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Compile procedure calls

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This commit is contained in:
Eugen Wissner
2025-04-24 23:01:12 +02:00
parent f343296463
commit 2e0c958aa3
4 changed files with 812 additions and 185 deletions
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45
boot/common-boot.s
View File

@ -1,4 +1,4 @@
.global is_alpha, is_digit, is_alnum, is_upper, is_lower, write_out, read_file, exit, memcmp, write_error
.global _is_alpha, _is_digit, _is_alnum, _is_upper, _is_lower, _write_out, _read_file, exit, _memcmp, _write_error
.section .rodata
@ -16,8 +16,8 @@ new_line: .ascii "\n"
# Write the current token to stderr.
# a0 - String pointer.
# a1 - String length.
.type write_error, @function
write_error:
.type _write_error, @function
_write_error:
mv t0, a0
mv t1, a1
@ -40,8 +40,8 @@ write_error:
# a2 - The length to compare.
#
# Returns 0 in a0 if memory regions are equal.
.type memcmp, @function
memcmp:
.type _memcmp, @function
_memcmp:
mv t0, a0
li a0, 0
@ -64,7 +64,8 @@ memcmp:
ret
# Detects if a0 is an uppercase character. Sets a0 to 1 if so, otherwise to 0.
is_upper:
.type _is_upper, @function
_is_upper:
li t0, 'A' - 1
sltu t1, t0, a0 # t1 = a0 >= 'A'
@ -74,8 +75,8 @@ is_upper:
ret
# Detects if a0 is an lowercase character. Sets a0 to 1 if so, otherwise to 0.
.type is_lower, @function
is_lower:
.type _is_lower, @function
_is_lower:
li t0, 'a' - 1
sltu t2, t0, a0 # t2 = a0 >= 'a'
@ -87,8 +88,8 @@ is_lower:
# Detects if the passed character is a 7-bit alpha character or an underscore.
# The character is passed in a0.
# Sets a0 to 1 if the character is an alpha character or underscore, sets it to 0 otherwise.
.type is_alpha, @function
is_alpha:
.type _is_alpha, @function
_is_alpha:
# Prologue.
addi sp, sp, -16
sw ra, 12(sp)
@ -97,11 +98,11 @@ is_alpha:
sw a0, 4(sp)
call is_upper
call _is_upper
sw a0, 0(sp)
lw a0, 4(sp)
call is_lower
call _is_lower
lw t0, 4(sp)
xori t1, t0, '_'
@ -117,8 +118,8 @@ is_alpha:
addi sp, sp, 16
ret
.type is_digit, @function
is_digit:
.type _is_digit, @function
_is_digit:
li t0, '0' - 1
sltu t1, t0, a0 # t1 = a0 >= '0'
@ -128,8 +129,8 @@ is_digit:
ret
.type is_alnum, @function
is_alnum:
.type _is_alnum, @function
_is_alnum:
# Prologue.
addi sp, sp, -16
sw ra, 12(sp)
@ -138,11 +139,11 @@ is_alnum:
sw a0, 4(sp)
call is_alpha
call _is_alpha
sw a0, 0(sp)
lw a0, 4(sp)
call is_digit
call _is_digit
lw a1, 0(sp)
or a0, a0, a1
@ -153,8 +154,8 @@ is_alnum:
addi sp, sp, 16
ret
.type write, @function
write_out:
.type _write_out, @function
_write_out:
# Prologue.
addi sp, sp, -8
sw ra, 4(sp)
@ -178,8 +179,8 @@ write_out:
# a1 - Buffer size.
#
# Returns the result in a0.
.type read_file, @function
read_file:
.type _read_file, @function
_read_file:
# Prologue.
addi sp, sp, -8
sw ra, 4(sp)

449
boot/echo-boot.s
View File

@ -11,6 +11,325 @@ 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
@ -53,7 +372,7 @@ _read_token:
add t1, s1, t6
lbu a0, (t1) # a0 = Current character.
