def optimize_OpLogicalOr(module, inst):
# x or true -> true
if inst.operands[1].inst.is_constant_value(True):
return inst.operands[1].inst
# x or false -> x
if inst.operands[1].inst.is_constant_value(False):
return inst.operands[0].inst
# x or x -> x
if inst.operands[0] == inst.operands[1]:
return inst.operands[0].inst
# undef or undef -> undef
if (inst.operands[0].inst.op_name == 'OpUndef'
and inst.operands[1].inst.op_name == 'OpUndef'):
return inst.operands[0].inst
# (not x) or (not y) -> not (x and y)
if (inst.operands[0].inst.op_name == 'OpLogicalNot'
and inst.operands[1].inst.op_name == 'OpLogicalNot'):
op_id0 = inst.operands[0].inst.operands[0]
op_id1 = inst.operands[1].inst.operands[0]
or_inst = ir.Instruction(module, 'OpLogicalAnd', inst.type_id,
[op_id0, op_id1])
or_inst.insert_before(inst)
not_inst = ir.Instruction(module, 'OpLogicalNot', inst.type_id,
[or_inst.result_id])
not_inst.insert_after(or_inst)
return not_inst
return inst
def canonicalize_inst(module, inst):
"""Canonicalize operand order if instruction is commutative.
The canonical form is that a commutative instruction with one constant
operand always has the constant as its second operand."""
if inst.op_name == 'OpExtInst':
extset_inst = inst.operands[0].inst
assert extset_inst.op_name == 'OpExtInstImport'
if extset_inst.operands[0] in ir.EXT_INST:
ext_ops = ir.EXT_INST[extset_inst.operands[0]]
if ext_ops[inst.operands[1]]['is_commutative']:
new_inst = ir.Instruction(module, 'OpExtInst', inst.type_id, [
inst.operands[0], inst.operands[1], inst.operands[3],
inst.operands[2]
])
new_inst.insert_before(inst)
return new_inst
elif (inst.is_commutative()
and inst.operands[0].inst.op_name in ir.CONSTANT_INSTRUCTIONS
and inst.operands[1].inst.op_name not in ir.CONSTANT_INSTRUCTIONS):
new_inst = ir.Instruction(module, inst.op_name, inst.type_id,
[inst.operands[1], inst.operands[0]])
new_inst.insert_before(inst)
return new_inst
return inst
def create_id(module, token, tag, type_id=None):
"""Create the 'real' ID from an ID token.
The IDs are generalized; it accepts e.g. type names such as 'f32'
where the ID for the 'OpTypeFloat' is returned. Valid generalized
IDs are:
* types
* integer scalar constants (the value can be decimal, binary, or
hexadecimal)
"""
if token in module.symbol_name_to_id:
return module.symbol_name_to_id[token]
elif tag == 'ID':
assert token[0] == '%'
if not token[1].isdigit():
new_id = ir.Id(module)
module.symbol_name_to_id[token] = new_id
name = token[1:]
inst = ir.Instruction(module, 'OpName', None, [new_id, name])
module.insert_global_inst(inst)
else:
value = int(token[1:])
if value in module.value_to_id:
return module.value_to_id[value]
new_id = ir.Id(module, value)
module.value_to_id[value] = new_id
return new_id
elif tag == 'INT' or token in ['true', 'false']:
value = get_scalar_value(token, tag, type_id)
inst = module.get_constant(type_id, value)
return inst.result_id
elif token in module.type_name_to_id:
return module.type_name_to_id[token]
else:
return get_or_create_type(module, token)
def parse_instruction(binary, module):
"""Parse one instruction."""
op_name, op_format = binary.get_next_opcode()
operands = []
inst_type_id = None
if op_format['type']:
inst_type_id = parse_id(binary, module)
result_id = None
if op_format['result']:
result_id = parse_id(binary, module)
if result_id.inst is not None:
raise ParseError('ID ' + str(result_id) + ' is already defined')
for kind in op_format['operands']:
operands = operands + parse_operand(binary, module, kind)
binary.expect_eol()
if op_name == 'OpFunction':
return ir.Function(module,
operands[0],
operands[1],
result_id=result_id)
else:
return ir.Instruction(module,
op_name,
inst_type_id,
operands,
result_id=result_id)
def update_conditional_branch(module, inst, dest_id):
"""Change the OpBranchConditional or OpSwitch to a branch to dest_id."""
