elna/boot/echo-boot.s

1326 lines
22 KiB
ArmAsm

.global _start
# s1 - Contains the current position in the source text.
.section .rodata
SOURCE_BUFFER_SIZE: .long 20480
.section .bss
.type source_code, @object
.size source_code, 20480
source_code: .zero 20480
.section .text
# Evalutes an expression and saves the result in a0.
.type _build_expression, @function
_build_expression:
# Prologue.
addi sp, sp, -32
sw ra, 28(sp)
sw s0, 24(sp)
addi s0, sp, 32
call _skip_spaces
call _read_token
sw s1, 20(sp)
sw a0, 16(sp)
# Integer literal.
addi a0, s1, 0
lb a0, (a0)
call _is_digit
bnez a0, .Lbuild_expression_number_literal
# Named identifier.
li t0, 0x202c30 # 0,_
sw t0, 12(sp)
li t0, 0x6120616c # la a
sw t0, 8(sp)
addi a0, sp, 8
li a1, 7
call _write_out
lw a0, 20(sp)
lw a1, 16(sp)
call _write_out
li t0, 0x0a # \n
sw t0, 12(sp)
addi a0, sp, 12
li a1, 1
call _write_out
j .Lbuild_expression_end
.Lbuild_expression_number_literal:
li t0, 0x202c30 # 0,_
sw t0, 12(sp)
li t0, 0x6120696c # li a
sw t0, 8(sp)
addi a0, sp, 8
li a1, 7
call _write_out
lw a0, 20(sp)
lw a1, 16(sp)
call _write_out
li t0, 0x0a # \n
sw t0, 12(sp)
addi a0, sp, 12
li a1, 1
call _write_out
j .Lbuild_expression_end
.Lbuild_expression_end:
lw a0, 16(sp)
add s1, s1, a0
# Epilogue.
lw ra, 28(sp)
lw s0, 24(sp)
addi sp, sp, 32
ret
# Compiles a statement beginning with an identifier.
#
# Left values should be variables named "loca n", where n is the offset
# of the variable on the stack, like loca8 or loca4.
.type _compile_identifier, @function
_compile_identifier:
# Prologue.
addi sp, sp, -32
sw ra, 28(sp)
sw s0, 24(sp)
addi s0, sp, 32
call _read_token
# Save the pointer to the identifier and its length on the stack.
sw s1, 20(sp)
sw a0, 16(sp)
add s1, s1, a0
call _skip_spaces
call _read_token
# Save the pointer and the length of the token following the identifier.
sw s1, 12(sp)
sw a0, 8(sp)
add s1, s1, a0 # Skip that token.
call _skip_spaces
li t0, 0x3d3a # :=
sw t0, 4(sp)
lw a0, 12(sp)
lw a1, 8(sp)
addi a2, sp, 4
call _token_compare
beqz a0, .Lcompile_identifier_assign
/* DEBUG
mv a0, s1
li a1, 4
call _write_error */
lw t0, 12(sp)
lbu t0, (t0)
li t1, 0x28 # (
beq t0, t1, .Lcompile_identifier_call
j .Lcompile_identifier_end
.Lcompile_identifier_call:
lw a0, 20(sp)
lw a1, 16(sp)
call _compile_call
j .Lcompile_identifier_end
.Lcompile_identifier_assign:
call _build_expression
li t0, 0x202c30 # 0,_
sw t0, 12(sp)
li t0, 0x61207773 # sw a
sw t0, 8(sp)
addi a0, sp, 8
li a1, 7
call _write_out
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
li t0, 0x0a # \n
sw t0, 12(sp)
li t0, 0x29707328 # (sp)
sw t0, 8(sp)
addi a0, sp, 8
li a1, 5
call _write_out
j .Lcompile_identifier_end
.Lcompile_identifier_end:
# Epilogue.
lw ra, 28(sp)
lw s0, 24(sp)
addi sp, sp, 32
ret
# Compiles a procedure call. Expects s1 to point to the first argument.
# a0 - Pointer to the procedure name.
# a1 - Length of the procedure name.
#
# Returns the procedure result in a0.
.type _compile_call, @function
_compile_call:
# Prologue.
addi sp, sp, -32
sw ra, 28(sp)
sw s0, 24(sp)
addi s0, sp, 32
sw a0, 20(sp)
sw a1, 16(sp)
sw zero, 12(sp) # Argument count for a procedure call.
