def p_if_end(p):
'''
if_end :
'''
label_index = codegen.pop_label_stack()
l1 = Factor(Scope.LOCAL, val=f"if.end.{label_index}")
codegen.push_code(llvmcodes.LLVMCodeBrUncond(l1))
codegen.push_code(llvmcodes.LLVMCodeRegisterLabel(f"if.end.{label_index}"))
def p_while_init(p):
'''
while_init :
'''
label_index = codegen.label_index()
l_init = Factor(Scope.LOCAL, val=f"while.init.{label_index}")
codegen.push_code(llvmcodes.LLVMCodeBrUncond(l_init))
codegen.push_code(llvmcodes.LLVMCodeRegisterLabel(f"while.init.{label_index}"))
def p_for_end(p):
'''
for_end :
'''
# statement 終了後は強制的に for.condition に戻して n < range_to を評価する
label_index = codegen.pop_label_stack()
l_cond = Factor(Scope.LOCAL, val=f"for.condition.{label_index}")
codegen.push_code(llvmcodes.LLVMCodeBrUncond(l_cond))
codegen.push_code(llvmcodes.LLVMCodeRegisterLabel(f"for.end.{label_index}"))
def p_for_init(p):
'''
for_init :
'''
# for n:= 2 to 100
# ↓
# for ident := range_from to range_to
ident = latest_id_name(p)
range_to = codegen.pop_factor()
range_from = codegen.pop_factor()
var = parse_variable(ident)
label_index = codegen.label_index()
# n := 2
codegen.push_code(llvmcodes.LLVMCodeStore(range_from, var))
# 初期化時は無条件で statement に移動
l_body = Factor(Scope.LOCAL, val=f"for.body.{label_index}")
codegen.push_code(llvmcodes.LLVMCodeBrUncond(l_body))
# statement が終わったあとに戻ってくる for.condition のポイントを作成
codegen.push_code(llvmcodes.LLVMCodeRegisterLabel(f"for.condition.{label_index}"))
# n++
## n をレジスタに読み込み
reg_ident = Factor(Scope.LOCAL, val=codegen.register())
codegen.push_code(llvmcodes.LLVMCodeLoad(reg_ident, var))
## n + 1
one = Factor(Scope.CONSTANT, val=1)
reg_ident_increased = Factor(Scope.LOCAL, val=codegen.register())
codegen.push_code(llvmcodes.LLVMCodeAdd(reg_ident, one, reg_ident_increased))
## レジスタの内容を n に戻す
codegen.push_code(llvmcodes.LLVMCodeStore(reg_ident_increased, var))
# n が range_from に到達したかのチェック
## n <= range_to
cond = Factor(Scope.LOCAL, val=codegen.register())
codegen.push_code(llvmcodes.LLVMCodeIcmp(llvmcodes.CmpType.SLE, reg_ident_increased, range_to, cond))
l_end = Factor(Scope.LOCAL, val=f"for.end.{label_index}")
codegen.push_code(llvmcodes.LLVMCodeBrCond(cond, l_body, l_end))
codegen.push_code(llvmcodes.LLVMCodeRegisterLabel(f"for.body.{label_index}"))
def p_if_condition(p):
'''
if_condition :
'''
label_index = codegen.label_index()
cond = codegen.pop_factor()
l1 = Factor(Scope.LOCAL, val=f"if.true.{label_index}")
l2 = Factor(Scope.LOCAL, val=f"if.else.{label_index}")
codegen.push_code(llvmcodes.LLVMCodeBrCond(cond, l1, l2))
codegen.push_code(llvmcodes.LLVMCodeRegisterLabel(f"if.true.{label_index}"))
def p_while_condition(p):
'''
while_condition :
'''
label_index = codegen.pop_label_stack(keep=True)
cond = codegen.pop_factor()
l1 = Factor(Scope.LOCAL, val=f"while.body.{label_index}")
l2 = Factor(Scope.LOCAL, val=f"while.end.{label_index}")
codegen.push_code(llvmcodes.LLVMCodeBrCond(cond, l1, l2))
codegen.push_code(llvmcodes.LLVMCodeRegisterLabel(f"while.body.{label_index}"))