diff options
Diffstat (limited to 'disas/nanomips.cpp')
| -rw-r--r-- | disas/nanomips.cpp | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/disas/nanomips.cpp b/disas/nanomips.cpp index 5f6c93c9b4..a086f65143 100644 --- a/disas/nanomips.cpp +++ b/disas/nanomips.cpp @@ -406,6 +406,32 @@ uint64 NMD::encode_gpr4_zero(uint64 d) } +/* + * NMD::decode_gpr_gpr4() - decoder for 'gpr4' gpr encoding type + * + * Map a 4-bit code to the 5-bit register space according to this pattern: + * + * 1 0 + * 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 + * | | | | | | | | | | | | | | | | + * | | | | | | | | | | | | | | | | + * | | | | | | | | | | | └---------------┐ + * | | | | | | | | | | └---------------┐ | + * | | | | | | | | | └---------------┐ | | + * | | | | | | | | └---------------┐ | | | + * | | | | | | | | | | | | | | | | + * | | | | | | | | | | | | | | | | + * 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 + * 3 2 1 0 + * + * Used in handling following instructions: + * + * - ADDU[4X4] + * - LW[4X4] + * - MOVEP[REV] + * - MUL[4X4] + * - SW[4X4] + */ uint64 NMD::decode_gpr_gpr4(uint64 d) { static uint64 register_list[] = { 8, 9, 10, 11, 4, 5, 6, 7, |