Start over

1 files changed, 759 insertions, 1297 deletions

diff --git a/boot/stage2.elna b/boot/stage2.elna
index b4f359e..a9de48d 100644
--- a/boot/stage2.elna
+++ b/boot/stage2.elna
@@ -1,1393 +1,855 @@
-program
+# This Source Code Form is subject to the terms of the Mozilla Public License,
+# v. 2.0. If a copy of the MPL was not distributed with this file, You can
+# obtain one at https://mozilla.org/MPL/2.0/.
 
-import dummy
+# Stage2 compiler.
+#
+# It supports declaring and calling procedures without arguments.
+# A procedure name should start with an underscore.
 
-var
-	source_code: [81920]Byte
+.section .rodata
 
-proc _compile_import()
-var loca0: Word
-begin
-	_advance(6);
-	_skip_spaces();
-	loca0 := _read_token();
-	_advance(loca0)
-end
-
-proc _build_binary_expression()
-var
-	loca0: Word
-	loca4: Word
-	loca8: Word
-	loca12: ^Byte
-	loca16: Word
-	loca20: Word
-	loca24: Bool
-begin
-	_build_expression(0);
-
-	loca4 := 0x2c306120;
-	loca8 := 0x0a316120;
-
-	_skip_spaces();
-	loca20 := _read_token();
-	loca12 := _current();
-
-	loca16 := 0x26;
-	loca24 := _token_compare(loca12, loca20, @loca16);
-	if loca24 = 0 then
-		goto .L_build_binary_expression_and
-	end;
-
-	loca16 := 0x726f;
-	loca24 := _token_compare(loca12, loca20, @loca16);
-	if loca24 = 0 then
-		goto .L_build_binary_expression_or
-	end;
-
-	loca16 := 0x3d;
-	loca24 := _token_compare(loca12, loca20, @loca16);
-	if loca24 = 0 then
-		goto .L_build_binary_expression_equal
-	end;
-
-	loca16 := 0x2b;
-	loca24 := _token_compare(loca12, loca20, @loca16);
-	if loca24 = 0 then
-		goto .L_build_binary_expression_plus
-	end;
-
-	loca16 := 0x2d;
-	loca24 := _token_compare(loca12, loca20, @loca16);
-	if loca24 = 0 then
-		goto .L_build_binary_expression_minus
-	end;
-
-	loca16 := 0x2a;
-	loca24 := _token_compare(loca12, loca20, @loca16);
-	if loca24 = 0 then
-		goto .L_build_binary_expression_product
-	end;
-
-	goto .Lbuild_binary_expression_end;
-
-	.L_build_binary_expression_equal;
-	_advance(1);
-	_build_expression(1);
-
-	loca0 := 0x627573;
-	_write_s(3, @loca0);
-	_write_s(4, @loca4);
-	_write_s(4, @loca4);
-	_write_s(4, @loca8);
-
-	loca0 := 0x7a716573;
-	_write_s(4, @loca0);
-	_write_s(4, @loca4);
-	_write_s(3, @loca4);
-	_write_c(0x0a);
-
-	goto .Lbuild_binary_expression_end;
-
-	.L_build_binary_expression_and;
-	_advance(1);
-	_build_expression(1);
-	loca0 := 0x646e61;
-	_write_s(3, @loca0);
-	_write_s(4, @loca4);
-	_write_s(4, @loca4);
-	_write_s(4, @loca8);
-
-	goto .Lbuild_binary_expression_end;
-
-	.L_build_binary_expression_or;
-	_advance(2);
-	_build_expression(1);
-	loca0 := 0x726f;
-	_write_s(2, @loca0);
-	_write_s(4, @loca4);
-	_write_s(4, @loca4);
-	_write_s(4, @loca8);
-
-	goto .Lbuild_binary_expression_end;
-
-	.L_build_binary_expression_plus;
-	_advance(1);
-	_build_expression(1);
-	loca0 := 0x646461;
-	_write_s(3, @loca0);
-	_write_s(4, @loca4);
-	_write_s(4, @loca4);
-	_write_s(4, @loca8);
-
-	goto .Lbuild_binary_expression_end;
-
-	.L_build_binary_expression_minus;
-	_advance(1);
-	_build_expression(1);
-	loca0 := 0x627573;
-	_write_s(3, @loca0);
-	_write_s(4, @loca4);
-	_write_s(4, @loca4);
-	_write_s(4, @loca8);
-
-	goto .Lbuild_binary_expression_end;
-
-	.L_build_binary_expression_product;
-	_advance(1);
-	_build_expression(1);
-	loca0 := 0x6c756d;
-	_write_s(3, @loca0);
-	_write_s(4, @loca4);
-	_write_s(4, @loca4);
-	_write_s(4, @loca8);
-
-	goto .Lbuild_binary_expression_end;
-
-	.Lbuild_binary_expression_end
-end
-
-proc _compile_identifier_expression(loca84: Word, loca80: Byte)
-var
-	loca0: Word
-	loca4: ^Byte
-	loca8: Word
-	loca12: Bool
-	loca16: Word
-	loca20: Word
-	loca24: ^Byte
-	loca28: Byte
+.type keyword_equ, @object
+keyword_equ: .ascii ".equ"
+.equ KEYWORD_EQU_SIZE, 4
+
+.type keyword_section, @object
+keyword_section: .ascii ".section"
+.equ KEYWORD_SECTION_SIZE, 8
+
+.type keyword_type, @object
+keyword_type: .ascii ".type"
+.equ KEYWORD_TYPE_SIZE, 5
+
+.type keyword_ret, @object
+keyword_ret: .ascii "ret"
+.equ KEYWORD_RET_SIZE, 3
+
+.type keyword_global, @object
+keyword_global: .ascii ".globl"
+.equ KEYWORD_GLOBAL_SIZE, 6
+
+.type keyword_proc, @object
+keyword_proc: .ascii "proc "
+.equ KEYWORD_PROC_SIZE, 5
+
+.type keyword_end, @object
+keyword_end: .ascii "end"
+.equ KEYWORD_END_SIZE, 3
+
+.type keyword_begin, @object
+keyword_begin: .ascii "begin"
+.equ KEYWORD_BEGIN_SIZE, 5
+
+.type keyword_var, @object
+keyword_var: .ascii "var"
+.equ KEYWORD_VAR_SIZE, 3
+
+.type asm_prologue, @object
+asm_prologue: .string "\taddi sp, sp, -32\n\tsw ra, 28(sp)\n\tsw s0, 24(sp)\n\taddi s0, sp, 32\n"
+
+.type asm_epilogue, @object
+asm_epilogue: .string "\tlw ra, 28(sp)\n\tlw s0, 24(sp)\n\taddi sp, sp, 32\n\tret\n"
+
+.type asm_type_directive, @object
+asm_type_directive: .string ".type "
+
+.type asm_type_function, @object
+asm_type_function: .string ", @function\n"
+
+.type asm_colon, @object
+asm_colon: .string ":\n"
+
+.type asm_call, @object
+asm_call: .string "\tcall "
+
+.type asm_j, @object
+asm_j: .string "\tj "
+
+.type asm_li, @object
+asm_li: .string "\tli "
+
+.type asm_lw, @object
+asm_lw: .string "\tlw "
+
