From 6ab8abfcde46dba211732ab860be9afba2b54399 Mon Sep 17 00:00:00 2001 From: Aleksandar Markovic Date: Tue, 25 Dec 2018 15:18:18 +0100 Subject: [PATCH] disas: nanoMIPS: Comment the decoder of 'gpr3.src.store' gpr encoding type Comment the decoder of 'gpr3.src.store' gpr encoding type in nanoMIPS disassembler. Reviewed-by: Aleksandar Rikalo Signed-off-by: Aleksandar Markovic --- disas/nanomips.cpp | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) diff --git a/disas/nanomips.cpp b/disas/nanomips.cpp index 7c561620c25..1c313f329f4 100644 --- a/disas/nanomips.cpp +++ b/disas/nanomips.cpp @@ -349,6 +349,38 @@ uint64 NMD::decode_gpr_gpr3(uint64 d) } +/* + * NMD::decode_gpr_gpr3_src_store() - decoder for 'gpr3.src.store' gpr encoding + * type + * + * Map a 3-bit code to the 5-bit register space according to this pattern: + * + * 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 + * + * This pattern is the same one used for 'gpr3' gpr encoding type, except for + * the input value 0, that is mapped to the output value 0 instead of 16. + * + * Used in handling following instructions: + * + * - SB[16] + * - SH[16] + * - SW[16] + * - SW[GP16] + */ uint64 NMD::decode_gpr_gpr3_src_store(uint64 d) { static uint64 register_list[] = { 0, 17, 18, 19, 4, 5, 6, 7 }; -- 2.39.2