Implement simple if conditions

This commit is contained in:
2024-03-17 01:00:44 +01:00
parent 8240443cd1
commit 17b0650f77
13 changed files with 592 additions and 33 deletions

View File

@ -18,13 +18,24 @@ namespace elna::riscv
return *this;
}
instruction& instruction::s(std::uint32_t imm1, funct3_t funct3, x_register rs1, x_register rs2)
instruction& instruction::s(std::uint32_t imm, funct3_t funct3, x_register rs1, x_register rs2)
{
this->representation |= ((imm1 & 0b11111) << 7)
this->representation |= ((imm & 0x1f) << 7)
| (static_cast<std::underlying_type<funct3_t>::type>(funct3) << 12)
| (static_cast<std::underlying_type<x_register>::type>(rs1) << 15)
| (static_cast<std::underlying_type<x_register>::type>(rs2) << 20)
| ((imm1 & 0b111111100000) << 20);
| ((imm & 0xfe0) << 20);
return *this;
}
instruction& instruction::b(std::uint32_t imm, funct3_t funct3, x_register rs1, x_register rs2)
{
this->representation |= ((imm & 0x800) >> 4) | ((imm & 0x1e) << 7)
| (static_cast<std::underlying_type<funct3_t>::type>(funct3) << 12)
| (static_cast<std::underlying_type<x_register>::type>(rs1) << 15)
| (static_cast<std::underlying_type<x_register>::type>(rs2) << 20)
| ((imm & 0x7e0) << 20) | ((imm & 0x1000) << 19);
return *this;
}
@ -47,6 +58,14 @@ namespace elna::riscv
return *this;
}
instruction& instruction::j(x_register rd, std::uint32_t imm)
{
this->representation |= (static_cast<std::underlying_type<x_register>::type>(rd) << 7)
| (imm & 0xff000) | ((imm & 0x800) << 9) | ((imm & 0x7fe) << 20) | ((imm & 0x100000) << 11);
return *this;
}
const std::byte *instruction::cbegin() const
{
return reinterpret_cast<const std::byte *>(&this->representation);
@ -108,13 +127,46 @@ namespace elna::riscv
this->instructions.push_back(instruction(base_opcode::opImm)
.i(x_register::a1, funct3_t::addi, x_register::a0, 0));
auto format_string = this->read_only.label("%d\n");
this->references.push_back(reference());
this->references.back().name = ".CL0";
this->references.back().name = format_string->first;
this->references.back().offset = instructions.size() * 4;
this->references.back().target = address_t::high20;
this->instructions.push_back(instruction(base_opcode::lui).u(x_register::a5, 0));
this->references.push_back(reference());
this->references.back().name = ".CL0";
this->references.back().name = format_string->first;
this->references.back().offset = instructions.size() * 4;
this->references.back().target = address_t::lower12i;
this->instructions.push_back(instruction(base_opcode::opImm)
.i(x_register::a0, funct3_t::addi, x_register::a5, 0));
this->references.push_back(reference());
this->references.back().name = "printf";
this->references.back().offset = instructions.size() * 4;
this->references.back().target = address_t::text;
this->instructions.push_back(instruction(base_opcode::auipc).u(x_register::ra, 0));
this->instructions.push_back(instruction(base_opcode::jalr)
.i(x_register::ra, funct3_t::jalr, x_register::ra, 0));
}
void visitor::visit(source::question_mark_statement *statement)
{
statement->body().accept(this);
// Print the result.
this->instructions.push_back(instruction(base_opcode::opImm)
.i(x_register::a1, funct3_t::addi, x_register::a0, 0));
auto format_string = this->read_only.label("%d\n");
this->references.push_back(reference());
this->references.back().name = format_string->first;
this->references.back().offset = instructions.size() * 4;
this->references.back().target = address_t::high20;
this->instructions.push_back(instruction(base_opcode::lui).u(x_register::a5, 0));
this->references.push_back(reference());
this->references.back().name = format_string->first;
this->references.back().offset = instructions.size() * 4;
this->references.back().target = address_t::lower12i;
@ -149,6 +201,25 @@ namespace elna::riscv
.s(variable_symbol->offset, funct3_t::sw, x_register::s0, x_register::a0));
}
void visitor::visit(source::if_statement *statement)
{
const auto free_register = this->register_in_use ? x_register::a0 : x_register::t0;
statement->prerequisite().accept(this);
auto before_branch = instructions.size();
instructions.push_back(instruction(base_opcode::branch));
statement->body().accept(this);
instructions[before_branch]
.b((instructions.size() - before_branch) * 4 - 3, funct3_t::beq, x_register::zero, free_register);
}
void visitor::visit(source::while_statement *statement)
{
statement->prerequisite().accept(this);
statement->body().accept(this);
}
void visitor::visit(source::variable_expression *variable)
{
const auto free_register = this->register_in_use ? x_register::a0 : x_register::t0;
@ -170,16 +241,6 @@ namespace elna::riscv
}
}
void visitor::visit(source::integer_literal *number)
{
const auto free_register = this->register_in_use ? x_register::a0 : x_register::t0;
this->instructions.push_back(
instruction(base_opcode::opImm) // movl $x, %eax; where $x is a number.
.i(free_register, funct3_t::addi, x_register::zero, number->number())
);
}
void visitor::visit(source::binary_expression *expression)
{
const auto lhs_register = this->register_in_use ? x_register::a0 : x_register::t0;
@ -222,4 +283,24 @@ namespace elna::riscv
break;
}
}
void visitor::visit(source::integer_literal *number)
{
const auto free_register = this->register_in_use ? x_register::a0 : x_register::t0;
this->instructions.push_back(
instruction(base_opcode::opImm) // movl $x, %eax; where $x is a number.
.i(free_register, funct3_t::addi, x_register::zero, number->number())
);
}
void visitor::visit(source::boolean_literal *number)
{
const auto free_register = this->register_in_use ? x_register::a0 : x_register::t0;
this->instructions.push_back(
instruction(base_opcode::opImm) // movl $x, %eax; where $x is a number.
.i(free_register, funct3_t::addi, x_register::zero, number->boolean())
);
}
}

