diff --git a/.gitignore b/.gitignore
index 0ee919a..0f4ebfc 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,3 @@
 /build/
 a.out
+/vendor/
diff --git a/Gemfile b/Gemfile
new file mode 100644
index 0000000..235744c
--- /dev/null
+++ b/Gemfile
@@ -0,0 +1,6 @@
+# frozen_string_literal: true
+
+source 'https://rubygems.org'
+
+gem 'term-ansicolor', '~> 1.2'
+gem 'rake', '~> 13.2'
diff --git a/Gemfile.lock b/Gemfile.lock
new file mode 100644
index 0000000..3521a74
--- /dev/null
+++ b/Gemfile.lock
@@ -0,0 +1,22 @@
+GEM
+  remote: https://rubygems.org/
+  specs:
+    bigdecimal (3.1.9)
+    rake (13.2.1)
+    sync (0.5.0)
+    term-ansicolor (1.11.2)
+      tins (~> 1.0)
+    tins (1.38.0)
+      bigdecimal
+      sync
+
+PLATFORMS
+  ruby
+  x86_64-linux
+
+DEPENDENCIES
+  rake (~> 13.2)
+  term-ansicolor (~> 1.2)
+
+BUNDLED WITH
+   2.6.7
diff --git a/Rakefile b/Rakefile
index e04bff1..3fa065e 100644
--- a/Rakefile
+++ b/Rakefile
@@ -1,5 +1,8 @@
+# frozen_string_literal: true
+
 require 'open3'
 require 'rake/clean'
+require 'term/ansicolor'
 
 CLOBBER.include 'build'
 
@@ -10,7 +13,7 @@ QEMU = 'qemu-riscv32'
 def assemble_stage(output, compiler, source)
   arguments = [QEMU, '-L', SYSROOT, *compiler]
 
-  puts(arguments * ' ')
+  puts Term::ANSIColor.green(arguments * ' ')
   puts
   Open3.popen2(*arguments) do |qemu_in, qemu_out|
     qemu_in.write File.read(*source)
@@ -27,7 +30,7 @@ task default: ['build/stage2b', 'build/stage2b.s', 'boot/stage2.elna'] do |t|
 
   cat_arguments = ['cat', source]
   compiler_arguments = [QEMU, '-L', SYSROOT, exe]
-  diff_arguments = ['diff', '-Nur', previous_output, '-']
+  diff_arguments = ['diff', '-Nur', '--text', previous_output, '-']
   Open3.pipeline(cat_arguments, compiler_arguments, diff_arguments)
 end
 
@@ -70,7 +73,8 @@ task :statistics do
     word.start_with?('(*') ||
       word.start_with?('*)') ||
       ('A'..'Z').include?(word[0]) ||
-      /^[[:alpha:]][[:digit:]]$/.match(word)
+      /^[[:alpha:]][[:digit:]]$/.match(word) ||
+      ['end', 'if'].include?(word)
   end
 
   lines = File.read('boot/stage2.elna')
diff --git a/boot/common-boot.s b/boot/common-boot.s
index c6fcb98..e8eba52 100644
--- a/boot/common-boot.s
+++ b/boot/common-boot.s
@@ -1,5 +1,6 @@
 .global _is_alpha, _is_digit, _is_alnum, _is_upper, _is_lower
-.global _write_out, _read_file, exit, _memcmp, _write_error, _put_char
+.global _write_out, _read_file, _memcmp, _write_error, _put_char, _printi
+.global _divide_by_zero_error, _exit
 
 .section .rodata
 
@@ -119,6 +120,13 @@ _is_alpha:
 	addi sp, sp, 16
 	ret
 
+# 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.
 .type _is_digit, @function
 _is_digit:
 	li t0, '0' - 1
@@ -201,10 +209,68 @@ _read_file:
 	ret
 
