From 259cb68491ab36427e7e5d820fe543d53b006ec6 Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Mon, 14 Sep 2015 14:39:47 +0100 Subject: [PATCH] target-arm: Use setcond and movcond for csel Reviewed-by: Peter Maydell Signed-off-by: Richard Henderson Message-id: 1441909103-24666-5-git-send-email-rth@twiddle.net Signed-off-by: Peter Maydell --- target-arm/translate-a64.c | 85 ++++++++++++++++++++++---------------- 1 file changed, 49 insertions(+), 36 deletions(-) diff --git a/target-arm/translate-a64.c b/target-arm/translate-a64.c index bb70185eae..1ab2c8d9aa 100644 --- a/target-arm/translate-a64.c +++ b/target-arm/translate-a64.c @@ -167,6 +167,31 @@ void gen_a64_set_pc_im(uint64_t val) tcg_gen_movi_i64(cpu_pc, val); } +typedef struct DisasCompare64 { + TCGCond cond; + TCGv_i64 value; +} DisasCompare64; + +static void a64_test_cc(DisasCompare64 *c64, int cc) +{ + DisasCompare c32; + + arm_test_cc(&c32, cc); + + /* Sign-extend the 32-bit value so that the GE/LT comparisons work + * properly. The NE/EQ comparisons are also fine with this choice. */ + c64->cond = c32.cond; + c64->value = tcg_temp_new_i64(); + tcg_gen_ext_i32_i64(c64->value, c32.value); + + arm_free_cc(&c32); +} + +static void a64_free_cc(DisasCompare64 *c64) +{ + tcg_temp_free_i64(c64->value); +} + static void gen_exception_internal(int excp) { TCGv_i32 tcg_excp = tcg_const_i32(excp); @@ -3607,7 +3632,8 @@ static void disas_cc(DisasContext *s, uint32_t insn) static void disas_cond_select(DisasContext *s, uint32_t insn) { unsigned int sf, else_inv, rm, cond, else_inc, rn, rd; - TCGv_i64 tcg_rd, tcg_src; + TCGv_i64 tcg_rd, zero; + DisasCompare64 c; if (extract32(insn, 29, 1) || extract32(insn, 11, 1)) { /* S == 1 or op2<1> == 1 */ @@ -3622,48 +3648,35 @@ static void disas_cond_select(DisasContext *s, uint32_t insn) rn = extract32(insn, 5, 5); rd = extract32(insn, 0, 5); - if (rd == 31) { - /* silly no-op write; until we use movcond we must special-case - * this to avoid a dead temporary across basic blocks. - */ - return; - } - tcg_rd = cpu_reg(s, rd); - if (cond >= 0x0e) { /* condition "always" */ - tcg_src = read_cpu_reg(s, rn, sf); - tcg_gen_mov_i64(tcg_rd, tcg_src); + a64_test_cc(&c, cond); + zero = tcg_const_i64(0); + + if (rn == 31 && rm == 31 && (else_inc ^ else_inv)) { + /* CSET & CSETM. */ + tcg_gen_setcond_i64(tcg_invert_cond(c.cond), tcg_rd, c.value, zero); + if (else_inv) { + tcg_gen_neg_i64(tcg_rd, tcg_rd); + } } else { - /* OPTME: we could use movcond here, at the cost of duplicating - * a lot of the arm_gen_test_cc() logic. - */ - TCGLabel *label_match = gen_new_label(); - TCGLabel *label_continue = gen_new_label(); - - arm_gen_test_cc(cond, label_match); - /* nomatch: */ - tcg_src = cpu_reg(s, rm); - + TCGv_i64 t_true = cpu_reg(s, rn); + TCGv_i64 t_false = read_cpu_reg(s, rm, 1); if (else_inv && else_inc) { - tcg_gen_neg_i64(tcg_rd, tcg_src); + tcg_gen_neg_i64(t_false, t_false); } else if (else_inv) { - tcg_gen_not_i64(tcg_rd, tcg_src); + tcg_gen_not_i64(t_false, t_false); } else if (else_inc) { - tcg_gen_addi_i64(tcg_rd, tcg_src, 1); - } else { - tcg_gen_mov_i64(tcg_rd, tcg_src); + tcg_gen_addi_i64(t_false, t_false, 1); } - if (!sf) { - tcg_gen_ext32u_i64(tcg_rd, tcg_rd); - } - tcg_gen_br(label_continue); - /* match: */ - gen_set_label(label_match); - tcg_src = read_cpu_reg(s, rn, sf); - tcg_gen_mov_i64(tcg_rd, tcg_src); - /* continue: */ - gen_set_label(label_continue); + tcg_gen_movcond_i64(c.cond, tcg_rd, c.value, zero, t_true, t_false); + } + + tcg_temp_free_i64(zero); + a64_free_cc(&c); + + if (!sf) { + tcg_gen_ext32u_i64(tcg_rd, tcg_rd); } }