diff options
| -rw-r--r-- | qtmips_machine/core.cpp | 4 | ||||
| -rw-r--r-- | qtmips_machine/tests/testcore.cpp | 3 |
2 files changed, 5 insertions, 2 deletions
diff --git a/qtmips_machine/core.cpp b/qtmips_machine/core.cpp index fd6c6f4..5ce0c70 100644 --- a/qtmips_machine/core.cpp +++ b/qtmips_machine/core.cpp @@ -133,7 +133,7 @@ struct Core::dtExecute Core::execute(const struct dtDecode &dt) { std::uint32_t alu_sec = dt.val_rt; if (dt.alusrc) - alu_sec = ((dt.inst.immediate() & 0x8000) << 16) | (dt.inst.immediate() & 0x7FFF); // Sign extend to 32bit + alu_sec = ((dt.inst.immediate() & 0x8000) ? 0xFFFF0000 : 0) | (dt.inst.immediate()); // Sign extend to 32bit return { .inst = dt.inst, @@ -217,7 +217,7 @@ void Core::handle_pc(const struct dtDecode &dt) { } if (branch) - regs->pc_jmp((std::int32_t)(((dt.inst.immediate() & 0x7fff) << 2) | ((dt.inst.immediate() & 0x8000) << 16))); + regs->pc_jmp((std::int32_t)(((dt.inst.immediate() & 0x8000) ? 0xFFFF0000 : 0) | (dt.inst.immediate() << 2))); else regs->pc_inc(); } diff --git a/qtmips_machine/tests/testcore.cpp b/qtmips_machine/tests/testcore.cpp index c38eb26..3a1ce48 100644 --- a/qtmips_machine/tests/testcore.cpp +++ b/qtmips_machine/tests/testcore.cpp @@ -231,6 +231,9 @@ static void core_jmp_data() { QTest::newRow("BEQ") << Instruction(4, 14, 16, 61) \ << regs \ << regs.read_pc() + 4 + (61 << 2); + QTest::newRow("BEQ-BACK") << Instruction(4, 14, 16, -4) \ + << regs \ + << regs.read_pc() + 4 - 16; QTest::newRow("BNE") << Instruction(5, 14, 15, 61) \ << regs \ << regs.read_pc() + 4 + (61 << 2); |