.Lcompile_call_paren:
call _skip_spaces
call _read_token
lbu t0, (s1)
li t1, 0x29 # )
beq t0, t1, .Lcompile_call_complete
.Lcompile_call_argument:
call _build_expression
li t0, 0x202c30 # 0,_
sw t0, 8(sp)
li t0, 0x61207773 # sw a
sw t0, 4(sp)
addi a0, sp, 4
li a1, 7
call _write_out
lw t0, 12(sp) # Argument count for a procedure call.
# Only 8 arguments are supported with a0-a7.
# 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, 84
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 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
call _skip_spaces
call _read_token
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)
addi s1, s1, 1 # Skip the comma between the arguments.
j .Lcompile_call_argument
.Lcompile_call_complete:
sw zero, 12(sp)
.Lcompile_call_restore:
# Just go through all a0-a7 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, 7
bgt t0, t1, .Lcompile_call_perform
li t0, 0x6120776c # lw a
sw t0, 4(sp)
addi a0, sp, 4
li a1, 4
call _write_out
lw t0, 12(sp) # Argument count for a procedure call.
li t1, -4
mul t1, t0, t1
addi t1, t1, 84
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, 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)
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
sw t0, 4(sp)
addi a0, sp, 4
li a1, 5
call _write_out
lw a0, 20(sp)
lw a1, 16(sp)
call _write_out
li t0, 0x0a # \n
sw t0, 8(sp)
addi a0, sp, 8
li a1, 1
call _write_out
call _skip_spaces
addi s1, s1, 1 # Skip the close paren.
# Epilogue.
lw ra, 28(sp)
lw s0, 24(sp)
addi sp, sp, 32
ret
# Reads a token and returns its length in a0.
# _read_token doesn't change s1, it finds the length of the token s1 is pointing to.
.type _read_token, @function
_read_token:
# Prologue.
addi sp, sp, -16
sw ra, 12(sp)
sw s0, 8(sp)
addi s0, sp, 16
lbu t0, (s1) # t0 = Current character.
sw zero, 4(sp)
li t1, '.'
beq t0, t1, .Ltoken_character_single
li t1, ','
beq t0, t1, .Ltoken_character_single
li t1, ':'
beq t0, t1, .Ltoken_character_colon
li t1, ';'
beq t0, t1, .Ltoken_character_single
li t1, '('
beq t0, t1, .Ltoken_character_single
li t1, ')'
beq t0, t1, .Ltoken_character_single
li t1, '['
beq t0, t1, .Ltoken_character_single
li t1, ']'
beq t0, t1, .Ltoken_character_single
.Ltoken_character_loop_do: # Expect an identifier or a number.
lw t6, 4(sp)
add t1, s1, t6
lbu a0, (t1) # a0 = Current character.
call _is_alnum
beqz a0, .Ltoken_character_end
lw t6, 4(sp)
addi t6, t6, 1
sw t6, 4(sp)
j .Ltoken_character_loop_do
.Ltoken_character_single:
lw t6, 4(sp)
addi t6, t6, 1
sw t6, 4(sp)
j .Ltoken_character_end
.Ltoken_character_colon:
lbu t0, 1(s1) # t0 = The character after the colon.
lw t6, 4(sp)
addi t6, t6, 1
sw t6, 4(sp)
li t1, '='
beq t0, t1, .Ltoken_character_single
j .Ltoken_character_end
.Ltoken_character_end:
lw a0, 4(sp)
# Epilogue.
lw ra, 12(sp)
lw s0, 8(sp)
addi sp, sp, 16
ret
# Skips the spaces till the next non space character.
.type _skip_spaces, @function
_skip_spaces:
.Lspace_loop_do:
lbu t0, (s1) # t0 = Current character.
li t1, ' '
beq t0, t1, .Lspace_loop_repeat
li t1, '\t'
beq t0, t1, .Lspace_loop_repeat
li t1, '\n'
beq t0, t1, .Lspace_loop_repeat
li t1, '\r'
beq t0, t1, .Lspace_loop_repeat
j .Lspace_loop_end
.Lspace_loop_repeat:
addi s1, s1, 1
j .Lspace_loop_do
.Lspace_loop_end:
ret
# Skips tabs at the line beginning.
.type _skip_indentation, @function
_skip_indentation:
.Lskip_indentation_do:
lbu t0, (s1)
li t1, '\t'
beq t0, t1, .Lskip_indentation_skip
j .Lskip_indentation_end
.Lskip_indentation_skip:
addi s1, s1, 1
j .Lskip_indentation_do
.Lskip_indentation_end:
ret
# Parameters:
# a0 - Line length.
.type _skip_comment, @function
_skip_comment:
add s1, s1, a0
addi s1, s1, 1 # Skip the new line.
