def test_various_nans(self):
# check patterns that should preserve the mantissa across nan conversions
maxmant64 = (1 << 52) - 1 # maximum double mantissa
maxmant16 = (1 << 10) - 1 # maximum float16 mantissa
assert maxmant64 >> 42 == maxmant16
exp = 0xfff << 52
for i in range(20):
val_to_preserve = exp | ((maxmant16 - i) << 42)
a = ieee.float_unpack(val_to_preserve, 8)
assert isnan(a), 'i %d, maxmant %s' % (i, hex(val_to_preserve))
b = ieee.float_pack(a, 8)
assert b == val_to_preserve, 'i %d, val %s b %s' % (i, hex(val_to_preserve), hex(b))
b = ieee.float_pack(a, 2)
assert b == 0xffff - i, 'i %d, b%s' % (i, hex(b))
def test_various_nans(self):
# check patterns that should preserve the mantissa across nan conversions
maxmant64 = (1 << 52) - 1 # maximum double mantissa
maxmant16 = (1 << 10) - 1 # maximum float16 mantissa
assert maxmant64 >> 42 == maxmant16
exp = 0xfff << 52
for i in range(20):
val_to_preserve = exp | ((maxmant16 - i) << 42)
a = ieee.float_unpack(val_to_preserve, 8)
assert isnan(a), 'i %d, maxmant %s' % (i, hex(val_to_preserve))
b = ieee.float_pack(a, 8)
assert b == val_to_preserve, 'i %d, val %s b %s' % (
i, hex(val_to_preserve), hex(b))
b = ieee.float_pack(a, 2)
assert b == 0xffff - i, 'i %d, b%s' % (i, hex(b))
def test_halffloat_inexact(self):
# testcases generated from numpy.float16(x).view('uint16')
cases = [[10.001, 18688, 10.0], [-10.001, 51456, -10], [0.027588, 10000, 0.027587890625], [22001, 30047, 22000]]
for c, h, f in cases:
hbit = ieee.float_pack(c, 2)
assert hbit == h
assert f == ieee.float_unpack(h, 2)
def test_halffloat_exact(self):
# testcases generated from numpy.float16(x).view('uint16')
cases = [[0, 0], [10, 18688], [-10, 51456], [10e3, 28898], [float("inf"), 31744], [-float("inf"), 64512]]
for c, h in cases:
hbit = ieee.float_pack(c, 2)
assert hbit == h
assert c == ieee.float_unpack(h, 2)
def check_float(self, x):
# check roundtrip
for size in [10, 12, 16]:
for be in [False, True]:
Q = []
ieee.pack_float80(Q, x, size, be)
Q = Q[0]
y = ieee.unpack_float80(Q, be)
assert repr(x) == repr(y), '%r != %r, Q=%r' % (x, y, Q)
for be in [False, True]:
Q = []
ieee.pack_float(Q, x, 8, be)
Q = Q[0]
y = ieee.unpack_float(Q, be)
assert repr(x) == repr(y), '%r != %r, Q=%r' % (x, y, Q)
# check that packing agrees with the struct module
struct_pack8 = struct.unpack('<Q', struct.pack('<d', x))[0]
float_pack8 = ieee.float_pack(x, 8)
assert struct_pack8 == float_pack8
# check that packing agrees with the struct module
try:
struct_pack4 = struct.unpack('<L', struct.pack('<f', x))[0]
except OverflowError:
struct_pack4 = "overflow"
try:
float_pack4 = ieee.float_pack(x, 4)
except OverflowError:
float_pack4 = "overflow"
assert struct_pack4 == float_pack4
if float_pack4 == "overflow":
return
# if we didn't overflow, try round-tripping the binary32 value
roundtrip = ieee.float_pack(ieee.float_unpack(float_pack4, 4), 4)
assert float_pack4 == roundtrip
try:
float_pack2 = ieee.float_pack(x, 2)
except OverflowError:
return
roundtrip = ieee.float_pack(ieee.float_unpack(float_pack2, 2), 2)
assert (float_pack2, x) == (roundtrip, x)
