coding the weird udiv10 and utoa

This commit is contained in:
Torsten Ruger
2014-05-16 19:55:46 +03:00
parent 823c11a381
commit b3f7b66ceb
2 changed files with 37 additions and 48 deletions

View File

@ -37,11 +37,42 @@ module Core
block = function.body
buffer = Vm::StringConstant.new(" ")
context.program.add_object buffer
# should be another level of indirection, ie write(io,str)
ret = Vm::CMachine.instance.integer_to_s(block , buffer)
function.return_type = ret
str_addr = Vm::Integer.new(0) # address of the
block.add_code Vm::CMachine.instance.mov( str_addr , right: Vm::Integer.new(1)) #move arg up
block.add_code Vm::CMachine.instance.add( str_addr , left: buffer) # 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 , {})
# function.return_type = ret
function
end
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)
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 ) #and increment TODO check
# CMP r1, #0 # quotient non-zero?
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
extend ClassMethods