ret
# Parameters:
# a0 - Line length.
.type _compile_assembly, @function
_compile_assembly:
# Prologue.
addi sp, sp, -16
sw ra, 12(sp)
sw s0, 8(sp)
addi s0, sp, 16
sw a0, 4(sp) # a0 - Line length.
# Write the source to the standard output.
mv a0, s1
lw a1, 4(sp)
call _write_out
lw t0, 4(sp)
add s1, s1, t0
li t0, '\n'
sb t0, 0(sp)
addi a0, sp, 0
li a1, 1
call _write_out
addi s1, s1, 1 # Skip the new line.
# Epilogue.
lw ra, 12(sp)
lw s0, 8(sp)
addi sp, sp, 16
ret
.type _compile_program, @function
_compile_program:
# Prologue.
addi sp, sp, -32
sw ra, 28(sp)
sw s0, 24(sp)
addi s0, sp, 32
# .global _start
li t0, 0x0a7472 # rt\n
sw t0, 20(sp)
li t0, 0x6174735f # _sta
sw t0, 16(sp)
li t0, 0x206c6162 # bal_
sw t0, 12(sp)
li t0, 0x6f6c672e # .glo
sw t0, 8(sp)
addi a0, sp, 8
li a1, 15
call _write_out
addi s1, s1, 8 # program\n.
# Epilogue.
lw ra, 28(sp)
lw s0, 24(sp)
addi sp, sp, 32
ret
.type _compile_constant_section, @function
_compile_constant_section:
# Prologue.
addi sp, sp, -32
sw ra, 28(sp)
sw s0, 24(sp)
addi s0, sp, 32
# .section .rodata
li t0, 0x0a # \n
sw t0, 20(sp)
li t0, 0x61746164 # data
sw t0, 16(sp)
li t0, 0x6f722e20 # _.ro
sw t0, 12(sp)
li t0, 0x6e6f6974 # tion
sw t0, 8(sp)
li t0, 0x6365732e # .sec
sw t0, 4(sp)
addi a0, sp, 4
li a1, 17
call _write_out
addi s1, s1, 6 # const\n.
.Lcompile_constant_section_item:
call _skip_spaces
lbu a0, (s1)
call _is_upper
beqz a0, .Lcompile_constant_section_end
call _compile_constant
j .Lcompile_constant_section_item
.Lcompile_constant_section_end:
# Epilogue.
lw ra, 28(sp)
lw s0, 24(sp)
addi sp, sp, 32
ret
.type _compile_constant, @function
_compile_constant:
# Prologue.
addi sp, sp, -16
sw ra, 12(sp)
sw s0, 8(sp)
addi s0, sp, 16
call _read_token
mv a1, a0 # The identifier length from _read_token should be in a1.
mv a0, s1 # Save the identifier pointer before advancing it.
add s1, s1, a1
call _write_out
call _skip_spaces
call _read_token
addi s1, s1, 2 # Skip the assignment sign.
# : .long
li t0, 0x20676e6f # ong_
sw t0, 4(sp)
li t0, 0x6c2e203a # : .l
sw t0, 0(sp)
mv a0, sp
li a1, 8
call _write_out
call _skip_spaces
call _read_token
mv a1, a0 # The literal length from _read_token should be in a1.
mv a0, s1 # Save the literal pointer before advancing it.
add s1, s1, a1
call _write_out
li t0, '\n'
sw t0, 4(sp)
addi a0, sp, 4
li a1, 1
call _write_out
# Epilogue.
lw ra, 12(sp)
lw s0, 8(sp)
addi sp, sp, 16
ret
.type _compile_variable_section, @function
_compile_variable_section:
# Prologue.
addi sp, sp, -24
sw ra, 20(sp)
sw s0, 16(sp)
addi s0, sp, 24
# .section .bss
li t0, 0x0a73 # s\n
sw t0, 12(sp)
li t0, 0x73622e20 # _.bs
sw t0, 8(sp)
li t0, 0x6e6f6974 # tion
sw t0, 4(sp)
li t0, 0x6365732e # .sec
sw t0, 0(sp)
addi a0, sp, 0
li a1, 14
call _write_out
addi s1, s1, 4 # var\n.