call is_alnum
call _is_alnum
beqz a0, .Ltoken_character_end
lw t6, 4(sp)
@ -150,7 +469,7 @@ _compile_assembly:
# Write the source to the standard output.
mv a0, s1
lw a1, 4(sp)
call write_out
call _write_out
lw t0, 4(sp)
add s1, s1, t0
@ -159,7 +478,7 @@ _compile_assembly:
sb t0, 0(sp)
addi a0, sp, 0
li a1, 1
call write_out
call _write_out
addi s1, s1, 1 # Skip the new line.
@ -189,7 +508,7 @@ _compile_program:
addi a0, sp, 8
li a1, 15
call write_out
call _write_out
addi s1, s1, 8 # program\n.
@ -221,14 +540,14 @@ _compile_constant_section:
addi a0, sp, 4
li a1, 17
call write_out
call _write_out
addi s1, s1, 6 # const\n.
.Lcompile_constant_section_item:
call _skip_spaces
lbu a0, (s1)
call is_upper
call _is_upper
beqz a0, .Lcompile_constant_section_end
call _compile_constant
@ -254,7 +573,7 @@ _compile_constant:
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 _write_out
call _skip_spaces
call _read_token
@ -267,7 +586,7 @@ _compile_constant:
sw t0, 0(sp)
mv a0, sp
li a1, 8
call write_out
call _write_out
call _skip_spaces
call _read_token
@ -275,13 +594,13 @@ _compile_constant:
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
call _write_out
li t0, '\n'
sw t0, 4(sp)
addi a0, sp, 4
li a1, 1
call write_out
call _write_out
# Epilogue.
lw ra, 12(sp)
@ -309,14 +628,14 @@ _compile_variable_section:
addi a0, sp, 0
li a1, 14
call write_out
call _write_out
addi s1, s1, 4 # var\n.
.Lcompile_variable_section_item:
call _skip_spaces
lbu a0, (s1)
call is_lower
call _is_lower
beqz a0, .Lcompile_variable_section_end
call _compile_variable
@ -371,11 +690,11 @@ _compile_variable:
sw t0, 8(sp)
addi a0, sp, 8
li a1, 6
call write_out
call _write_out
lw a0, 28(sp)
lw a1, 24(sp)
call write_out
call _write_out
li t0, 0x0a74 # t\n
sw t0, 12(sp)
@ -385,7 +704,7 @@ _compile_variable:
sw t0, 4(sp)
addi a0, sp, 4
li a1, 10
call write_out
call _write_out
# .size identifier, size
li t0, 0x2065 # e_
@ -394,32 +713,32 @@ _compile_variable:
sw t0, 8(sp)
addi a0, sp, 8
li a1, 6
call write_out
call _write_out
lw a0, 28(sp)
lw a1, 24(sp)
call write_out
call _write_out
li t0, 0x202c # ,
sw t0, 12(sp)
addi a0, sp, 12
li a1, 2
call write_out
call _write_out
lw a0, 20(sp)
lw a1, 16(sp)
call write_out
call _write_out
li t0, 0x0a # \n
sw t0, 12(sp)
addi a0, sp, 12
li a1, 1
call write_out
call _write_out
# identifier: .zero size
lw a0, 28(sp)
lw a1, 24(sp)
call write_out
call _write_out
li t0, 0x206f7265 # ero_
sw t0, 12(sp)
@ -427,17 +746,17 @@ _compile_variable:
sw t0, 8(sp)
addi a0, sp, 8
li a1, 8
call write_out
call _write_out
lw a0, 20(sp)
lw a1, 16(sp)
call write_out
call _write_out
li t0, 0x0a # \n
sw t0, 12(sp)
