[Qemu-devel] [PULL 06/26] target/arm: optimize cross-page direct jumps in softmmu

[Richard Henderson <rth@twiddle.net>]

From: "Emilio G. Cota" <cota@braap.org>

Instead of unconditionally exiting to the exec loop, use the
lookup_and_goto_ptr helper to jump to the target if it is valid.

Perf impact: see next commit's log.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Emilio G. Cota <cota@braap.org>
Message-Id: <1493263764-18657-7-git-send-email-cota@braap.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
---
 target/arm/translate.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/target/arm/translate.c b/target/arm/translate.c
index ae6646c..d72953f 100644
--- a/target/arm/translate.c
+++ b/target/arm/translate.c
@@ -4157,8 +4157,12 @@ static inline void gen_goto_tb(DisasContext *s, int n, target_ulong dest)
         gen_set_pc_im(s, dest);
         tcg_gen_exit_tb((uintptr_t)s->tb + n);
     } else {
+        TCGv addr = tcg_temp_new();
+
         gen_set_pc_im(s, dest);
-        tcg_gen_exit_tb(0);
+        tcg_gen_extu_i32_tl(addr, cpu_R[15]);
+        tcg_gen_lookup_and_goto_ptr(addr);
+        tcg_temp_free(addr);
     }
 }
 
-- 
2.9.4