From 45b71a795e5add347f0ba7aba526896132e9b986 Mon Sep 17 00:00:00 2001
From: Max Filippov <jcmvbkbc@gmail.com>
Date: Wed, 30 Jan 2019 14:48:22 -0800
Subject: [PATCH] target/xtensa: add generic instruction post-processing

Some opcodes may need additional actions at every exit from the
translated instruction or may need to amend TB exit slots available to
jumps generated for the instruction. Add gen_postprocess function and
call it from the gen_jump_slot and from the disas_xtensa_insn.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
---
 target/xtensa/cpu.h       |  8 ++++++++
 target/xtensa/translate.c | 33 +++++++++++++++++++++++++--------
 2 files changed, 33 insertions(+), 8 deletions(-)

diff --git a/target/xtensa/cpu.h b/target/xtensa/cpu.h
index c59f79e563..a3bab9c5a2 100644
--- a/target/xtensa/cpu.h
+++ b/target/xtensa/cpu.h
@@ -368,9 +368,17 @@ enum {
 
     XTENSA_OP_DIVIDE_BY_ZERO = 0x100,
 
+    /* Postprocessing flags */
     XTENSA_OP_CHECK_INTERRUPTS = 0x200,
     XTENSA_OP_EXIT_TB_M1 = 0x400,
     XTENSA_OP_EXIT_TB_0 = 0x800,
+    XTENSA_OP_SYNC_REGISTER_WINDOW = 0x1000,
+
+    XTENSA_OP_POSTPROCESS =
+        XTENSA_OP_CHECK_INTERRUPTS |
+        XTENSA_OP_EXIT_TB_M1 |
+        XTENSA_OP_EXIT_TB_0 |
+        XTENSA_OP_SYNC_REGISTER_WINDOW,
 
     XTENSA_OP_NAME_ARRAY = 0x8000,
 
diff --git a/target/xtensa/translate.c b/target/xtensa/translate.c
index bda4e9469b..e7ef6a8998 100644
--- a/target/xtensa/translate.c
+++ b/target/xtensa/translate.c
@@ -71,6 +71,7 @@ struct DisasContext {
 
     unsigned cpenable;
 
+    uint32_t op_flags;
     uint32_t *raw_arg;
     xtensa_insnbuf insnbuf;
     xtensa_insnbuf slotbuf;
@@ -363,6 +364,8 @@ static bool gen_check_cpenable(DisasContext *dc, uint32_t cp_mask)
     return true;
 }
 
+static int gen_postprocess(DisasContext *dc, int slot);
+
 static void gen_jump_slot(DisasContext *dc, TCGv dest, int slot)
 {
     tcg_gen_mov_i32(cpu_pc, dest);
@@ -372,6 +375,9 @@ static void gen_jump_slot(DisasContext *dc, TCGv dest, int slot)
     if (dc->base.singlestep_enabled) {
         gen_exception(dc, EXCP_DEBUG);
     } else {
+        if (dc->op_flags & XTENSA_OP_POSTPROCESS) {
+            slot = gen_postprocess(dc, slot);
+        }
         if (slot >= 0) {
             tcg_gen_goto_tb(slot);
             tcg_gen_exit_tb(dc->base.tb, slot);
@@ -846,6 +852,19 @@ static inline unsigned xtensa_op0_insn_len(DisasContext *dc, uint8_t op0)
     return xtensa_isa_length_from_chars(dc->config->isa, &op0);
 }
 
+static int gen_postprocess(DisasContext *dc, int slot)
+{
+    uint32_t op_flags = dc->op_flags;
+
+    if (op_flags & XTENSA_OP_CHECK_INTERRUPTS) {
+        gen_check_interrupts(dc);
+    }
+    if (op_flags & XTENSA_OP_EXIT_TB_M1) {
+        slot = -1;
+    }
+    return slot;
+}
+
 struct opcode_arg_info {
     uint32_t resource;
     int index;
@@ -1211,6 +1230,8 @@ static void disas_xtensa_insn(CPUXtensaState *env, DisasContext *dc)
         }
     }
 
+    dc->op_flags = op_flags;
+
     for (slot = 0; slot < slots; ++slot) {
         struct slot_prop *pslot = ordered[slot];
         XtensaOpcodeOps *ops = pslot->ops;
@@ -1220,21 +1241,17 @@ static void disas_xtensa_insn(CPUXtensaState *env, DisasContext *dc)
     }
 
     if (dc->base.is_jmp == DISAS_NEXT) {
-        if (op_flags & XTENSA_OP_CHECK_INTERRUPTS) {
-            gen_check_interrupts(dc);
-        }
-
+        gen_postprocess(dc, 0);
+        dc->op_flags = 0;
         if (op_flags & XTENSA_OP_EXIT_TB_M1) {
             /* Change in mmu index, memory mapping or tb->flags; exit tb */
             gen_jumpi_check_loop_end(dc, -1);
         } else if (op_flags & XTENSA_OP_EXIT_TB_0) {
             gen_jumpi_check_loop_end(dc, 0);
+        } else {
+            gen_check_loop_end(dc, 0);
         }
     }
-
-    if (dc->base.is_jmp == DISAS_NEXT) {
-        gen_check_loop_end(dc, 0);
-    }
     dc->pc = dc->base.pc_next;
 }
 
-- 
2.11.0