 # Terminates the program. a0 contains the return code.
+#
+# Parameters:
+# a0 - Status code.
 .type _exit, @function
-exit:
+_exit:
 	li a7, SYS_EXIT
 	ecall
+	# ret
+
+.type _divide_by_zero_error, @function
+_divide_by_zero_error:
+    addi a7, zero, 172 # getpid
+    ecall
+
+    addi a1, zero, 8 # SIGFPE
+    addi a7, zero, 129 # kill
+    ecall
+    ret
+
+# a0 - Whole number.
+# t1 - Constant 10.
+# a1 - Local buffer.
+# t2 - Current character.
+# t3 - Whether the number is negative.
+.type printi, @function
+_printi:
+    addi sp, sp, -16
+    sw s0, 0(sp)
+    sw ra, 4(sp)
+    addi s0, sp, 16
+    addi t1, zero, 10
+    addi a1, s0, -1
+
+    addi t3, zero, 0
+    bge a0, zero, .digit10
+    addi t3, zero, 1
+    sub a0, zero, a0
+
+.digit10:
+    rem t2, a0, t1
+    addi t2, t2, '0'
+    sb t2, 0(a1)
+    div a0, a0, t1
+    addi a1, a1, -1
+    bne zero, a0, .digit10
+
+    beq zero, t3, .write_call
+    addi t2, zero, '-'
+    sb t2, 0(a1)
+    addi a1, a1, -1
+
+.write_call:
+    addi a0, zero, 1
+    addi a1, a1, 1
+    sub a2, s0, a1
+    addi a7, zero, 64 # write
+    ecall
+
+    lw s0, 0(sp)
+    lw ra, 4(sp)
+    addi sp, sp, 16
+    ret
 
 # Writes a character from a0 into the standard output.
 .type _put_char, @function
diff --git a/boot/stage1.s b/boot/stage1.s
index 5989ac9..61dcdec 100644
--- a/boot/stage1.s
+++ b/boot/stage1.s
@@ -1,5 +1,8 @@
 .global _start # Program entry point.
+
+# Global variables or registers.
 # s1 - Contains the current position in the source text.
+# s2 - Label counter.
 
 .equ SOURCE_BUFFER_SIZE, 81920
 
@@ -29,10 +32,17 @@ asm_add_a0_a1: .ascii "add a0, a0, a1\n"
 .equ ASM_ADD_A0_A1_SIZE, . - asm_add_a0_a1
 asm_sub_a0_a1: .ascii "sub a0, a0, a1\n"
 .equ ASM_SUB_A0_A1_SIZE, . - asm_sub_a0_a1
+asm_mul_a0_a1: .ascii "mul a0, a0, a1\n"
+.equ ASM_MUL_A0_A1_SIZE, . - asm_mul_a0_a1
 asm_seqz_a0: .ascii "seqz a0, a0\n"
 .equ ASM_SEQZ_A0_SIZE, . - asm_seqz_a0
+asm_neg_a0: .ascii "neg a0, a0\n"
+.equ ASM_NEG_A0_SIZE, . - asm_neg_a0
 asm_type: .ascii ".type "
 .equ ASM_TYPE_SIZE, . - asm_type
+asm_restore_parameters:
+	.ascii "lw a0, 60(sp)\nlw a1, 56(sp)\nlw a2, 52(sp)\nlw a3, 48(sp)\nlw a4, 44(sp)\nlw a5, 40(sp)\n"
+.equ ASM_RESTORE_PARAMETERS_SIZE, . - asm_restore_parameters
 
 .section .bss
 .type source_code, @object
@@ -116,6 +126,14 @@ _build_binary_expression:
 	call _token_compare
 	beqz a0, .L_build_binary_expression_minus
 
+	li t0, '*'
+	sw t0, 16(sp)
+	mv a0, s1
+	lw a1, 20(sp)
+	addi a2, sp, 16
+	call _token_compare
+	beqz a0, .L_build_binary_expression_product
+
 	j .Lbuild_binary_expression_end
 
 .L_build_binary_expression_equal:
@@ -172,6 +190,16 @@ _build_binary_expression:
 
 	j .Lbuild_binary_expression_end
 
+.L_build_binary_expression_product:
+	addi s1, s1, 1 # Skip *.
+	li a0, 1
+	call _build_expression
+	la a0, asm_mul_a0_a1
+	li a1, ASM_MUL_A0_A1_SIZE
+	call _write_out
+
+	j .Lbuild_binary_expression_end
+
 .Lbuild_binary_expression_end:
 	# Epilogue.
 	lw ra, 28(sp)
@@ -198,18 +226,19 @@ _build_expression:
 	sw s1, 24(sp)
 	sw a0, 20(sp)
 
-	addi a0, s1, 0
-	lbu a0, (a0)
+	lbu a0, (s1)
+	li t0, '-'
+	beq a0, t0, .Lbuild_expression_negate
+
+	lbu a0, (s1)
 	li t0, '@'
 	beq a0, t0, .Lbuild_expression_address
 
