/*
* Copyright (C) 2024 olang maintainers
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see .
*/
#include
#include
#include
#include "codegen_linux_x86_64.h"
#include "list.h"
#define SYS_exit (60)
size_t label_index;
static void
codegen_linux_x86_64_emit_start_entrypoint(FILE *out);
static void
codegen_linux_x86_64_emit_function(FILE *out, ast_fn_definition_t *fn);
void
codegen_linux_x86_64_emit_program(FILE *out, ast_node_t *node)
{
label_index = 0;
codegen_linux_x86_64_emit_start_entrypoint(out);
assert(node->kind == AST_NODE_PROGRAM);
ast_program_t program = node->as_program;
ast_fn_definition_t fn = program.fn->as_fn_def;
assert(string_view_eq_to_cstr(fn.identifier, "main"));
codegen_linux_x86_64_emit_function(out, &fn);
}
static void
codegen_linux_x86_64_emit_start_entrypoint(FILE *out)
{
fprintf(out, ".text\n");
fprintf(out, ".globl _start\n\n");
fprintf(out, "_start:\n");
fprintf(out, " call main\n");
fprintf(out, " mov %%eax, %%edi\n");
fprintf(out, " mov $%d, %%eax\n", SYS_exit);
fprintf(out, " syscall\n");
}
static size_t
codegen_linux_x86_64_get_next_label(void)
{
return ++label_index;
}
static void
codegen_linux_x86_64_emit_expression(FILE *out, ast_node_t *expr_node)
{
switch (expr_node->kind) {
case AST_NODE_LITERAL: {
ast_literal_t literal_u32 = expr_node->as_literal;
assert(literal_u32.kind == AST_LITERAL_U32);
uint32_t n = literal_u32.as_u32;
fprintf(out, " mov $%d, %%rax\n", n);
return;
}
case AST_NODE_BINARY_OP: {
ast_binary_op_t bin_op = expr_node->as_bin_op;
switch (bin_op.kind) {
case AST_BINOP_ADDITION: {
codegen_linux_x86_64_emit_expression(out, bin_op.rhs);
fprintf(out, " push %%rax\n");
codegen_linux_x86_64_emit_expression(out, bin_op.lhs);
fprintf(out, " pop %%rcx\n");
fprintf(out, " add %%rcx, %%rax\n");
return;
}
case AST_BINOP_MULTIPLICATION: {
codegen_linux_x86_64_emit_expression(out, bin_op.rhs);
fprintf(out, " push %%rax\n");
codegen_linux_x86_64_emit_expression(out, bin_op.lhs);
fprintf(out, " pop %%rcx\n");
fprintf(out, " mul %%rcx\n");
return;
}
case AST_BINOP_DIVISION: {
codegen_linux_x86_64_emit_expression(out, bin_op.rhs);
fprintf(out, " push %%rax\n");
codegen_linux_x86_64_emit_expression(out, bin_op.lhs);
fprintf(out, " pop %%rcx\n");
fprintf(out, " xor %%rdx, %%rdx\n");
fprintf(out, " div %%rcx\n");
return;
}
case AST_BINOP_REMINDER: {
codegen_linux_x86_64_emit_expression(out, bin_op.rhs);
fprintf(out, " push %%rax\n");
fprintf(out, " xor %%edx, %%edx\n");
codegen_linux_x86_64_emit_expression(out, bin_op.lhs);
fprintf(out, " pop %%rcx\n");
fprintf(out, " xor %%rdx, %%rdx\n");
fprintf(out, " div %%rcx\n");
fprintf(out, " mov %%edx, %%eax\n");
return;
}
case AST_BINOP_SUBTRACTION: {
codegen_linux_x86_64_emit_expression(out, bin_op.rhs);
fprintf(out, " push %%rax\n");
codegen_linux_x86_64_emit_expression(out, bin_op.lhs);
