[Qemu-devel] [PATCH v3 05/40] target/mips: Add nanoMIPS decoding and extraction utilities

[Stefan Markovic]

From: Yongbok Kim <address@hidden>

Add some basic utility functions and macros for nanoMIPS decoding
engine.

Signed-off-by: Yongbok Kim <address@hidden>
Signed-off-by: Aleksandar Markovic <address@hidden>
Signed-off-by: Stefan Markovic <address@hidden>
---
 target/mips/translate.c | 35 +++++++++++++++++++++++++++++++++++
 1 file changed, 35 insertions(+)

diff --git a/target/mips/translate.c b/target/mips/translate.c
index 67a0f70..4e6ae1f 100644
--- a/target/mips/translate.c
+++ b/target/mips/translate.c
@@ -16465,6 +16465,41 @@ enum {
  *
  */
 
+static int decode_gpr_gpr3(int r)
+{
+    static const int map[] = { 16, 17, 18, 19, 4, 5, 6, 7 };
+
+    return map[r & 0x7];
+}
+
+static int decode_gpr_gpr4(int r)
+{
+    static const int map[] = { 8, 9, 10, 11, 4, 5, 6, 7,
+                            16, 17, 18, 19, 20, 21, 22, 23 };
+
+    return map[r & 0xf];
+}
+
+/* Used for 16-bit store instructions.  */
+static int decode_gpr_gpr4_zero(int r)
+{
+    static const int map[] = { 8, 9, 10, 0, 4, 5, 6, 7,
+                            16, 17, 18, 19, 20, 21, 22, 23 };
+
+    return map[r & 0xf];
+}
+
+
+/* extraction utilities */
+
+#define NANOMIPS_EXTRACT_RD(op) ((op >> 7) & 0x7)
+#define NANOMIPS_EXTRACT_RS(op) ((op >> 4) & 0x7)
+#define NANOMIPS_EXTRACT_RS2(op) uMIPS_RS(op)
+#define NANOMIPS_EXTRACT_RS1(op) ((op >> 1) & 0x7)
+#define NANOMIPS_EXTRACT_RD5(op) ((op >> 5) & 0x1f)
+#define NANOMIPS_EXTRACT_RS5(op) (op & 0x1f)
+
+
 static int decode_nanomips_opc(CPUMIPSState *env, DisasContext *ctx)
 {
     return 2;
-- 
2.7.4