.Lcompile_variable_section_item:
call _skip_spaces
lbu a0, (s1)
call _is_lower
beqz a0, .Lcompile_variable_section_end
call _compile_variable
j .Lcompile_variable_section_item
.Lcompile_variable_section_end:
# Epilogue.
lw ra, 20(sp)
lw s0, 16(sp)
addi sp, sp, 24
ret
.type _compile_variable, @function
_compile_variable:
# Prologue.
addi sp, sp, -40
sw ra, 36(sp)
sw s0, 32(sp)
addi s0, sp, 40
call _read_token
# Save the identifier on the stack since it should emitted multiple times.
sw s1, 28(sp)
sw a0, 24(sp)
add s1, s1, a0
call _skip_spaces
addi s1, s1, 1 # Skip the colon in front of the type.
call _skip_spaces
addi s1, s1, 1 # Skip the opening bracket.
call _read_token
# Save the array size on the stack since it has to be emitted multiple times.
sw s1, 20(sp)
sw a0, 16(sp)
add s1, s1, a0
call _skip_spaces
addi s1, s1, 1 # Skip the closing bracket.
call _skip_spaces
call _read_token
add s1, s1, a0 # Skip the type.
# .type identifier, @object
li t0, 0x2065 # e_
sw t0, 12(sp)
li t0, 0x7079742e # .typ
sw t0, 8(sp)
addi a0, sp, 8
li a1, 6
call _write_out
lw a0, 28(sp)
lw a1, 24(sp)
call _write_out
li t0, 0x0a74 # t\n
sw t0, 12(sp)
li t0, 0x63656a62 # bjec
sw t0, 8(sp)
li t0, 0x6f40202c # , @o
sw t0, 4(sp)
addi a0, sp, 4
li a1, 10
call _write_out
# .size identifier, size
li t0, 0x2065 # e_
sw t0, 12(sp)
li t0, 0x7a69732e # .siz
sw t0, 8(sp)
addi a0, sp, 8
li a1, 6
call _write_out
lw a0, 28(sp)
lw a1, 24(sp)
call _write_out
li t0, 0x202c # ,
sw t0, 12(sp)
addi a0, sp, 12
li a1, 2
call _write_out
lw a0, 20(sp)
lw a1, 16(sp)
call _write_out
li t0, 0x0a # \n
sw t0, 12(sp)
addi a0, sp, 12
li a1, 1
call _write_out
# identifier: .zero size
lw a0, 28(sp)
lw a1, 24(sp)
call _write_out
li t0, 0x206f7265 # ero_
sw t0, 12(sp)
li t0, 0x7a2e203a # : .z
sw t0, 8(sp)
addi a0, sp, 8
li a1, 8
call _write_out
lw a0, 20(sp)
lw a1, 16(sp)
call _write_out
li t0, 0x0a # \n
sw t0, 12(sp)
addi a0, sp, 12
li a1, 1
call _write_out
# Epilogue.
lw ra, 36(sp)
lw s0, 32(sp)
addi sp, sp, 40
ret
.type _compile_procedure, @function
_compile_procedure:
# Prologue.
addi sp, sp, -32
sw ra, 28(sp)
sw s0, 24(sp)
addi s0, sp, 32
addi s1, s1, 5 # Skip proc_
call _read_token
sw s1, 20(sp)
sw a0, 16(sp)
add s1, s1, a0
# .type identifier, @function
li t0, 0x2065 # e_
sw t0, 12(sp)
li t0, 0x7079742e # .typ
sw t0, 8(sp)
addi a0, sp, 8
li a1, 6
call _write_out
lw a0, 20(sp)
lw a1, 16(sp)
call _write_out
li t0, 0x0a6e6f69 # ion\n
sw t0, 12(sp)
li t0, 0x74636e75 # unct
sw t0, 8(sp)
li t0, 0x6640202c # , @f
sw t0, 4(sp)
addi a0, sp, 4
li a1, 12
call _write_out
lw a0, 20(sp)
lw a1, 16(sp)
call _write_out
li t0, 0x0a3a # :\n
sw t0, 12(sp)
addi a0, sp, 12
li a1, 2
call _write_out
call _skip_spaces
addi s1, s1, 1 # Skip opening argument paren.