+.type asm_t0, @object
+asm_t0: .string "t0"
+
+.type asm_a0, @object
+asm_a0: .string "a0"
+
+.type asm_comma, @object
+asm_comma: .string ", "
+
+.type asm_sp, @object
+asm_sp: .string "(sp)"
+
+.section .bss
+
+.equ SOURCE_BUFFER_SIZE, 81920
+.type source_code, @object
+source_code: .zero SOURCE_BUFFER_SIZE
+
+.section .data
+
+.type source_code_position, @object
+source_code_position: .word source_code
+
+.section .text
+
+# Reads standard input into a buffer.
+# a0 - Buffer pointer.
+# a1 - Buffer size.
+#
+# Returns the amount of bytes written in a0.
+proc _read_file();
 begin
-	loca24 := _current();
-	loca0 := 0x61636f6c;
-	loca0 := _memcmp(@loca0, loca24, 4);
-
-	if loca0 = 0 then
-		loca8 := 0x6120776c;
-		_write_s(4, @loca8);
-		loca8 := 0x00202c00 or loca80;
-		_write_s(3, @loca8);
-
-		loca4 := loca24 + 4;
-		loca0 := loca84 - 4;
-		_write_s(loca0, loca4);
-
-		loca8 := 0x29707328;
-		_write_s(4, @loca8);
-		_write_c(0x0a);
-
-		goto .Lcompile_identifier_expression_end
-	end;
-	loca0 := _front(loca24);
-	loca8 := loca84 = 2;
-	loca12 := loca0 = 0x73;
-	if loca8 & loca12 then
-		loca8 := 0x6120766d;
-		_write_s(4, @loca8);
-		loca8 := 0x00202c00 or loca80;
-		_write_s(3, @loca8);
-		_write_s(loca84, loca24);
-		_write_c(0x0a);
-
-		goto .Lcompile_identifier_expression_end
-	end;
-
-	loca8 := 0x6120616c;
-	_write_s(4, @loca8);
-	loca8 := 0x00202c00 or loca80;
-	_write_s(3, @loca8);
-
-	_write_s(loca84, loca24);
-	_write_c(0x0a);
-
-	if _is_upper(loca0) then
-		loca8 := 0x6120776c;
-		_write_s(4, @loca8);
-		loca8 := 0x28202c00 or loca28;
-		_write_s(4, @loca8);
-		_write_c(0x61);
-		_write_c(loca28);
-		_write_c(0x29);
-		_write_c(0x0a);
-
-		goto .Lcompile_identifier_expression_end
-	end;
-
-	.Lcompile_identifier_expression_end
-end
-
-proc _build_expression(loca84: Word)
-var
-	loca0: Word
-	loca4: ^Byte
-	loca8: Word
-	loca12: Word
-	loca16: Word
-	loca20: Word
-	loca24: ^Byte
-	loca28: Word
+	mv a2, a1
+	mv a1, a0
+	# STDIN.
+	li a0, 0
+	li a7, 63 # SYS_READ.
+	ecall
+end;
+
+# Writes to the standard output.
+#
+# Parameters:
+# a0 - Buffer.
+# a1 - Buffer length.
+proc _write();
 begin
-	loca28 := loca84 + 0x30;
-
-	_skip_spaces();
-	loca20 := _read_token();
-	loca24 := _current();
-	loca0 := _front(loca24);
-
-	if loca0 = 0x2d then
-		goto .Lbuild_expression_negate
-	end;
-
-	if loca0 = 0x40 then
-		goto .Lbuild_expression_address
-	end;
-
-	if _is_digit(loca0) then
-		goto .Lbuild_expression_literal
-	end;
-
-	if loca0 = 0x5f then
-		goto .Lbuild_expression_call
-	end;
-
-	_compile_identifier_expression(loca20, loca28);
-	goto .Lbuild_expression_advance;
-
-	.Lbuild_expression_negate;
-	_advance(1);
-	_build_expression(0);
-
-	loca8 := 0x2067656e;
-	_write_s(4, @loca8);
-	loca8 := 0x202c3061;
-	_write_s(4, @loca8);
-	loca8 := 0x0a3061;
-	_write_s(3, @loca8);
-
-	goto .Lbuild_expression_advance;
-
-	.Lbuild_expression_address;
-	loca8 := 0x69646461;
-	_write_s(4, @loca8);
-	loca8 := 0x6120;
-	_write_s(2, @loca8);
-	_write_c(loca28);
-	loca8 := 0x7073202c;
-	_write_s(4, @loca8);
-	loca8 := 0x202c;
-	_write_s(2, @loca8);
-
-	_advance(1);
-	_skip_spaces();
-	loca24 := _current();
-	loca20 := _read_token();
-
-	loca4 := loca24 + 4;
-	loca0 := loca20 - 4;
-	_write_s(loca0, loca4);
-
-	_write_c(0xa);
-
-	goto .Lbuild_expression_advance;
-
-	.Lbuild_expression_call;
-	_advance(loca20);
-	_advance(1);
-	_compile_call(loca24, loca20);
-
-	goto .Lbuild_expression_end;
-
-	.Lbuild_expression_literal;
-	loca8 := 0x6120696c;
-	_write_s(4, @loca8);
-	loca8 := 0x00202c00 or loca28;
-	_write_s(3, @loca8);
-
-	_write_s(loca20, loca24);
-	_write_c(0x0a);
-
-	goto .Lbuild_expression_advance;
-
-	.Lbuild_expression_advance;
-	_advance(loca20);
-
-	.Lbuild_expression_end
-end
-
-proc _compile_designator_expression(loca84: ^Byte, loca80: Word)
-var
-	loca0: Word
-	loca4: Int
-	loca8: Char
-	loca12: Bool
-	loca16: Bool
+	mv a2, a1
+	mv a1, a0
+	# STDOUT.
+	li a0, 1
+	li a7, 64 # SYS_WRITE.
+	ecall
+end;
+
+# Writes a character from a0 into the standard output.
+proc _write_c();
 begin
-	loca0 := 0x61636f6c;
-	loca4 := _memcmp(@loca0, loca84, 4);
-
-	if loca4 = 0 then
-		loca0 := 0x61207773;
-		_write_s(4, @loca0);
-		loca0 := 0x202c30;
-		_write_s(3, @loca0);
-
-		loca84 := loca84 + 4;
-		loca80 := loca80 - 4;
-		_write_s(loca80, loca84);
-
-		loca0 := 0x29707328;
-		_write_s(4, @loca0);
-		_write_c(0x0a);
-
-		goto .Lcompile_designator_expression_end
-	end;
-	loca8 := _front(loca84);
-	loca12 := loca8 = 0x73;
-	loca16 := loca80 = 2;
-	if loca12 & loca16 then
-		loca0 := 0x20766d;
-		_write_s(3, @loca0);
-		_write_s(loca80, loca84);
-		loca0 := 0x3061202c;
-		_write_s(4, @loca0);
-		_write_c(0x0a);
-
-		goto .Lcompile_designator_expression_end
-	end;
-
-	.Lcompile_designator_expression_end
-end
-
-proc _compile_identifier()
-var
-	loca0: Word
-	loca4: Bool
-	loca8: Word
-	loca12: ^Byte
-	loca16: Word
-	loca20: ^Byte
+	sb a0, 20(sp)
+	addi a0, sp, 20
+	li a1, 1
+	_write();
+end;
+
+# Write null terminated string.
+#
+# Parameters:
+# a0 - String.
+proc _write_z();
 begin
-	loca20 := _current();
-	loca16 := _read_token();
+	sw a0, 20(sp)
 