-	addi a0, s1, 0
-	lbu a0, (a0)
+	lbu a0, (s1)
 	call _is_digit
 	bnez a0, .Lbuild_expression_literal
 
-	addi a0, s1, 0
-	lbu a0, (a0)
+	lbu a0, (s1)
 	li t0, '_'
 	beq a0, t0, .Lbuild_expression_call
 
@@ -241,6 +270,17 @@ _build_expression:
 
 	j .Lbuild_expression_advance
 
+.Lbuild_expression_negate:
+	addi s1, s1, 1 # Skip the -.
+	mv a0, zero
+	call _build_expression
+
+	la a0, asm_neg_a0
+	li a1, ASM_NEG_A0_SIZE
+	call _write_out
+
+	j .Lbuild_expression_advance
+
 .Lbuild_expression_address:
 	lw t1, 28(sp)
 	li t0, 0x20 # _
@@ -464,26 +504,10 @@ _compile_call:
 
 	# Only 6 arguments are supported with a0-a5.
 	# Save all arguments on the stack so they aren't overriden afterwards.
-	# The offset on the stack always has two digits in this case.
-	li t1, -4
-	mul t1, t0, t1
-	addi t1, t1, 60
-	li t2, 10
-	div t3, t1, t2
-	rem t4, t1, t2
-	addi t3, t3, '0'
-	addi t4, t4, '0'
-
-	sw t3, 8(sp)
-	sw t4, 4(sp)
-
-	addi a0, sp, 8
-	li a1, 1
-	call _write_out
-
-	addi a0, sp, 4
-	li a1, 1
-	call _write_out
+	li a0, -4
+	mul a0, t0, a0
+	addi a0, a0, 60
+	call _printi
 
 	li t0, '\n'
 	sw t0, 8(sp)
@@ -511,52 +535,14 @@ _compile_call:
 .Lcompile_call_restore:
 	# Just go through all a0-a5 registers and read them from stack.
 	# If this stack value contains garbage, the procedure just shouldn't use it.
-	lw t0, 12(sp)
-	li t1, 5
-	bgt t0, t1, .Lcompile_call_perform
-
-	li t0, 0x6120776c # lw a
-	sw t0, 4(sp)
-	addi a0, sp, 4
-	li a1, 4
+	la a0, asm_restore_parameters
+	li a1, ASM_RESTORE_PARAMETERS_SIZE
 	call _write_out
 
-	lw t0, 12(sp) # Argument count for a procedure call.
-
-	li t1, -4
-	mul t1, t0, t1
-	addi t1, t1, 60
-	li t2, 10
-	div t3, t1, t2
-	rem t4, t1, t2
-	addi t3, t3, '0'
-	addi t4, t4, '0'
-	addi t0, t0, '0'
-
-	li t5, '\n'
-	sb t5, 11(sp)
-	li t5, 0x29707328 # (sp)
-	sw t5, 7(sp)
-	sb t4, 6(sp)
-	sb t3, 5(sp)
-	li t5, 0x202c # ,_
-	sh t5, 3(sp)
-	sb t0, 2(sp)
-
-	addi a0, sp, 2
-	li a1, 10
-	call _write_out
-
-	lw t0, 12(sp) # Increment.
-	addi t0, t0, 1
-	sw t0, 12(sp)
-
-	j .Lcompile_call_restore
-
 .Lcompile_call_perform:
 	li t0, 0x20
 	sw t0, 8(sp)
-	li t0, 0x6c6c6163
+	li t0, 0x6c6c6163 # call
 	sw t0, 4(sp)
 	addi a0, sp, 4
 	li a1, 5
@@ -566,11 +552,8 @@ _compile_call:
 	lw a1, 16(sp)
 	call _write_out
 
-	li t0, '\n'
-	sw t0, 8(sp)
-	addi a0, sp, 8
-	li a1, 1
-	call _write_out
+	li a0, '\n'
+	call _put_char
 
 	call _skip_spaces
 	addi s1, s1, 1 # Skip the close paren.
@@ -633,6 +616,9 @@ _read_token:
 	li t1, '-'
 	beq t0, t1, .Ltoken_character_single
 
