[Qemu-devel] [PATCH 4/4] tcg/aarch64: implement sign/zero extend operations

[Claudio Fontana <claudio.fontana@huawei.com>]

implement the optional sign/zero extend operations with the dedicated
aarch64 instructions.

Signed-off-by: Claudio Fontana <claudio.fontana@huawei.com>
---
 tcg/aarch64/tcg-target.c | 58 ++++++++++++++++++++++++++++++++++++++++++++++--
 tcg/aarch64/tcg-target.h | 20 ++++++++---------
 2 files changed, 66 insertions(+), 12 deletions(-)

diff --git a/tcg/aarch64/tcg-target.c b/tcg/aarch64/tcg-target.c
index aa19a17..5d0f300 100644
--- a/tcg/aarch64/tcg-target.c
+++ b/tcg/aarch64/tcg-target.c
@@ -674,6 +674,24 @@ static inline void tcg_out_rev16(TCGContext *s, int ext, TCGReg rd, TCGReg rm)
     tcg_out32(s, base | rm << 5 | rd);
 }
 
+static inline void tcg_out_sxt(TCGContext *s, int ext, int s_bits,
+                               TCGReg rd, TCGReg rn)
+{
+    /* using ALIASes SXTB 0x13001c00, SXTH 0x13003c00, SXTW 0x93407c00
+       of SBFM Xd, Xn, #0, #7|15|31 */
+    int bits = 8 * (1 << s_bits) - 1;
+    tcg_out_sbfm(s, ext, rd, rn, 0, bits);
+}
+
+static inline void tcg_out_uxt(TCGContext *s, int s_bits,
+                               TCGReg rd, TCGReg rn)
+{
+    /* using ALIASes UXTB 0x53001c00, UXTH 0x53003c00
+       of UBFM Wd, Wn, #0, #7|15 */
+    int bits = 8 * (1 << s_bits) - 1;
+    tcg_out_ubfm(s, 0, rd, rn, 0, bits);
+}
+
 #ifdef CONFIG_SOFTMMU
 #include "exec/softmmu_defs.h"
 
@@ -721,8 +739,7 @@ static void tcg_out_qemu_ld(TCGContext *s, const TCGArg *args, int opc)
     tcg_out_callr(s, TCG_REG_TMP);
 
     if (opc & 0x04) { /* sign extend */
-        unsigned int bits = 8 * (1 << s_bits) - 1;
-        tcg_out_sbfm(s, 1, data_reg, TCG_REG_X0, 0, bits); /* 7|15|31 */
+        tcg_out_sxt(s, 1, s_bits, data_reg, TCG_REG_X0);
     } else {
         tcg_out_movr(s, 1, data_reg, TCG_REG_X0);
     }
@@ -1037,6 +1054,31 @@ static void tcg_out_op(TCGContext *s, TCGOpcode opc,
         tcg_out_rev16(s, 0, args[0], args[1]);
         break;
 
+    case INDEX_op_ext8s_i64:
+        ext = 1; /* fall through */
+    case INDEX_op_ext8s_i32:
+        tcg_out_sxt(s, ext, 0, args[0], args[1]);
+        break;
+    case INDEX_op_ext16s_i64:
+        ext = 1; /* fall through */
+    case INDEX_op_ext16s_i32:
+        tcg_out_sxt(s, ext, 1, args[0], args[1]);
+        break;
+    case INDEX_op_ext32s_i64:
+        tcg_out_sxt(s, 1, 2, args[0], args[1]);
+        break;
+    case INDEX_op_ext8u_i64:
+    case INDEX_op_ext8u_i32:
+        tcg_out_uxt(s, 0, args[0], args[1]);
+        break;
+    case INDEX_op_ext16u_i64:
+    case INDEX_op_ext16u_i32:
+        tcg_out_uxt(s, 1, args[0], args[1]);
+        break;
+    case INDEX_op_ext32u_i64:
+        tcg_out_movr(s, 0, args[0], args[1]);
+        break;
+
     default:
         tcg_abort(); /* opcode not implemented */
     }
@@ -1125,6 +1167,18 @@ static const TCGTargetOpDef aarch64_op_defs[] = {
     { INDEX_op_bswap32_i64, { "r", "r" } },
     { INDEX_op_bswap64_i64, { "r", "r" } },
 
+    { INDEX_op_ext8s_i32, { "r", "r" } },
+    { INDEX_op_ext16s_i32, { "r", "r" } },
+    { INDEX_op_ext8u_i32, { "r", "r" } },
+    { INDEX_op_ext16u_i32, { "r", "r" } },
+
+    { INDEX_op_ext8s_i64, { "r", "r" } },
+    { INDEX_op_ext16s_i64, { "r", "r" } },
+    { INDEX_op_ext32s_i64, { "r", "r" } },
+    { INDEX_op_ext8u_i64, { "r", "r" } },
+    { INDEX_op_ext16u_i64, { "r", "r" } },
+    { INDEX_op_ext32u_i64, { "r", "r" } },
+
     { -1 },
 };
 
diff --git a/tcg/aarch64/tcg-target.h b/tcg/aarch64/tcg-target.h
index 247ef43..97e4a5b 100644
--- a/tcg/aarch64/tcg-target.h
+++ b/tcg/aarch64/tcg-target.h
@@ -40,10 +40,10 @@ typedef enum {
 
 /* optional instructions */
 #define TCG_TARGET_HAS_div_i32          0
-#define TCG_TARGET_HAS_ext8s_i32        0
-#define TCG_TARGET_HAS_ext16s_i32       0
-#define TCG_TARGET_HAS_ext8u_i32        0
-#define TCG_TARGET_HAS_ext16u_i32       0
+#define TCG_TARGET_HAS_ext8s_i32        1
+#define TCG_TARGET_HAS_ext16s_i32       1
+#define TCG_TARGET_HAS_ext8u_i32        1
+#define TCG_TARGET_HAS_ext16u_i32       1
 #define TCG_TARGET_HAS_bswap16_i32      1
 #define TCG_TARGET_HAS_bswap32_i32      1
 #define TCG_TARGET_HAS_not_i32          0
@@ -62,12 +62,12 @@ typedef enum {
 #define TCG_TARGET_HAS_muls2_i32        0
 
 #define TCG_TARGET_HAS_div_i64          0
-#define TCG_TARGET_HAS_ext8s_i64        0
-#define TCG_TARGET_HAS_ext16s_i64       0
-#define TCG_TARGET_HAS_ext32s_i64       0
-#define TCG_TARGET_HAS_ext8u_i64        0
-#define TCG_TARGET_HAS_ext16u_i64       0
-#define TCG_TARGET_HAS_ext32u_i64       0
+#define TCG_TARGET_HAS_ext8s_i64        1
+#define TCG_TARGET_HAS_ext16s_i64       1
+#define TCG_TARGET_HAS_ext32s_i64       1
+#define TCG_TARGET_HAS_ext8u_i64        1
+#define TCG_TARGET_HAS_ext16u_i64       1
+#define TCG_TARGET_HAS_ext32u_i64       1
 #define TCG_TARGET_HAS_bswap16_i64      1
 #define TCG_TARGET_HAS_bswap32_i64      1
 #define TCG_TARGET_HAS_bswap64_i64      1
-- 
1.8.1