From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:54464) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dgZ84-0003CX-2W for qemu-devel@nongnu.org; Sat, 12 Aug 2017 12:19:13 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dgZ80-000173-2v for qemu-devel@nongnu.org; Sat, 12 Aug 2017 12:19:12 -0400 From: Richard Henderson Date: Sat, 12 Aug 2017 09:19:03 -0700 Message-Id: <20170812161903.8622-1-richard.henderson@linaro.org> Subject: [Qemu-devel] [PATCH] target/arm: Avoid an extra temporary for store_exclusive List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: peter.maydell@linaro.org, qemu-arm@nongnu.org Instead of copying addr to a local temp, reuse the value (which we have just compared as equal) already saved in cpu_exclusive_addr. Signed-off-by: Richard Henderson --- target/arm/translate-a64.c | 26 +++++++++----------------- 1 file changed, 9 insertions(+), 17 deletions(-) diff --git a/target/arm/translate-a64.c b/target/arm/translate-a64.c index f3643ac8dc..f3a1b1cecc 100644 --- a/target/arm/translate-a64.c +++ b/target/arm/translate-a64.c @@ -1896,7 +1896,7 @@ static void gen_load_exclusive(DisasContext *s, int rt, int rt2, } static void gen_store_exclusive(DisasContext *s, int rd, int rt, int rt2, - TCGv_i64 inaddr, int size, int is_pair) + TCGv_i64 addr, int size, int is_pair) { /* if (env->exclusive_addr == addr && env->exclusive_val == [addr] * && (!is_pair || env->exclusive_high == [addr + datasize])) { @@ -1912,13 +1912,8 @@ static void gen_store_exclusive(DisasContext *s, int rd, int rt, int rt2, */ TCGLabel *fail_label = gen_new_label(); TCGLabel *done_label = gen_new_label(); - TCGv_i64 addr = tcg_temp_local_new_i64(); TCGv_i64 tmp; - /* Copy input into a local temp so it is not trashed when the - * basic block ends at the branch insn. - */ - tcg_gen_mov_i64(addr, inaddr); tcg_gen_brcond_i64(TCG_COND_NE, addr, cpu_exclusive_addr, fail_label); tmp = tcg_temp_new_i64(); @@ -1929,27 +1924,24 @@ static void gen_store_exclusive(DisasContext *s, int rd, int rt, int rt2, } else { tcg_gen_concat32_i64(tmp, cpu_reg(s, rt2), cpu_reg(s, rt)); } - tcg_gen_atomic_cmpxchg_i64(tmp, addr, cpu_exclusive_val, tmp, + tcg_gen_atomic_cmpxchg_i64(tmp, cpu_exclusive_addr, + cpu_exclusive_val, tmp, get_mem_index(s), MO_64 | MO_ALIGN | s->be_data); tcg_gen_setcond_i64(TCG_COND_NE, tmp, tmp, cpu_exclusive_val); } else if (s->be_data == MO_LE) { - gen_helper_paired_cmpxchg64_le(tmp, cpu_env, addr, cpu_reg(s, rt), - cpu_reg(s, rt2)); + gen_helper_paired_cmpxchg64_le(tmp, cpu_env, cpu_exclusive_addr, + cpu_reg(s, rt), cpu_reg(s, rt2)); } else { - gen_helper_paired_cmpxchg64_be(tmp, cpu_env, addr, cpu_reg(s, rt), - cpu_reg(s, rt2)); + gen_helper_paired_cmpxchg64_be(tmp, cpu_env, cpu_exclusive_addr, + cpu_reg(s, rt), cpu_reg(s, rt2)); } } else { - TCGv_i64 val = cpu_reg(s, rt); - tcg_gen_atomic_cmpxchg_i64(tmp, addr, cpu_exclusive_val, val, - get_mem_index(s), + tcg_gen_atomic_cmpxchg_i64(tmp, cpu_exclusive_addr, cpu_exclusive_val, + cpu_reg(s, rt), get_mem_index(s), size | MO_ALIGN | s->be_data); tcg_gen_setcond_i64(TCG_COND_NE, tmp, tmp, cpu_exclusive_val); } - - tcg_temp_free_i64(addr); - tcg_gen_mov_i64(cpu_reg(s, rd), tmp); tcg_temp_free_i64(tmp); tcg_gen_br(done_label); -- 2.13.4