addi a0, sp, 12
li a1, 1
call write_out
call _write_out
# Epilogue.
lw ra, 36(sp)
@ -466,11 +785,11 @@ _compile_procedure:
sw t0, 8(sp)
addi a0, sp, 8
li a1, 6
call write_out
call _write_out
lw a0, 20(sp)
lw a1, 16(sp)
call write_out
call _write_out
li t0, 0x0a6e6f69 # ion\n
sw t0, 12(sp)
@ -480,17 +799,17 @@ _compile_procedure:
sw t0, 4(sp)
addi a0, sp, 4
li a1, 12
call write_out
call _write_out
lw a0, 20(sp)
lw a1, 16(sp)
call write_out
call _write_out
li t0, 0x0a3a # :\n
sw t0, 12(sp)
addi a0, sp, 12
li a1, 2
call write_out
call _write_out
call _skip_spaces
addi s1, s1, 1 # Skip opening argument paren.
@ -521,24 +840,24 @@ _compile_procedure:
sw t0, 12(sp)
addi a0, sp, 12
li a1, 4
call write_out
call _write_out
li t0, 0x2c707320 # _sp,
sw t0, 12(sp)
addi a0, sp, 12
li a1, 4
call write_out
call _write_out
addi a0, sp, 12
li a1, 4
call write_out
call _write_out
li t0, 0x0a36392d # -96\n
sw t0, 12(sp)
addi a0, sp, 12
li a1, 4
call write_out
call _write_out
li t0, 0x0a29 # )\n
sw t0, 12(sp)
@ -550,7 +869,7 @@ _compile_procedure:
sw t0, 0(sp)
addi a0, sp, 0
li a1, 14
call write_out
call _write_out
li t0, 0x0a29 # )\n
sw t0, 12(sp)
@ -562,7 +881,7 @@ _compile_procedure:
sw t0, 0(sp)
addi a0, sp, 0
li a1, 14
call write_out
call _write_out
li t0, 0x0a363920 # _96\n
sw t0, 12(sp)
@ -574,7 +893,7 @@ _compile_procedure:
sw t0, 0(sp)
addi a0, sp, 0
li a1, 16
call write_out
call _write_out
# Generate the body of the procedure.
.Lcompile_procedure_body:
@ -586,7 +905,7 @@ _compile_procedure:
mv a0, s1
addi a1, sp, 8
li a2, 4
call memcmp
call _memcmp
beqz a0, .Lcompile_procedure_end
@ -608,7 +927,7 @@ _compile_procedure:
sw t0, 0(sp)
addi a0, sp, 0
li a1, 14
call write_out
call _write_out
li t0, 0x0a29 # )\n
sw t0, 12(sp)
@ -620,36 +939,36 @@ _compile_procedure:
sw t0, 0(sp)
addi a0, sp, 0
li a1, 14
call write_out
call _write_out
li t0, 0x69646461 # addi
sw t0, 12(sp)
addi a0, sp, 12
li a1, 4
call write_out
call _write_out
li t0, 0x2c707320 # _sp,
sw t0, 12(sp)
addi a0, sp, 12
li a1, 4
call write_out
call _write_out
addi a0, sp, 12
li a1, 4
call write_out
call _write_out
li t0, 0x0a3639 # 96\n
sw t0, 12(sp)
addi a0, sp, 12
li a1, 3
call write_out
call _write_out
li t0, 0x0a746572 # ret\n
sw t0, 12(sp)
