a bit of cleanup and the good news is, we can output a (small) number

This commit is contained in:
Torsten Ruger
2014-05-16 23:24:19 +03:00
parent fee82643e5
commit a08661955f
2 changed files with 12 additions and 28 deletions

View File

@ -41,7 +41,7 @@ module Core
reg1 = Vm::Integer.new(1)
block.add_code Vm::CMachine.instance.mov( reg1 , right: str_addr ) #move arg up
block.add_code Vm::CMachine.instance.add( str_addr , left: buffer ) # string to write to
block.add_code Vm::CMachine.instance.add( str_addr , left: str_addr , right:6 ) # string to write to
block.add_code Vm::CMachine.instance.add( str_addr , left: str_addr , right: (buffer.length-3)) # string to write to
context.str_addr = str_addr
itos_fun = context.program.get_or_create_function(:utoa)
block.add_code Vm::CMachine.instance.call( itos_fun , {})
@ -49,32 +49,26 @@ module Core
block.add_code Vm::CMachine.instance.add( str_addr , left: buffer ) # string to write to
block.add_code Vm::CMachine.instance.mov( reg1 , right: buffer.length )
ret = Vm::CMachine.instance.write_stdout(block)
# function.return_type = ret
function
end
# The conversion to base10 is quite a bit more complicated than i thought. The bulk of it is in div10
# We set up variables, do the devision and write the result to the string
# then check if were done and recurse if neccessary
# As we write before we recurse (save a push) we write the number backwards
def utoa context
function = Vm::Function.new(:utoa , [Vm::Integer , Vm::Integer ] )
block = function.body
str_addr = context.str_addr
number = Vm::Integer.new(str_addr.register + 1)
remainder = Vm::Integer.new( number.register + 1)
#STMFD sp!, {r9, r10, lr} #function entry save working regs (for recursion)
#automatic block.add_code push( [:lr ] , {} ) #and the return address.
# MOV r9, r1 # preserve arguments over following
# MOV r10, r2 # function calls
# BL udiv10 # r1 = r1 / 10
Vm::CMachine.instance.div10( block , number , remainder )
# ADD r10, r10, 48 #'0' # make char out of digit (by using ascii encoding)
# make char out of digit (by using ascii encoding) 48 == "0"
block.add_code Vm::CMachine.instance.add( remainder , left: remainder , right: 48 )
#STRB r10, [r1], 1 # store digit at end of buffer
# block.add_code Vm::CMachine.instance.strb( remainder , right: str_addr, offset: 1 , flagie: 1)
block.add_code Vm::CMachine.instance.strb( remainder, right: str_addr , :offset => -1 , flaggie: 1) # CMP r1, #0 # quotient non-zero?
block.add_code Vm::CMachine.instance.strb( remainder, right: str_addr )
block.add_code Vm::CMachine.instance.sub( str_addr, left: str_addr , right: 1 )
block.add_code Vm::CMachine.instance.cmp( number , right: 0 )
#BLNE utoa # conditional recursive call to utoa
block.add_code Vm::CMachine.instance.callne( function , {} )
#LDMFD sp!, {r9, r10, pc} # function exit - restore and return
#automatic block.add_code pop( [:pc] , {} )
return function
end
end