target/xtensa: extract test for window overflow exception

- add ps.callinc to the TB flags, that allows testing all instructions
  for window overflow statically;
- drop gen_window_check* functions; replace them with get_window_check
  that accepts bitmask of used registers;
- add XtensaOpcodeOps::test_overflow that returns bitmask of implicitly
  used registers; use it for entry and call{,x}{4,8,12};
- drop window overflow test from the entry helper;
- drop parameter 0 from translate_[di]cache and use translate_nop for
  d/i cache opcodes that don't need memory accessibility check;
- add bitmask XtensaOpcodeOps::windowed_register_op that marks opcode
  arguments that refer to windowed registers;
- translate windowed_register_op mask to a mask of actually used
  registers in the disassembly loop;
- add check for window overflow right after the check for debug
  exception;

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

target/xtensa/cpu.h

@@ -351,6 +351,9 @@ typedef void (*XtensaOpcodeOp)(DisasContext *dc, const uint32_t arg[],
 typedef bool (*XtensaOpcodeBoolTest)(DisasContext *dc,
                                      const uint32_t arg[],
                                      const uint32_t par[]);
+typedef uint32_t (*XtensaOpcodeUintTest)(DisasContext *dc,
+                                         const uint32_t arg[],
+                                         const uint32_t par[]);
 
 enum {
     XTENSA_OP_ILL = 0x1,
@@ -374,8 +377,10 @@ typedef struct XtensaOpcodeOps {
     const char *name;
     XtensaOpcodeOp translate;
     XtensaOpcodeBoolTest test_ill;
+    XtensaOpcodeUintTest test_overflow;
     const uint32_t *par;
     uint32_t op_flags;
+    uint32_t windowed_register_op;
 } XtensaOpcodeOps;
 
 typedef struct XtensaOpcodeTranslators {
@@ -686,6 +691,8 @@ static inline int cpu_mmu_index(CPUXtensaState *env, bool ifetch)
 #define XTENSA_TBFLAG_WINDOW_SHIFT 15
 #define XTENSA_TBFLAG_YIELD 0x20000
 #define XTENSA_TBFLAG_CWOE 0x40000
+#define XTENSA_TBFLAG_CALLINC_MASK 0x180000
+#define XTENSA_TBFLAG_CALLINC_SHIFT 19
 
 static inline void cpu_get_tb_cpu_state(CPUXtensaState *env, target_ulong *pc,
         target_ulong *cs_base, uint32_t *flags)
@@ -724,6 +731,8 @@ static inline void cpu_get_tb_cpu_state(CPUXtensaState *env, target_ulong *pc,
         uint32_t w = ctz32(windowstart | 0x8);
 
         *flags |= (w << XTENSA_TBFLAG_WINDOW_SHIFT) | XTENSA_TBFLAG_CWOE;
+        *flags |= extract32(env->sregs[PS], PS_CALLINC_SHIFT,
+                            PS_CALLINC_LEN) << XTENSA_TBFLAG_CALLINC_SHIFT;
     } else {
         *flags |= 3 << XTENSA_TBFLAG_WINDOW_SHIFT;
     }

target/xtensa/op_helper.c

@@ -253,12 +253,7 @@ void HELPER(wsr_windowbase)(CPUXtensaState *env, uint32_t v)
 void HELPER(entry)(CPUXtensaState *env, uint32_t pc, uint32_t s, uint32_t imm)
 {
     int callinc = (env->sregs[PS] & PS_CALLINC) >> PS_CALLINC_SHIFT;
-    uint32_t windowstart = xtensa_replicate_windowstart(env) >>
-        (env->sregs[WINDOW_BASE] + 1);
 
-    if (windowstart & ((1 << callinc) - 1)) {
-        HELPER(window_check)(env, pc, callinc);
-    }
     env->regs[(callinc << 2) | (s & 3)] = env->regs[s] - imm;
     xtensa_rotate_window(env, callinc);
     env->sregs[WINDOW_START] |=