assert inst.op_name == 'OpBranchConditional' or inst.op_name == 'OpSwitch'
basic_block = inst.basic_block
branch_inst = ir.Instruction(module, 'OpBranch', None, [dest_id])
inst.replace_with(branch_inst)
if basic_block.insts[-2].op_name in ['OpSelectionMerge', 'OpLoopMerge']:
basic_block.insts[-2].destroy()
def optimize_OpBitcast(module, inst):
operand_inst = inst.operands[0].inst
# bitcast(bitcast(x)) -> bitcast(x) or x
if operand_inst.op_name == 'OpBitcast':
if inst.type_id == operand_inst.operands[0].inst.type_id:
return operand_inst.operands[0].inst
else:
new_inst = ir.Instruction(module, 'OpBitcast', inst.type_id,
[operand_inst.operands[0]])
new_inst.copy_decorations(inst)
new_inst.insert_before(inst)
return new_inst
# bitcast(undef) -> undef
if operand_inst.op_name == 'OpUndef':
new_inst = ir.Instruction(module, 'OpUndef', inst.type_id, [])
new_inst.insert_before(inst)
return new_inst
return inst
def parse_instruction(lexer, module):
"""Parse one instruction."""
_, tag = lexer.get_next_token(peek=True)
if tag == 'ID':
result_id = parse_id(lexer, module)
if result_id.inst is not None:
id_name = get_id_name(module, result_id)
raise ParseError(id_name + ' is already defined')
lexer.get_next_token('=')
else:
result_id = None
op_name, tag = lexer.get_next_token()
if tag != 'NAME':
raise ParseError('Expected an operation name')
if op_name not in ir.INST_FORMAT:
raise ParseError('Invalid operation ' + op_name)
op_format = ir.INST_FORMAT[op_name]
if op_format['type']:
type_id = parse_type(lexer, module)
else:
type_id = None
parse_decorations(lexer, module, result_id, op_name)
if op_name == 'OpExtInst':
operands = parse_extinst_operands(lexer, module, type_id)
else:
operands = parse_operands(lexer, module, op_format, type_id)
lexer.done_with_line()
if op_name == 'OpFunction':
function = ir.Function(module, operands[0], operands[1],
result_id=result_id)
module.inst_to_line[function.inst] = lexer.line_no
module.inst_to_line[function.end_inst] = lexer.line_no
return function
elif op_name == 'OpLabel':
basic_block = ir.BasicBlock(module, result_id)
module.inst_to_line[basic_block.inst] = lexer.line_no
return basic_block
else:
inst = ir.Instruction(module, op_name, type_id, operands,
result_id=result_id)
module.inst_to_line[inst] = lexer.line_no
return inst
def optimize_OpIMul(module, inst):
# x * 0 -> 0
if inst.operands[1].inst.is_constant_value(0):
return inst.operands[1].inst
# x * 1 -> 1
if inst.operands[1].inst.is_constant_value(1):
return inst.operands[0].inst
# x * -1 -> -x
if inst.operands[1].inst.is_constant_value(-1):
new_inst = ir.Instruction(module, 'OpSNegate', inst.type_id,
[inst.operands[0]])
new_inst.insert_before(inst)
return new_inst
# x * undef -> undef
if inst.operands[1].inst.op_name == 'OpUndef':
return inst.operands[1].inst
# undef * x -> undef
if inst.operands[0].inst.op_name == 'OpUndef':
return inst.operands[0].inst
return inst
def optimize_OpLogicalNotEqual(module, inst):
# NotEqual(x, false) -> x
if inst.operands[1].inst.is_constant_value(False):
return inst.operands[0].inst
# NotEqual(x, true) -> not(x)
if inst.operands[1].inst.is_constant_value(True):
new_inst = ir.Instruction(module, 'OpLogicalNot', inst.type_id,
[inst.operands[0]])
new_inst.insert_before(inst)
return new_inst
# NotEqual(x, x) -> false
if inst.operands[0] == inst.operands[1]:
return module.get_constant(inst.type_id, False)
# NotEqual(x, undef) -> undef
if inst.operands[1].inst.op_name == 'OpUndef':
return inst.operands[1].inst
# NotEqual(undef, x) -> undef
if inst.operands[0].inst.op_name == 'OpUndef':
return inst.operands[0].inst
return inst
def parse_function_definition(lexer, module):
"""Parse the 'definition' line of a pretty-printed function."""