def check_float(self, x):
# check roundtrip
for size in [10, 12, 16]:
for be in [False, True]:
Q = []
ieee.pack_float80(Q, x, size, be)
Q = Q[0]
y = ieee.unpack_float80(Q, be)
assert repr(x) == repr(y), '%r != %r, Q=%r' % (x, y, Q)
for be in [False, True]:
Q = []
ieee.pack_float(Q, x, 8, be)
Q = Q[0]
y = ieee.unpack_float(Q, be)
assert repr(x) == repr(y), '%r != %r, Q=%r' % (x, y, Q)
# check that packing agrees with the struct module
struct_pack8 = struct.unpack('<Q', struct.pack('<d', x))[0]
float_pack8 = ieee.float_pack(x, 8)
assert struct_pack8 == float_pack8
# check that packing agrees with the struct module
try:
struct_pack4 = struct.unpack('<L', struct.pack('<f', x))[0]
except OverflowError:
struct_pack4 = "overflow"
try:
float_pack4 = ieee.float_pack(x, 4)
except OverflowError:
float_pack4 = "overflow"
assert struct_pack4 == float_pack4
if float_pack4 == "overflow":
return
# if we didn't overflow, try round-tripping the binary32 value
roundtrip = ieee.float_pack(ieee.float_unpack(float_pack4, 4), 4)
assert float_pack4 == roundtrip
try:
float_pack2 = ieee.float_pack(x, 2)
except OverflowError:
return
roundtrip = ieee.float_pack(ieee.float_unpack(float_pack2, 2), 2)
assert (float_pack2, x) == (roundtrip, x)
def test_halffloat_exact(self):
#testcases generated from numpy.float16(x).view('uint16')
cases = [[0, 0], [10, 18688], [-10, 51456], [10e3, 28898],
[float('inf'), 31744], [-float('inf'), 64512]]
for c, h in cases:
hbit = ieee.float_pack(c, 2)
assert hbit == h
assert c == ieee.float_unpack(h, 2)
def test_halffloat_inexact(self):
#testcases generated from numpy.float16(x).view('uint16')
cases = [[10.001, 18688, 10.], [-10.001, 51456, -10],
[0.027588, 10000, 0.027587890625], [22001, 30047, 22000]]
for c, h, f in cases:
hbit = ieee.float_pack(c, 2)
assert hbit == h
assert f == ieee.float_unpack(h, 2)
def fetch(self, space, n0):
from rpython.rlib.rstruct.ieee import float_pack
r = float_pack(self.value, 8) # C double
if n0 == 0:
return space.wrap_uint(r_uint(intmask(r >> 32)))
else:
# bounds-check for primitive access is done in the primitive
assert n0 == 1
return space.wrap_uint(r_uint(intmask(r)))
def store(self, space, n0, w_obj):
uint = r_ulonglong(space.unwrap_uint(w_obj))
r = float_pack(self.getvalue(), 8)
if n0 == 0:
r = ((r << 32) >> 32) | (uint << 32)
else:
assert n0 == 1
r = ((r >> 32) << 32) | uint
self.value = float_unpack(r, 8)
def store(self, space, n0, w_obj):
uint = r_ulonglong(space.unwrap_uint(w_obj))
r = float_pack(self.getvalue(), 8)
if n0 == 0:
r = ((r << 32) >> 32) | (uint << 32)
else:
assert n0 == 1
r = ((r >> 32) << 32) | uint
self.value = float_unpack(r, 8)
def test_halffloat_overunderflow(self):
cases = [[670000, float('inf')], [-67000, -float('inf')], [1e-08, 0],
[-1e-8, -0.]]
for f1, f2 in cases:
try:
f_out = ieee.float_unpack(ieee.float_pack(f1, 2), 2)
except OverflowError:
f_out = math.copysign(float('inf'), f1)
assert f_out == f2
assert math.copysign(1., f_out) == math.copysign(1., f2)
def test_halffloat_overunderflow(self):
import math
cases = [[670000, float('inf')], [-67000, -float('inf')],
[1e-08, 0], [-1e-8, -0.]]
