; flat assembler core
; Copyright (c) 1999-2021, Tomasz Grysztar.
; All rights reserved.
convert_expression:
push ebp
call get_fp_value
jnc fp_expression
mov [current_offset],esp
expression_loop:
push edi
mov edi,single_operand_operators
call get_operator
pop edi
or al,al
jz expression_element
cmp al,82h
je expression_loop
push eax
jmp expression_loop
expression_element:
mov al,[esi]
cmp al,1Ah
je expression_number
cmp al,22h
je expression_number
cmp al,'('
je expression_number
mov al,'!'
stos byte [edi]
jmp expression_operator
expression_number:
call convert_number
expression_operator:
push edi
mov edi,operators
call get_operator
pop edi
or al,al
jz expression_end
operators_loop:
cmp esp,[current_offset]
je push_operator
mov bl,al
and bl,0F0h
mov bh,byte [esp]
and bh,0F0h
cmp bl,bh
ja push_operator
pop ebx
mov byte [edi],bl
inc edi
jmp operators_loop
push_operator:
push eax
jmp expression_loop
expression_end:
cmp esp,[current_offset]
je expression_converted
pop eax
stos byte [edi]
jmp expression_end
expression_converted:
pop ebp
ret
fp_expression:
mov al,'.'
stos byte [edi]
mov eax,[fp_value]
stos dword [edi]
mov eax,[fp_value+4]
stos dword [edi]
mov eax,[fp_value+8]
stos dword [edi]
pop ebp
ret
convert_number:
lea eax,[edi+20h]
mov edx,[memory_end]
cmp [source_start],0
je check_memory_for_number
mov edx,[labels_list]
check_memory_for_number:
cmp eax,edx
jae out_of_memory
mov eax,esp
sub eax,[stack_limit]
cmp eax,100h
jb stack_overflow
cmp byte [esi],'('
je expression_value
inc edi
call get_number
jc symbol_value
or ebp,ebp
jz valid_number
mov byte [edi-1],0Fh
ret
valid_number:
cmp dword [edi+4],0
jne qword_number
cmp word [edi+2],0
jne dword_number
cmp byte [edi+1],0
jne word_number
byte_number:
mov byte [edi-1],1
inc edi
ret
qword_number:
mov byte [edi-1],8
add edi,8
ret
dword_number:
mov byte [edi-1],4
scas dword [edi]
ret
word_number:
mov byte [edi-1],2
scas word [edi]
ret
expression_value:
inc esi
push [current_offset]
call convert_expression
pop [current_offset]
lods byte [esi]
cmp al,')'
je subexpression_closed
dec esi
mov al,'!'
stosb
subexpression_closed:
ret
symbol_value:
mov eax,[source_start]
test eax,eax
jz preprocessor_value
cmp eax,-1
je invalid_value
push edi esi
lods word [esi]
cmp al,1Ah
jne no_address_register
movzx ecx,ah
call get_symbol
jc no_address_register
cmp al,10h
jne no_address_register
mov al,ah
shr ah,4
cmp ah,4
je register_value
and ah,not 1
cmp ah,8
je register_value
cmp ah,0Ch
jae register_value
cmp ah,6
je register_value
cmp al,23h
je register_value
cmp al,25h
je register_value
cmp al,26h
je register_value
cmp al,27h
je register_value
no_address_register:
pop esi
mov edi,directive_operators
call get_operator
pop edi
or al,al
jnz broken_value
lods byte [esi]
cmp al,1Ah
jne invalid_value
lods byte [esi]
movzx ecx,al
call get_label_id
store_label_value:
mov byte [edi-1],11h
stos dword [edi]
ret
broken_value:
mov eax,0Fh
jmp store_label_value
register_value:
pop edx edi
mov byte [edi-1],10h
stos byte [edi]
ret
preprocessor_value:
dec edi
lods byte [esi]
cmp al,1Ah
