tcg/tci: Implement goto_ptr

This operation is critical to staying within the interpretation
loop longer, which avoids the overhead of setup and teardown for
many TBs.

The check in tcg_prologue_init is disabled because TCI does
want to use NULL to indicate exit, as opposed to branching to
a real epilogue.

Tested-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

1 files changed, 7 insertions, 1 deletions

diff --git a/tcg/tcg.c b/tcg/tcg.c
index 6472c6a8f4..dd584f3bba 100644
--- a/tcg/tcg.c
+++ b/tcg/tcg.c
@@ -785,10 +785,16 @@ void tcg_prologue_init(TCGContext *s)
     }
 #endif
 
-    /* Assert that goto_ptr is implemented completely.  */
+#ifndef CONFIG_TCG_INTERPRETER
+    /*
+     * Assert that goto_ptr is implemented completely, setting an epilogue.
+     * For tci, we use NULL as the signal to return from the interpreter,
+     * so skip this check.
+     */
     if (TCG_TARGET_HAS_goto_ptr) {
         tcg_debug_assert(tcg_code_gen_epilogue != NULL);
     }
+#endif
 }
 
 void tcg_func_start(TCGContext *s)