-	_advance(loca16);
-	_skip_spaces();
+.write_z_loop:
+	# Check for 0 character.
+	lb a0, (a0)
+	beqz a0, .write_z_end
 
-	loca12 := _current();
-	loca8 := _read_token();
+	# Print a character.
+	lw a0, 20(sp)
+	lb a0, (a0)
+	_write_c();
 
-	_advance(loca8);
-	_skip_spaces();
+	# Advance the input string by one byte.
+	lw a0, 20(sp)
+	addi a0, a0, 1
+	sw a0, 20(sp)
 
-	loca0 := 0x3d3a;
-	loca4 := _token_compare(loca12, loca8, @loca0);
-	if loca4 = 0 then
-		_build_binary_expression();
-		_compile_designator_expression(loca20, loca16);
+	j .write_z_loop
 
-		goto .Lcompile_identifier_end
-	end;
-	if _front(loca12) = 0x28 then
-		_compile_call(loca20, loca16);
+.write_z_end:
+end;
 
-		goto .Lcompile_identifier_end
-	end;
+# Detects if a0 is an uppercase character. Sets a0 to 1 if so, otherwise to 0.
+proc _is_upper();
+begin
+	li t0, 'A' - 1
+	sltu t1, t0, a0 # t1 = a0 >= 'A'
 
-	.Lcompile_identifier_end
-end
+	sltiu t2, a0, 'Z' + 1 # t2 = a0 <= 'Z'
+	and a0, t1, t2 # t1 = a0 >= 'A' & a0 <= 'Z'
+end;
 
-proc _compile_call(loca84: ^Byte, loca80: Word)
-var
-	loca0: Word
-	loca4: Word
-	loca8: ^Byte
-	loca12: Word
+# Detects if a0 is an lowercase character. Sets a0 to 1 if so, otherwise to 0.
+proc _is_lower();
 begin
-	loca12 := 0;
-
-	.Lcompile_call_paren;
-	_skip_spaces();
-	loca8 := _current();
-	if _front(loca8) = 0x29 then
-		goto .Lcompile_call_complete
-	end;
-
-	.Lcompile_call_argument;
-	_build_expression(0);
-
-	loca0 := 0x61207773;
-	_write_s(4, @loca0);
-	loca0 := 0x202c30;
-	_write_s(3, @loca0);
-
-	loca0 := -4 * loca12;
-	loca0 := loca0 + 60;
-	_write_i(loca0);
-
-	loca0 := 0x29707328;
-	_write_s(4, @loca0);
-	_write_c(0x0a);
-
-	_skip_spaces();
-	loca8 := _current();
-	loca0 := _front(loca8) = 0x2c;
-	if loca0 = 0 then
-		goto .Lcompile_call_paren
-	end;
-
-	loca12 := loca12 + 1;
-
-	_advance(1);
-	goto .Lcompile_call_argument;
-
-	.Lcompile_call_complete;
-	loca12 := 0;
-
-	.Lcompile_call_restore;
-
-	loca0 := 0x6120776c;
-	_write_s(4, @loca0);
-	loca4 := 0x36202c30;
-	_write_s(4, @loca4);
-	loca4 := 0x70732830;
-	_write_s(4, @loca4);
-	loca4 := 0x0a29;
-	_write_s(2, @loca4);
-
-	_write_s(4, @loca0);
-	loca4 := 0x35202c31;
-	_write_s(4, @loca4);
-	loca4 := 0x70732836;
-	_write_s(4, @loca4);
-	loca4 := 0x0a29;
-	_write_s(2, @loca4);
-
-	_write_s(4, @loca0);
-	loca4 := 0x35202c32;
-	_write_s(4, @loca4);
-	loca4 := 0x70732832;
-	_write_s(4, @loca4);
-	loca4 := 0x0a29;
-	_write_s(2, @loca4);
-
-	_write_s(4, @loca0);
-	loca4 := 0x34202c33;
-	_write_s(4, @loca4);
-	loca4 := 0x70732838;
-	_write_s(4, @loca4);
-	loca4 := 0x0a29;
-	_write_s(2, @loca4);
-
-	_write_s(4, @loca0);
-	loca4 := 0x34202c34;
-	_write_s(4, @loca4);
-	loca4 := 0x70732834;
-	_write_s(4, @loca4);
-	loca4 := 0x0a29;
-	_write_s(2, @loca4);
-
-	_write_s(4, @loca0);
-	loca4 := 0x34202c35;
-	_write_s(4, @loca4);
-	loca4 := 0x70732830;
-	_write_s(4, @loca4);
-	loca4 := 0x0a29;
-	_write_s(2, @loca4);
-
-	loca0 := 0x6c6c6163;
-	_write_s(4, @loca0);
-	_write_c(0x20);
-
-	_write_s(loca80, loca84);
-	_write_c(0x0a);
-
-	_skip_spaces();
-	_advance(1)
-end
-
-proc _read_token()
-var
-	loca0: Word
-	loca4: Word
-	loca8: ^Byte
+	li t0, 'a' - 1
+	sltu t2, t0, a0 # t2 = a0 >= 'a'
+
+	sltiu t3, a0, 'z' + 1 # t3 = a0 <= 'z'
+	and a0, t2, t3 # t2 = a0 >= 'a' & a0 <= 'z'
+end;
+
+# Detects if the passed character is a 7-bit alpha character or an underscore.
+#
+# Paramters:
+# a0 - Tested character.
+#
+# Sets a0 to 1 if the character is an alpha character or underscore, sets it to 0 otherwise.
+proc _is_alpha();
 begin
-	loca8 := _current();
-	loca0 := _front(loca8);
-	loca4 := 0;
-
-	if loca0 = 0x2e then
-		goto .Ltoken_character_single
-	end;
-
-	if loca0 = 0x2c then
-		goto .Ltoken_character_single
-	end;
-
-	if loca0 = 0x3a then
-		goto .Ltoken_character_colon
-	end;
-
-	if loca0 = 0x3b then
-		goto .Ltoken_character_single
-	end;
-
-	if loca0 = 0x28 then
-		goto .Ltoken_character_single
-	end;
-
-	if loca0 = 0x29 then
-		goto .Ltoken_character_single
-	end;
-
-	if loca0 = 0x5b then
-		goto .Ltoken_character_single
-	end;
-
-	if loca0 = 0x5d then
-		goto .Ltoken_character_single
-	end;
-
-	if loca0 = 0x5e then
-		goto .Ltoken_character_single
-	end;
-
-	if loca0 = 0x26 then
-		goto .Ltoken_character_single
-	end;
-
-	if loca0 = 0x3d then
-		goto .Ltoken_character_single
-	end;
-
-	if loca0 = 0x2b then
-		goto .Ltoken_character_single
-	end;
-
-	if loca0 = 0x2d then
-		goto .Ltoken_character_single
-	end;
-
-	if loca0 = 0x2a then
-		goto .Ltoken_character_single
-	end;
-
-	if loca0 = 0x40 then
-		goto .Ltoken_character_single
-	end;
-
-	.Ltoken_character_loop_do;
-	loca0 := loca8 + loca4;
-	loca0 := _front(loca0);
-
-	if _is_alnum(loca0) then
-		loca4 := loca4 + 1;
-		goto .Ltoken_character_loop_do;
-
-		.Ltoken_character_single;
-		loca4 := loca4 + 1;
-		goto .Ltoken_character_end;
-
-		.Ltoken_character_colon;
-		loca0 := loca8 + 1;
-		loca0 := _front(loca0);
-		loca4 := loca4 + 1;
-
-		if loca0 = 0x3d then
-			goto .Ltoken_character_single
-		end
-	end;
-	.Ltoken_character_end;
-	return loca4
-end
-
-proc _skip_spaces()
-var
-	loca0: Byte
-	loca4: ^Byte
+	sw a0, 20(sp)
+
+	_is_upper();
+	sw a0, 16(sp)
+
+	lw a0, 20(sp)
+	_is_lower();
+
+	lw t0, 20(sp)
+	xori t1, t0, '_'
+	seqz t1, t1
+
+	lw t0, 16(sp)
+	or a0, a0, t0
+	or a0, a0, t1
+end;
+
+# Detects whether the passed character is a digit
+# (a value between 0 and 9).
+#
+# Parameters:
+# a0 - Exemined value.
+#
+# Sets a0 to 1 if it is a digit, to 0 otherwise.
+proc _is_digit();
 begin
-	.Lspace_loop_do;
-	loca4 := _current();
-	loca0 := _front(loca4);
-
-	if loca0 = 0x20 then
-		goto .Lspace_loop_repeat
-	end;
-	if loca0 = 0x09 then
-		goto .Lspace_loop_repeat
-	end;
-	if loca0 = 0x0a then
-		goto .Lspace_loop_repeat
-	end;
-	if loca0 = 0x0d then
-		goto .Lspace_loop_repeat
-	end;
-
-	goto .Lspace_loop_end;
-	.Lspace_loop_repeat;
-	_advance(1);
-	goto .Lspace_loop_do;
-
-	.Lspace_loop_end
-end
-
-proc _compile_assembly(loca84: Word)
-var loca0: ^Byte
+	li t0, '0' - 1
+	sltu t1, t0, a0 # t1 = a0 >= '0'
+
+	sltiu t2, a0, '9' + 1 # t2 = a0 <= '9'
+
+	and a0, t1, t2
+end;
+
+# Reads the next token.
+#
+# Returns token length in a0.
+proc _read_token();
 begin
-	loca0 := _current();
+	la t0, source_code_position # Token pointer.
+	lw t0, (t0)
+	sw t0, 20(sp) # Current token position.
+	sw zero, 16(sp) # Token length.
+
+.read_token_loop:
+	lb t0, (t0) # Current character.
+
+	# First we try to read a derictive.
+	# A derictive can contain a dot and characters.
+	li t1, '.'
+	beq t0, t1, .read_token_next
+
+	lw a0, 20(sp)
+	lb a0, (a0)
+	_is_alpha();
+	bnez a0, .read_token_next
+
+	lw a0, 20(sp)
+	lb a0, (a0)
+	_is_digit();
+	bnez a0, .read_token_next
+
+	j .read_token_end
+
+.read_token_next:
+	# Advance the source code position and token length.
+	lw t0, 16(sp)
+	addi t0, t0, 1
+	sw t0, 16(sp)
+
+	lw t0, 20(sp)
+	addi t0, t0, 1
+	sw t0, 20(sp)
+
+	j .read_token_loop
+
+.read_token_end:
+	lw a0, 16(sp)
+end;
+
+# a0 - First pointer.
+# a1 - Second pointer.
+# a2 - The length to compare.
+#
+# Returns 0 in a0 if memory regions are equal.
+proc _memcmp();
+begin
+	mv t0, a0
+	li a0, 0
 