addi a0, sp, 12
li a1, 4
call write_out
call _write_out
# Epilogue.
lw ra, 28(sp)
@ -726,7 +1045,7 @@ _compile_line:
mv a0, s1
addi a1, sp, 12
li a2, 8
call memcmp
call _memcmp
beqz a0, .Lcompile_line_program
li t0, 0x0a74 # t\n
@ -736,7 +1055,7 @@ _compile_line:
mv a0, s1
addi a1, sp, 12
li a2, 6
call memcmp
call _memcmp
beqz a0, .Lcompile_line_const
li t0, 0x0a726176 # var\n
@ -744,7 +1063,7 @@ _compile_line:
mv a0, s1
addi a1, sp, 16
li a2, 4
call memcmp
call _memcmp
beqz a0, .Lcompile_line_var
li t0, 0x20 # _
@ -754,7 +1073,7 @@ _compile_line:
mv a0, s1
addi a1, sp, 12
li a2, 5
call memcmp
call _memcmp
beqz a0, .Lcompile_line_procedure
li t0, 0x0a6e # n\n
@ -764,7 +1083,7 @@ _compile_line:
mv a0, s1
addi a1, sp, 12
li a2, 6
call memcmp
call _memcmp
beqz a0, .Lcompile_line_begin
li t0, 0x2e646e65 # end.
@ -772,11 +1091,27 @@ _compile_line:
mv a0, s1
addi a1, sp, 16
li a2, 4
call memcmp
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
@ -796,12 +1131,6 @@ _compile_line:
j .Lcompile_line_end
.Lcompile_line_var:
/* DEBUG
mv a0, s1
li a1, 20
call write_error */
call _compile_variable_section
j .Lcompile_line_section
@ -853,7 +1182,7 @@ _compile_text_section:
addi a0, sp, 0
li a1, 15
call write_out
call _write_out
# Epilogue.
lw ra, 20(sp)
@ -888,7 +1217,7 @@ _compile_entry_point:
sw t0, 24(sp)
addi a0, sp, 24
li a1, 32
call write_out
call _write_out
addi s1, s1, 6 # Skip begin\n.
@ -925,7 +1254,7 @@ _compile_exit:
sw t0, 28(sp)
addi a0, sp, 28
li a1, 25
call write_out
call _write_out
addi s1, s1, 4 # Skip end.
call _skip_spaces # Read the possible new line at the end of the file.
@ -986,7 +1315,7 @@ _start:
la a0, source_code
la a1, SOURCE_BUFFER_SIZE # Buffer size.
lw a1, (a1)
call read_file
call _read_file
la s1, source_code # s1 = Source code position.
call _compile

12
boot/goto-boot.elna
View File

@ -1,12 +0,0 @@
program
import dummy
var source_code: [2048]Byte
begin
read_file(source_code, 2048);
s1 := source_code;
end.

491
boot/stage2.elna
View File

@ -9,6 +9,293 @@ var
.section .text
# Evalutes an expression and saves the result in a0.
proc _build_expression()
begin
_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
end
# 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.
proc _compile_identifier()
begin
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
_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.
_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:
end
# 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.
proc _compile_call()
begin
sw a0, 20(sp)
sw a1, 16(sp)
sw zero, 12(sp) # Argument count for a procedure call.
.Lcompile_call_paren:
_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
_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)
_advance(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
_skip_spaces()
_advance(1) # Skip the close paren.
end
# 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.
proc _read_token()
@ -45,7 +332,7 @@ begin
add t1, s1, t6
lbu a0, (t1) # a0 = Current character.
call is_alnum
call _is_alnum
beqz a0, .Ltoken_character_end
lw t6, 4(sp)
@ -90,7 +377,7 @@ begin
j .Lspace_loop_end
.Lspace_loop_repeat:
addi s1, s1, 1
_advance(1)
j .Lspace_loop_do
.Lspace_loop_end:
@ -108,7 +395,7 @@ begin
j .Lskip_indentation_end
.Lskip_indentation_skip:
addi s1, s1, 1
_advance(1)
j .Lskip_indentation_do
.Lskip_indentation_end:
@ -119,7 +406,7 @@ end
proc _skip_comment()
begin
add s1, s1, a0
addi s1, s1, 1 # Skip the new line.
_advance(1) # Skip the new line.
end
# Parameters:
@ -131,7 +418,7 @@ begin
# Write the source to the standard output.
mv a0, s1
lw a1, 4(sp)
call write_out
call _write_out
lw t0, 4(sp)
add s1, s1, t0
@ -140,9 +427,9 @@ begin
sb t0, 0(sp)
addi a0, sp, 0
li a1, 1
call write_out
call _write_out
addi s1, s1, 1 # Skip the new line.
