diff options
| -rw-r--r-- | qtmips_machine/core.cpp | 14 | ||||
| -rw-r--r-- | qtmips_machine/core.h | 2 |
2 files changed, 10 insertions, 6 deletions
diff --git a/qtmips_machine/core.cpp b/qtmips_machine/core.cpp index 980a736..f290659 100644 --- a/qtmips_machine/core.cpp +++ b/qtmips_machine/core.cpp @@ -462,7 +462,7 @@ void Core::writeback(const struct dtMemory &dt) { regs->write_gp(dt.rwrite, dt.towrite_val); } -bool Core::handle_pc(const struct dtDecode &dt) { +bool Core::handle_pc(const struct dtDecode &dt, int32_t rel_adj) { bool branch = false; emit instruction_program_counter(dt.inst, dt.inst_addr, EXCAUSE_NONE); @@ -497,10 +497,14 @@ bool Core::handle_pc(const struct dtDecode &dt) { emit fetch_jump_reg_value(false); emit fetch_branch_value(branch); - if (branch) - regs->pc_jmp((std::int32_t)(((dt.inst.immediate() & 0x8000) ? 0xFFFF0000 : 0) | (dt.inst.immediate() << 2))); - else + if (branch) { + std::int32_t rel_offset = dt.inst.immediate() << 2; + if (rel_offset & (1 << 17)) + rel_offset -= 1 << 18; + regs->pc_jmp(rel_offset + rel_adj); + } else { regs->pc_inc(); + } return branch; } @@ -596,7 +600,7 @@ void CoreSingle::do_step(bool skip_break) { jump_branch_pc = jmp_delay_decode->inst_addr; *jmp_delay_decode = d; // Copy current decode } else { - handle_pc(d); + handle_pc(d, 4); jump_branch_pc = d.inst_addr; } diff --git a/qtmips_machine/core.h b/qtmips_machine/core.h index f70a19d..1c44550 100644 --- a/qtmips_machine/core.h +++ b/qtmips_machine/core.h @@ -245,7 +245,7 @@ protected: struct dtExecute execute(const struct dtDecode&); struct dtMemory memory(const struct dtExecute&); void writeback(const struct dtMemory&); - bool handle_pc(const struct dtDecode&); + bool handle_pc(const struct dtDecode&, std::int32_t rel_adj = 0); enum ExceptionCause memory_special(enum AccessControl memctl, int mode, bool memread, bool memwrite, |