-	_write_s(loca84, loca0);
-	_advance(loca84);
+.Lmemcmp_loop:
+	beqz a2, .Lmemcmp_end
 
-	_write_c(0xa);
+	lbu t1, (t0)
+	lbu t2, (a1)
+	sub a0, t1, t2
 
-	_advance(1)
-end
+	bnez a0, .Lmemcmp_end
 
-proc _compile_program()
-var loca0: Word
-begin
-	loca0 := 0x6f6c672e;
-	_write_s(4, @loca0);
-	loca0 := 0x206c6162;
-	_write_s(4, @loca0);
-	loca0 := 0x6174735f;
-	_write_s(4, @loca0);
-	loca0 := 0x0a7472;
-	_write_s(3, @loca0);
-
-	_advance(8)
-end
-
-proc _compile_variable_section()
-var
-	loca0: Word
-	loca4: ^Byte
+	addi t0, t0, 1
+	addi a1, a1, 1
+	addi a2, a2, -1
+
+	j .Lmemcmp_loop
+
+.Lmemcmp_end:
+end;
+
+# Advances the token stream by a0 bytes.
+proc _advance_token();
 begin
-	loca0 := 0x6365732e;
-	_write_s(4, @loca0);
-	loca0 := 0x6e6f6974;
-	_write_s(4, @loca0);
-	loca0 := 0x73622e20;
-	_write_s(4, @loca0);
-	loca0 := 0x0a73;
-	_write_s(2, @loca0);
-
-	_advance(4);
-
-	.Lcompile_variable_section_item;
-	_skip_spaces();
-	loca4 := _current();
-
-	loca0 := 0x636f7270;
-	loca0 := _memcmp(@loca0, loca4, 4);
-
-	if loca0 = 0 then
-		goto .Lcompile_variable_section_end
-	end;
-	_compile_variable();
-	goto .Lcompile_variable_section_item;
-
-	.Lcompile_variable_section_end
-end
-
-proc _compile_variable()
-var
-	loca0: Word
-	loca4: Word
-	loca8: Word
-	loca12: Word
-	loca16: ^Byte
-	loca20: Word
-	loca24: Word
-	loca28: ^Byte
+	# Skip the .equ directive.
+	la t0, source_code_position
+	lw t1, (t0)
+	add t1, t1, a0
+	sw t1, (t0)
+end;
+
+# Prints the current token.
+#
+# Parameters:
+# a0 - Token length.
+#
+# Returns a0 unchanged.
+proc _write_token();
 begin
-	loca24 := _read_token();
-	loca28 := _current();
+	sw a0, 20(sp)
 
-	_advance(loca24);
+	la a0, source_code_position
+	lw a0, (a0)
+	lw a1, 20(sp)
+	_write();
 
-	_skip_spaces();
-	_advance(1);
+	lw a0, 20(sp)
+end;
 
-	_skip_spaces();
-	_advance(1);
+proc _compile_section();
+begin
+	# Print and skip the .section directive and a space after it.
+	li a0, KEYWORD_SECTION_SIZE + 1
+	_write_token();
+	_advance_token();
 
-	loca16 := _read_token();
-	loca20 := _current();
-	_advance(loca16);
+	# Read the section name.
+	_read_token();
+	addi a0, a0, 1
 
-	_skip_spaces();
-	_advance(1);
+	_write_token();
+	_advance_token();
+end;
 
-	_skip_spaces();
-	loca0 := _read_token();
-	_advance(loca0);
+# Prints and skips a line.
+proc _skip_comment();
+begin
+	la t0, source_code_position
+	lw t1, (t0)
 
