From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:53983) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dLEHF-00012a-1V for qemu-devel@nongnu.org; Wed, 14 Jun 2017 15:48:29 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dLEHC-0008SX-T4 for qemu-devel@nongnu.org; Wed, 14 Jun 2017 15:48:28 -0400 Received: from mail-qt0-x244.google.com ([2607:f8b0:400d:c0d::244]:35998) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1dLEHC-0008Rp-Os for qemu-devel@nongnu.org; Wed, 14 Jun 2017 15:48:26 -0400 Received: by mail-qt0-x244.google.com with SMTP id s33so2212542qtg.3 for ; Wed, 14 Jun 2017 12:48:26 -0700 (PDT) Sender: Richard Henderson From: Richard Henderson Date: Wed, 14 Jun 2017 12:48:17 -0700 Message-Id: <20170614194821.8754-2-rth@twiddle.net> In-Reply-To: <20170614194821.8754-1-rth@twiddle.net> References: <20170614194821.8754-1-rth@twiddle.net> Subject: [Qemu-devel] [PATCH v2 1/5] tcg: Refactor helper_lookup_tb_ptr List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: alex.bennee@linaro.org, cota@braap.org, pbonzini@redhat.com We can call tb_htable_lookup even when the tb_jmp_cache is completely empty. Therefore, un-nest most of the code dependent on tb != NULL from the read from the cache. Signed-off-by: Richard Henderson --- tcg-runtime.c | 34 ++++++++++++++++++---------------- 1 file changed, 18 insertions(+), 16 deletions(-) diff --git a/tcg-runtime.c b/tcg-runtime.c index 7fa90ce..a35c725 100644 --- a/tcg-runtime.c +++ b/tcg-runtime.c @@ -147,30 +147,32 @@ uint64_t HELPER(ctpop_i64)(uint64_t arg) void *HELPER(lookup_tb_ptr)(CPUArchState *env, target_ulong addr) { CPUState *cpu = ENV_GET_CPU(env); + void *ret = tcg_ctx.code_gen_epilogue; 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; - } + uint32_t flags, addr_hash; + + addr_hash = tb_jmp_cache_hash_func(addr); + tb = atomic_rcu_read(&cpu->tb_jmp_cache[addr_hash]); + cpu_get_tb_cpu_state(env, &pc, &cs_base, &flags); + + if (unlikely(!(tb + && tb->pc == addr + && tb->cs_base == cs_base + && tb->flags == flags))) { 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; + if (!tb) { + return ret; } + atomic_set(&cpu->tb_jmp_cache[addr_hash], tb); } - return tcg_ctx.code_gen_epilogue; - found: + + ret = tb->tc_ptr; qemu_log_mask_and_addr(CPU_LOG_EXEC, addr, "Chain %p [%d: " TARGET_FMT_lx "] %s\n", - tb->tc_ptr, cpu->cpu_index, addr, + ret, cpu->cpu_index, addr, lookup_symbol(addr)); - return tb->tc_ptr; + return ret; } void HELPER(exit_atomic)(CPUArchState *env) -- 2.9.4