jne invalid_value
lods byte [esi]
mov cl,al
mov ch,10b
call get_preprocessor_symbol
jc invalid_value
test edx,edx
jz special_preprocessor_value
push esi
mov esi,[edx+8]
push [current_offset]
call convert_expression
pop [current_offset]
pop esi
ret
special_preprocessor_value:
cmp eax,preprocessed_line_value
jne invalid_value
call get_current_line_from_file
mov al,4
stos byte [edi]
mov eax,[ebx+4]
stos dword [edi]
ret
get_number:
xor ebp,ebp
lods byte [esi]
cmp al,22h
je get_text_number
cmp al,1Ah
jne not_number
lods byte [esi]
movzx ecx,al
mov [number_start],esi
mov al,[esi]
cmp al,'$'
je number_begin
sub al,30h
cmp al,9
ja invalid_number
number_begin:
mov ebx,esi
add esi,ecx
push esi
dec esi
mov dword [edi],0
mov dword [edi+4],0
cmp byte [ebx],'$'
je pascal_hex_number
cmp word [ebx],'0x'
je get_hex_number
mov al,[esi]
dec esi
cmp al,'h'
je get_hex_number
cmp al,'b'
je get_bin_number
cmp al,'d'
je get_dec_number
cmp al,'o'
je get_oct_number
cmp al,'q'
je get_oct_number
cmp al,'H'
je get_hex_number
cmp al,'B'
je get_bin_number
cmp al,'D'
je get_dec_number
cmp al,'O'
je get_oct_number
cmp al,'Q'
je get_oct_number
inc esi
get_dec_number:
mov ebx,esi
mov esi,[number_start]
get_dec_digit:
cmp esi,ebx
ja number_ok
cmp byte [esi],27h
je next_dec_digit
cmp byte [esi],'_'
je next_dec_digit
xor edx,edx
mov eax,[edi]
shld edx,eax,2
shl eax,2
add eax,[edi]
adc edx,0
add eax,eax
adc edx,edx
mov [edi],eax
mov eax,[edi+4]
add eax,eax
jc dec_out_of_range
add eax,eax
jc dec_out_of_range
add eax,[edi+4]
jc dec_out_of_range
add eax,eax
jc dec_out_of_range
add eax,edx
jc dec_out_of_range
mov [edi+4],eax
movzx eax,byte [esi]
sub al,30h
jc bad_number
cmp al,9
ja bad_number
add [edi],eax
adc dword [edi+4],0
jc dec_out_of_range
next_dec_digit:
inc esi
jmp get_dec_digit
dec_out_of_range:
cmp esi,ebx
ja dec_out_of_range_finished
lods byte [esi]
cmp al,27h
je bad_number
cmp al,'_'
je bad_number
sub al,30h
jc bad_number
cmp al,9
ja bad_number
jmp dec_out_of_range
dec_out_of_range_finished:
or ebp,-1
jmp number_ok
bad_number:
pop eax
invalid_number:
mov esi,[number_start]
dec esi
not_number:
dec esi
stc
ret
get_bin_number:
xor bl,bl
get_bin_digit:
cmp esi,[number_start]
jb number_ok
movzx eax,byte [esi]
cmp al,27h
je bin_digit_skip
cmp al,'_'
je bin_digit_skip
sub al,30h
cmp al,1
ja bad_number
xor edx,edx
mov cl,bl
dec esi
cmp bl,64
je bin_out_of_range
inc bl
cmp cl,32
jae bin_digit_high
shl eax,cl
or dword [edi],eax
jmp get_bin_digit
bin_digit_high:
sub cl,32
shl eax,cl
or dword [edi+4],eax
jmp get_bin_digit
bin_out_of_range:
or al,al
jz get_bin_digit
or ebp,-1
jmp get_bin_digit
bin_digit_skip:
dec esi
jmp get_bin_digit
pascal_hex_number:
cmp cl,1
je bad_number
get_hex_number:
xor bl,bl
get_hex_digit:
cmp esi,[number_start]
jb number_ok
movzx eax,byte [esi]
cmp al,27h
je hex_digit_skip
cmp al,'_'
je hex_digit_skip
cmp al,'x'
je hex_number_ok
cmp al,'$'
je pascal_hex_ok
sub al,30h
cmp al,9
jbe hex_digit_ok
sub al,7
cmp al,15
jbe hex_letter_digit_ok
sub al,20h
cmp al,15
ja bad_number
hex_letter_digit_ok:
cmp al,10
jb bad_number