fprintf(out, " pop %%rcx\n");
fprintf(out, " sub %%rcx, %%rax\n");
return;
}
case AST_BINOP_CMP_EQ: {
codegen_linux_x86_64_emit_expression(out, bin_op.rhs);
fprintf(out, " push %%rax\n");
codegen_linux_x86_64_emit_expression(out, bin_op.lhs);
fprintf(out, " pop %%rcx\n");
fprintf(out, " cmp %%rcx, %%rax\n");
fprintf(out, " sete %%al\n");
fprintf(out, " movzb %%al, %%rax\n");
return;
}
case AST_BINOP_CMP_LT: {
codegen_linux_x86_64_emit_expression(out, bin_op.rhs);
fprintf(out, " push %%rax\n");
codegen_linux_x86_64_emit_expression(out, bin_op.lhs);
fprintf(out, " pop %%rcx\n");
fprintf(out, " cmp %%rcx, %%rax\n");
fprintf(out, " setl %%al\n");
fprintf(out, " movzb %%al, %%rax\n");
return;
}
case AST_BINOP_CMP_GT: {
codegen_linux_x86_64_emit_expression(out, bin_op.rhs);
fprintf(out, " push %%rax\n");
codegen_linux_x86_64_emit_expression(out, bin_op.lhs);
fprintf(out, " pop %%rcx\n");
fprintf(out, " cmp %%rcx, %%rax\n");
fprintf(out, " setg %%al\n");
fprintf(out, " movzb %%al, %%rax\n");
return;
}
case AST_BINOP_CMP_NEQ: {
codegen_linux_x86_64_emit_expression(out, bin_op.rhs);
fprintf(out, " push %%rax\n");
codegen_linux_x86_64_emit_expression(out, bin_op.lhs);
fprintf(out, " pop %%rcx\n");
fprintf(out, " cmp %%rcx, %%rax\n");
fprintf(out, " setne %%al\n");
fprintf(out, " movzb %%al, %%rax\n");
return;
}
case AST_BINOP_CMP_LEQ: {
codegen_linux_x86_64_emit_expression(out, bin_op.rhs);
fprintf(out, " push %%rax\n");
codegen_linux_x86_64_emit_expression(out, bin_op.lhs);
fprintf(out, " pop %%rcx\n");
fprintf(out, " cmp %%rcx, %%rax\n");
fprintf(out, " setle %%al\n");
fprintf(out, " movzb %%al, %%rax\n");
return;
}
case AST_BINOP_CMP_GEQ: {
codegen_linux_x86_64_emit_expression(out, bin_op.rhs);
fprintf(out, " push %%rax\n");
codegen_linux_x86_64_emit_expression(out, bin_op.lhs);
fprintf(out, " pop %%rcx\n");
fprintf(out, " cmp %%rcx, %%rax\n");
fprintf(out, " setge %%al\n");
fprintf(out, " movzb %%al, %%rax\n");
return;
}
case AST_BINOP_BITWISE_LSHIFT: {
codegen_linux_x86_64_emit_expression(out, bin_op.rhs);
fprintf(out, " push %%rax\n");
codegen_linux_x86_64_emit_expression(out, bin_op.lhs);
fprintf(out, " pop %%rcx\n");
fprintf(out, " shl %%cl, %%rax\n");
return;
}
case AST_BINOP_BITWISE_RSHIFT: {
codegen_linux_x86_64_emit_expression(out, bin_op.rhs);
fprintf(out, " push %%rax\n");
codegen_linux_x86_64_emit_expression(out, bin_op.lhs);
fprintf(out, " pop %%rcx\n");
fprintf(out, " shr %%cl, %%rax\n");
return;
}
case AST_BINOP_BITWISE_XOR: {
codegen_linux_x86_64_emit_expression(out, bin_op.rhs);
fprintf(out, " push %%rax\n");
codegen_linux_x86_64_emit_expression(out, bin_op.lhs);
fprintf(out, " pop %%rcx\n");
fprintf(out, " xor %%ecx, %%eax\n");
return;
}
case AST_BINOP_BITWISE_AND: {
codegen_linux_x86_64_emit_expression(out, bin_op.rhs);