_advance(1) # Skip the new line.
end
proc _compile_program()
@ -159,9 +446,9 @@ begin
addi a0, sp, 8
li a1, 15
call write_out
call _write_out
addi s1, s1, 8 # program\n.
_advance(8) # program\n.
end
proc _compile_constant_section()
@ -180,14 +467,14 @@ begin
addi a0, sp, 4
li a1, 17
call write_out
call _write_out
addi s1, s1, 6 # const\n.
_advance(6) # const\n.
.Lcompile_constant_section_item:
call _skip_spaces
_skip_spaces()
lbu a0, (s1)
call is_upper
call _is_upper
beqz a0, .Lcompile_constant_section_end
call _compile_constant
@ -203,11 +490,11 @@ begin
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 _write_out
call _skip_spaces
_skip_spaces()
call _read_token
addi s1, s1, 2 # Skip the assignment sign.
_advance(2) # Skip the assignment sign.
# : .long
li t0, 0x20676e6f # ong_
@ -216,21 +503,21 @@ begin
sw t0, 0(sp)
mv a0, sp
li a1, 8
call write_out
call _write_out
call _skip_spaces
_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
call _write_out
li t0, '\n'
sw t0, 4(sp)
addi a0, sp, 4
li a1, 1
call write_out
call _write_out
end
proc _compile_variable_section()
@ -247,14 +534,14 @@ begin
addi a0, sp, 0
li a1, 14
call write_out
call _write_out
addi s1, s1, 4 # var\n.
_advance(4) # var\n.
.Lcompile_variable_section_item:
call _skip_spaces
_skip_spaces()
lbu a0, (s1)
call is_lower
call _is_lower
beqz a0, .Lcompile_variable_section_end
call _compile_variable
@ -272,11 +559,11 @@ begin
sw a0, 24(sp)
add s1, s1, a0
call _skip_spaces
addi s1, s1, 1 # Skip the colon in front of the type.
_skip_spaces()
_advance(1) # Skip the colon in front of the type.
call _skip_spaces
addi s1, s1, 1 # Skip the opening bracket.
_skip_spaces()
_advance(1) # Skip the opening bracket.
call _read_token
@ -285,10 +572,10 @@ begin
sw a0, 16(sp)
add s1, s1, a0
call _skip_spaces
addi s1, s1, 1 # Skip the closing bracket.
_skip_spaces()
_advance(1) # Skip the closing bracket.
call _skip_spaces
_skip_spaces()
call _read_token
add s1, s1, a0 # Skip the type.
@ -299,11 +586,11 @@ begin
sw t0, 8(sp)
addi a0, sp, 8
li a1, 6
call write_out
call _write_out
lw a0, 28(sp)
lw a1, 24(sp)
call write_out
call _write_out
li t0, 0x0a74 # t\n
sw t0, 12(sp)
@ -313,7 +600,7 @@ begin
sw t0, 4(sp)
addi a0, sp, 4
li a1, 10
call write_out
call _write_out
# .size identifier, size
li t0, 0x2065 # e_
@ -322,32 +609,32 @@ begin
sw t0, 8(sp)
addi a0, sp, 8
li a1, 6
call write_out
call _write_out
lw a0, 28(sp)
lw a1, 24(sp)
call write_out
call _write_out
li t0, 0x202c # ,
sw t0, 12(sp)
addi a0, sp, 12
li a1, 2
call write_out
call _write_out
lw a0, 20(sp)
lw a1, 16(sp)
call write_out
call _write_out
li t0, 0x0a # \n
sw t0, 12(sp)
addi a0, sp, 12
li a1, 1
call write_out
call _write_out
# identifier: .zero size
lw a0, 28(sp)
lw a1, 24(sp)
call write_out
call _write_out
li t0, 0x206f7265 # ero_
sw t0, 12(sp)
@ -355,22 +642,22 @@ begin
