rubyx/stash/vm/method_compiler/if_statement.rb
Torsten Ruger 5fe0ba06ab stash old vm
moving on to getting mom to work and can’t have both
interpreter and elf broke, about 100 tests  went
2018-03-11 17:02:42 +05:30

42 lines
1.2 KiB
Ruby

module Vm
module IfStatement
# an if evaluates the condition and jumps to the true block if true
# so the else block is automatically after that.
# But then the else needs to jump over the true block unconditionally.
def on_IfStatement( statement )
# branch_type , condition , if_true , if_false = *statement
true_block = compile_if_condition( statement )
merge = compile_if_false( statement )
add_code true_block
compile_if_true(statement)
add_code merge
nil # statements don't return anything
end
private
def compile_if_condition( statement )
reset_regs
process(statement.condition)
branch_class = Object.const_get "Risc::Is#{statement.branch_type.capitalize}"
true_block = Risc.label(statement, "if_true")
add_code branch_class.new( statement.condition , true_block )
return true_block
end
def compile_if_true( statement )
reset_regs
process(statement.if_true)
end
def compile_if_false( statement )
reset_regs
process(statement.if_false) if statement.if_false.statements
merge = Risc.label(statement , "if_merge")
add_code Risc::Branch.new(statement.if_false, merge )
merge
end
end
end