target-arm: A64: add support for 1-src RBIT insn

This adds support for the C5.6.147 RBIT instruction.

Signed-off-by: Alexander Graf <agraf@suse.de>
[claudio: adapted to new decoder, use bswap64,
          make RBIT part standalone from the rest of the patch,
	  splitting REV into a separate patch]
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:
Alexander Graf 2013-12-17 19:42:35 +00:00 committed by Peter Maydell
parent 680ead216e
commit 82e14b02a2
3 changed files with 39 additions and 0 deletions

View File

@ -49,3 +49,21 @@ uint64_t HELPER(clz64)(uint64_t x)
{
return clz64(x);
}
uint64_t HELPER(rbit64)(uint64_t x)
{
/* assign the correct byte position */
x = bswap64(x);
/* assign the correct nibble position */
x = ((x & 0xf0f0f0f0f0f0f0f0ULL) >> 4)
| ((x & 0x0f0f0f0f0f0f0f0fULL) << 4);
/* assign the correct bit position */
x = ((x & 0x8888888888888888ULL) >> 3)
| ((x & 0x4444444444444444ULL) >> 1)
| ((x & 0x2222222222222222ULL) << 1)
| ((x & 0x1111111111111111ULL) << 3);
return x;
}

View File

@ -19,3 +19,4 @@
DEF_HELPER_FLAGS_2(udiv64, TCG_CALL_NO_RWG_SE, i64, i64, i64)
DEF_HELPER_FLAGS_2(sdiv64, TCG_CALL_NO_RWG_SE, s64, s64, s64)
DEF_HELPER_FLAGS_1(clz64, TCG_CALL_NO_RWG_SE, i64, i64)
DEF_HELPER_FLAGS_1(rbit64, TCG_CALL_NO_RWG_SE, i64, i64)

View File

@ -1062,6 +1062,24 @@ static void handle_clz(DisasContext *s, unsigned int sf,
}
}
static void handle_rbit(DisasContext *s, unsigned int sf,
unsigned int rn, unsigned int rd)
{
TCGv_i64 tcg_rd, tcg_rn;
tcg_rd = cpu_reg(s, rd);
tcg_rn = cpu_reg(s, rn);
if (sf) {
gen_helper_rbit64(tcg_rd, tcg_rn);
} else {
TCGv_i32 tcg_tmp32 = tcg_temp_new_i32();
tcg_gen_trunc_i64_i32(tcg_tmp32, tcg_rn);
gen_helper_rbit(tcg_tmp32, tcg_tmp32);
tcg_gen_extu_i32_i64(tcg_rd, tcg_tmp32);
tcg_temp_free_i32(tcg_tmp32);
}
}
/* C3.5.7 Data-processing (1 source)
* 31 30 29 28 21 20 16 15 10 9 5 4 0
* +----+---+---+-----------------+---------+--------+------+------+
@ -1084,6 +1102,8 @@ static void disas_data_proc_1src(DisasContext *s, uint32_t insn)
switch (opcode) {
case 0: /* RBIT */
handle_rbit(s, sf, rn, rd);
break;
case 1: /* REV16 */
case 2: /* REV32 */
case 3: /* REV64 */