tcg-s390: Implement direct chaining of TBs

Signed-off-by: NRichard Henderson <rth@twiddle.net>

include/exec/exec-all.h

@@ -131,6 +131,7 @@ static inline void tlb_flush(CPUState *cpu, int flush_global)
 #if defined(__arm__) || defined(_ARCH_PPC) \
     || defined(__x86_64__) || defined(__i386__) \
     || defined(__sparc__) || defined(__aarch64__) \
+    || defined(__s390x__) \
     || defined(CONFIG_TCG_INTERPRETER)
 #define USE_DIRECT_JUMP
 #endif
@@ -232,6 +233,14 @@ static inline void tb_set_jmp_target1(uintptr_t jmp_addr, uintptr_t addr)
     stl_le_p((void*)jmp_addr, addr - (jmp_addr + 4));
     /* no need to flush icache explicitly */
 }
+#elif defined(__s390x__)
+static inline void tb_set_jmp_target1(uintptr_t jmp_addr, uintptr_t addr)
+{
+    /* patch the branch destination */
+    intptr_t disp = addr - (jmp_addr - 2);
+    stl_be_p((void*)jmp_addr, disp / 2);
+    /* no need to flush icache explicitly */
+}
 #elif defined(__aarch64__)
 void aarch64_tb_set_jmp_target(uintptr_t jmp_addr, uintptr_t addr);
 #define tb_set_jmp_target1 aarch64_tb_set_jmp_target

tcg/s390/tcg-target.c

@@ -1703,7 +1703,9 @@ static inline void tcg_out_op(TCGContext *s, TCGOpcode opc,
 
     case INDEX_op_goto_tb:
         if (s->tb_jmp_offset) {
-            tcg_abort();
+            tcg_out16(s, RIL_BRCL | (S390_CC_ALWAYS << 4));
+            s->tb_jmp_offset[args[0]] = tcg_current_code_size(s);
+            s->code_ptr += 2;
         } else {
             /* load address stored at s->tb_next + args[0] */
             tcg_out_ld_abs(s, TCG_TYPE_PTR, TCG_TMP0, s->tb_next + args[0]);