diff options
Diffstat (limited to 'qtmips_machine/alu.cpp')
| -rw-r--r-- | qtmips_machine/alu.cpp | 14 |
1 files changed, 6 insertions, 8 deletions
diff --git a/qtmips_machine/alu.cpp b/qtmips_machine/alu.cpp index fa9b7d2..8016444 100644 --- a/qtmips_machine/alu.cpp +++ b/qtmips_machine/alu.cpp @@ -45,6 +45,8 @@ std::uint32_t machine::alu_operate(enum AluOp operation, std::uint32_t s, std::u discard = false; switch(operation) { + case ALU_OP_NOP: + return 0; case ALU_OP_SLL: return t << sa; case ALU_OP_SRL: @@ -59,12 +61,6 @@ std::uint32_t machine::alu_operate(enum AluOp operation, std::uint32_t s, std::u case ALU_OP_SRAV: // Note: same note as in case of SRA return (std::int32_t)t >> s; - case ALU_OP_JR: - // Do nothing as we solve this when we are handling program counter in instruction decode (handle_pc) - return 0; - case ALU_OP_JALR: - // Pass return value in rt to save PC after isntruction, program counter is handled in handle_pc - return t; case ALU_OP_MOVZ: // Signal discard of result when condition is not true discard = t != 0; @@ -73,8 +69,6 @@ std::uint32_t machine::alu_operate(enum AluOp operation, std::uint32_t s, std::u // Same note as for MOVZ applies here discard = t == 0; return discard ? 0: s; - case ALU_OP_BREAK: - return 0; case ALU_OP_MFHI: return regs->read_hi_lo(true); case ALU_OP_MTHI: @@ -136,6 +130,10 @@ std::uint32_t machine::alu_operate(enum AluOp operation, std::uint32_t s, std::u return t << 16; case ALU_OP_PASS_T: // Pass s argument without change for JAL return t; + case ALU_OP_BREAK: + return 0; + case ALU_OP_SYSCALL: // Pass s argument without change for JAL + return 0; default: throw QTMIPS_EXCEPTION(UnsupportedAluOperation, "Unknown ALU operation", QString::number(operation, 16)); } |