lexer.get_next_token('define')
return_type = parse_type(lexer, module)
result_id = parse_id(lexer, module)
parameters = parse_parameters(lexer, module)
if result_id.inst is not None:
id_name = get_id_name(module, result_id)
raise ParseError(id_name + ' is already defined')
operands = [return_type] + [param[0] for param in parameters]
function_type_inst = module.get_global_inst('OpTypeFunction', None,
operands)
function = ir.Function(module, [], function_type_inst.result_id,
result_id=result_id) # XXX
for param_type, param_id in parameters:
param_inst = ir.Instruction(module, 'OpFunctionParameter', param_type,
[], result_id=param_id)
function.append_parameter(param_inst)
return function
def parse_decorations(lexer, module, variable_name, op_name):
"""Parse pretty-printed decorations."""
while True:
token, _ = lexer.get_next_token(peek=True, accept_eol=True)
if token == '':
return
elif token not in spirv.spv['Decoration']:
return
# XXX We should check that the decorations are valid for the
# operation.
#
# In particular 'Uniform' is both a decoration and a storage class,
# so instructions that have 'StorageClass' as first operand must
# not parse 'Uniform' as a decoration (and 'Uniform' is not a valid
# decoration for those operations). At this as a special case
# here until the real decoration check has been implemented.
if op_name in ['OpTypePointer', 'OpVariable'] and token == 'Uniform':
return
decoration, _ = lexer.get_next_token()
if not decoration in spirv.spv['Decoration']:
raise ParseError('Unknown decoration ' + decoration)
token, _ = lexer.get_next_token(peek=True, accept_eol=True)
operands = [variable_name, decoration]
if token == '(':
lexer.get_next_token()
while True:
operands.append(parse_literal_number(lexer))
token, _ = lexer.get_next_token()
if token == ')':
break
if token != ',':
raise ParseError('Syntax error in decoration')
inst = ir.Instruction(module, 'OpDecorate', None, operands)
module.insert_global_inst(inst)
def optimize_OpCompositeConstruct(module, inst):
# Code of the form
# %20 = OpCompositeExtract f32 %19, 0
# %21 = OpCompositeExtract f32 %19, 1
# %22 = OpCompositeExtract f32 %19, 2
# %23 = OpCompositeConstruct <3 x f32> %20, %21, %22
# can be changed to a OpVectorShuffle if all OpCompositeExtract
# comes from one or two vectors.
if inst.type_id.inst.op_name == 'OpTypeVector':
sources = []
for operand in inst.operands:
if operand.inst.op_name != 'OpCompositeExtract':
break
src_inst = operand.inst.operands[0].inst
if src_inst.result_id not in sources:
if src_inst.type_id.inst.op_name != 'OpTypeVector':
break
sources.append(src_inst.result_id)
if len(sources) > 2:
break
else:
vec1_id = sources[0]
vec2_id = sources[0] if len(sources) == 1 else sources[1]
vec1_len = vec1_id.inst.type_id.inst.operands[1]
vecshuffle_operands = [vec1_id, vec2_id]
for operand in inst.operands:
idx = operand.inst.operands[1]
if operand.inst.operands[0] != vec1_id:
idx = idx + vec1_len
vecshuffle_operands.append(idx)
new_inst = ir.Instruction(module, 'OpVectorShuffle', inst.type_id,
vecshuffle_operands)
new_inst.copy_decorations(inst)
new_inst.insert_before(inst)
return new_inst
return inst
def optimize_variable(module, func, var_inst):
"""Promote/eliminate the var_inst variable if possible."""
# Delete variable if it is not used.
if not var_inst.result_id.uses:
var_inst.destroy()
return
# We only handle simple loads and stores.
for inst in var_inst.uses():
if inst.op_name not in ['OpLoad', 'OpStore']:
return
# Eliminate loads/store instructions for the variable
pred = calculate_pred(func)
exit_value = {}
phi_nodes = []
undef_insts = []
var_type_id = var_inst.type_id.inst.operands[1]
for basic_block in func.basic_blocks:
# Get the variable's value at start of the basic block.
if not pred[basic_block]:
stored_inst = None
elif len(pred[basic_block]) == 1:
stored_inst = exit_value[pred[basic_block][0]]
else:
stored_inst = ir.Instruction(module, 'OpPhi', var_type_id, [])
basic_block.prepend_inst(stored_inst)
phi_nodes.append(stored_inst)