-	loca0 := 0x7079742e;
-	_write_s(4, @loca0);
-	loca0 := 0x2065;
-	_write_s(2, @loca0);
+.skip_comment_loop:
+	# Check for newline character.
+	lb t2, (t1)
+	li t3, '\n'
+	beq t2, t3, .skip_comment_end
 
-	_write_s(loca24, loca28);
+	# Advance the input string by one byte.
+	addi t1, t1, 1
+	sw t1, (t0)
 
-	loca0 := 0x6f40202c;
-	_write_s(4, @loca0);
-	loca0 := 0x63656a62;
-	_write_s(4, @loca0);
-	loca0 := 0x0a74;
-	_write_s(2, @loca0);
+	j .skip_comment_loop
 
-	loca0 := 0x7a69732e;
-	_write_s(4, @loca0);
-	loca0 := 0x2065;
-	_write_s(2, @loca0);
+.skip_comment_end:
+	# Skip the newline.
+	addi t1, t1, 1
+	sw t1, (t0)
+end;
 
-	_write_s(loca24, loca28);
+# Prints and skips a line.
+proc _compile_line();
+begin
+.compile_line_loop:
+	la a0, source_code_position
+	lw a1, (a0)
 
-	loca0 := 0x202c;
-	_write_s(2, @loca0);
+	lb t0, (a1)
+	li t1, '\n'
+	beq t0, t1, .compile_line_end
 
-	_write_s(loca16, loca20);
-	_write_c(0x0a);
+	# Print a character.
+	lw a0, (a1)
+	_write_c();
 
-	_write_s(loca24, loca28);
+	# Advance the input string by one byte.
+	li a0, 1
+	_advance_token();
 
-	loca0 := 0x7a2e203a;
-	_write_s(4, @loca0);
-	loca0 := 0x206f7265;
-	_write_s(4, @loca0);
+	j .compile_line_loop
 
-	_write_s(loca16, loca20);
+.compile_line_end:
+	li a0, '\n'
+	_write_c();
 
-	_write_c(0x0a)
-end
+	li a0, 1
+	_advance_token();
+end;
 
-proc _compile_procedure()
-var
-	loca0: Word
-	loca4: Word
-	loca8: Word
-	loca12: Word
-	loca16: Word
-	loca20: ^Byte
-	loca24: ^Byte
+proc _compile_integer_literal();
 begin
-	_advance(5);
-	loca16 := _read_token();
-	loca20 := _current();
-	_advance(loca16);
-
-	loca0 := 0x7079742e;
-	_write_s(4, @loca0);
-	loca0 := 0x2065;
-	_write_s(2, @loca0);
-
-	_write_s(loca16, loca20);
-
-	loca0 := 0x6640202c;
-	_write_s(4, @loca0);
-	loca0 := 0x74636e75;
-	_write_s(4, @loca0);
-	loca0 := 0x0a6e6f69;
-	_write_s(4, @loca0);
-
-	_write_s(loca16, loca20);
-
-	loca0 := 0x0a3a;
-	_write_s(2, @loca0);
-
-	_skip_spaces();
-	_advance(1);
-	_skip_spaces();
-	_advance(1);
-
-	loca12 := 0x6e;
-	loca8 := 0x69676562;
-
-	.Lcompile_procedure_begin;
-	_skip_spaces();
-	loca0 := _read_token();
-
-	loca24 := _current();
-	_advance(loca0);
-	loca0 := _token_compare(loca24, loca0, @loca8);
-
-	if loca0 = 1 then
-		goto .Lcompile_procedure_begin
-	end;
-
-	loca0 := 0x69646461;
-	_write_s(4, @loca0);
-
-	loca0 := 0x2c707320;
-	_write_s(4, @loca0);
-	_write_s(4, @loca0);
-
-	loca0 := 0x0a36392d;
-	_write_s(4, @loca0);
-
-	loca0 := 0x72207773;
-	_write_s(4, @loca0);
-	loca0 := 0x39202c61;
-	_write_s(4, @loca0);
-	loca0 := 0x70732832;
-	_write_s(4, @loca0);
-	loca0 := 0x0a29;
-	_write_s(2, @loca0);
-
-	loca0 := 0x73207773;
-	_write_s(4, @loca0);
-	loca0 := 0x38202c30;
-	_write_s(4, @loca0);
-	loca0 := 0x70732838;
-	_write_s(4, @loca0);
-	loca0 := 0x0a29;
-	_write_s(2, @loca0);
-
-	loca0 := 0x69646461;
-	_write_s(4, @loca0);
-	loca0 := 0x2c307320;
-	_write_s(4, @loca0);
-	loca0 := 0x2c707320;
-	_write_s(4, @loca0);
-	loca0 := 0x0a363920;
-	_write_s(4, @loca0);
-
-	loca0 := 0x61207773;
-	_write_s(4, @loca0);
-	loca4 := 0x38202c30;
-	_write_s(4, @loca4);
-	loca8 := 0x70732834;
-	_write_s(4, @loca8);
-	loca12 := 0x0a29;
-	_write_s(2, @loca12);
-
-	_write_s(4, @loca0);
-	loca4 := 0x38202c31;
-	_write_s(4, @loca4);
-	loca8 := 0x70732830;
-	_write_s(4, @loca8);
-	_write_s(2, @loca12);
-
-	_write_s(4, @loca0);
-	loca4 := 0x37202c32;
-	_write_s(4, @loca4);
-	loca8 := 0x70732836;
-	_write_s(4, @loca8);
-	_write_s(2, @loca12);
-
-	_write_s(4, @loca0);
-	loca4 := 0x37202c33;
-	_write_s(4, @loca4);
-	loca8 := 0x70732832;
-	_write_s(4, @loca8);
-	_write_s(2, @loca12);
-
-	_write_s(4, @loca0);
-	loca4 := 0x36202c34;
-	_write_s(4, @loca4);
-	loca8 := 0x70732838;
-	_write_s(4, @loca8);
-	_write_s(2, @loca12);
-
-	_write_s(4, @loca0);
-	loca4 := 0x36202c35;
-	_write_s(4, @loca4);
-	loca8 := 0x70732838;
-	_write_s(4, @loca8);
-	_write_s(2, @loca12);
-
-	.Lcompile_procedure_body;
-	_skip_spaces();
-	loca12 := _read_line();
-	loca8 := 0x0a646e65;
-	loca24 := _current();
-	loca8 := _memcmp(loca24, @loca8, 4);
-
-	if loca8 = 0 then
-		goto .Lcompile_procedure_end
-	end;
-
-	_compile_line(loca12);
-	goto .Lcompile_procedure_body;
-
-	.Lcompile_procedure_end;
-	_advance(4);
-
-	loca0 := 0x7220776c;
-	_write_s(4, @loca0);
-	loca0 := 0x39202c61;
-	_write_s(4, @loca0);
-	loca0 := 0x70732832;
-	_write_s(4, @loca0);
-	loca0 := 0x0a29;
-	_write_s(2, @loca0);
-
-	loca0 := 0x7320776c;
-	_write_s(4, @loca0);
-	loca0 := 0x38202c30;
-	_write_s(4, @loca0);
-	loca0 := 0x70732838;
-	_write_s(4, @loca0);
-	loca0 := 0x0a29;
-	_write_s(2, @loca0);
-
-	loca0 := 0x69646461;
-	_write_s(4, @loca0);
-
-	loca0 := 0x2c707320;
-	_write_s(4, @loca0);
-	_write_s(4, @loca0);
-
-	loca0 := 0x0a3639;
-	_write_s(4, @loca0);
-
-	loca0 := 0x0a746572;
-	_write_s(4, @loca0)
-end
-
-proc _token_compare(loca84: ^Byte, loca80: Word, loca76: ^Byte)
-var
-	loca0: Bool
-	loca4: Byte
-	loca8: Word
-	loca12: Byte
+	la a0, asm_li
+	_write_z();
+
+	la a0, asm_a0
+	_write_z();
+
+	la a0, asm_comma
+	_write_z();
+
+	_read_token();
+	_write_token();
+	_advance_token();
+
+	li a0, '\n'
+	_write_c();
+end;
+
+proc _compile_character_literal();
 begin
-	.Ltoken_compare_loop;
-	loca4 := _front(loca76);
-
-	loca8 := loca4 or loca80;
-	if loca8 = 0 then
-		goto .Ltoken_compare_equal
-	end;
-	if loca80 = 0 then
-		goto .Ltoken_compare_not_equal
-	end;
-	if loca4 = 0 then
-		goto .Ltoken_compare_not_equal
-	end;
-	loca12 := _front(loca84);
-	if loca4 = loca12 then
-		goto .Ltoken_compare_continue
-	end;
-	goto .Ltoken_compare_not_equal;
-
-	.Ltoken_compare_continue;
-
-	loca84 := loca84 + 1;
-	loca80 := loca80 - 1;
-	loca76 := loca76 + 1;
-	goto .Ltoken_compare_loop;
-
-	.Ltoken_compare_not_equal;
-	loca0 := 1;
-	goto .Ltoken_compare_end;
-
-	.Ltoken_compare_equal;
-	loca0 := 0;
-
-	.Ltoken_compare_end;
-	return loca0
-end
-
-proc _compile_goto()
-var
-	loca0: Word
-	loca4: Word
-	loca8: ^Byte
+	la a0, asm_li
+	_write_z();
+
+	la a0, asm_a0
+	_write_z();
+
+	la a0, asm_comma
+	_write_z();
+
+.compile_character_literal_loop:
+	la a0, source_code_position
+	lw a0, (a0)
+	li a1, 1
+	_write();
+	li a0, 1
+	_advance_token();
+
+	la t0, source_code_position
+	lw t0, (t0)
+	lb a0, (t0)
+	li t1, '\''
+	beq a0, t1, .compile_character_literal_end
+
+	j .compile_character_literal_loop
+	
+.compile_character_literal_end:
+	li a0, '\''
+	_write_c();
+
+	li a0, '\n'
+	_write_c();
+
+	li a0, 1
+	_advance_token();
+end;
+
+proc _compile_variable_expression();
 begin
-	_advance(4);
+	la a0, asm_lw
+	_write_z();
+
+	la a0, asm_a0
+	_write_z();
 
