Skip to content

Fixes issues in handling conditional branches #531

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
pgoodman merged 1 commit into from
Jul 7, 2021
Merged

Fixes issues in handling conditional branches #531

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
14 changes: 6 additions & 8 deletions lib/Arch/AArch32/Decode.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -920,8 +920,6 @@ static bool DecodeCondition(Instruction &inst, uint32_t cond) {
auto _8_type = llvm::Type::getInt8Ty(*inst.arch->context);
const auto _1 = llvm::ConstantInt::get(_8_type, 1u, false);

// Use ~0 -> 11111111 with XOR op for negation
const auto negate = llvm::ConstantInt::get(_8_type, ~0u, false);
bool negate_conditions = false;
bool is_cond = true;

Expand Down Expand Up @@ -952,7 +950,7 @@ static bool DecodeCondition(Instruction &inst, uint32_t cond) {
auto c_expr = inst.EmplaceRegister("C");
auto z_expr = inst.EmplaceRegister("Z");
z_expr = inst.EmplaceBinaryOp(llvm::Instruction::Xor, z_expr,
inst.EmplaceConstant(negate));
inst.EmplaceConstant(_1));
op_expr = inst.EmplaceBinaryOp(llvm::Instruction::And, z_expr, c_expr);
break;
}
Expand All @@ -962,7 +960,7 @@ static bool DecodeCondition(Instruction &inst, uint32_t cond) {
auto v_expr = inst.EmplaceRegister("V");
op_expr = inst.EmplaceBinaryOp(llvm::Instruction::Xor, n_expr, v_expr);
op_expr = inst.EmplaceBinaryOp(llvm::Instruction::Xor, op_expr,
inst.EmplaceConstant(negate));
inst.EmplaceConstant(_1));
break;
}
case 0b1101: negate_conditions = true; [[clang::fallthrough]];
Expand All @@ -971,10 +969,10 @@ static bool DecodeCondition(Instruction &inst, uint32_t cond) {
auto v_expr = inst.EmplaceRegister("V");
op_expr = inst.EmplaceBinaryOp(llvm::Instruction::Xor, n_expr, v_expr);
op_expr = inst.EmplaceBinaryOp(llvm::Instruction::Xor, op_expr,
inst.EmplaceConstant(negate));
inst.EmplaceConstant(_1));
auto z_expr = inst.EmplaceRegister("Z");
z_expr = inst.EmplaceBinaryOp(llvm::Instruction::Xor, z_expr,
inst.EmplaceConstant(negate));
inst.EmplaceConstant(_1));
op_expr = inst.EmplaceBinaryOp(llvm::Instruction::And, z_expr, op_expr);
break;
}
Expand All @@ -991,7 +989,7 @@ static bool DecodeCondition(Instruction &inst, uint32_t cond) {

if (negate_conditions) {
op_expr = inst.EmplaceBinaryOp(llvm::Instruction::Xor, op_expr,
inst.EmplaceConstant(negate));
inst.EmplaceConstant(_1));
}

AddExprOp(inst, op_expr, 8u);
Expand Down Expand Up @@ -3494,7 +3492,7 @@ bool AArch32Arch::DecodeInstruction(uint64_t address,
}

auto ret = decoder(inst, bits);
LOG(ERROR) << inst.Serialize();
// LOG(ERROR) << inst.Serialize();
return ret;
}

Expand Down