hex_digit_ok:
xor edx,edx
mov cl,bl
dec esi
cmp bl,64
je hex_out_of_range
add bl,4
cmp cl,32
jae hex_digit_high
shl eax,cl
or dword [edi],eax
jmp get_hex_digit
hex_digit_high:
sub cl,32
shl eax,cl
or dword [edi+4],eax
jmp get_hex_digit
hex_out_of_range:
or al,al
jz get_hex_digit
or ebp,-1
jmp get_hex_digit
hex_digit_skip:
dec esi
jmp get_hex_digit
get_oct_number:
xor bl,bl
get_oct_digit:
cmp esi,[number_start]
jb number_ok
movzx eax,byte [esi]
cmp al,27h
je oct_digit_skip
cmp al,'_'
je oct_digit_skip
sub al,30h
cmp al,7
ja bad_number
oct_digit_ok:
xor edx,edx
mov cl,bl
dec esi
cmp bl,63
ja oct_out_of_range
jne oct_range_ok
cmp al,1
ja oct_out_of_range
oct_range_ok:
add bl,3
cmp cl,30
je oct_digit_wrap
ja oct_digit_high
shl eax,cl
or dword [edi],eax
jmp get_oct_digit
oct_digit_wrap:
shl eax,cl
adc dword [edi+4],0
or dword [edi],eax
jmp get_oct_digit
oct_digit_high:
sub cl,32
shl eax,cl
or dword [edi+4],eax
jmp get_oct_digit
oct_digit_skip:
dec esi
jmp get_oct_digit
oct_out_of_range:
or al,al
jz get_oct_digit
or ebp,-1
jmp get_oct_digit
hex_number_ok:
dec esi
pascal_hex_ok:
cmp esi,[number_start]
jne bad_number
number_ok:
pop esi
number_done:
clc
ret
get_text_number:
lods dword [esi]
mov edx,eax
xor bl,bl
mov dword [edi],0
mov dword [edi+4],0
get_text_character:
sub edx,1
jc number_done
movzx eax,byte [esi]
inc esi
mov cl,bl
cmp bl,64
je text_out_of_range
add bl,8
cmp cl,32
jae text_character_high
shl eax,cl
or dword [edi],eax
jmp get_text_character
text_character_high:
sub cl,32
shl eax,cl
or dword [edi+4],eax
jmp get_text_character
text_out_of_range:
or ebp,-1
jmp get_text_character
get_fp_value:
push edi esi
lods byte [esi]
cmp al,1Ah
je fp_value_start
cmp al,'-'
je fp_sign_ok
cmp al,'+'
jne not_fp_value
fp_sign_ok:
lods byte [esi]
cmp al,1Ah
jne not_fp_value
fp_value_start:
lods byte [esi]
movzx ecx,al
cmp cl,1
jbe not_fp_value
lea edx,[esi+1]
xor ah,ah
check_fp_value:
lods byte [esi]
cmp al,'.'
je fp_character_dot
cmp al,'E'
je fp_character_exp
cmp al,'e'
je fp_character_exp
cmp al,'F'
je fp_last_character
cmp al,'f'
je fp_last_character
digit_expected:
cmp al,'0'
jb not_fp_value
cmp al,'9'
ja not_fp_value
jmp fp_character_ok
fp_character_dot:
cmp esi,edx
je not_fp_value
or ah,ah
jnz not_fp_value
or ah,1
lods byte [esi]
loop digit_expected
not_fp_value:
pop esi edi
stc
ret
fp_last_character:
cmp cl,1
jne not_fp_value
or ah,4
jmp fp_character_ok
fp_character_exp:
cmp esi,edx
je not_fp_value
cmp ah,1
ja not_fp_value
or ah,2
cmp ecx,1
jne fp_character_ok
cmp byte [esi],'+'
je fp_exp_sign
cmp byte [esi],'-'
jne fp_character_ok
fp_exp_sign:
inc esi
cmp byte [esi],1Ah
jne not_fp_value
inc esi
lods byte [esi]
movzx ecx,al
inc ecx
fp_character_ok:
dec ecx
jnz check_fp_value
or ah,ah
jz not_fp_value
pop esi
lods byte [esi]
mov [fp_sign],0
cmp al,1Ah
je fp_get
inc esi
cmp al,'+'
je fp_get
mov [fp_sign],1
fp_get:
lods byte [esi]
movzx ecx,al
xor edx,edx
mov edi,fp_value
mov [edi],edx
mov [edi+4],edx
mov [edi+12],edx
call fp_optimize
mov [fp_format],0
mov al,[esi]
fp_before_dot:
lods byte [esi]
cmp al,'.'