-	loca0 := 0x206a;
-	_write_s(2, @loca0);
+	la a0, asm_comma
+	_write_z();
 
-	_skip_spaces();
-	loca8 := _current();
-	_advance(1);
+	la a0, source_code_position
+	lw a0, (a0)
+	addi a0, a0, 1
+	li a1, 2
+	_write();
 
-	loca0 := _read_token();
-	_advance(loca0);
-	loca0 := loca0 + 1;
-	_write_s(loca0, loca8);
+	la a0, asm_sp
+	_write_z();
 
-	_advance(1);
-	_write_c(0x0a)
-end
+	li a0, '\n'
+	_write_c();
 
-proc _compile_label(loca84: Word)
-var
-	loca0: Word
-	loca4: Word
-	loca8: ^Byte
+	li a0, 3
+	_advance_token();
+
+end;
+
+proc _compile_expression();
 begin
-	loca0 := _current();
+	la t0, source_code_position
+	lw t0, (t0)
+	lb a0, (t0)
 
-	loca0 := loca0 + loca84;
-	loca0 := loca0 - 1;
-	loca4 := loca84;
+	li t1, '\''
+	beq a0, t1, .compile_expression_character_literal
 
-	loca0 := _front(loca0);
-	if loca0 = 0x3b then
-		loca4 := loca4 - 1
-	end;
-	loca8 := _current();
-	_write_s(loca4, loca8);
+	li t1, 'v'
+	beq a0, t1, .compile_expression_variable
 
-	_write_c(0x3a);
-	_write_c(0x0a);
+	_is_digit();
+	bnez a0, .compile_expression_integer_literal
 
-	_advance(loca84)
-end
+	j .compile_expression_end
 
-proc _compile_return()
-begin
-	_advance(6);
-	_skip_spaces();
-	_build_binary_expression()
-end
-
-proc _compile_if()
-var
-	loca0: Word
-	loca4: ^Byte
-	loca8: Word
-	loca12: Word
-	loca16: Word
-	loca20: Word
-	loca24: Word
-begin
-	_advance(2);
-	_skip_spaces();
+.compile_expression_character_literal:
+	_compile_character_literal();
+	j .compile_expression_end
+
+.compile_expression_integer_literal:
+	_compile_integer_literal();
+	j .compile_expression_end
+
+.compile_expression_variable:
+	_compile_variable_expression();
+	j .compile_expression_end;
 
-	_build_binary_expression();
+.compile_expression_end:
+end;
 
-	_skip_spaces();
-	_advance(4);
+proc _compile_call();
+begin
+	_read_token();
+	sw a0, 20(sp)
+	la t0, source_code_position
+	lw t0, (t0)
+	sw t0, 16(sp)
 
-	loca20 := 0x00646e65;
-	loca16 := 0x66694c2e;
+	# Skip the identifier and left paren.
+	addi a0, a0, 1
+	_advance_token();
 
-	loca12 := 0x7a716562;
-	_write_s(4, @loca12);
-	loca12 := 0x2c306120;
-	_write_s(4, @loca12);
-	_write_c(0x20);
+	la t0, source_code_position
+	lw t0, (t0)
+	lb t0, (t0)
 
-	loca24 := _label_counter(1);
-	_write_s(4, @loca16);
-	_write_i(loca24);
+	li t1, ')'
+	beq t0, t1, .compile_call_finalize
 
-	_write_c(0x0a);
+	_compile_expression();
 
-	.Lcompile_if_loop;
-	_skip_spaces();
-	loca12 := _read_token();
+.compile_call_finalize:
+	la a0, asm_call
+	_write_z();
 
-	loca4 := _current();
-	loca8 := _token_compare(loca4, loca12, @loca20);
+	lw a0, 16(sp)
+	lw a1, 20(sp)
+	_write();
 
-	if loca8 then
-		loca12 := _read_line();
-		_compile_line(loca12, 1);
+	# Skip the right paren.
+	li a0, 1
+	_advance_token();
+end;
 
-		goto .Lcompile_if_loop
-	end;
+proc _compile_goto();
+begin
+	li a0, 5
+	_advance_token();
 
-	_write_s(4, @loca16);
-	_write_i(loca24);
+	_read_token();
+	sw a0, 20(sp)
 
-	loca12 := 0x0a3a0a3a;
-	_write_s(2, @loca12);
+	la a0, asm_j
+	_write_z();
 
-	_advance(4)
-end
+	lw a0, 20(sp)
+	_write_token();
+	_advance_token();
+end;
 