# Eliminate loads/store instructions.
ordered_uses = [
inst for inst in basic_block.insts
if inst in var_inst.result_id.uses
]
for inst in ordered_uses:
if inst.op_name == 'OpLoad':
if stored_inst is None:
stored_inst = ir.Instruction(module, 'OpUndef',
inst.type_id, [])
undef_insts.append(stored_inst)
stored_inst.insert_before(inst)
inst.replace_uses_with(stored_inst)
inst.destroy()
elif inst.op_name == 'OpStore':
stored_inst = inst.operands[1].inst
inst.destroy()
# Save the variable's value at end of the basic block.
exit_value[basic_block] = stored_inst
# Add operands to the phi-nodes.
for inst in phi_nodes:
for pred_bb in pred[inst.basic_block]:
if exit_value[pred_bb] is None:
undef_inst = ir.Instruction(module, 'OpUndef', var_type_id, [])
undef_insts.append(undef_inst)
last_insts = pred_bb.insts[-2:]
if (last_insts[0].op_name
in ['OpLoopMerge', 'OpSelectionMerge']
or last_insts[0].op_name in ir.BRANCH_INSTRUCTIONS):
undef_inst.insert_before(last_insts[0])
else:
undef_inst.insert_after(last_insts[0])
exit_value[pred_bb] = undef_inst
inst.add_to_phi(exit_value[pred_bb], pred_bb.inst)
# Destroy obviously dead instructions.
for inst in reversed(phi_nodes):
if not inst.result_id.uses:
inst.destroy()
for inst in undef_insts:
if not inst.result_id.uses:
inst.destroy()
var_inst.destroy()
def optimize_OpVectorShuffle(module, inst):
vec1_inst = inst.operands[0].inst
vec2_inst = inst.operands[1].inst
components = inst.operands[2:]
# VectorShuffle of undef -> undef
if vec1_inst.op_name == 'OpUndef' and vec2_inst.op_name == 'OpUndef':
new_inst = ir.Instruction(module, 'OpUndef', inst.type_id, [])
new_inst.insert_before(inst)
return new_inst
# Change vector shuffles "A, unused" or "unused, A" to "A, A" where
# the second operand is not used (and change to OpUndef if no elements
# of the input vectors are used).
#
# We use this form for swizzles instead of using an OpUndef for the
# unused vector in order to avoid adding an extra instruction for the
# OpUndef. This form also makes the constant folder handle the shuffle
# for constant A without needing to special the case where one operand
# is constant, and one is OpUndef.
using_vec1 = False
using_vec2 = False
vec1_type_inst = vec1_inst.type_id.inst
assert vec1_type_inst.op_name == 'OpTypeVector'
vec1_len = vec1_type_inst.operands[1]
for component in components:
if component != 0xffffffff:
if component < vec1_len:
using_vec1 = True
else:
using_vec2 = True
if not using_vec1 and not using_vec2:
new_inst = ir.Instruction(module, 'OpUndef', inst.type_id, [])
new_inst.insert_before(inst)
return new_inst
elif not using_vec2:
vec2_inst = vec1_inst
elif not using_vec1:
for idx, component in enumerate(components):
if component != 0xffffffff:
components[idx] = component - vec1_len
vec1_inst = vec2_inst
# Change shuffle "A, A" so that only the first is used.
if vec1_inst == vec2_inst:
vec1_type_inst = vec1_inst.type_id.inst
assert vec1_type_inst.op_name == 'OpTypeVector'
vec1_len = vec1_type_inst.operands[1]
for idx, component in enumerate(components):
if component != 0xffffffff and component >= vec1_len:
components[idx] = component - vec1_len
# Eliminate identity swizzles.
if vec1_inst == vec2_inst:
if inst.type_id == vec1_inst.type_id:
for idx, component in enumerate(components):
if component != 0xffffffff and component != idx:
break
else:
return vec1_inst
# Create new inst if we have changed the instruction.
operands = [vec1_inst.result_id, vec2_inst.result_id] + components
if operands != inst.operands:
new_inst = ir.Instruction(module, 'OpVectorShuffle', inst.type_id,
operands)
new_inst.copy_decorations(inst)
new_inst.insert_before(inst)
return new_inst
return inst