je fp_dot
cmp al,'E'
je fp_exponent
cmp al,'e'
je fp_exponent
cmp al,'F'
je fp_done
cmp al,'f'
je fp_done
sub al,30h
mov edi,fp_value+16
xor edx,edx
mov dword [edi+12],edx
mov dword [edi],edx
mov dword [edi+4],edx
mov [edi+7],al
mov dl,7
mov dword [edi+8],edx
call fp_optimize
mov edi,fp_value
push ecx
mov ecx,10
call fp_mul
pop ecx
mov ebx,fp_value+16
call fp_add
loop fp_before_dot
fp_dot:
mov edi,fp_value+16
xor edx,edx
mov [edi],edx
mov [edi+4],edx
mov byte [edi+7],80h
mov [edi+8],edx
mov dword [edi+12],edx
dec ecx
jz fp_done
fp_after_dot:
lods byte [esi]
cmp al,'E'
je fp_exponent
cmp al,'e'
je fp_exponent
cmp al,'F'
je fp_done
cmp al,'f'
je fp_done
inc [fp_format]
cmp [fp_format],80h
jne fp_counter_ok
mov [fp_format],7Fh
fp_counter_ok:
dec esi
mov edi,fp_value+16
push ecx
mov ecx,10
call fp_div
push dword [edi]
push dword [edi+4]
push dword [edi+8]
push dword [edi+12]
lods byte [esi]
sub al,30h
movzx ecx,al
call fp_mul
mov ebx,edi
mov edi,fp_value
call fp_add
mov edi,fp_value+16
pop dword [edi+12]
pop dword [edi+8]
pop dword [edi+4]
pop dword [edi]
pop ecx
dec ecx
jnz fp_after_dot
jmp fp_done
fp_exponent:
or [fp_format],80h
xor edx,edx
xor ebp,ebp
dec ecx
jnz get_exponent
cmp byte [esi],'+'
je fp_exponent_sign
cmp byte [esi],'-'
jne fp_done
not ebp
fp_exponent_sign:
add esi,2
lods byte [esi]
movzx ecx,al
get_exponent:
movzx eax,byte [esi]
inc esi
sub al,30h
cmp al,10
jae exponent_ok
imul edx,10
cmp edx,8000h
jae value_out_of_range
add edx,eax
loop get_exponent
exponent_ok:
mov edi,fp_value
or edx,edx
jz fp_done
mov ecx,edx
or ebp,ebp
jnz fp_negative_power
fp_power:
push ecx
mov ecx,10
call fp_mul
pop ecx
loop fp_power
jmp fp_done
fp_negative_power:
push ecx
mov ecx,10
call fp_div
pop ecx
loop fp_negative_power
fp_done:
mov edi,fp_value
mov al,[fp_format]
mov [edi+10],al
mov al,[fp_sign]
mov [edi+11],al
test byte [edi+15],80h
jz fp_ok
add dword [edi],1
adc dword [edi+4],0
jnc fp_ok
mov eax,[edi+4]
shrd [edi],eax,1
shr eax,1
or eax,80000000h
mov [edi+4],eax
inc word [edi+8]
fp_ok:
pop edi
clc
ret
fp_mul:
or ecx,ecx
jz fp_zero
mov eax,[edi+12]
mul ecx
mov [edi+12],eax
mov ebx,edx
mov eax,[edi]
mul ecx
add eax,ebx
adc edx,0
mov [edi],eax
mov ebx,edx
mov eax,[edi+4]
mul ecx
add eax,ebx
adc edx,0
mov [edi+4],eax
.loop:
or edx,edx
jz .done
mov eax,[edi]
shrd [edi+12],eax,1
mov eax,[edi+4]
shrd [edi],eax,1
shrd eax,edx,1
mov [edi+4],eax
shr edx,1
inc dword [edi+8]
cmp dword [edi+8],8000h
jge value_out_of_range
jmp .loop
.done:
ret
fp_div:
mov eax,[edi+4]
xor edx,edx
div ecx
mov [edi+4],eax
mov eax,[edi]
div ecx
mov [edi],eax
mov eax,[edi+12]
div ecx
mov [edi+12],eax
mov ebx,eax
or ebx,[edi]
or ebx,[edi+4]
jz fp_zero
.loop:
test byte [edi+7],80h
jnz .exp_ok
mov eax,[edi]
shld [edi+4],eax,1