for f1, f2 in cases:
try:
f_out = ieee.float_unpack(ieee.float_pack(f1, 2), 2)
except OverflowError:
f_out = math.copysign(float('inf'), f1)
assert f_out == f2
assert math.copysign(1., f_out) == math.copysign(1., f2)
def store(self, space, n0, w_obj):
from rpython.rlib.rstruct.ieee import float_unpack, float_pack
from rpython.rlib.rarithmetic import r_ulonglong
uint = r_ulonglong(space.unwrap_uint(w_obj))
r = float_pack(self.value, 8)
if n0 == 0:
r = ((r << 32) >> 32) | (uint << 32)
else:
assert n0 == 1
r = ((r >> 32) << 32) | uint
self.value = float_unpack(r, 8)
def pack_float(space, packer, repetitions):
if repetitions > len(packer.args_w) - packer.args_index:
raise space.error(space.w_ArgumentError, "too few arguments")
for i in xrange(packer.args_index, repetitions + packer.args_index):
w_item = packer.args_w[i]
if not (isinstance(w_item, W_FloatObject) or isinstance(w_item, W_FixnumObject)):
raise space.error(space.w_TypeError,
"can't convert %s into Float" % space.obj_to_s(space.getclass(w_item))
)
doubleval = space.float_w(w_item)
l = ["\0"] * size
try:
unsigned = float_pack(doubleval, size)
except OverflowError:
unsigned = float_pack(rfloat.copysign(rfloat.INFINITY, doubleval), size)
for i in xrange(size):
l[i] = chr((unsigned >> (i * 8)) & 0xff)
if bigendian:
l.reverse()
packer.result.extend(l)
packer.args_index += repetitions
def fetch(self, space, n0):
r = float_pack(self.getvalue(), 8) # C double
if n0 == 0:
return space.wrap_int(r_uint32(intmask(r >> 32)))
else:
# bounds-check for primitive access is done in the primitive
assert n0 == 1
if constants.IS_64BIT:
# mask the bits above 32
return space.wrap_int(r_uint32(intmask(r & 0xffffffff)))
else:
return space.wrap_int(r_uint32(intmask(r)))
def fetch(self, space, n0):
r = float_pack(self.getvalue(), 8) # C double
if n0 == 0:
return space.wrap_int(r_uint32(intmask(r >> 32)))
else:
# bounds-check for primitive access is done in the primitive
assert n0 == 1
if constants.IS_64BIT:
# mask the bits above 32
return space.wrap_int(r_uint32(intmask(r & 0xffffffff)))
else:
return space.wrap_int(r_uint32(intmask(r)))
def pack_float(space, packer, repetitions):
if repetitions > len(packer.args_w) - packer.args_index:
raise space.error(space.w_ArgumentError, "too few arguments")
for i in xrange(packer.args_index, repetitions + packer.args_index):
w_item = packer.args_w[i]
if not (isinstance(w_item, W_FloatObject) or isinstance(w_item, W_FixnumObject)):
raise space.error(space.w_TypeError,
"can't convert %s into Float" % space.obj_to_s(space.getclass(w_item))
)
doubleval = space.float_w(w_item)
l = ["\0"] * size
try:
unsigned = float_pack(doubleval, size)
except OverflowError:
unsigned = float_pack(math.copysign(special_value.INF, doubleval), size)
for i in xrange(size):
l[i] = chr((unsigned >> (i * 8)) & 0xff)
if bigendian:
l.reverse()
packer.result.extend(l)
packer.args_index += repetitions
def float2bits(flt):
#data_str = struct.pack ( 'f', flt )
#bits = struct.unpack( 'I', data_str )[0]
# float_pack returns an r_int rather than an int, must cast it or
# arithmetic operations behave differently!
try:
bits = trim(intmask(ieee.float_pack(flt, 4)))
# float_pack also will throw an OverflowError if the computed value
# won't fit in the expected number of bytes, catch this and return
# the encoding for inf/-inf
except OverflowError:
bits = 0x7f800000 if flt > 0 else 0xff800000
return bits
def toBytes(self):
# float_pack() takes a double and gives us the packed integer; we need
# to reinterpret it as packed ASCII and repack into bytes.
x = float_pack(self._d, 8)
return "".join([chr(x >> ((7 - i) * 8) & 0xff) for i in range(8)])
def setvalue(self, v):
# This will only be called if we `become' a W_MutableFloat, should be rare
r = float_pack(v, 8)
# just shift and mask
self.high = r_uint32(r >> 32)
self.low = r_uint32(r)
def toBytes(self):
# float_pack() takes a double and gives us the packed integer; we need
# to reinterpret it as packed ASCII and repack into bytes.
x = float_pack(self._d, 8)
return "".join([chr(x >> ((7 - i) * 8) & 0xff) for i in range(8)])
def setvalue(self, v):
# This will only be called if we `become' a W_MutableFloat, should be rare
r = float_pack(v, 8)
# just shift and mask
self.high = r_uint32(r >> 32)
self.low = r_uint32(r)
