def emit_atomic_update(self, codegen_state, lhs_atomicity, lhs_var,
lhs_expr, rhs_expr, lhs_dtype, rhs_type_context):
from pymbolic.mapper.stringifier import PREC_NONE
# FIXME: Could detect operations, generate atomic_{add,...} when
# appropriate.
if isinstance(lhs_dtype, NumpyType) and lhs_dtype.numpy_dtype in [
np.int32, np.int64, np.float32, np.float64
]:
from cgen import Block, DoWhile, Assign
from loopy.target.c import POD
old_val_var = codegen_state.var_name_generator("loopy_old_val")
new_val_var = codegen_state.var_name_generator("loopy_new_val")
from loopy.kernel.data import TemporaryVariable, AddressSpace
ecm = codegen_state.expression_to_code_mapper.with_assignments({
old_val_var:
TemporaryVariable(old_val_var, lhs_dtype),
new_val_var:
TemporaryVariable(new_val_var, lhs_dtype),
})
lhs_expr_code = ecm(lhs_expr, prec=PREC_NONE, type_context=None)
from pymbolic.mapper.substitutor import make_subst_func
from pymbolic import var
from loopy.symbolic import SubstitutionMapper
subst = SubstitutionMapper(
make_subst_func({lhs_expr: var(old_val_var)}))
rhs_expr_code = ecm(subst(rhs_expr),
prec=PREC_NONE,
type_context=rhs_type_context,
needed_dtype=lhs_dtype)
if lhs_dtype.numpy_dtype.itemsize == 4:
func_name = "atomic_cmpxchg"
elif lhs_dtype.numpy_dtype.itemsize == 8:
func_name = "atom_cmpxchg"
else:
raise LoopyError("unexpected atomic size")
cast_str = ""
old_val = old_val_var
new_val = new_val_var
if lhs_dtype.numpy_dtype.kind == "f":
if lhs_dtype.numpy_dtype == np.float32:
ctype = "int"
elif lhs_dtype.numpy_dtype == np.float64:
ctype = "long"
else:
assert False
from loopy.kernel.data import (TemporaryVariable, ArrayArg)
if (isinstance(lhs_var, ArrayArg)
and lhs_var.address_space == AddressSpace.GLOBAL):
var_kind = "__global"
elif (isinstance(lhs_var, ArrayArg)
and lhs_var.address_space == AddressSpace.LOCAL):
var_kind = "__local"
elif (isinstance(lhs_var, TemporaryVariable)
and lhs_var.address_space == AddressSpace.LOCAL):
var_kind = "__local"
elif (isinstance(lhs_var, TemporaryVariable)
and lhs_var.address_space == AddressSpace.GLOBAL):
var_kind = "__global"
else:
raise LoopyError("unexpected kind of variable '%s' in "
"atomic operation: " %
(lhs_var.name, type(lhs_var).__name__))
old_val = "*(%s *) &" % ctype + old_val
new_val = "*(%s *) &" % ctype + new_val
cast_str = "(%s %s *) " % (var_kind, ctype)
return Block([
POD(self, NumpyType(lhs_dtype.dtype, target=self.target),
old_val_var),
POD(self, NumpyType(lhs_dtype.dtype, target=self.target),
new_val_var),
DoWhile(
"%(func_name)s("
"%(cast_str)s&(%(lhs_expr)s), "
"%(old_val)s, "
"%(new_val)s"
") != %(old_val)s" % {
"func_name": func_name,
"cast_str": cast_str,
"lhs_expr": lhs_expr_code,
"old_val": old_val,
"new_val": new_val,
},
Block([
Assign(old_val_var, lhs_expr_code),
Assign(new_val_var, rhs_expr_code),
]))
])
else:
raise NotImplementedError("atomic update for '%s'" % lhs_dtype)
def emit_atomic_update(self, codegen_state, lhs_atomicity, lhs_var,
lhs_expr, rhs_expr, lhs_dtype, rhs_type_context):
from pymbolic.primitives import Sum
from cgen import Statement
from pymbolic.mapper.stringifier import PREC_NONE
if isinstance(lhs_dtype, NumpyType) and lhs_dtype.numpy_dtype in [
np.int32, np.int64, np.float32, np.float64
]:
# atomicAdd
if isinstance(rhs_expr, Sum):
ecm = self.get_expression_to_code_mapper(codegen_state)
new_rhs_expr = Sum(
tuple(c for c in rhs_expr.children if c != lhs_expr))
lhs_expr_code = ecm(lhs_expr)
rhs_expr_code = ecm(new_rhs_expr)
return Statement("atomicAdd(&{}, {})".format(
lhs_expr_code, rhs_expr_code))
else:
from cgen import Block, DoWhile, Assign
from loopy.target.c import POD
old_val_var = codegen_state.var_name_generator("loopy_old_val")
new_val_var = codegen_state.var_name_generator("loopy_new_val")
from loopy.kernel.data import TemporaryVariable
ecm = codegen_state.expression_to_code_mapper.with_assignments(
{
old_val_var: TemporaryVariable(old_val_var, lhs_dtype),
new_val_var: TemporaryVariable(new_val_var, lhs_dtype),
})
lhs_expr_code = ecm(lhs_expr,
prec=PREC_NONE,
type_context=None)
from pymbolic.mapper.substitutor import make_subst_func
from pymbolic import var
from loopy.symbolic import SubstitutionMapper
subst = SubstitutionMapper(
make_subst_func({lhs_expr: var(old_val_var)}))
rhs_expr_code = ecm(subst(rhs_expr),
prec=PREC_NONE,
type_context=rhs_type_context,
needed_dtype=lhs_dtype)
cast_str = ""
old_val = old_val_var
new_val = new_val_var
if lhs_dtype.numpy_dtype.kind == "f":
if lhs_dtype.numpy_dtype == np.float32:
ctype = "int"
elif lhs_dtype.numpy_dtype == np.float64:
ctype = "long"
else:
raise AssertionError()
old_val = "*(%s *) &" % ctype + old_val
new_val = "*(%s *) &" % ctype + new_val
cast_str = "(%s *) " % (ctype)
return Block([
POD(self, NumpyType(lhs_dtype.dtype, target=self.target),
old_val_var),
POD(self, NumpyType(lhs_dtype.dtype, target=self.target),
new_val_var),
DoWhile(
"atomicCAS("
"%(cast_str)s&(%(lhs_expr)s), "
"%(old_val)s, "
"%(new_val)s"
") != %(old_val)s" % {
"cast_str": cast_str,
"lhs_expr": lhs_expr_code,
"old_val": old_val,
"new_val": new_val,
},
Block([
Assign(old_val_var, lhs_expr_code),
Assign(new_val_var, rhs_expr_code),
]))
])
else:
raise NotImplementedError("atomic update for '%s'" % lhs_dtype)