+	li t1, '*'
+	beq t0, t1, .Ltoken_character_single
+
 	li t1, '@'
 	beq t0, t1, .Ltoken_character_single
 # Expect an identifier or a number.
@@ -1325,6 +1311,97 @@ _compile_return:
 	addi sp, sp, 16
 	ret
 
+.type _compile_if, @function
+_compile_if:
+	# Prologue.
+	addi sp, sp, -32
+	sw ra, 28(sp)
+	sw s0, 24(sp)
+	addi s0, sp, 32
+
+	addi s1, s1, 2 # Skip the if.
+	call _skip_spaces
+
+	call _build_binary_expression
+
+	call _skip_spaces
+	addi s1, s1, 4 # Skip the then.
+
+	# if end marker.
+	li t0, 0x00646e65 # end\0
+	sw t0, 20(sp)
+
+	# Label prefix.
+	li t0, 0x66694c2e # .Lif
+	sw t0, 16(sp)
+
+	li t0, 0x202c3061 # a0,_
+	sw t0, 12(sp)
+	li t0, 0x207a7165 # eqz_
+	sw t0, 8(sp)
+	li t0, 0x62626262 # bbbb
+	sb t0, 7(sp)
+
+	addi a0, sp, 7
+	li a1, 13
+	call _write_out
+
+	# Write the label counter.
+	mv a0, s2
+	call _printi
+
+	li a0, '\n'
+	call _put_char
+
+.Lcompile_if_loop:
+	/* DEBUG
+	mv a0, s1
+	li a1, 6
+	call _write_error
+	call _divide_by_zero_error */
+
+	call _skip_spaces
+	call _read_token
+
+	mv a1, a0
+	mv a0, s1
+	addi a2, sp, 20
+	call _token_compare
+
+	beqz a0, .Lcompile_if_end
+
+	call _read_line
+	li a1, 1
+	call _compile_line
+
+	j .Lcompile_if_loop
+
+.Lcompile_if_end:
+	# Write the label prefix.
+	addi a0, sp, 16
+	li a1, 4
+	call _write_out
+
+	# Write the label counter.
+	mv a0, s2
+	call _printi
+
+	# Finalize the label.
+	li t0, 0x0a3a0a3a # :\n:\n
+	sh t0, 12(sp)
+	addi a0, sp, 12
+	li a1, 2
+	call _write_out
+
+	addi s2, s2, 1 # Increment the label counter.
+	addi s1, s1, 4 # Skip the end with newline.
+
+	# Epilogue.
+	lw ra, 28(sp)
+	lw s0, 24(sp)
+	addi sp, sp, 32
+	ret
+
 # Parameters:
 # a0 - Line length.
 # a1 - Whether the section header was already emitted. If not it should be
@@ -1442,6 +1519,14 @@ _compile_line:
 	call _memcmp
 	beqz a0, .Lcompile_line_return
 
+	li t0, 0x6669 # if
+	sw t0, 12(sp)
+	mv a0, s1
+	addi a1, sp, 12
+	li a2, 2
+	call _memcmp
+	beqz a0, .Lcompile_line_if
+
 	lbu t0, (s1)
 	li t1, '.'
 	beq t0, t1, .Lcompile_line_label
@@ -1450,16 +1535,16 @@ _compile_line:
 
 	j .Lcompile_line_unchanged # Else.
 
+.Lcompile_line_if:
+	call _compile_if
+	j .Lcompile_line_section
+
 .Lcompile_line_label:
 	lw a0, 20(sp)
 	call _compile_label
 	j .Lcompile_line_section
 
 .Lcompile_line_return:
-	/* DEBUG
-	mv a0, s1
-	li a1, 6
-	call _write_error */
 	call _compile_return
 	j .Lcompile_line_section
 
@@ -1659,9 +1744,10 @@ _start:
 	li a1, SOURCE_BUFFER_SIZE # Buffer size.
 	call _read_file
 
+	li s2, 1
 	la s1, source_code # s1 = Source code position.
 	call _compile
 
 	# Call exit.
 	li a0, 0   # Use 0 return code.
-	call exit
+	call _exit
diff --git a/boot/stage2.elna b/boot/stage2.elna
index 3ee1f32..0eb713c 100644
--- a/boot/stage2.elna
+++ b/boot/stage2.elna
@@ -14,6 +14,9 @@ type checking.
 hexadecimal format).
 
