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Re: [Qemu-arm] [PATCH 09/17] target/arm: Implement the SUBP instruction
From: |
Peter Maydell |
Subject: |
Re: [Qemu-arm] [PATCH 09/17] target/arm: Implement the SUBP instruction |
Date: |
Thu, 7 Feb 2019 17:38:21 +0000 |
On Mon, 14 Jan 2019 at 01:12, Richard Henderson
<address@hidden> wrote:
>
> Signed-off-by: Richard Henderson <address@hidden>
> ---
> target/arm/translate-a64.c | 24 ++++++++++++++++++++++--
> 1 file changed, 22 insertions(+), 2 deletions(-)
>
> diff --git a/target/arm/translate-a64.c b/target/arm/translate-a64.c
> index 6583ad93b1..98ff60c161 100644
> --- a/target/arm/translate-a64.c
> +++ b/target/arm/translate-a64.c
> @@ -5111,19 +5111,39 @@ static void handle_crc32(DisasContext *s,
> */
> static void disas_data_proc_2src(DisasContext *s, uint32_t insn)
> {
> - unsigned int sf, rm, opcode, rn, rd;
> + unsigned int sf, rm, opcode, rn, rd, setflag;
> sf = extract32(insn, 31, 1);
> + setflag = extract32(insn, 29, 1);
> rm = extract32(insn, 16, 5);
> opcode = extract32(insn, 10, 6);
> rn = extract32(insn, 5, 5);
> rd = extract32(insn, 0, 5);
>
> - if (extract32(insn, 29, 1)) {
> + if (setflag && opcode != 0) {
> unallocated_encoding(s);
> return;
> }
>
> switch (opcode) {
> + case 0: /* SUBP(S) */
> + if (sf == 0 || !dc_isar_feature(aa64_mte_insn_reg, s)) {
> + goto do_unallocated;
> + } else {
> + TCGv_i64 tcg_n, tcg_m, tcg_d;
> +
> + tcg_n = read_cpu_reg_sp(s, rn, true);
> + tcg_m = read_cpu_reg_sp(s, rm, true);
> + tcg_gen_sextract_i64(tcg_n, tcg_n, 0, 55);
> + tcg_gen_sextract_i64(tcg_m, tcg_m, 0, 55);
Shouldn't the lengths here be 56, not 55 ? We're doing the
sign-extend of bits [55:0] to 64 bits.
> + tcg_d = cpu_reg(s, rd);
> +
> + if (setflag) {
> + gen_sub_CC(true, tcg_d, tcg_n, tcg_m);
> + } else {
> + tcg_gen_sub_i64(tcg_d, tcg_n, tcg_m);
> + }
> + }
> + break;
> case 2: /* UDIV */
> handle_div(s, false, sf, rm, rn, rd);
> break;
> --
> 2.17.2
Otherwise
Reviewed-by: Peter Maydell <address@hidden>
thanks
-- PMM
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