-proc _compile_line(loca84: Word, loca80: Bool)
-var
-	loca0: Char
-	loca4: Int
-	loca8: Bool
-	loca12: Word
-	loca16: ^Byte
+proc _compile_statement();
 begin
-	if loca84 = 0 then
-		goto .Lcompile_line_empty
-	end;
-
-	loca16 := _current();
-	loca0 := _front(loca16);
-
-	loca12 := 0x676f7270;
-	loca4 := _memcmp(loca16, @loca12, 4);
-	if loca4 = 0 then
-		goto .Lcompile_line_program
-	end;
-
-	loca12 := 0x0a726176;
-	loca4 := _memcmp(loca16, @loca12, 4);
-	if loca4 = 0 then
-		goto .Lcompile_line_var
-	end;
-
-	loca12 := 0x636f7270;
-	loca4 := _memcmp(loca16, @loca12, 4);
-	if loca4 = 0 then
-		goto .Lcompile_line_procedure
-	end;
-
-	loca12 := 0x69676562;
-	loca4 := _memcmp(loca16, @loca12, 4);
-	if loca4 = 0 then
-		goto .Lcompile_line_begin
-	end;
-
-	loca12 := 0x2e646e65;
-	loca4 := _memcmp(loca16, @loca12, 4);
-	if loca4 = 0 then
-		goto .Lcompile_line_exit
-	end;
-
-	loca12 := 0x61636f6c;
-	loca4 := _memcmp(loca16, @loca12, 4);
-	if loca4 = 0 then
-		goto .Lcompile_line_identifier
-	end;
-	loca4 := _front(loca16);
-	if loca4 = 0x73 then
-		goto .Lcompile_line_identifier
-	end;
-
-	loca12 := 0x6f706d69;
-	loca4 := _memcmp(loca16, @loca12, 4);
-	if loca4 = 0 then
-		goto .Lcompile_line_import
-	end;
-
-	loca12 := 0x6f746f67;
-	loca4 := _memcmp(loca16, @loca12, 4);
-	if loca4 = 0 then
-		goto .Lcompile_line_goto
-	end;
-
-	loca12 := 0x75746572;
-	loca4 := _memcmp(loca16, @loca12, 4);
-	if loca4 = 0 then
-		goto .Lcompile_line_return
-	end;
-
-	loca12 := 0x6669;
-	loca4 := _memcmp(loca16, @loca12, 2);
-	if loca4 = 0 then
-		goto .Lcompile_line_if
-	end;
-
-	if loca0 = 0x2e then
-		goto .Lcompile_line_label
-	end;
-	if loca0 = 0x5f then
-		goto .Lcompile_line_identifier
-	end;
-	goto .Lcompile_line_unchanged;
-
-	.Lcompile_line_if;
-	_compile_if();
-	goto .Lcompile_line_section;
-
-	.Lcompile_line_label;
-	_compile_label(loca84);
-	goto .Lcompile_line_section;
-
-	.Lcompile_line_return;
-	_compile_return();
-	goto .Lcompile_line_section;
-
-	.Lcompile_line_goto;
+	# This is a call if the statement starts with an underscore.
+	la t0, source_code_position
+	lw t0, (t0)
+	# First character after alignment tab.
+	addi t0, t0, 1
+	lb t0, (t0)
+	
+	li t1, '_'
+	beq t0, t1, .compile_statement_call
+
+	li t1, 'g'
+	beq t0, t1, .compile_statement_goto
+
+	_compile_line();
+	j .compile_statement_end
+
+.compile_statement_call:
+	li a0, 1
+	_advance_token();
+	_compile_call();
+
+	j .compile_statement_semicolon
+
+.compile_statement_goto:
+	li a0, 1
+	_advance_token();
 	_compile_goto();
-	goto .Lcompile_line_section;
-
-	.Lcompile_line_import;
-	_compile_import();
-	goto .Lcompile_line_section;
-
-	.Lcompile_line_identifier;
-	_compile_identifier();
-	goto .Lcompile_line_section;
-
-	.Lcompile_line_exit;
-	_compile_exit();
-	goto .Lcompile_line_section;
-
-	.Lcompile_line_begin;
-
-	if loca80 = 1 then
-		goto .Lcompile_line_compile_entry
-	end;
-	_compile_text_section();
-	.Lcompile_line_compile_entry;
-	_compile_entry_point();
-	loca8 := 1;
-	goto .Lcompile_line_end;
-
-	.Lcompile_line_procedure;
-	if loca80 = 1 then
-		goto .Lcompile_line_compile_procedure
-	end;
-	_compile_text_section();
-	.Lcompile_line_compile_procedure;
-	_compile_procedure();
-	loca8 := 1;
-	goto .Lcompile_line_end;
 
-	.Lcompile_line_var;
-	_compile_variable_section();
-	goto .Lcompile_line_section;
+	j .compile_statement_semicolon
 
-	.Lcompile_line_program;
-	_compile_program();
-	goto .Lcompile_line_section;
+.compile_statement_semicolon:
+	li a0, 2
+	_advance_token();
 
-	.Lcompile_line_empty;
-	_advance(1);
-	goto .Lcompile_line_section;
+	li a0, '\n'
+	_write_c();
 
-	.Lcompile_line_unchanged;
-	_compile_assembly(loca84);
-	goto .Lcompile_line_section;
+.compile_statement_end:
+end;
 
-	.Lcompile_line_section;
-	loca8 := 0;
+proc _compile_procedure_body();
+begin
+.compile_procedure_body_loop:
+	la a0, source_code_position
+	lw a0, (a0)
+	la a1, keyword_end
+	li a2, KEYWORD_END_SIZE
+	_memcmp();
+
+	beqz a0, .compile_procedure_body_epilogue
 
-	.Lcompile_line_end;
-	_skip_spaces();
+	_compile_statement();
+	j .compile_procedure_body_loop
 
-	return loca8
-end
+.compile_procedure_body_epilogue:
+end;
 