 - Comments are accepted only at the end of a line.
+
+- Return can be used only as the last statement of a procedure. It
+doesn't actually return, but sets a0 to the appropriate value.
 *)
 program
 
@@ -36,7 +39,7 @@ begin
 end
 
 proc _build_binary_expression()
-var loca0, loca4, loca8: Word
+var loca0, loca4, loca8, loca20: Word
 begin
 	_build_expression(0)
 
@@ -44,8 +47,7 @@ begin
 	loca8 := 0x0a316120 (* _a1\n *)
 
 	_skip_spaces()
-	call _read_token
-	sw a0, 20(sp)
+	loca20 := _read_token()
 
 	li t0, 0x26 # &
 	sw t0, 16(sp)
@@ -87,6 +89,14 @@ begin
 	call _token_compare
 	beqz a0, .L_build_binary_expression_minus
 
+	li t0, 0x2a # *
+	sw t0, 16(sp)
+	mv a0, s1
+	lw a1, 20(sp)
+	addi a2, sp, 16
+	call _token_compare
+	beqz a0, .L_build_binary_expression_product
+
 	goto .Lbuild_binary_expression_end
 
 	.L_build_binary_expression_equal
@@ -146,6 +156,19 @@ begin
 	_write_out(@loca4, 4)
 	_write_out(@loca8, 4)
 
+	goto .Lbuild_binary_expression_end
+
+	.L_build_binary_expression_product
+	_advance(1) (* Skip *. *)
+	_build_expression(1)
+	loca0 := 0x6c756d (* mul *)
+	_write_out(@loca0, 3)
+	_write_out(@loca4, 4)
+	_write_out(@loca4, 4)
+	_write_out(@loca8, 4)
+
+	goto .Lbuild_binary_expression_end
+
 	.Lbuild_binary_expression_end
 end
 
@@ -156,28 +179,30 @@ a0 - X in aX, the register number to save the result.
 *)
 proc _build_expression()
 var
-	loca20, loca28, loca8: Word
-	loca24: ^Byte
+	loca0, loca20, loca28, loca8: Word
+	loca24, loca4: ^Byte
 begin
-	addi a0, a0, '0' # Make the register number to a character.
-	sw a0, 28(sp) # And save it.
+	(* Make the register number to a character and save it. *)
+	loca28 := loca84 + 0x30 (* 0 *)
 
 	_skip_spaces()
 	loca20 := _read_token()
 	loca24 := _current()
 
-	addi a0, s1, 0
-	lbu a0, (a0)
+	lbu a0, (s1)
+	li t0, '-'
+	beq a0, t0, .Lbuild_expression_negate
+
+	lbu a0, (s1)
 	li t0, '@'
 	beq a0, t0, .Lbuild_expression_address
 
-	addi a0, s1, 0
-	lbu a0, (a0)
-	call _is_digit
-	bnez a0, .Lbuild_expression_literal
+	loca0 := _front()
+	if _is_digit(loca0) then
+		goto .Lbuild_expression_literal
+	end
 
-	addi a0, s1, 0
-	lbu a0, (a0)
+	lbu a0, (s1)
 	li t0, '_'
 	beq a0, t0, .Lbuild_expression_call
 
@@ -200,6 +225,19 @@ begin
 
 	goto .Lbuild_expression_advance
 
+	.Lbuild_expression_negate
+	_advance(1) (* Skip the -. *)
+	_build_expression(0)
+
+	loca8 := 0x2067656e (* neg_ *)
+	_write_out(@loca8, 4)
+	loca8 := 0x202c3061 (* a0,_ *)
+	_write_out(@loca8, 4)
+	loca8 := 0x0a3061 (* a0,_ *)
+	_write_out(@loca8, 3)
+
+	goto .Lbuild_expression_advance
+
 	.Lbuild_expression_address
 	loca8 := 0x69646461 (* addi *)
 	_write_out(@loca8, 4)
@@ -216,40 +254,28 @@ begin
 	loca24 := _current()
 	loca20 := _read_token()
 
-	lw a0, 24(sp)
-	lw a1, 20(sp)
-	addi a0, a0, 4 # Skip the "loca" variable prefix.
-	addi a1, a1, -4 # Skip the "loca" variable prefix.
-	call _write_out
+	(* Skip the "loca" variable prefix. *)
+	loca4 := loca24 + 4
+	loca0 := loca20 - 4
+	_write_out(loca4, loca0)
 
