[Qemu-devel] [PATCH v5 18/76] target/mips: Add nanoMIPS decoding and extraction utilities

[Aleksandar Markovic <aleksandar.markovic@rt-rk.com>]

From: Aleksandar Markovic <amarkovic@wavecomp.com>

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

Signed-off-by: Yongbok Kim <yongbok.kim@mips.com>
Signed-off-by: Aleksandar Markovic <amarkovic@wavecomp.com>
Signed-off-by: Stefan Markovic <smarkovic@wavecomp.com>
---
 target/mips/translate.c | 45 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 45 insertions(+)

diff --git a/target/mips/translate.c b/target/mips/translate.c
index c59ef5c..aba42be 100644
--- a/target/mips/translate.c
+++ b/target/mips/translate.c
@@ -16475,6 +16475,51 @@ enum {
  *
  */
 
+/* Implement nanoMIPS pseudocode decode_gpr(encoded_gpr, 'gpr3'). */
+static inline int decode_gpr_gpr3(int r)
+{
+    static const int map[] = { 16, 17, 18, 19,  4,  5,  6,  7 };
+
+    return map[r & 0x7];
+}
+
+/* Implement nanoMIPS pseudocode decode_gpr(encoded_gpr, 'gpr3.src.store'). */
+static inline int decode_gpr_gpr3_src_store(int r)
+{
+    static const int map[] = {  0, 17, 18, 19,  4,  5,  6,  7 };
+
+    return map[r & 0x7];
+}
+
+/* Implement nanoMIPS pseudocode decode_gpr(encoded_gpr, 'gpr4'). */
+static inline 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];
+}
+
+/* Implement nanoMIPS pseudocode decode_gpr(encoded_gpr, 'gpr4.zero'). */
+static inline 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