call _skip_spaces
addi s1, s1, 1 # Skip closing argument paren.
li t0, 0x6e # n
sw t0, 12(sp)
li t0, 0x69676562 # begi
sw t0, 8(sp)
# Skip all declarations until we find the "begin" keyword, denoting the
# beginning of the procedure body.
.Lcompile_procedure_begin:
call _skip_spaces
call _read_token
mv a1, a0
mv a0, s1
addi a2, sp, 8
add s1, s1, a1
call _token_compare
bnez a0, .Lcompile_procedure_begin
# Generate the procedure prologue with a predefined stack size.
li t0, 0x69646461 # addi
sw t0, 12(sp)
addi a0, sp, 12
li a1, 4
call _write_out
li t0, 0x2c707320 # _sp,
sw t0, 12(sp)
addi a0, sp, 12
li a1, 4
call _write_out
addi a0, sp, 12
li a1, 4
call _write_out
li t0, 0x0a36392d # -96\n
sw t0, 12(sp)
addi a0, sp, 12
li a1, 4
call _write_out
li t0, 0x0a29 # )\n
sw t0, 12(sp)
li t0, 0x70732832 # 2(sp
sw t0, 8(sp)
li t0, 0x39202c61 # a, 9
sw t0, 4(sp)
li t0, 0x72207773 # sw r
sw t0, 0(sp)
addi a0, sp, 0
li a1, 14
call _write_out
li t0, 0x0a29 # )\n
sw t0, 12(sp)
li t0, 0x70732838 # 2(sp
sw t0, 8(sp)
li t0, 0x38202c30 # 0, 8
sw t0, 4(sp)
li t0, 0x73207773 # sw s
sw t0, 0(sp)
addi a0, sp, 0
li a1, 14
call _write_out
li t0, 0x0a363920 # _96\n
sw t0, 12(sp)
li t0, 0x2c707320 # _sp,
sw t0, 8(sp)
li t0, 0x2c307320 # _s0,
sw t0, 4(sp)
li t0, 0x69646461 # addi
sw t0, 0(sp)
addi a0, sp, 0
li a1, 16
call _write_out
# Generate the body of the procedure.
.Lcompile_procedure_body:
call _skip_indentation
call _read_line
sw a0, 12(sp)
li t0, 0x0a646e65 # end\n
sw t0, 8(sp)
mv a0, s1
addi a1, sp, 8
li a2, 4
call _memcmp
beqz a0, .Lcompile_procedure_end
lw a0, 12(sp)
call _compile_line
j .Lcompile_procedure_body
.Lcompile_procedure_end:
add s1, s1, 4 # Skip end\n.
# Generate the procedure epilogue with a predefined stack size.
li t0, 0x0a29 # )\n
sw t0, 12(sp)
li t0, 0x70732832 # 2(sp
sw t0, 8(sp)
li t0, 0x39202c61 # a, 9
sw t0, 4(sp)
li t0, 0x7220776c # lw r
sw t0, 0(sp)
addi a0, sp, 0
li a1, 14
call _write_out
li t0, 0x0a29 # )\n
sw t0, 12(sp)
li t0, 0x70732838 # 2(sp
sw t0, 8(sp)
li t0, 0x38202c30 # 0, 8
sw t0, 4(sp)
li t0, 0x7320776c # lw s
sw t0, 0(sp)
addi a0, sp, 0
li a1, 14
call _write_out
li t0, 0x69646461 # addi
sw t0, 12(sp)
addi a0, sp, 12
li a1, 4
call _write_out
li t0, 0x2c707320 # _sp,
sw t0, 12(sp)
addi a0, sp, 12
li a1, 4
call _write_out
addi a0, sp, 12
li a1, 4
call _write_out
li t0, 0x0a3639 # 96\n
sw t0, 12(sp)
addi a0, sp, 12
li a1, 3
call _write_out
li t0, 0x0a746572 # ret\n
sw t0, 12(sp)
addi a0, sp, 12
li a1, 4
call _write_out
# Epilogue.
lw ra, 28(sp)
lw s0, 24(sp)