-proc _compile_text_section()
-var loca0: Word
+proc _compile_procedure();
 begin
-	loca0 := 0x6365732e;
-	_write_s(4, @loca0);
-	loca0 := 0x6e6f6974;
-	_write_s(4, @loca0);
-	loca0 := 0x65742e20;
-	_write_s(4, @loca0);
-	loca0 := 0x0a7478;
-	_write_s(3, @loca0)
-end
-
-proc _compile_entry_point()
-var loca0: Word
+	# Skip "proc ".
+	li a0, KEYWORD_PROC_SIZE
+	_advance_token();
+
+	_read_token();
+	sw a0, 20(sp) # Save the procedure name length.
+
+	# Write .type _procedure_name, @function.
+	la a0, asm_type_directive
+	_write_z();
+
+	lw a0, 20(sp)
+	_write_token();
+
+	la a0, asm_type_function
+	_write_z();
+
+	# Write procedure label, _procedure_name:
+	lw a0, 20(sp)
+	_write_token();
+
+	la a0, asm_colon
+	_write_z();
+
+	# Skip the function name and trailing parens, semicolon, "begin" and newline.
+	lw a0, 20(sp)
+	addi a0, a0, KEYWORD_BEGIN_SIZE + 1 + 4
+	_advance_token();
+
+	la a0, asm_prologue
+	_write_z();
+
+	_compile_procedure_body();
+
+	# Write the epilogue.
+	la a0, asm_epilogue
+	_write_z();
+
+	li a0, KEYWORD_END_SIZE + 2
+	_advance_token();
+end;
+
+proc _compile_type();
 begin
-	loca0 := 0x7079742e;
-	_write_s(4, @loca0);
-	loca0 := 0x735f2065;
-	_write_s(4, @loca0);
-	loca0 := 0x74726174;
-	_write_s(4, @loca0);
-	loca0 := 0x6640202c;
-	_write_s(4, @loca0);
-	loca0 := 0x74636e75;
-	_write_s(4, @loca0);
-	loca0 := 0x0a6e6f69;
-	_write_s(4, @loca0);
-	loca0 := 0x6174735f;
-	_write_s(4, @loca0);
-	loca0 := 0x0a3a7472;
-	_write_s(4, @loca0);
-
-	_advance(6)
-end
-
-proc _compile_exit()
-var loca0: Word
+	# Print and skip the .type directive and a space after it.
+	li a0, KEYWORD_TYPE_SIZE + 1
+	_write_token();
+	_advance_token();
+
+	# Read and print the symbol name.
+	_read_token();
+	sw a0, 20(sp)
+
+	# Print and skip the symbol name, comma, space and @.
+	lw a0, 20(sp)
+	addi a0, a0, 3
+	_write_token();
+	_advance_token();
+
+	# Read the symbol type.
+	_read_token();
+	sw a0, 16(sp)
+	la t0, source_code_position
+	lw t0, (t0)
+	sw t0, 12(sp)
+
+	# Print the symbol type and newline.
+	lw a0, 16(sp)
+	addi a0, a0, 1
+	_write_token();
+	_advance_token();
+
+	# Write the object definition itself.
+	_compile_line();
+
+.compile_type_end:
+end;
+
+proc _compile_equ();
 begin
-	loca0 := 0x6120696c;
-	_write_s(4, @loca0);
-	loca0 := 0x30202c30;
-	_write_s(4, @loca0);
-	loca0 := 0x20696c0a;
-	_write_s(4, @loca0);
-	loca0 := 0x202c3761;
-	_write_s(4, @loca0);
-	loca0 := 0x650a3339;
-	_write_s(4, @loca0);
-	loca0 := 0x6c6c6163;
-	_write_s(4, @loca0);
-	loca0 := 0x0a;
-	_write_s(1, @loca0);
-
-	_advance(4);
-	_skip_spaces()
-end
-
-proc _read_line()
-var
-	loca0: ^Byte
-	loca4: Byte
+	# Print and skip the .equ directive and a space after it.
+	li a0, KEYWORD_EQU_SIZE + 1
+	_write_token();
+	_advance_token();
+
+	# Read and print the constant name.
+	_read_token();
+	sw a0, 20(sp)
+
+	# Print and skip the constant name, comma and space.
+	lw a0, 20(sp)
+	addi a0, a0, 2
+	_write_token();
+	_advance_token();
+
+	# Read the constant value.
+	_read_token();
+	sw a0, 16(sp)
+
+	# Print and skip the constant value and newline.
+	lw a0, 16(sp)
+	addi a0, a0, 1
+	_write_token();
+	_advance_token();
+end;
+
+proc _skip_newlines();
 begin
-	loca0 := _current();
-
-	.Lread_line_do;
-	loca4 := _front(loca0);
-	if loca4 = 0 then
-		goto .Lread_line_end
-	end;
-	if loca4 = 0x0a then
-		goto .Lread_line_end
-	end;
-	loca0 := loca0 + 1;
-	goto .Lread_line_do;
-
-	.Lread_line_end;
-	loca4 := _current();
-	return loca0 - loca4
-end
-
-proc _compile()
-var
-	loca0: Word
-	loca4: Word
-	loca8: Bool
-	loca12: Char
-	loca16: ^Byte
+	# Skip newlines.
+	la t0, source_code_position
+	lw t1, (t0)
+
+.skip_newlines_loop:
+	lb t2, (t1)
+	li t3, '\n'
+	bne t2, t3, .skip_newlines_end
+	beqz t2, .skip_newlines_end
+
+	addi t1, t1, 1
+	sw t1, (t0)
+
+	j .skip_newlines_loop
+
+.skip_newlines_end:
+end;
+
+# Process the source code and print the generated code.
+proc _compile();
 begin
-	loca4 := 0;
+.compile_loop:
+	_skip_newlines();
 
-	.Lcompile_do;
-	loca16 := _current();
-	loca12 := _front(loca16);
+	la t0, source_code_position
+	lw t0, (t0)
+	lb t0, (t0)
+	beqz t0, .compile_end
+	li t1, '#'
+	beq t0, t1, .compile_comment
 
-	if loca12 = 0 then
-		goto .Lcompile_end
-	end;
+	la a0, source_code_position
+	lw a0, (a0)
+	la a1, keyword_equ
+	li a2, KEYWORD_EQU_SIZE
+	_memcmp();
 
-	_skip_spaces();
-	loca0 := _read_line();
-	loca8 := _compile_line(loca0, loca4);
+	beqz a0, .compile_equ
 
-	if loca8 = 0 then
-		goto .Lcompile_do
-	end;
-	loca4 := loca4 or loca8;
+	la a0, source_code_position
+	lw a0, (a0)
+	la a1, keyword_section
+	li a2, KEYWORD_SECTION_SIZE
+	_memcmp();
 
-	goto .Lcompile_do;
-	.Lcompile_end
-end
+	beqz a0, .compile_section
 
-proc _front(loca84: ^Word)
-begin
-	return _get(loca84) & 0xff
-end
+	la a0, source_code_position
+	lw a0, (a0)
+	la a1, keyword_type
+	li a2, KEYWORD_TYPE_SIZE
+	_memcmp();
 
-proc _main()
-begin
-	_read_file(source_code, 81920);
+	beqz a0, .compile_type
+
+	la a0, source_code_position
+	lw a0, (a0)
+	la a1, keyword_proc
+	li a2, KEYWORD_PROC_SIZE
+	_memcmp();
+
+	beqz a0, .compile_procedure
+
+	la a0, source_code_position
+	lw a0, (a0)
+	la a1, keyword_global
+	li a2, KEYWORD_GLOBAL_SIZE
+	_memcmp();
+
+	beqz a0, .compile_global
+	# Not a known token, exit.
+	j .compile_end
+
+.compile_equ:
+	_compile_equ();
+
+	j .compile_loop
+
+.compile_section:
+	_compile_section();
+
+	j .compile_loop
+
+.compile_type:
+	_compile_type();
+
+	j .compile_loop
+
+.compile_global:
+	_compile_line();
+
+	j .compile_loop
+
+.compile_comment:
+	_skip_comment();
+
+	j .compile_loop
+
+.compile_procedure:
+	_compile_procedure();
+
+	j .compile_loop
 
-	_label_counter(0)
-end
+.compile_end:
+end;
 
+# Entry point.
+.globl _start
+proc _start();
 begin
-	_main();
-	_compile()
-end.
+	# Read the source from the standard input.
+	la a0, source_code
+	li a1, SOURCE_BUFFER_SIZE # Buffer size.
+	_read_file();
+	_compile();
+
+	# Call exit.
+	li a0, 0 # Use 0 return code.
+	li a7, 93 # SYS_EXIT.
+	ecall
+end;