target-arm: A64: add support for conditional compare insns

this patch adds support for C3.5.4 - C3.5.5
Conditional compare (both immediate and register)

Signed-off-by: Claudio Fontana <claudio.fontana@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
This commit is contained in:
Claudio Fontana 2014-01-04 22:15:46 +00:00 committed by Peter Maydell
parent 643dbb07d2
commit 750813cfaa
1 changed files with 60 additions and 13 deletions

View File

@ -2483,16 +2483,67 @@ static void disas_adc_sbc(DisasContext *s, uint32_t insn)
}
}
/* Conditional compare (immediate) */
static void disas_cc_imm(DisasContext *s, uint32_t insn)
/* C3.5.4 - C3.5.5 Conditional compare (immediate / register)
* 31 30 29 28 27 26 25 24 23 22 21 20 16 15 12 11 10 9 5 4 3 0
* +--+--+--+------------------------+--------+------+----+--+------+--+-----+
* |sf|op| S| 1 1 0 1 0 0 1 0 |imm5/rm | cond |i/r |o2| Rn |o3|nzcv |
* +--+--+--+------------------------+--------+------+----+--+------+--+-----+
* [1] y [0] [0]
*/
static void disas_cc(DisasContext *s, uint32_t insn)
{
unsupported_encoding(s, insn);
}
unsigned int sf, op, y, cond, rn, nzcv, is_imm;
int label_continue = -1;
TCGv_i64 tcg_tmp, tcg_y, tcg_rn;
/* Conditional compare (register) */
static void disas_cc_reg(DisasContext *s, uint32_t insn)
{
unsupported_encoding(s, insn);
if (!extract32(insn, 29, 1)) {
unallocated_encoding(s);
return;
}
if (insn & (1 << 10 | 1 << 4)) {
unallocated_encoding(s);
return;
}
sf = extract32(insn, 31, 1);
op = extract32(insn, 30, 1);
is_imm = extract32(insn, 11, 1);
y = extract32(insn, 16, 5); /* y = rm (reg) or imm5 (imm) */
cond = extract32(insn, 12, 4);
rn = extract32(insn, 5, 5);
nzcv = extract32(insn, 0, 4);
if (cond < 0x0e) { /* not always */
int label_match = gen_new_label();
label_continue = gen_new_label();
arm_gen_test_cc(cond, label_match);
/* nomatch: */
tcg_tmp = tcg_temp_new_i64();
tcg_gen_movi_i64(tcg_tmp, nzcv << 28);
gen_set_nzcv(tcg_tmp);
tcg_temp_free_i64(tcg_tmp);
tcg_gen_br(label_continue);
gen_set_label(label_match);
}
/* match, or condition is always */
if (is_imm) {
tcg_y = new_tmp_a64(s);
tcg_gen_movi_i64(tcg_y, y);
} else {
tcg_y = cpu_reg(s, y);
}
tcg_rn = cpu_reg(s, rn);
tcg_tmp = tcg_temp_new_i64();
if (op) {
gen_sub_CC(sf, tcg_tmp, tcg_rn, tcg_y);
} else {
gen_add_CC(sf, tcg_tmp, tcg_rn, tcg_y);
}
tcg_temp_free_i64(tcg_tmp);
if (cond < 0x0e) { /* continue */
gen_set_label(label_continue);
}
}
/* C3.5.6 Conditional select
@ -2846,11 +2897,7 @@ static void disas_data_proc_reg(DisasContext *s, uint32_t insn)
disas_adc_sbc(s, insn);
break;
case 0x2: /* Conditional compare */
if (insn & (1 << 11)) { /* (immediate) */
disas_cc_imm(s, insn);
} else { /* (register) */
disas_cc_reg(s, insn);
}
disas_cc(s, insn); /* both imm and reg forms */
break;
case 0x4: /* Conditional select */
disas_cond_select(s, insn);