mov eax,[edi+12]
shld [edi],eax,1
add eax,eax
mov [edi+12],eax
dec dword [edi+8]
add edx,edx
jmp .loop
.exp_ok:
mov eax,edx
xor edx,edx
div ecx
add [edi+12],eax
adc dword [edi],0
adc dword [edi+4],0
jnc .done
mov eax,[edi+4]
mov ebx,[edi]
shrd [edi],eax,1
shrd [edi+12],ebx,1
shr eax,1
or eax,80000000h
mov [edi+4],eax
inc dword [edi+8]
.done:
ret
fp_add:
cmp dword [ebx+8],8000h
je .done
cmp dword [edi+8],8000h
je .copy
mov eax,[ebx+8]
cmp eax,[edi+8]
jge .exp_ok
mov eax,[edi+8]
.exp_ok:
call .change_exp
xchg ebx,edi
call .change_exp
xchg ebx,edi
mov edx,[ebx+12]
mov eax,[ebx]
mov ebx,[ebx+4]
add [edi+12],edx
adc [edi],eax
adc [edi+4],ebx
jnc .done
mov eax,[edi]
shrd [edi+12],eax,1
mov eax,[edi+4]
shrd [edi],eax,1
shr eax,1
or eax,80000000h
mov [edi+4],eax
inc dword [edi+8]
.done:
ret
.copy:
mov eax,[ebx]
mov [edi],eax
mov eax,[ebx+4]
mov [edi+4],eax
mov eax,[ebx+8]
mov [edi+8],eax
mov eax,[ebx+12]
mov [edi+12],eax
ret
.change_exp:
push ecx
mov ecx,eax
sub ecx,[ebx+8]
mov edx,[ebx+4]
jecxz .exp_done
.exp_loop:
mov ebp,[ebx]
shrd [ebx+12],ebp,1
shrd [ebx],edx,1
shr edx,1
inc dword [ebx+8]
loop .exp_loop
.exp_done:
mov [ebx+4],edx
pop ecx
ret
fp_optimize:
mov eax,[edi]
mov ebp,[edi+4]
or ebp,[edi]
or ebp,[edi+12]
jz fp_zero
.loop:
test byte [edi+7],80h
jnz .done
shld [edi+4],eax,1
mov ebp,[edi+12]
shld eax,ebp,1
mov [edi],eax
shl dword [edi+12],1
dec dword [edi+8]
jmp .loop
.done:
ret
fp_zero:
mov dword [edi+8],8000h
ret
preevaluate_logical_expression:
xor al,al
preevaluate_embedded_logical_expression:
mov [logical_value_wrapping],al
push edi
call preevaluate_logical_value
preevaluation_loop:
cmp al,0FFh
je invalid_logical_expression
mov dl,[esi]
inc esi
cmp dl,'|'
je preevaluate_or
cmp dl,'&'
je preevaluate_and
cmp dl,92h
je preevaluation_done
or dl,dl
jnz invalid_logical_expression
preevaluation_done:
pop edx
dec esi
ret
preevaluate_or:
cmp al,'1'
je quick_true
cmp al,'0'
je leave_only_following
push edi
mov al,dl
stos byte [edi]
call preevaluate_logical_value
pop ebx
cmp al,'0'
je leave_only_preceding
cmp al,'1'
jne preevaluation_loop
stos byte [edi]
xor al,al
jmp preevaluation_loop
preevaluate_and:
cmp al,'0'
je quick_false
cmp al,'1'
je leave_only_following
push edi
mov al,dl
stos byte [edi]
call preevaluate_logical_value
pop ebx
cmp al,'1'
je leave_only_preceding
cmp al,'0'
jne preevaluation_loop
stos byte [edi]
xor al,al
jmp preevaluation_loop
leave_only_following:
mov edi,[esp]
call preevaluate_logical_value
jmp preevaluation_loop
leave_only_preceding:
mov edi,ebx
xor al,al
jmp preevaluation_loop
quick_true:
call skip_logical_value
jc invalid_logical_expression
mov edi,[esp]
mov al,'1'
jmp preevaluation_loop
quick_false:
call skip_logical_value
jc invalid_logical_expression
mov edi,[esp]