fprintf(out, " push %%rax\n");
codegen_linux_x86_64_emit_expression(out, bin_op.lhs);
fprintf(out, " pop %%rcx\n");
fprintf(out, " and %%ecx, %%eax\n");
return;
}
case AST_BINOP_BITWISE_OR: {
codegen_linux_x86_64_emit_expression(out, bin_op.rhs);
fprintf(out, " push %%rax\n");
codegen_linux_x86_64_emit_expression(out, bin_op.lhs);
fprintf(out, " pop %%rcx\n");
fprintf(out, " or %%ecx, %%eax\n");
return;
}
case AST_BINOP_LOGICAL_AND: {
size_t label_exit = codegen_linux_x86_64_get_next_label();
codegen_linux_x86_64_emit_expression(out, bin_op.lhs);
fprintf(out, " cmp $0, %%rax\n");
fprintf(out, " je .L%ld\n", label_exit);
codegen_linux_x86_64_emit_expression(out, bin_op.rhs);
fprintf(out, " cmp $0, %%rax\n");
fprintf(out, " je .L%ld\n", label_exit);
fprintf(out, " mov $1, %%rax\n");
fprintf(out, ".L%ld:\n", label_exit);
return;
}
case AST_BINOP_LOGICAL_OR: {
size_t label_t = codegen_linux_x86_64_get_next_label();
size_t label_f = codegen_linux_x86_64_get_next_label();
codegen_linux_x86_64_emit_expression(out, bin_op.lhs);
fprintf(out, " cmp $0, %%rax\n");
fprintf(out, " jne .L%ld\n", label_t);
codegen_linux_x86_64_emit_expression(out, bin_op.rhs);
fprintf(out, " cmp $0, %%rax\n");
fprintf(out, " je .L%ld\n", label_f);
fprintf(out, ".L%ld:\n", label_t);
fprintf(out, " mov $1, %%rax\n");
fprintf(out, ".L%ld:\n", label_f);
return;
}
default: {
assert(0 && "unsupported binary operation");
return;
}
}
}
default:
assert(0 && "unsupported expression");
}
}
static void
codegen_linux_x86_64_emit_block(FILE *out, ast_block_t *block)
{
size_t nodes_len = list_size(block->nodes);
for (size_t i = 0; i < nodes_len; ++i) {
ast_node_t *node = list_get(block->nodes, i)->value;
switch (node->kind) {
case AST_NODE_RETURN_STMT: {
ast_return_stmt_t return_stmt = node->as_return_stmt;
ast_node_t *expr = return_stmt.data;
codegen_linux_x86_64_emit_expression(out, expr);
fprintf(out, " ret\n");
break;
}
case AST_NODE_IF_STMT: {
ast_if_stmt_t if_stmt = node->as_if_stmt;
ast_node_t *cond = if_stmt.cond;
ast_node_t *then = if_stmt.then;
size_t end_if_label = codegen_linux_x86_64_get_next_label();
codegen_linux_x86_64_emit_expression(out, cond);
fprintf(out, " jnz .L%ld\n", end_if_label);
assert(then->kind == AST_NODE_BLOCK && "invalid if-then block");
ast_block_t then_block = then->as_block;
codegen_linux_x86_64_emit_block(out, &then_block);
fprintf(out, ".L%ld:\n", end_if_label);
break;
}
default: {
assert(0 && "unsupported block statement");
break;
}
}
}
}
static void
codegen_linux_x86_64_emit_function(FILE *out, ast_fn_definition_t *fn)
{
ast_node_t *block_node = fn->block;
fprintf(out, "" SV_FMT ":\n", SV_ARG(fn->identifier));
assert(block_node->kind == AST_NODE_BLOCK);
ast_block_t block = block_node->as_block;
codegen_linux_x86_64_emit_block(out, &block);
}