addi sp, sp, 32
ret
# Compares two string, which of one has a length, the other one is null-terminated.
#
# a0 - The address of the token string.
# a1 - The length of the string in a0.
# a2 - The address of the null-terminated string.
#
# If the strings match sets a0 to 0, otherwise sets it to 1.
.type _token_compare, @function
_token_compare:
addi t0, a0, 0
addi t1, a1, 0
addi t2, a2, 0
.Ltoken_compare_loop:
lbu t3, (t2)
# Will only be 0 if the current character in the null terminated string is \0 and the remaining length of the
# another string is 0.
or t4, t3, t1
beqz t4, .Ltoken_compare_equal
beqz t1, .Ltoken_compare_not_equal
beqz t3, .Ltoken_compare_not_equal
lbu t4, (t0)
bne t3, t4, .Ltoken_compare_not_equal
addi t0, t0, 1
addi t1, t1, -1
addi t2, t2, 1
j .Ltoken_compare_loop
.Ltoken_compare_not_equal:
li a0, 1
j .Ltoken_compare_end
.Ltoken_compare_equal:
li a0, 0
.Ltoken_compare_end:
ret
# Parameters:
# a0 - Line length.
# Returns 1 in a0 if the parsed line contained a text section element such a
# procedure or the program entry point. Otherwise sets a0 to 0.
.type _compile_line, @function
_compile_line:
# Prologue.
addi sp, sp, -32
sw ra, 28(sp)
sw s0, 24(sp)
addi s0, sp, 32
sw a0, 20(sp) # a0 - Line length.
beqz a0, .Lcompile_line_empty # Skip an empty line.
lbu t0, (s1)
li t1, '#'
beq t0, t1, .Lcompile_line_comment
li t0, 0x0a6d6172 # ram\n
sw t0, 16(sp)
li t0, 0x676f7270 # prog
sw t0, 12(sp)
mv a0, s1
addi a1, sp, 12
li a2, 8
call _memcmp
beqz a0, .Lcompile_line_program
li t0, 0x0a74 # t\n
sw t0, 16(sp)
li t0, 0x736e6f63 # cons
sw t0, 12(sp)
mv a0, s1
addi a1, sp, 12
li a2, 6
call _memcmp
beqz a0, .Lcompile_line_const
li t0, 0x0a726176 # var\n
sw t0, 16(sp)
mv a0, s1
addi a1, sp, 16
li a2, 4
call _memcmp
beqz a0, .Lcompile_line_var
li t0, 0x20 # _
sw t0, 16(sp)
li t0, 0x636f7270 # proc
sw t0, 12(sp)
mv a0, s1
addi a1, sp, 12
li a2, 5
call _memcmp
beqz a0, .Lcompile_line_procedure
li t0, 0x0a6e # n\n
sw t0, 16(sp)
li t0, 0x69676562 # begi
sw t0, 12(sp)
mv a0, s1
addi a1, sp, 12
li a2, 6
call _memcmp
beqz a0, .Lcompile_line_begin
li t0, 0x2e646e65 # end.
sw t0, 16(sp)
mv a0, s1
addi a1, sp, 16
li a2, 4
call _memcmp
beqz a0, .Lcompile_line_exit
li t0, 0x61636f6c # loca
sw t0, 16(sp)
mv a0, s1
addi a1, sp, 16
li a2, 4
call _memcmp
beqz a0, .Lcompile_line_identifier
lbu t0, (s1)
li t1, '_'
beq t0, t1, .Lcompile_line_identifier
j .Lcompile_line_unchanged # Else.
.Lcompile_line_identifier:
call _compile_identifier
j .Lcompile_line_section
.Lcompile_line_exit:
call _compile_exit
j .Lcompile_line_section
.Lcompile_line_begin:
call _compile_entry_point
li a0, 1
j .Lcompile_line_end
.Lcompile_line_const:
call _compile_constant_section
j .Lcompile_line_section
.Lcompile_line_procedure:
call _compile_procedure
li a0, 1
j .Lcompile_line_end
.Lcompile_line_var:
call _compile_variable_section
j .Lcompile_line_section
.Lcompile_line_program:
call _compile_program
j .Lcompile_line_section
.Lcompile_line_comment:
lw a0, 20(sp)
call _skip_comment
j .Lcompile_line_section
.Lcompile_line_empty:
addi s1, s1, 1
j .Lcompile_line_section
.Lcompile_line_unchanged:
lw a0, 20(sp)
call _compile_assembly
j .Lcompile_line_section
.Lcompile_line_section:
mv a0, zero
.Lcompile_line_end:
