Method emit_branch_condition

LiveRecomp/live_generator.cpp:1481–1574

}

void N64Recomp::LiveGenerator::emit_branch_condition(const ConditionalBranchOp& op, const InstructionContext& ctx) const {
    // Make sure there's no pending jump.
    if(context->cur_branch_jump != nullptr) {
        assert(false);
        errored = true;
        return;
    }

    // Branch conditions do not allow unary ops, except for ToS64 on the first operand to indicate the branch comparison is signed.
    if(op.operands.operand_operations[0] != UnaryOpType::None && op.operands.operand_operations[0] != UnaryOpType::ToS64) {
        assert(false);
        errored = true;
        return;
    }

    if (op.operands.operand_operations[1] != UnaryOpType::None) {
        assert(false);
        errored = true;
        return;
    }

    // Branch conditions do not allow float u32l operands.
    if (is_fpr_u32l(op.operands.operands[0]) || is_fpr_u32l(op.operands.operands[1])) {
        assert(false);
        errored = true;
        return;
    }

    sljit_s32 condition_type;
    bool cmp_signed = op.operands.operand_operations[0] == UnaryOpType::ToS64;
    // Comparisons need to be inverted to account for the fact that the generator is expected to generate a code block that only runs if
    // the condition is met, meaning the branch should be taken if the condition isn't met.
    switch (op.comparison) {
        case BinaryOpType::Equal:
            condition_type = SLJIT_NOT_EQUAL;
            break;
        case BinaryOpType::NotEqual:
            condition_type = SLJIT_EQUAL;
            break;
        case BinaryOpType::GreaterEq:
            if (cmp_signed) {
                condition_type = SLJIT_SIG_LESS;
            }
            else {
                condition_type = SLJIT_LESS;
            }
            break;
        case BinaryOpType::Greater:
            if (cmp_signed) {
                condition_type = SLJIT_SIG_LESS_EQUAL;
            }
            else {
                condition_type = SLJIT_LESS_EQUAL;
            }
            break;
        case BinaryOpType::LessEq:
            if (cmp_signed) {
                condition_type = SLJIT_SIG_GREATER;