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fix: Handle STI instruction near end of page

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This commit is contained in:
Fabian 2025-12-25 19:59:06 +01:00
parent 946819902b
commit 880fa18e35
1 changed files with 19 additions and 18 deletions
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37
src/rust/jit.rs
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@ -485,7 +485,7 @@ fn jit_find_basic_blocks(
let mut pages: HashSet<Page> = HashSet::new();
let mut page_blacklist = HashSet::new();
// 16-bit doesn't not work correctly, most likely due to instruction pointer wrap-around
// 16-bit doesn't work correctly, most likely due to instruction pointer wrap-around
let max_pages = if cpu.state_flags.is_32() { unsafe { MAX_PAGES } } else { 1 };
for virt_addr in entry_points {
@ -539,13 +539,22 @@ fn jit_find_basic_blocks(
..cpu
};
let analysis = analysis::analyze_step(&mut cpu);
current_block.number_of_instructions += 1;
let has_next_instruction = !analysis.no_next_instruction;
current_address = cpu.eip;
dbg_assert!(Page::page_of(current_address) == Page::page_of(addr_before_instruction));
let current_virt_addr = to_visit & !0xFFF | current_address as i32 & 0xFFF;
if analysis.ty == AnalysisType::STI && is_near_end_of_page(current_address) {
// cut off before the STI so that it is handled by interpreted mode
profiler::stat_increment(stat::COMPILE_CUT_OFF_AT_END_OF_PAGE);
break;
}
current_block.number_of_instructions += 1;
current_block.last_instruction_addr = addr_before_instruction;
current_block.end_addr = current_address;
match analysis.ty {
AnalysisType::Normal | AnalysisType::STI => {
dbg_assert!(has_next_instruction);
@ -557,26 +566,22 @@ fn jit_find_basic_blocks(
marked_as_entry.insert(current_virt_addr);
to_visit_stack.push(current_virt_addr);
current_block.last_instruction_addr = addr_before_instruction;
current_block.end_addr = current_address;
break;
}
if analysis.ty == AnalysisType::STI {
current_block.has_sti = true;
dbg_assert!(
!is_near_end_of_page(current_address),
"TODO: Handle STI instruction near end of page"
"should be handled above"
);
current_block.has_sti = true;
}
else {
// Only split non-STI blocks (one instruction needs to run after STI before
// handle_irqs may be called)
if basic_blocks.contains_key(&current_address) {
current_block.last_instruction_addr = addr_before_instruction;
current_block.end_addr = current_address;
dbg_assert!(!is_near_end_of_page(current_address));
current_block.ty = BasicBlockType::Normal {
next_block_addr: Some(current_address),
@ -629,9 +634,6 @@ fn jit_find_basic_blocks(
jump_offset_is_32: is_32,
};
current_block.last_instruction_addr = addr_before_instruction;
current_block.end_addr = current_address;
break;
},
AnalysisType::Jump {
@ -669,8 +671,6 @@ fn jit_find_basic_blocks(
jump_offset: offset,
jump_offset_is_32: is_32,
};
current_block.last_instruction_addr = addr_before_instruction;
current_block.end_addr = current_address;
break;
},
@ -690,20 +690,21 @@ fn jit_find_basic_blocks(
current_block.ty = BasicBlockType::AbsoluteEip;
}
current_block.last_instruction_addr = addr_before_instruction;
current_block.end_addr = current_address;
break;
},
}
if is_near_end_of_page(current_address) {
current_block.last_instruction_addr = addr_before_instruction;
current_block.end_addr = current_address;
profiler::stat_increment(stat::COMPILE_CUT_OFF_AT_END_OF_PAGE);
break;
}
}
if current_block.number_of_instructions == 0 {
// Empty basic block, don't insert (only happens when STI is found near end of page)
continue;
}
let previous_block = basic_blocks
.range(..current_block.addr)
.next_back()