From 118671f02faf4d67f283731eafc96bb72b125431 Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Thu, 8 Jul 2021 14:15:56 -0700 Subject: [PATCH] target/openrisc: Cache constant 0 in DisasContext MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit We are virtually certain to have fetched constant 0 once, at the beginning of the TB, so we might as well use it elsewhere. Reviewed-by: Stafford Horne Reviewed-by: Philippe Mathieu-Daudé Signed-off-by: Richard Henderson --- target/openrisc/translate.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/target/openrisc/translate.c b/target/openrisc/translate.c index 2db529b7de..6aba4c2ffc 100644 --- a/target/openrisc/translate.c +++ b/target/openrisc/translate.c @@ -52,6 +52,8 @@ typedef struct DisasContext { /* The temporary corresponding to register 0 for this compilation. */ TCGv R0; + /* The constant zero. */ + TCGv zero; } DisasContext; static inline bool is_user(DisasContext *dc) @@ -536,10 +538,8 @@ static bool trans_l_extbz(DisasContext *dc, arg_da *a) static bool trans_l_cmov(DisasContext *dc, arg_dab *a) { - TCGv zero = tcg_constant_tl(0); - check_r0_write(dc, a->d); - tcg_gen_movcond_tl(TCG_COND_NE, cpu_R(dc, a->d), cpu_sr_f, zero, + tcg_gen_movcond_tl(TCG_COND_NE, cpu_R(dc, a->d), cpu_sr_f, dc->zero, cpu_R(dc, a->a), cpu_R(dc, a->b)); return true; } @@ -630,9 +630,8 @@ static void do_bf(DisasContext *dc, arg_l_bf *a, TCGCond cond) target_ulong tmp_pc = dc->base.pc_next + a->n * 4; TCGv t_next = tcg_constant_tl(dc->base.pc_next + 8); TCGv t_true = tcg_constant_tl(tmp_pc); - TCGv t_zero = tcg_constant_tl(0); - tcg_gen_movcond_tl(cond, jmp_pc, cpu_sr_f, t_zero, t_true, t_next); + tcg_gen_movcond_tl(cond, jmp_pc, cpu_sr_f, dc->zero, t_true, t_next); dc->delayed_branch = 2; } @@ -1594,8 +1593,9 @@ static void openrisc_tr_tb_start(DisasContextBase *db, CPUState *cs) /* Allow the TCG optimizer to see that R0 == 0, when it's true, which is the common case. */ + dc->zero = tcg_constant_tl(0); if (dc->tb_flags & TB_FLAGS_R0_0) { - dc->R0 = tcg_constant_tl(0); + dc->R0 = dc->zero; } else { dc->R0 = cpu_regs[0]; }