 	_put_char(0xa)
 
 	goto .Lbuild_expression_advance
 
 	.Lbuild_expression_identifier
-	lw t1, 28(sp)
-	li t0, 0x00202c00 # \0,_
-	or t0, t0, t1
-	sw t0, 8(sp)
-	li t0, 0x6120776c # lw a
-	sw t0, 4(sp)
-	addi a0, sp, 4
-	li a1, 7
-	call _write_out
+	loca8 := 0x6120776c (* lw a *)
+	_write_out(@loca8, 4)
+	loca8 := 0x00202c00 or loca28 # \0,_
+	_write_out(@loca8, 3)
 
-	lw a0, 24(sp)
-	lw a1, 20(sp)
-	addi a0, a0, 4 # Skip the "loca" variable prefix.
-	addi a1, a1, -4 # Skip the "loca" variable prefix.
-	call _write_out
+	loca4 := loca24 + 4
+	loca0 := loca20 - 4
+	_write_out(loca4, loca0) (* Skip the "loca" variable prefix. *)
 
-	li t0, 0x0a # \n
-	sw t0, 8(sp)
-	li t0, 0x29707328 # (sp)
-	sw t0, 4(sp)
-	addi a0, sp, 4
-	li a1, 5
-	call _write_out
+	loca8 := 0x29707328 (* (sp) *)
+	_write_out(@loca8, 4)
+	_put_char(0x0a) (* \n *)
 
 	goto .Lbuild_expression_advance
 
@@ -261,18 +287,13 @@ begin
 	goto .Lbuild_expression_end
 
 	.Lbuild_expression_literal
-	lw t1, 28(sp)
-	li t0, 0x00202c00 # \0,_
-	or t0, t0, t1
-	sw t0, 8(sp)
-	li t0, 0x6120696c # li a
-	sw t0, 4(sp)
-	addi a0, sp, 4
-	li a1, 7
-	call _write_out
+	loca8 := 0x6120696c (* li a *)
+	_write_out(@loca8, 4)
+	loca8 := 0x00202c00 or loca28 (* \0,_ *)
+	_write_out(@loca8, 3)
 
 	_write_out(loca24, loca20)
-	_put_char(0x0a) # \n
+	_put_char(0x0a) (* \n *)
 
 	goto .Lbuild_expression_advance
 
@@ -335,11 +356,9 @@ begin
 	loca0 := 0x202c30 (* 0,_ *)
 	_write_out(@loca0, 3)
 
-	lw a0, 20(sp)
-	lw a1, 16(sp)
-	addi a0, a0, 4 # Skip the "loca" variable prefix.
-	addi a1, a1, -4 # Skip the "loca" variable prefix.
-	call _write_out
+	loca20 := loca20 + 4
+	loca16 := loca16 - 4
+	_write_out(loca20, loca16)
 
 	loca0 := 0x29707328 (* (sp) *)
 	_write_out(@loca0, 4)
@@ -359,7 +378,7 @@ Returns the procedure result in a0.
 *)
 proc _compile_call(loca84: ^Byte, loca80: Word)
 var
-	loca0, loca12: Word
+	loca0, loca4, loca12: Word
 begin
 	loca12 := 0 (* Argument count for a procedure call. *)
 
@@ -377,49 +396,24 @@ begin
 	loca0 := 0x202c30 (* 0,_ *)
 	_write_out(@loca0, 3)
 
-	lw t0, 12(sp) # Argument count for a procedure call.
-
 	(*
 	Only 6 arguments are supported with a0-a5.
 	Save all arguments on the stack so they aren't overriden afterwards.
-	The offset on the stack always has two digits in this case.
 	*)
-	li t1, -4
-	mul t1, t0, t1
-	addi t1, t1, 60
-	li t2, 10
-	div t3, t1, t2
-	rem t4, t1, t2
-	addi t3, t3, '0'
-	addi t4, t4, '0'
+	loca0 := -4 * loca12
+	loca0 := loca0 + 60
+	_printi(loca0)
 