sw t0, 8(sp)
addi a0, sp, 8
li a1, 8
call write_out
call _write_out
lw a0, 20(sp)
lw a1, 16(sp)
call write_out
call _write_out
li t0, 0x0a # \n
sw t0, 12(sp)
addi a0, sp, 12
li a1, 1
call write_out
call _write_out
end
proc _compile_procedure()
begin
addi s1, s1, 5 # Skip proc_
_advance(5) # Skip proc_
call _read_token
sw s1, 20(sp)
sw a0, 16(sp)
@ -383,11 +670,11 @@ begin
sw t0, 8(sp)
addi a0, sp, 8
li a1, 6
call write_out
call _write_out
lw a0, 20(sp)
lw a1, 16(sp)
call write_out
call _write_out
li t0, 0x0a6e6f69 # ion\n
sw t0, 12(sp)
@ -397,22 +684,22 @@ begin
sw t0, 4(sp)
addi a0, sp, 4
li a1, 12
call write_out
call _write_out
lw a0, 20(sp)
lw a1, 16(sp)
call write_out
call _write_out
li t0, 0x0a3a # :\n
sw t0, 12(sp)
addi a0, sp, 12
li a1, 2
call write_out
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.
_skip_spaces()
_advance(1) # Skip opening argument paren.
_skip_spaces()
_advance(1) # Skip closing argument paren.
li t0, 0x6e # n
sw t0, 12(sp)
@ -422,7 +709,7 @@ begin
# Skip all declarations until we find the "begin" keyword, denoting the
# beginning of the procedure body.
.Lcompile_procedure_begin:
call _skip_spaces
_skip_spaces()
call _read_token
mv a1, a0
@ -438,24 +725,24 @@ begin
sw t0, 12(sp)
addi a0, sp, 12
li a1, 4
call write_out
call _write_out
li t0, 0x2c707320 # _sp,
sw t0, 12(sp)
addi a0, sp, 12
li a1, 4
call write_out
call _write_out
addi a0, sp, 12
li a1, 4
call write_out
call _write_out
li t0, 0x0a36392d # -96\n
sw t0, 12(sp)
addi a0, sp, 12
li a1, 4
call write_out
call _write_out
li t0, 0x0a29 # )\n
sw t0, 12(sp)
@ -467,7 +754,7 @@ begin
sw t0, 0(sp)
addi a0, sp, 0
li a1, 14
call write_out
call _write_out
li t0, 0x0a29 # )\n
sw t0, 12(sp)
@ -479,7 +766,7 @@ begin
sw t0, 0(sp)
addi a0, sp, 0
li a1, 14
call write_out
call _write_out
li t0, 0x0a363920 # _96\n
sw t0, 12(sp)
@ -491,11 +778,11 @@ begin
sw t0, 0(sp)
addi a0, sp, 0
li a1, 16
call write_out
call _write_out
# Generate the body of the procedure.
.Lcompile_procedure_body:
call _skip_indentation
_skip_indentation()
call _read_line
sw a0, 12(sp)
li t0, 0x0a646e65 # end\n
@ -503,7 +790,7 @@ begin
mv a0, s1
addi a1, sp, 8
li a2, 4
call memcmp
call _memcmp
beqz a0, .Lcompile_procedure_end
@ -525,7 +812,7 @@ begin
sw t0, 0(sp)
addi a0, sp, 0
li a1, 14
call write_out
call _write_out
li t0, 0x0a29 # )\n
sw t0, 12(sp)
@ -537,36 +824,36 @@ begin
sw t0, 0(sp)
addi a0, sp, 0
li a1, 14
call write_out
call _write_out
li t0, 0x69646461 # addi
sw t0, 12(sp)
addi a0, sp, 12
li a1, 4
call write_out
call _write_out
li t0, 0x2c707320 # _sp,
sw t0, 12(sp)
addi a0, sp, 12
li a1, 4
call write_out
call _write_out
addi a0, sp, 12
li a1, 4
call write_out
call _write_out
li t0, 0x0a3639 # 96\n
sw t0, 12(sp)
addi a0, sp, 12
li a1, 3
call write_out
call _write_out
li t0, 0x0a746572 # ret\n
sw t0, 12(sp)
