tcg: Introduce goto_ptr opcode and tcg_gen_lookup_and_goto_ptr

Instead of exporting goto_ptr directly to TCG frontends, export
tcg_gen_lookup_and_goto_ptr(), which calls goto_ptr with the pointer
returned by the lookup_tb_ptr() helper. This is the only use case
we have for goto_ptr and lookup_tb_ptr, so having this function is
very convenient. Furthermore, it trivially allows us to avoid calling
the lookup helper if goto_ptr is not implemented by the backend.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Emilio G. Cota <cota@braap.org>
Message-Id: <1493263764-18657-2-git-send-email-cota@braap.org>
Message-Id: <1493263764-18657-3-git-send-email-cota@braap.org>
Message-Id: <1493263764-18657-4-git-send-email-cota@braap.org>
Message-Id: <1493263764-18657-5-git-send-email-cota@braap.org>
[rth: Squashed 4 related commits.]
Signed-off-by: Richard Henderson <rth@twiddle.net>

1 files changed, 32 insertions, 0 deletions

diff --git a/tcg-runtime.c b/tcg-runtime.c
index 4c60c96658..7fa90ce508 100644
--- a/tcg-runtime.c
+++ b/tcg-runtime.c
@@ -27,6 +27,9 @@
 #include "exec/helper-proto.h"
 #include "exec/cpu_ldst.h"
 #include "exec/exec-all.h"
+#include "exec/tb-hash.h"
+#include "disas/disas.h"
+#include "exec/log.h"
 
 /* 32-bit helpers */
 
@@ -141,6 +144,35 @@ uint64_t HELPER(ctpop_i64)(uint64_t arg)
     return ctpop64(arg);
 }
 
+void *HELPER(lookup_tb_ptr)(CPUArchState *env, target_ulong addr)
+{
+    CPUState *cpu = ENV_GET_CPU(env);
+    TranslationBlock *tb;
+    target_ulong cs_base, pc;
+    uint32_t flags;
+
+    tb = atomic_rcu_read(&cpu->tb_jmp_cache[tb_jmp_cache_hash_func(addr)]);
+    if (likely(tb)) {
+        cpu_get_tb_cpu_state(env, &pc, &cs_base, &flags);
+        if (likely(tb->pc == addr && tb->cs_base == cs_base &&
+                   tb->flags == flags)) {
+            goto found;
+        }
+        tb = tb_htable_lookup(cpu, addr, cs_base, flags);
+        if (likely(tb)) {
+            atomic_set(&cpu->tb_jmp_cache[tb_jmp_cache_hash_func(addr)], tb);
+            goto found;
+        }
+    }
+    return tcg_ctx.code_gen_epilogue;
+ found:
+    qemu_log_mask_and_addr(CPU_LOG_EXEC, addr,
+                           "Chain %p [%d: " TARGET_FMT_lx "] %s\n",
+                           tb->tc_ptr, cpu->cpu_index, addr,
+                           lookup_symbol(addr));
+    return tb->tc_ptr;
+}
+
 void HELPER(exit_atomic)(CPUArchState *env)
 {
     cpu_loop_exit_atomic(ENV_GET_CPU(env), GETPC());