mov al,'0'
jmp preevaluation_loop
invalid_logical_expression:
pop edi
mov esi,edi
mov al,0FFh
stos byte [edi]
ret
skip_logical_value:
cmp byte [esi],'~'
jne negation_skipped
inc esi
jmp skip_logical_value
negation_skipped:
mov al,[esi]
cmp al,91h
jne skip_simple_logical_value
inc esi
xchg al,[logical_value_wrapping]
push eax
skip_logical_expression:
call skip_logical_value
lods byte [esi]
or al,al
jz wrongly_structured_logical_expression
cmp al,0Fh
je wrongly_structured_logical_expression
cmp al,'|'
je skip_logical_expression
cmp al,'&'
je skip_logical_expression
cmp al,92h
jne wrongly_structured_logical_expression
pop eax
mov [logical_value_wrapping],al
logical_value_skipped:
clc
ret
wrongly_structured_logical_expression:
pop eax
stc
ret
skip_simple_logical_value:
mov [logical_value_parentheses],0
find_simple_logical_value_end:
mov al,[esi]
or al,al
jz logical_value_skipped
cmp al,0Fh
je logical_value_skipped
cmp al,'|'
je logical_value_skipped
cmp al,'&'
je logical_value_skipped
cmp al,91h
je skip_logical_value_internal_parenthesis
cmp al,92h
jne skip_logical_value_symbol
sub [logical_value_parentheses],1
jnc skip_logical_value_symbol
cmp [logical_value_wrapping],91h
jne skip_logical_value_symbol
jmp logical_value_skipped
skip_logical_value_internal_parenthesis:
inc [logical_value_parentheses]
skip_logical_value_symbol:
call skip_symbol
jmp find_simple_logical_value_end
preevaluate_logical_value:
mov ebp,edi
preevaluate_negation:
cmp byte [esi],'~'
jne preevaluate_negation_ok
movs byte [edi],[esi]
jmp preevaluate_negation
preevaluate_negation_ok:
mov ebx,esi
cmp byte [esi],91h
jne preevaluate_simple_logical_value
lods byte [esi]
stos byte [edi]
push ebp
mov dl,[logical_value_wrapping]
push edx
call preevaluate_embedded_logical_expression
pop edx
mov [logical_value_wrapping],dl
pop ebp
cmp al,0FFh
je invalid_logical_value
cmp byte [esi],92h
jne invalid_logical_value
or al,al
jnz preevaluated_expression_value
movs byte [edi],[esi]
ret
preevaluated_expression_value:
inc esi
lea edx,[edi-1]
sub edx,ebp
test edx,1
jz expression_negation_ok
xor al,1
expression_negation_ok:
mov edi,ebp
ret
invalid_logical_value:
mov edi,ebp
mov al,0FFh
ret
preevaluate_simple_logical_value:
xor edx,edx
mov [logical_value_parentheses],edx
find_logical_value_boundaries:
mov al,[esi]
or al,al
jz logical_value_boundaries_found
cmp al,91h
je logical_value_internal_parentheses
cmp al,92h
je logical_value_boundaries_parenthesis_close
cmp al,'|'
je logical_value_boundaries_found
cmp al,'&'
je logical_value_boundaries_found
or edx,edx
jnz next_symbol_in_logical_value
cmp al,0F0h
je preevaluable_logical_operator
cmp al,0F7h
je preevaluable_logical_operator
cmp al,0F6h
jne next_symbol_in_logical_value
preevaluable_logical_operator:
