], hex_next_PC);
+    if (ctx->base.singlestep_enabled) {
+        gen_exception_raw(EXCP_DEBUG);
+    } else {
+        tcg_gen_exit_tb(NULL, 0);
+    }
+    ctx->base.is_jmp = DISAS_NORETURN;
+}
+
+static void gen_exception_end_tb(DisasContext *ctx, int excp)
+{
+    gen_exec_counters(ctx);
+    tcg_gen_mov_tl(hex_gpr[HEX_REG_PC], hex_next_PC);
+    gen_exception_raw(excp);
+    ctx->base.is_jmp = DISAS_NORETURN;
+
 }
 
 #if HEX_DEBUG
@@ -225,8 +249,7 @@ static void gen_insn(CPUHexagonState *env, DisasContext *ctx,
         mark_implicit_writes(ctx, insn);
         insn->generate(env, ctx, insn, pkt);
     } else {
-        gen_exception(HEX_EXCP_INVALID_OPCODE);
-        ctx->base.is_jmp = DISAS_NORETURN;
+        gen_exception_end_tb(ctx, HEX_EXCP_INVALID_OPCODE);
     }
 }
 
@@ -447,14 +470,6 @@ static void update_exec_counters(DisasContext *ctx, Packet *pkt)
     ctx->num_insns += num_real_insns;
 }
 
-static void gen_exec_counters(DisasContext *ctx)
-{
-    tcg_gen_addi_tl(hex_gpr[HEX_REG_QEMU_PKT_CNT],
-                    hex_gpr[HEX_REG_QEMU_PKT_CNT], ctx->num_packets);
-    tcg_gen_addi_tl(hex_gpr[HEX_REG_QEMU_INSN_CNT],
-                    hex_gpr[HEX_REG_QEMU_INSN_CNT], ctx->num_insns);
-}
-
 static void gen_commit_packet(DisasContext *ctx, Packet *pkt)
 {
     gen_reg_writes(ctx);
@@ -478,7 +493,7 @@ static void gen_commit_packet(DisasContext *ctx, Packet *pkt)
 #endif
 
     if (pkt->pkt_has_cof) {
-        ctx->base.is_jmp = DISAS_NORETURN;
+        gen_end_tb(ctx);
     }
 }
 
@@ -491,8 +506,7 @@ static void decode_and_translate_packet(CPUHexagonState *env, DisasContext *ctx)
 
     nwords = read_packet_words(env, ctx, words);
     if (!nwords) {
-        gen_exception(HEX_EXCP_INVALID_PACKET);
-        ctx->base.is_jmp = DISAS_NORETURN;
+        gen_exception_end_tb(ctx, HEX_EXCP_INVALID_PACKET);
         return;
     }
 
@@ -505,8 +519,7 @@ static void decode_and_translate_packet(CPUHexagonState *env, DisasContext *ctx)
         gen_commit_packet(ctx, &pkt);
         ctx->base.pc_next += pkt.encod_pkt_size_in_bytes;
     } else {
-        gen_exception(HEX_EXCP_INVALID_PACKET);
-        ctx->base.is_jmp = DISAS_NORETURN;
+        gen_exception_end_tb(ctx, HEX_EXCP_INVALID_PACKET);
     }
 }
 
@@ -536,9 +549,7 @@ static bool hexagon_tr_breakpoint_check(DisasContextBase *dcbase, CPUState *cpu,
 {
     DisasContext *ctx = container_of(dcbase, DisasContext, base);
 
-    tcg_gen_movi_tl(hex_gpr[HEX_REG_PC], ctx->base.pc_next);
-    ctx->base.is_jmp = DISAS_NORETURN;
-    gen_exception_debug();
+    gen_exception_end_tb(ctx, EXCP_DEBUG);
     /*
      * The address covered by the breakpoint must be included in
      * [tb->pc, tb->pc + tb->size) in order to for it to be
@@ -601,19 +612,12 @@ static void hexagon_tr_tb_stop(DisasContextBase *dcbase, CPUState *cpu)
         gen_exec_counters(ctx);
         tcg_gen_movi_tl(hex_gpr[HEX_REG_PC], ctx->base.pc_next);
         if (ctx->base.singlestep_enabled) {
-            gen_exception_debug();
+            gen_exception_raw(EXCP_DEBUG);
         } else {
             tcg_gen_exit_tb(NULL, 0);
         }
         break;
     case DISAS_NORETURN:
-        gen_exec_counters(ctx);
-        tcg_gen_mov_tl(hex_gpr[HEX_REG_PC], hex_next_PC);
-        if (ctx->base.singlestep_enabled) {
-            gen_exception_debug();
-        } else {
-            tcg_gen_exit_tb(NULL, 0);
-        }
         break;
     default:
         g_assert_not_reached();
diff --git a/target/hexagon/translate.h b/target/hexagon/translate.h
index 938f7fb..12506c8 100644
--- a/target/hexagon/translate.h
+++ b/target/hexagon/translate.h
@@ -86,8 +86,5 @@ extern TCGv hex_llsc_addr;
 extern TCGv hex_llsc_val;
 extern TCGv_i64 hex_llsc_val_i64;
 
-void gen_exception(int excp);
-void gen_exception_debug(void);
-
 void process_store(DisasContext *ctx, Packet *pkt, int slot_num);
 #endif
-- 
2.7.4