-	sw t3, 8(sp)
-	sw t4, 4(sp)
-
-	addi a0, sp, 8
-	li a1, 1
-	call _write_out
-
-	addi a0, sp, 4
-	li a1, 1
-	call _write_out
-
-	li t0, 0x0a # \n
-	sw t0, 8(sp)
-	li t0, 0x29707328 # (sp)
-	sw t0, 4(sp)
-	addi a0, sp, 4
-	li a1, 5
-	call _write_out
+	loca0 := 0x29707328 (* (sp) *)
+	_write_out(@loca0, 4)
+	_put_char(0x0a) (* \n *)
 
 	_skip_spaces()
 	lbu t0, (s1)
 	li t1, ','
 	bne t0, t1, .Lcompile_call_paren
 
-	lw t0, 12(sp) # Argument count for a procedure call.
-	addi t0, t0, 1
-	sw t0, 12(sp)
+	loca12 := loca12 + 1 (* Argument count for a procedure call. *)
 
 	_advance(1) (* Skip the comma between the arguments. *)
 	goto .Lcompile_call_argument
@@ -432,47 +426,62 @@ begin
 	Just go through all a0-a5 registers and read them from stack.
 	If this stack value contains garbage, the procedure just shouldn't use it.
 	*)
-	lw t0, 12(sp)
-	li t1, 5
-	bgt t0, t1, .Lcompile_call_perform
+	loca0 := 0x6120776c (* lw a *)
+	(* lw a0, 60(sp) *)
+	_write_out(@loca0, 4)
+	loca4 := 0x36202c30 (* 0, 6 *)
+	_write_out(@loca4, 4)
+	loca4 := 0x70732830 (* 0(sp *)
+	_write_out(@loca4, 4)
+	loca4 := 0x0a29 (* )\n *)
+	_write_out(@loca4, 2)
 
-	li t0, 0x6120776c # lw a
-	sw t0, 4(sp)
-	addi a0, sp, 4
-	li a1, 4
-	call _write_out
+	(* lw a1, 56(sp) *)
+	_write_out(@loca0, 4)
+	loca4 := 0x35202c31 (* 1, 5 *)
+	_write_out(@loca4, 4)
+	loca4 := 0x70732836 (* 6(sp *)
+	_write_out(@loca4, 4)
+	loca4 := 0x0a29 (* )\n *)
+	_write_out(@loca4, 2)
 
-	lw t0, 12(sp) # Argument count for a procedure call.
+	(* lw a2, 52(sp) *)
+	_write_out(@loca0, 4)
+	loca4 := 0x35202c32 (* 2, 5 *)
+	_write_out(@loca4, 4)
+	loca4 := 0x70732832 (* 2(sp *)
+	_write_out(@loca4, 4)
+	loca4 := 0x0a29 (* )\n *)
+	_write_out(@loca4, 2)
 
-	li t1, -4
-	mul t1, t0, t1
-	addi t1, t1, 60
-	li t2, 10
-	div t3, t1, t2
-	rem t4, t1, t2
-	addi t3, t3, '0'
-	addi t4, t4, '0'
-	addi t0, t0, '0'
+	(* lw a3, 48(sp) *)
+	_write_out(@loca0, 4)
+	loca4 := 0x34202c33 (* 3, 4 *)
+	_write_out(@loca4, 4)
+	loca4 := 0x70732838 (* 8(sp *)
+	_write_out(@loca4, 4)
+	loca4 := 0x0a29 (* )\n *)
+	_write_out(@loca4, 2)
 
-	li t5, 0x0a # \n
-	sb t5, 11(sp)
-	li t5, 0x29707328 # (sp)
-	sw t5, 7(sp)
-	sb t4, 6(sp)
-	sb t3, 5(sp)
-	li t5, 0x202c # ,_
-	sh t5, 3(sp)
-	sb t0, 2(sp)
+	(* lw a4, 44(sp) *)
+	_write_out(@loca0, 4)
+	loca4 := 0x34202c34 (* 4, 4 *)
+	_write_out(@loca4, 4)
+	loca4 := 0x70732834 (* 4(sp *)
+	_write_out(@loca4, 4)
+	loca4 := 0x0a29 (* )\n *)
+	_write_out(@loca4, 2)
 
-	addi a0, sp, 2
-	li a1, 10
-	call _write_out
+	(* lw a5, 40(sp) *)
+	_write_out(@loca0, 4)
+	loca4 := 0x34202c35 (* 5, 4 *)
+	_write_out(@loca4, 4)
+	loca4 := 0x70732830 (* 0(sp *)
+	_write_out(@loca4, 4)
+	loca4 := 0x0a29 (* )\n *)
+	_write_out(@loca4, 2)
 
