[Qemu-devel] [PATCH v3 6/8] target-arm: A64: add support for move wide instructions

[Peter Maydell <peter.maydell@linaro.org>]

From: Alex Bennée <alex.bennee@linaro.org>

This patch adds emulation for the mov wide instructions
(MOVN, MOVZ, MOVK).

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
---
 target-arm/translate-a64.c | 51 ++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 49 insertions(+), 2 deletions(-)

diff --git a/target-arm/translate-a64.c b/target-arm/translate-a64.c
index 00dd369..a6f1945 100644
--- a/target-arm/translate-a64.c
+++ b/target-arm/translate-a64.c
@@ -1641,10 +1641,57 @@ static void disas_logic_imm(DisasContext *s, uint32_t insn)
     }
 }
 
-/* Move wide (immediate) */
+/*
+ * C3.4.5 Move wide (immediate)
+ *
+ *  31 30 29 28         23 22 21 20             5 4    0
+ * +--+-----+-------------+-----+----------------+------+
+ * |sf| opc | 1 0 0 1 0 1 |  hw |  imm16         |  Rd  |
+ * +--+-----+-------------+-----+----------------+------+
+ *
+ * sf: 0 -> 32 bit, 1 -> 64 bit
+ * opc: 00 -> N, 10 -> Z, 11 -> K
+ * hw: shift/16 (0,16, and sf only 32, 48)
+ */
 static void disas_movw_imm(DisasContext *s, uint32_t insn)
 {
-    unsupported_encoding(s, insn);
+    int rd = extract32(insn, 0, 5);
+    uint64_t imm = extract32(insn, 5, 16);
+    int sf = extract32(insn, 31, 1);
+    int opc = extract32(insn, 29, 2);
+    int pos = extract32(insn, 21, 2) << 4;
+    TCGv_i64 tcg_rd = cpu_reg(s, rd);
+    TCGv_i64 tcg_imm;
+
+    if (!sf && (pos >= 32)) {
+        unallocated_encoding(s);
+        return;
+    }
+
+    switch (opc) {
+    case 0: /* MOVN */
+    case 2: /* MOVZ */
+        imm <<= pos;
+        if (opc == 0) {
+            imm = ~imm;
+        }
+        if (!sf) {
+            imm &= 0xffffffffu;
+        }
+        tcg_gen_movi_i64(tcg_rd, imm);
+        break;
+    case 3: /* MOVK */
+        tcg_imm = tcg_const_i64(imm);
+        tcg_gen_deposit_i64(tcg_rd, tcg_rd, tcg_imm, pos, 16);
+        tcg_temp_free_i64(tcg_imm);
+        if (!sf) {
+            tcg_gen_ext32u_i64(tcg_rd, tcg_rd);
+        }
+        break;
+    default:
+        unallocated_encoding(s);
+        break;
+    }
 }
 
 /* C3.4.2 Bitfield
-- 
1.8.5