def _write_bit(ctx, i, base_index, offset_index, bit):
if operand.is_memory(ctx, i, base_index):
# nasty case, indexing into in-memory bitstring; offset can be
# > word_size
base = operand.get_address(ctx, i, base_index)
offset = operand.get(ctx, i, offset_index)
offset_sign = ctx.tmp(8)
byte_offset = ctx.tmp(base.size)
tmp0 = ctx.tmp(offset.size)
byte = ctx.tmp(8)
bitmask = ctx.tmp(8)
ctx.emit(and_(offset, imm(sign_bit(offset.size), offset.size), tmp0))
ctx.emit(bisnz_(tmp0, offset_sign))
ctx.emit(and_(offset, imm(~sign_bit(offset.size), offset.size),
offset))
ctx.emit(div_(offset, imm(8, offset.size), byte_offset))
ctx.emit(mod_(offset, imm(8, offset.size), offset))
ctx.emit(jcc_(offset_sign, 'negative_offset'))
ctx.emit(add_(base, byte_offset, base))
ctx.emit(jcc_(imm(1, 8), 'base_calculated'))
ctx.emit('negative_offset')
ctx.emit(sub_(base, byte_offset, base))
ctx.emit('base_calculated')
ctx.emit(ldm_(base, byte))
ctx.emit(lshl_(imm(1, 8), offset, bitmask))
ctx.emit(xor_(bitmask, imm(mask(8), 8), bitmask))
ctx.emit(and_(byte, bitmask, byte))
ctx.emit(lshl_(bit, offset, bitmask))
ctx.emit(or_(byte, bit, byte))
ctx.emit(stm_(byte, base))
else:
# simple case, it's a register
a = operand.get(ctx, i, base_index)
offset = operand.get(ctx, i, offset_index)
bitmask = ctx.tmp(a.size)
tmp0 = ctx.tmp(a.size)
tmp1 = ctx.tmp(a.size)
ctx.emit(lshl_(imm(1, a.size), offset, bitmask))
ctx.emit(xor_(bitmask, imm(mask(a.size), a.size), bitmask))
ctx.emit(and_(a, bitmask, tmp0))
ctx.emit(str_(bit, tmp1))
ctx.emit(lshl_(tmp1, offset, tmp1))
ctx.emit(or_(tmp0, tmp1, tmp1))
operand.set(ctx, i, base_index, tmp1)
def _write_bit(ctx, i, base_index, offset_index, bit):
if operand.is_memory(ctx, i, base_index):
# nasty case, indexing into in-memory bitstring; offset can be
# > word_size
base = operand.get_address(ctx, i, base_index)
offset = operand.get(ctx, i, offset_index)
offset_sign = ctx.tmp(8)
byte_offset = ctx.tmp(base.size)
tmp0 = ctx.tmp(offset.size)
byte = ctx.tmp(8)
bitmask = ctx.tmp(8)
ctx.emit( and_ (offset, imm(sign_bit(offset.size), offset.size), tmp0))
ctx.emit( bisnz_(tmp0, offset_sign))
ctx.emit( and_ (offset, imm(~sign_bit(offset.size), offset.size), offset))
ctx.emit( div_ (offset, imm(8, offset.size), byte_offset))
ctx.emit( mod_ (offset, imm(8, offset.size), offset))
ctx.emit( jcc_ (offset_sign, 'negative_offset'))
ctx.emit( add_ (base, byte_offset, base))
ctx.emit( jcc_ (imm(1, 8), 'base_calculated'))
ctx.emit('negative_offset')
ctx.emit( sub_ (base, byte_offset, base))
ctx.emit('base_calculated')
ctx.emit( ldm_ (base, byte))
ctx.emit( lshl_ (imm(1, 8), offset, bitmask))
ctx.emit( xor_ (bitmask, imm(mask(8), 8), bitmask))
ctx.emit( and_ (byte, bitmask, byte))
ctx.emit( lshl_ (bit, offset, bitmask))
ctx.emit( or_ (byte, bit, byte))
ctx.emit( stm_ (byte, base))
else:
# simple case, it's a register
a = operand.get(ctx, i, base_index)
offset = operand.get(ctx, i, offset_index)
bitmask = ctx.tmp(a.size)
tmp0 = ctx.tmp(a.size)
tmp1 = ctx.tmp(a.size)
ctx.emit( lshl_ (imm(1, a.size), offset, bitmask))
ctx.emit( xor_ (bitmask, imm(mask(a.size), a.size), bitmask))
ctx.emit( and_ (a, bitmask, tmp0))
ctx.emit( str_ (bit, tmp1))
ctx.emit( lshl_ (tmp1, offset, tmp1))
ctx.emit( or_ (tmp0, tmp1, tmp1))
operand.set(ctx, i, base_index, tmp1)
def x86_lea(ctx, i):
address = operand.get_address(ctx, i, 1)
operand.set(ctx, i, 0, address, clear=True)