addi a0, sp, 12
li a1, 4
call write_out
call _write_out
end
# Compares two string, which of one has a length, the other one is null-terminated.
@ -632,7 +919,7 @@ begin
mv a0, s1
addi a1, sp, 12
li a2, 8
call memcmp
call _memcmp
beqz a0, .Lcompile_line_program
li t0, 0x0a74 # t\n
@ -642,7 +929,7 @@ begin
mv a0, s1
addi a1, sp, 12
li a2, 6
call memcmp
call _memcmp
beqz a0, .Lcompile_line_const
li t0, 0x0a726176 # var\n
@ -650,7 +937,7 @@ begin
mv a0, s1
addi a1, sp, 16
li a2, 4
call memcmp
call _memcmp;
beqz a0, .Lcompile_line_var
li t0, 0x20 # _
@ -660,7 +947,7 @@ begin
mv a0, s1
addi a1, sp, 12
li a2, 5
call memcmp
call _memcmp
beqz a0, .Lcompile_line_procedure
li t0, 0x0a6e # n\n
@ -670,7 +957,7 @@ begin
mv a0, s1
addi a1, sp, 12
li a2, 6
call memcmp
call _memcmp
beqz a0, .Lcompile_line_begin
li t0, 0x2e646e65 # end.
@ -678,11 +965,27 @@ begin
mv a0, s1
addi a1, sp, 16
li a2, 4
call memcmp
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
@ -702,12 +1005,6 @@ begin
j .Lcompile_line_end
.Lcompile_line_var:
/* DEBUG
mv a0, s1
li a1, 20
call write_error */
call _compile_variable_section
j .Lcompile_line_section
@ -721,7 +1018,7 @@ begin
j .Lcompile_line_section
.Lcompile_line_empty:
addi s1, s1, 1
_advance(1)
j .Lcompile_line_section
.Lcompile_line_unchanged:
@ -749,7 +1046,7 @@ begin
addi a0, sp, 0
li a1, 15
call write_out
call _write_out
end
proc _compile_entry_point()
@ -773,9 +1070,9 @@ begin
sw t0, 24(sp)
addi a0, sp, 24
li a1, 32
call write_out
call _write_out
addi s1, s1, 6 # Skip begin\n.
_advance(6) # Skip begin\n.
end
proc _compile_exit()
@ -799,10 +1096,10 @@ begin
sw t0, 28(sp)
addi a0, sp, 28
li a1, 25
call write_out
call _write_out
addi s1, s1, 4 # Skip end.
call _skip_spaces # Read the possible new line at the end of the file.
_advance(4) # Skip end.
_skip_spaces() # Read the possible new line at the end of the file.
end
# Finds the end of the line and returns its length in a0.
@ -829,7 +1126,7 @@ begin
lbu t0, (s1) # t0 = Current character.
beqz t0, .Lcompile_end # Exit the loop on the NUL character.
call _skip_indentation
_skip_indentation()
call _read_line
call _compile_line
@ -837,13 +1134,25 @@ begin
.Lcompile_end:
end
# Returns the pointer to the current position in the source text in a0.
proc _current()
begin
mv a0, s1
end
# a0 is the number of bytes to advance in the source text.
proc _advance()
begin
add s1, s1, a0
end
# Entry point.
begin
# Read the source from the standard input.
la a0, source_code
la a1, SOURCE_BUFFER_SIZE # Buffer size.
lw a1, (a1)
call read_file
call _read_file
la s1, source_code # s1 = Source code position.
call _compile