From: Claudio Fontana <claudio.font...@linaro.org>
This patch adds support for decoding 1-src data processing insns,
and the first user, C5.6.40 CLZ (count leading zeroes).
Signed-off-by: Claudio Fontana <claudio.font...@linaro.org>
Signed-off-by: Peter Maydell <peter.mayd...@linaro.org>
Reviewed-by: Richard Henderson <r...@twiddle.net>
---
target-arm/helper-a64.c | 5 +++++
target-arm/helper-a64.h | 1 +
target-arm/translate-a64.c | 52 ++++++++++++++++++++++++++++++++++++++++++++--
3 files changed, 56 insertions(+), 2 deletions(-)
diff --git a/target-arm/helper-a64.c b/target-arm/helper-a64.c
index abb98c0..e4c5346 100644
--- a/target-arm/helper-a64.c
+++ b/target-arm/helper-a64.c
@@ -44,3 +44,8 @@ int64_t HELPER(sdiv64)(int64_t num, int64_t den)
}
return num / den;
}
+
+uint64_t HELPER(clz64)(uint64_t x)
+{
+ return clz64(x);
+}
diff --git a/target-arm/helper-a64.h b/target-arm/helper-a64.h
index e0d6506..b10b6c3 100644
--- a/target-arm/helper-a64.h
+++ b/target-arm/helper-a64.h
@@ -18,3 +18,4 @@
*/
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)
diff --git a/target-arm/translate-a64.c b/target-arm/translate-a64.c
index acf30c3..e5481da 100644
--- a/target-arm/translate-a64.c
+++ b/target-arm/translate-a64.c
@@ -1044,10 +1044,58 @@ static void disas_cond_select(DisasContext *s, uint32_t
insn)
}
}
-/* Data-processing (1 source) */
+static void handle_clz(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_clz64(tcg_rd, tcg_rn);
+ } else {
+ TCGv_i32 tcg_tmp32 = tcg_temp_new_i32();
+ tcg_gen_trunc_i64_i32(tcg_tmp32, tcg_rn);
+ gen_helper_clz(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
+ * +----+---+---+-----------------+---------+--------+------+------+
+ * | sf | 1 | S | 1 1 0 1 0 1 1 0 | opcode2 | opcode | Rn | Rd |
+ * +----+---+---+-----------------+---------+--------+------+------+
+ */
static void disas_data_proc_1src(DisasContext *s, uint32_t insn)
{
- unsupported_encoding(s, insn);
+ unsigned int sf, opcode, rn, rd;
+
+ if (extract32(insn, 29, 1) || extract32(insn, 16, 5)) {
+ unallocated_encoding(s);
+ return;
+ }
+
+ sf = extract32(insn, 31, 1);
+ opcode = extract32(insn, 10, 6);
+ rn = extract32(insn, 5, 5);
+ rd = extract32(insn, 0, 5);
+
+ switch (opcode) {
+ case 0: /* RBIT */
+ case 1: /* REV16 */
+ case 2: /* REV32 */
+ case 3: /* REV64 */
+ unsupported_encoding(s, insn);
+ break;
+ case 4: /* CLZ */
+ handle_clz(s, sf, rn, rd);
+ break;
+ case 5: /* CLS */
+ unsupported_encoding(s, insn);
+ break;
+ }
}
static void handle_div(DisasContext *s, bool is_signed, unsigned int sf,
--
1.8.5