View File

@ -33,13 +33,6 @@ namespace elna::riscv
// Create string table writer
ELFIO::string_section_accessor stra(str_sec);
// Create read only data section
ELFIO::section* ro_sec = writer.sections.add(".rodata");
ro_sec->set_type(ELFIO::SHT_PROGBITS);
ro_sec->set_flags(ELFIO::SHF_ALLOC);
ro_sec->set_addr_align(0x4);
ro_sec->set_data("%d\n");
// Create symbol table section
ELFIO::section* sym_sec = writer.sections.add(".symtab");
sym_sec->set_type(ELFIO::SHT_SYMTAB);
@ -57,24 +50,38 @@ namespace elna::riscv
rel_sec->set_link(sym_sec->get_index());
rel_sec->set_flags(ELFIO::SHF_ALLOC);
// Create read only data section
ELFIO::section* ro_sec = writer.sections.add(".rodata");
ro_sec->set_type(ELFIO::SHT_PROGBITS);
ro_sec->set_flags(ELFIO::SHF_ALLOC);
ro_sec->set_addr_align(0x4);
// Create symbol relocation table writers
ELFIO::symbol_section_accessor syma(writer, sym_sec);
ELFIO::relocation_section_accessor rela(writer, rel_sec);
ELFIO::Elf_Word digit_symbol = syma.add_symbol(stra, ".CL0", 0x00000000, strlen("%d\n") + 1,
ELFIO::STB_LOCAL, ELFIO::STT_NOTYPE, 0, ro_sec->get_index());
ELFIO::Elf_Word digit_symbol;
for (auto read_only_text : _visitor->read_only)
{
ro_sec->append_data(read_only_text.second.data(), read_only_text.second.size());
syma.add_symbol(stra, read_only_text.first.c_str(), 0x00000000,
read_only_text.first.size() + 1, ELFIO::STB_LOCAL, ELFIO::STT_NOTYPE, 0, ro_sec->get_index());
}
ELFIO::Elf_Word printf_symbol = syma.add_symbol(stra, "printf", 0x00000000, 0,
ELFIO::STB_GLOBAL, ELFIO::STT_NOTYPE, 0, ELFIO::SHN_UNDEF);
for (auto& reference : _visitor->references)
{
// The loop assumes that address_t::lower12i always follows address_t::high20.
switch (reference.target)
{
case address_t::high20:
digit_symbol = _visitor->read_only.lookup(reference.name) + 1;
rela.add_entry(reference.offset, digit_symbol, 26 /* ELFIO::R_RISCV_HI20 */);
rela.add_entry(reference.offset, digit_symbol, 51 /* ELFIO::R_RISCV_RELAX */);
break;
case address_t::lower12i:
digit_symbol = _visitor->read_only.lookup(reference.name) + 1;
rela.add_entry(reference.offset, digit_symbol, 27 /* ELFIO::R_RISCV_LO12_I */);
rela.add_entry(reference.offset, digit_symbol, 51 /* ELFIO::R_RISCV_RELAX */);
break;