cpu-exec: unify icount_decr and tcg_exit_req

The icount interrupt flag and tcg_exit_req serve almost the same
purpose, let's make them completely the same.

The former TB_EXIT_REQUESTED and TB_EXIT_ICOUNT_EXPIRED cases are
unified, since we can distinguish them from the value of the
interrupt flag.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 25 insertions, 28 deletions

diff --git a/include/exec/gen-icount.h b/include/exec/gen-icount.h
index 050de59b38..62d462e494 100644
--- a/include/exec/gen-icount.h
+++ b/include/exec/gen-icount.h
@@ -6,58 +6,55 @@
 /* Helpers for instruction counting code generation.  */
 
 static int icount_start_insn_idx;
-static TCGLabel *icount_label;
 static TCGLabel *exitreq_label;
 
 static inline void gen_tb_start(TranslationBlock *tb)
 {
-    TCGv_i32 count, flag, imm;
+    TCGv_i32 count, imm;
 
     exitreq_label = gen_new_label();
-    flag = tcg_temp_new_i32();
-    tcg_gen_ld_i32(flag, cpu_env,
-                   offsetof(CPUState, tcg_exit_req) - ENV_OFFSET);
-    tcg_gen_brcondi_i32(TCG_COND_NE, flag, 0, exitreq_label);
-    tcg_temp_free_i32(flag);
-
-    if (!(tb->cflags & CF_USE_ICOUNT)) {
-        return;
+    if (tb->cflags & CF_USE_ICOUNT) {
+        count = tcg_temp_local_new_i32();
+    } else {
+        count = tcg_temp_new_i32();
     }
 
-    icount_label = gen_new_label();
-    count = tcg_temp_local_new_i32();
     tcg_gen_ld_i32(count, cpu_env,
                    -ENV_OFFSET + offsetof(CPUState, icount_decr.u32));
 
-    imm = tcg_temp_new_i32();
-    /* We emit a movi with a dummy immediate argument. Keep the insn index
-     * of the movi so that we later (when we know the actual insn count)
-     * can update the immediate argument with the actual insn count.  */
-    icount_start_insn_idx = tcg_op_buf_count();
-    tcg_gen_movi_i32(imm, 0xdeadbeef);
+    if (tb->cflags & CF_USE_ICOUNT) {
+        imm = tcg_temp_new_i32();
+        /* We emit a movi with a dummy immediate argument. Keep the insn index
+         * of the movi so that we later (when we know the actual insn count)
+         * can update the immediate argument with the actual insn count.  */
+        icount_start_insn_idx = tcg_op_buf_count();
+        tcg_gen_movi_i32(imm, 0xdeadbeef);
+
+        tcg_gen_sub_i32(count, count, imm);
+        tcg_temp_free_i32(imm);
+    }
+
+    tcg_gen_brcondi_i32(TCG_COND_LT, count, 0, exitreq_label);
 
-    tcg_gen_sub_i32(count, count, imm);
-    tcg_temp_free_i32(imm);
+    if (tb->cflags & CF_USE_ICOUNT) {
+        tcg_gen_st16_i32(count, cpu_env,
+                         -ENV_OFFSET + offsetof(CPUState, icount_decr.u16.low));
+    }
 
-    tcg_gen_brcondi_i32(TCG_COND_LT, count, 0, icount_label);
-    tcg_gen_st16_i32(count, cpu_env,
-                     -ENV_OFFSET + offsetof(CPUState, icount_decr.u16.low));
     tcg_temp_free_i32(count);
 }
 
 static void gen_tb_end(TranslationBlock *tb, int num_insns)
 {
-    gen_set_label(exitreq_label);
-    tcg_gen_exit_tb((uintptr_t)tb + TB_EXIT_REQUESTED);
-
     if (tb->cflags & CF_USE_ICOUNT) {
         /* Update the num_insn immediate parameter now that we know
          * the actual insn count.  */
         tcg_set_insn_param(icount_start_insn_idx, 1, num_insns);
-        gen_set_label(icount_label);
-        tcg_gen_exit_tb((uintptr_t)tb + TB_EXIT_ICOUNT_EXPIRED);
     }
 
+    gen_set_label(exitreq_label);
+    tcg_gen_exit_tb((uintptr_t)tb + TB_EXIT_REQUESTED);
+
     /* Terminate the linked list.  */
     tcg_ctx.gen_op_buf[tcg_ctx.gen_op_buf[0].prev].next = 0;
 }