diff options
Diffstat (limited to 'target-arm/translate-a64.c')
| -rw-r--r-- | target-arm/translate-a64.c | 49 |
1 files changed, 47 insertions, 2 deletions
diff --git a/target-arm/translate-a64.c b/target-arm/translate-a64.c index 9677d01563..f9336ded93 100644 --- a/target-arm/translate-a64.c +++ b/target-arm/translate-a64.c @@ -704,10 +704,55 @@ static void disas_bitfield(DisasContext *s, uint32_t insn) unsupported_encoding(s, insn); } -/* Extract */ +/* C3.4.3 Extract + * 31 30 29 28 23 22 21 20 16 15 10 9 5 4 0 + * +----+------+-------------+---+----+------+--------+------+------+ + * | sf | op21 | 1 0 0 1 1 1 | N | o0 | Rm | imms | Rn | Rd | + * +----+------+-------------+---+----+------+--------+------+------+ + */ static void disas_extract(DisasContext *s, uint32_t insn) { - unsupported_encoding(s, insn); + unsigned int sf, n, rm, imm, rn, rd, bitsize, op21, op0; + + sf = extract32(insn, 31, 1); + n = extract32(insn, 22, 1); + rm = extract32(insn, 16, 5); + imm = extract32(insn, 10, 6); + rn = extract32(insn, 5, 5); + rd = extract32(insn, 0, 5); + op21 = extract32(insn, 29, 2); + op0 = extract32(insn, 21, 1); + bitsize = sf ? 64 : 32; + + if (sf != n || op21 || op0 || imm >= bitsize) { + unallocated_encoding(s); + } else { + TCGv_i64 tcg_rd, tcg_rm, tcg_rn; + + tcg_rd = cpu_reg(s, rd); + + if (imm) { + /* OPTME: we can special case rm==rn as a rotate */ + tcg_rm = read_cpu_reg(s, rm, sf); + tcg_rn = read_cpu_reg(s, rn, sf); + tcg_gen_shri_i64(tcg_rm, tcg_rm, imm); + tcg_gen_shli_i64(tcg_rn, tcg_rn, bitsize - imm); + tcg_gen_or_i64(tcg_rd, tcg_rm, tcg_rn); + if (!sf) { + tcg_gen_ext32u_i64(tcg_rd, tcg_rd); + } + } else { + /* tcg shl_i32/shl_i64 is undefined for 32/64 bit shifts, + * so an extract from bit 0 is a special case. + */ + if (sf) { + tcg_gen_mov_i64(tcg_rd, cpu_reg(s, rm)); + } else { + tcg_gen_ext32u_i64(tcg_rd, cpu_reg(s, rm)); + } + } + + } } /* C3.4 Data processing - immediate */ |