-	loca12 := loca12 + 1
-	goto .Lcompile_call_restore
-
-	.Lcompile_call_perform
-	loca0 := 0x6c6c6163
+	loca0 := 0x6c6c6163 (* call *)
 	_write_out(@loca0, 4)
 	_put_char(0x20) (* _ *)
 
@@ -532,6 +541,9 @@ begin
 	li t1, '-'
 	beq t0, t1, .Ltoken_character_single
 
+	li t1, '*'
+	beq t0, t1, .Ltoken_character_single
+
 	li t1, '@'
 	beq t0, t1, .Ltoken_character_single
 	(* Expect an identifier or a number. *)
@@ -1125,6 +1137,61 @@ begin
 	_build_binary_expression()
 end
 
+proc _compile_if()
+var
+	loca8, loca12, loca16, loca20: Word
+	loca4: ^Byte
+begin
+	_advance(2) (* Skip the if. *)
+	_skip_spaces()
+
+	_build_binary_expression()
+
+	_skip_spaces()
+	_advance(4) (* Skip the then. *)
+
+	loca20 := 0x00646e65 (* if end marker and newline. *)
+	loca16 := 0x66694c2e (* Label prefix ".Lif". *)
+
+	loca12 := 0x7a716562 (* beqz *)
+	_write_out(@loca12, 4)
+	loca12 := 0x2c306120 (* _a0, *)
+	_write_out(@loca12, 4)
+	_put_char(0x20) (* _ *)
+
+	(* Write the label *)
+	_write_out(@loca16, 4)
+	mv a0, s2
+	call _printi
+
+	_put_char(0x0a) (* \n *)
+
+	.Lcompile_if_loop
+	_skip_spaces()
+	loca12 := _read_token()
+
+	loca4 := _current()
+	loca8 := _token_compare(loca4, loca12, @loca20)
+
+	if loca8 then
+		loca12 := _read_line()
+		_compile_line(loca12, 1)
+
+		goto .Lcompile_if_loop
+	end
+
+	(* Write the label *)
+	_write_out(@loca16, 4)
+	mv a0, s2
+	call _printi
+
+	loca12 := 0x0a3a0a3a (* :\n:\n *)
+	_write_out(@loca12, 2)
+
+	addi s2, s2, 1 # Increment the label counter.
+	_advance(4) (* Skip the end with newline. *)
+end
+
 (*
 Parameters:
 	a0 - Line length.
@@ -1234,6 +1301,14 @@ begin
 	call _memcmp
 	beqz a0, .Lcompile_line_return
 
+	li t0, 0x6669 # if
+	sw t0, 12(sp)
+	mv a0, s1
+	addi a1, sp, 12
+	li a2, 2
+	call _memcmp
+	beqz a0, .Lcompile_line_if
+
 	lbu t0, (s1)
 	li t1, '.'
 	beq t0, t1, .Lcompile_line_label
@@ -1242,6 +1317,10 @@ begin
 
 	goto .Lcompile_line_unchanged (* Else. *)
 
+	.Lcompile_line_if:
+	_compile_if()
+	goto .Lcompile_line_section
+
 	.Lcompile_line_label
 	_compile_label(loca84)
 	goto .Lcompile_line_section
@@ -1409,7 +1488,9 @@ begin
 end
 
 proc _compile()
-var loca0, loca4: Word
+var
+	loca0, loca4: Word
+	loca8: Bool
 begin
 	loca4 := 0 (* Whether the text section header was already emitted. *)
 
@@ -1419,15 +1500,11 @@ begin
 
 	_skip_indentation()
 	loca0 := _read_line()
-	lw a0, 0(sp)
-	lw a1, 4(sp)
-	call _compile_line
+	loca8 := _compile_line(loca0, loca4)
 
 	beqz a0, .Lcompile_do
 	(* Update whether the text section header was already emitted. *)
-	lw t0, 4(sp)
-	or t0, t0, a0
-	sw t0, 4(sp)
+	loca4 := loca4 or loca8
 
 	goto .Lcompile_do
 	.Lcompile_end
@@ -1460,5 +1537,6 @@ begin
 	call _read_file
 
 	la s1, source_code # s1 = Source code position.
+	li s2, 1
 	_compile()
 end.