# Epilogue.
lw ra, 28(sp)
lw s0, 24(sp)
addi sp, sp, 32
ret
.type _compile_text_section, @function
_compile_text_section:
# Prologue.
addi sp, sp, -24
sw ra, 20(sp)
sw s0, 16(sp)
addi s0, sp, 24
# .section .text
li t0, 0x0a7478 # xt\n
sw t0, 12(sp)
li t0, 0x65742e20 # _.te
sw t0, 8(sp)
li t0, 0x6e6f6974 # tion
sw t0, 4(sp)
li t0, 0x6365732e # .sec
sw t0, 0(sp)
addi a0, sp, 0
li a1, 15
call _write_out
# Epilogue.
lw ra, 20(sp)
lw s0, 16(sp)
addi sp, sp, 24
ret
.type _compile_entry_point, @function
_compile_entry_point:
# Prologue.
addi sp, sp, -64
sw ra, 60(sp)
sw s0, 56(sp)
addi s0, sp, 64
# .type _start, @function
li t0, 0x0a3a7472 # rt:\n
sw t0, 52(sp)
li t0, 0x6174735f # _sta
sw t0, 48(sp)
li t0, 0x0a6e6f69 # ion\n
sw t0, 44(sp)
li t0, 0x74636e75 # unct
sw t0, 40(sp)
li t0, 0x6640202c # , @f
sw t0, 36(sp)
li t0, 0x74726174 # tart
sw t0, 32(sp)
li t0, 0x735f2065 # e _s
sw t0, 28(sp)
li t0, 0x7079742e # .typ
sw t0, 24(sp)
addi a0, sp, 24
li a1, 32
call _write_out
addi s1, s1, 6 # Skip begin\n.
# Epilogue.
lw ra, 60(sp)
lw s0, 56(sp)
addi sp, sp, 64
ret
.type _compile_exit, @function
_compile_exit:
# Prologue.
addi sp, sp, -64
sw ra, 60(sp)
sw s0, 56(sp)
addi s0, sp, 64
# li a0, 0
# li a7, SYS_EXIT
# ecall
li t0, 0x0a # \n
sw t0, 52(sp)
li t0, 0x6c6c6163 # call
sw t0, 48(sp)
li t0, 0x650a3339 # 93\ne
sw t0, 44(sp)
li t0, 0x202c3761 # a7,_
sw t0, 40(sp)
li t0, 0x20696c0a # \nli_
sw t0, 36(sp)
li t0, 0x30202c30 # 0, 0
sw t0, 32(sp)
li t0, 0x6120696c # li a
sw t0, 28(sp)
addi a0, sp, 28
li a1, 25
call _write_out
addi s1, s1, 4 # Skip end.
call _skip_spaces # Read the possible new line at the end of the file.
# Epilogue.
lw ra, 60(sp)
lw s0, 56(sp)
addi sp, sp, 64
ret
# Finds the end of the line and returns its length in a0.
.type _read_line, @function
_read_line:
mv t0, s1 # Local position in the source text.
.Lread_line_do:
lbu t1, (t0) # t1 = Current character.
beqz t1, .Lread_line_end # Exit the loop on the NUL character.
li t2, '\n'
beq t1, t2, .Lread_line_end # Exit the loop on the new line.
addi t0, t0, 1
j .Lread_line_do
.Lread_line_end:
sub a0, t0, s1 # Return the line length.
ret
.type _compile, @function
_compile:
# Prologue.
addi sp, sp, -16
sw ra, 12(sp)
sw s0, 8(sp)
addi s0, sp, 16
.Lcompile_do:
lbu t0, (s1) # t0 = Current character.
beqz t0, .Lcompile_end # Exit the loop on the NUL character.
call _skip_indentation
call _read_line
call _compile_line
j .Lcompile_do
.Lcompile_end:
# Epilogue.
lw ra, 12(sp)
lw s0, 8(sp)
addi sp, sp, 16
ret
# Entry point.
.type _start, @function
_start:
# Read the source from the standard input.
la a0, source_code
la a1, SOURCE_BUFFER_SIZE # Buffer size.
lw a1, (a1)
call _read_file
la s1, source_code # s1 = Source code position.
call _compile
# Call exit.
li a0, 0 # Use 0 return code.
call exit