def make_int_graph(cfg):
liveouts = flow.get_lives(cfg)
g = {}
for n in cfg.vertices.keys():
inst = cfg.inst(n)
if type(inst) != IR:
continue
defed = cfg.def_(n)
uninterfered = [defed]
if defed is None:
continue
if inst.opcode == 'move':
uninterfered.append(inst.rs)
if defed.typ != 'virtual':
continue
if defed not in g:
g[defed] = set()
for reg in liveouts[n]:
if reg in uninterfered or reg.typ != 'virtual':
continue
g[defed].add(reg)
if reg not in g:
g[reg] = set()
g[reg].add(defed)
return g, liveouts
def remove_placeholders(self):
'''
replace Prolog/Epilog/SaveRegisters/RestoreRegisters with real instructions
now that we know what registers are used
'''
cfg = flow.make_cfg(self.insts)
outs = flow.get_lives(cfg)
# t registers that need to be saved
tregs = []
for node in sorted(cfg.get_calls()):
tregs.append(sorted({reg for reg in outs[node]
if reg.typ == 't'}))
space = (max(len(regs) for regs in tregs) * 4
if len(tregs) > 0
else 0)
t_offset = self.alloc(size=space)
s_offset = self.alloc(size=len(self.sregs)*4+4)
# replace prologs/epilogs with stores and loads
insts = []
i = 0
if i < len(tregs):
regs = tregs[i]
i += 1
for inst in self.insts:
inst_type = type(inst)
if inst_type == Call:
store_regs(regs, t_offset, insts)
insts.append(
new_ir('add', rd=REG_SP, rs=REG_SP, rt=grammar.Int(-mulof4(inst.extra))))
insts.append(new_ir('jal', rs=funcname_to_branch(inst.name), rt=None, rd=None))
insts.append(
new_ir('add', rd=REG_SP, rs=REG_SP, rt=grammar.Int(mulof4(inst.extra))))
load_regs(regs, t_offset, insts)
if i < len(tregs):
regs = tregs[i]
i += 1
elif inst_type == Prolog:
# grow stack and store needed s registers
grow = new_ir('add',
rd=REG_SP,
rs=REG_SP,
rt=grammar.Int(-self.stack_size()))
insts.extend([
new_ir('move', rd=REG_FP, rs=REG_SP, rt=None),
grow
])
store_regs(self.sregs+[REG_RA], s_offset, insts)
elif inst_type == Epilog:
# restore used registers
load_regs(self.sregs+[REG_RA], s_offset, insts)
shrink = new_ir('add',
rd=REG_SP,
rs=REG_SP,
rt=grammar.Int(self.stack_size()))
insts.extend([
shrink,
new_ir('jr', rs=Register('ra', None), rt=None, rd=None)
])
else:
insts.append(inst)
self.insts = insts
def remove_placeholders(self):
'''
replace Prolog/Epilog/SaveRegisters/RestoreRegisters with real instructions
now that we know what registers are used
'''
cfg = flow.make_cfg(self.insts)
outs = flow.get_lives(cfg)
# t registers that need to be saved
tregs = []
for node in sorted(cfg.get_calls()):
tregs.append(sorted({reg for reg in outs[node] if reg.typ == 't'}))
space = (max(len(regs) for regs in tregs) * 4 if len(tregs) > 0 else 0)
t_offset = self.alloc(size=space)
s_offset = self.alloc(size=len(self.sregs) * 4 + 4)
# replace prologs/epilogs with stores and loads
insts = []
i = 0
if i < len(tregs):
regs = tregs[i]
i += 1
for inst in self.insts:
inst_type = type(inst)
if inst_type == Call:
store_regs(regs, t_offset, insts)
insts.append(
new_ir('add',
rd=REG_SP,
rs=REG_SP,
rt=grammar.Int(-mulof4(inst.extra))))
insts.append(
new_ir('jal',
rs=funcname_to_branch(inst.name),
rt=None,
rd=None))
insts.append(
new_ir('add',
rd=REG_SP,
rs=REG_SP,
rt=grammar.Int(mulof4(inst.extra))))
load_regs(regs, t_offset, insts)
if i < len(tregs):
regs = tregs[i]
i += 1
elif inst_type == Prolog:
# grow stack and store needed s registers
grow = new_ir('add',
rd=REG_SP,
rs=REG_SP,
rt=grammar.Int(-self.stack_size()))
insts.extend(
[new_ir('move', rd=REG_FP, rs=REG_SP, rt=None), grow])
store_regs(self.sregs + [REG_RA], s_offset, insts)
elif inst_type == Epilog:
# restore used registers
load_regs(self.sregs + [REG_RA], s_offset, insts)
shrink = new_ir('add',
rd=REG_SP,
rs=REG_SP,
rt=grammar.Int(self.stack_size()))
insts.extend([
shrink,
new_ir('jr', rs=Register('ra', None), rt=None, rd=None)
])
else:
insts.append(inst)
self.insts = insts