mov edx,esi
next_symbol_in_logical_value:
call skip_symbol
jmp find_logical_value_boundaries
logical_value_internal_parentheses:
inc [logical_value_parentheses]
jmp next_symbol_in_logical_value
logical_value_boundaries_parenthesis_close:
sub [logical_value_parentheses],1
jnc next_symbol_in_logical_value
cmp [logical_value_wrapping],91h
jne next_symbol_in_logical_value
logical_value_boundaries_found:
or edx,edx
jz non_preevaluable_logical_value
mov al,[edx]
cmp al,0F0h
je compare_symbols
cmp al,0F7h
je compare_symbol_types
cmp al,0F6h
je scan_symbols_list
non_preevaluable_logical_value:
mov ecx,esi
mov esi,ebx
sub ecx,esi
jz invalid_logical_value
cmp esi,edi
je leave_logical_value_intact
rep movs byte [edi],[esi]
xor al,al
ret
leave_logical_value_intact:
add edi,ecx
add esi,ecx
xor al,al
ret
compare_symbols:
lea ecx,[esi-1]
sub ecx,edx
mov eax,edx
sub eax,ebx
cmp ecx,eax
jne preevaluated_false
push esi edi
mov esi,ebx
lea edi,[edx+1]
repe cmps byte [esi],[edi]
pop edi esi
je preevaluated_true
preevaluated_false:
mov eax,edi
sub eax,ebp
test eax,1
jnz store_true
store_false:
mov edi,ebp
mov al,'0'
ret
preevaluated_true:
mov eax,edi
sub eax,ebp
test eax,1
jnz store_false
store_true:
mov edi,ebp
mov al,'1'
ret
compare_symbol_types:
push esi
lea esi,[edx+1]
type_comparison:
cmp esi,[esp]
je types_compared
mov al,[esi]
cmp al,[ebx]
jne different_type
cmp al,'('
jne equal_type
mov al,[esi+1]
mov ah,[ebx+1]
cmp al,ah
je equal_type
or al,al
jz different_type
or ah,ah
jz different_type
cmp al,'.'
je different_type
cmp ah,'.'
je different_type
equal_type:
call skip_symbol
xchg esi,ebx
call skip_symbol
xchg esi,ebx
jmp type_comparison
types_compared:
pop esi
cmp byte [ebx],0F7h
jne preevaluated_false
jmp preevaluated_true
different_type:
pop esi
jmp preevaluated_false
scan_symbols_list:
push edi esi
lea esi,[edx+1]
sub edx,ebx
lods byte [esi]
cmp al,'<'
jne invalid_symbols_list
get_next_from_list:
mov edi,esi
get_from_list:
cmp byte [esi],','
je compare_in_list
cmp byte [esi],'>'
je compare_in_list
cmp esi,[esp]
jae invalid_symbols_list
call skip_symbol
jmp get_from_list
compare_in_list:
mov ecx,esi
sub ecx,edi
cmp ecx,edx
jne not_equal_length_in_list
mov esi,ebx
repe cmps byte [esi],[edi]
mov esi,edi
jne not_equal_in_list
skip_rest_of_list:
cmp byte [esi],'>'
je check_list_end
cmp esi,[esp]
jae invalid_symbols_list
call skip_symbol
jmp skip_rest_of_list
check_list_end:
inc esi
cmp esi,[esp]
jne invalid_symbols_list
pop esi edi
jmp preevaluated_true
not_equal_in_list:
add esi,ecx
not_equal_length_in_list:
lods byte [esi]
cmp al,','
je get_next_from_list
cmp esi,[esp]
jne invalid_symbols_list
pop esi edi
jmp preevaluated_false
invalid_symbols_list:
pop esi edi
jmp invalid_logical_value