[Qemu-devel] [PATCH v9 22/84] target/mips: Add emulation of nanoMIPS 16-bit branch instructions

[Aleksandar Markovic]

From: Yongbok Kim <address@hidden>

Add emulation of nanoMIPS 16-bit branch instructions.

Reviewed-by: Richard Henderson <address@hidden>
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 | 36 ++++++++++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)

diff --git a/target/mips/translate.c b/target/mips/translate.c
index f9ec95b..05c8b8f 100644
--- a/target/mips/translate.c
+++ b/target/mips/translate.c
@@ -16746,14 +16746,50 @@ static int decode_nanomips_opc(CPUMIPSState *env, 
DisasContext *ctx)
     case NM_SWGP16:
         break;
     case NM_BC16:
+        gen_compute_branch(ctx, OPC_BEQ, 2, 0, 0,
+                           (sextract32(ctx->opcode, 0, 1) << 10) |
+                           (extract32(ctx->opcode, 1, 9) << 1), 0);
         break;
     case NM_BALC16:
+        gen_compute_branch(ctx, OPC_BGEZAL, 2, 0, 0,
+                           (sextract32(ctx->opcode, 0, 1) << 10) |
+                           (extract32(ctx->opcode, 1, 9) << 1), 0);
         break;
     case NM_BEQZC16:
+        gen_compute_branch(ctx, OPC_BEQ, 2, rt, 0,
+                           (sextract32(ctx->opcode, 0, 1) << 7) |
+                           (extract32(ctx->opcode, 1, 6) << 1), 0);
         break;
     case NM_BNEZC16:
+        gen_compute_branch(ctx, OPC_BNE, 2, rt, 0,
+                           (sextract32(ctx->opcode, 0, 1) << 7) |
+                           (extract32(ctx->opcode, 1, 6) << 1), 0);
         break;
     case NM_P16_BR:
+        switch (ctx->opcode & 0xf) {
+        case 0:
+            /* P16.JRC */
+            switch (extract32(ctx->opcode, 4, 1)) {
+            case NM_JRC:
+                gen_compute_branch(ctx, OPC_JR, 2,
+                                   extract32(ctx->opcode, 5, 5), 0, 0, 0);
+                break;
+            case NM_JALRC16:
+                gen_compute_branch(ctx, OPC_JALR, 2,
+                                   extract32(ctx->opcode, 5, 5), 31, 0, 0);
+                break;
+            }
+            break;
+        default:
+            {
+                /* P16.BRI */
+                uint32_t opc = extract32(ctx->opcode, 4, 3) <
+                               extract32(ctx->opcode, 7, 3) ? OPC_BEQ : 
OPC_BNE;
+                gen_compute_branch(ctx, opc, 2, rs, rt,
+                                   extract32(ctx->opcode, 0, 4) << 1, 0);
+            }
+            break;
+        }
         break;
     case NM_P16_SR:
         break;
-- 
2.7.4