def FunRemoveEmptyBbls(fun: ir.Fun) -> int:
keep = []
for bbl in fun.bbls:
if bbl.inss:
keep.append(bbl)
continue
succ = bbl.edge_out[0]
if succ == bbl:
# we have to keep infinite loop
keep.append(bbl)
continue
# print ("BBL -DELETE", bbl.name)
# print("IN", bbl.edge_in)
# print ("OUT", bbl.edge_out)
del fun.bbl_syms[bbl.name]
# assert bbl != fun.bbls[0], f"attempt to delete first bbl in fun {fun.name}"
assert len(bbl.edge_out) == 1, bbl
succ = bbl.edge_out[0]
bbl.DelEdgeOut(succ)
# We need to clone the edge list since we have destructive updates
# but while we are at it let's also process every predecessor only once
unique_preds: Set[str] = set(pred.name for pred in bbl.edge_in)
for pred_name in unique_preds:
pred = fun.bbl_syms[pred_name]
if pred.inss:
InsMaybePatchNewSuccessor(pred.inss[-1], bbl,
succ) # patch ins/jtb
pred.ReplaceEdgeOut(bbl, succ) # patch edg
discarded = len(fun.bbls) - len(keep)
fun.bbls = keep
return discarded
def FunRemoveUnreachableBbls(fun: ir.Fun) -> int:
reachable = set()
stack: List[ir.Bbl] = [fun.bbls[0]]
while stack:
curr = stack.pop(-1)
if curr.name in reachable:
continue
reachable.add(curr.name)
stack += curr.edge_out
discarded = len(fun.bbls) - len(reachable)
for bbl in fun.bbls:
if bbl.name in reachable:
continue
for succ in bbl.edge_out:
succ.edge_in.remove(bbl)
fun.bbls = [bbl for bbl in fun.bbls if bbl.name in reachable]
fun.bbl_syms = {bbl.name: bbl for bbl in fun.bbls}
return discarded
def FunAddUnconditionalBranches(fun: ir.Fun):
"""Re-insert necessary unconditional branches
sort of inverse of FunRemoveUnconditionalBranches
"""
bbls = []
for n, bbl in enumerate(fun.bbls):
bbls.append(bbl)
if bbl.inss and not bbl.inss[-1].opcode.has_fallthrough():
continue
if len(bbl.edge_out) == 1:
assert len(fun.bbls) > n
succ = bbl.edge_out[0]
if n + 1 == len(fun.bbls) or fun.bbls[n + 1] != succ:
bbl.inss.append(ir.Ins(o.BRA, [succ]))
continue
assert len(bbl.edge_out) == 2
cond_bra = bbl.inss[-1]
assert cond_bra.opcode.kind is o.OPC_KIND.COND_BRA, (
f"not a cond bra: {cond_bra} bbl: {bbl}")
target = cond_bra.operands[2]
other = bbl.edge_out[0] if target == bbl.edge_out[1] else bbl.edge_out[
1]
succ = fun.bbls[n + 1]
if succ in bbl.edge_out:
# target == other can happen if the cond_bra is pointless
if target == succ and target != other:
InsFlipCondBra(cond_bra, target, other)
continue
else:
bbl_bra = ir.Bbl(NewDerivedBblName(bbl.name, "bra", fun))
bbl_bra.inss.append(ir.Ins(o.BRA, [other]))
fun.bbl_syms[bbl_bra.name] = bbl_bra
# forward fallthrough to new bbl
if bbl.inss:
InsMaybePatchNewSuccessor(bbl.inss[-1], other, bbl_bra)
bbl.ReplaceEdgeOut(other, bbl_bra)
bbl_bra.AddEdgeOut(other)
bbls.append(bbl_bra)
fun.bbls = bbls
fun.flags &= ~ir.FUN_FLAG.CFG_NOT_LINEAR
def FunSplitBblsAtTerminators(fun: ir.Fun):
"""split bbls after terminator instructions and remove dead code after 'ret'"""
for bbl in fun.bbl_syms.values():
assert not bbl.forward_declared, f"bbl referenced but not defined {bbl}"
bbls = []
for bbl in fun.bbls:
_BblRemoveUnreachableIns(bbl)
ranges = _BblFindSubRanges(bbl)
# print ("@@@@ ranges", ranges)
inss = bbl.inss
for start, end in ranges:
new_bbl = bbl
if start != 0:
new_bbl = ir.Bbl(NewDerivedBblName(bbl.name, "_", fun))
fun.bbl_syms[bbl.name] = bbl
new_bbl.inss = inss[start:end]
bbls.append(new_bbl)
fun.bbl_syms[new_bbl.name] = new_bbl
fun.bbls = bbls
def FunRemoveEmptyBbls(fun: ir.Fun):
keep = []
for bbl in fun.bbls:
if bbl.inss:
keep.append(bbl)
continue
# print ("BBL -DELETE", bbl.name)
# print("IN", bbl.edge_in)
# print ("OUT", bbl.edge_out)
del fun.bbl_syms[bbl.name]
assert bbl != fun.bbls[0], "NYI"
assert len(bbl.edge_out) == 1, bbl
succ = bbl.edge_out[0]
bbl.DelEdgeOut(succ)
# We need to clone the edge list since we have destructive updates
# but while we are at it let's also process every predecessor only once
unique_preds: Set[ir.Bbl] = set(bbl.edge_in)
for pred in unique_preds:
if pred.inss:
InsMaybePatchNewSuccessor(pred.inss[-1], bbl,
succ) # patch ins/jtb
pred.ReplaceEdgeOut(bbl, succ) # patch edg
fun.bbls = keep
def GenerateFun(unit: ir.Unit, mod: wasm.Module, wasm_fun: wasm.Function,
fun: ir.Fun, global_table, addr_type):
# op_stack contains regs produced by GetOpReg (it may only occur a the position encoding in its name
op_stack: typing.List[typing.Union[ir.Reg, ir.Const]] = []
block_stack: typing.List[Block] = []
bbls: typing.List[ir.Bbl] = []
bbl_count = 0
jtb_count = 0
bbls.append(fun.AddBbl(ir.Bbl("start")))
loc_index = 0
assert fun.input_types[0] is addr_type
mem_base = fun.AddReg(ir.Reg("mem_base", addr_type))
bbls[-1].AddIns(ir.Ins(o.POPARG, [mem_base]))
for dk in fun.input_types[1:]:
reg = fun.AddReg(ir.Reg(f"$loc_{loc_index}", dk))
loc_index += 1
bbls[-1].AddIns(ir.Ins(o.POPARG, [reg]))
for locals in wasm_fun.impl.locals_list:
for i in range(locals.count):
reg = fun.AddReg(
ir.Reg(f"$loc_{loc_index}",
WASM_TYPE_TO_CWERG_TYPE[locals.kind]))
loc_index += 1
bbls[-1].AddIns(ir.Ins(o.MOV, [reg, ir.Const(reg.kind, 0)]))
DEBUG = False
if DEBUG:
print()
print(
f"# {fun.name} #ins:{len(wasm_fun.impl.expr.instructions)} in:{fun.input_types} out:{fun.output_types}"
)
opc = None
last_opc = None
for n, wasm_ins in enumerate(wasm_fun.impl.expr.instructions):
last_opc = opc
opc = wasm_ins.opcode
args = wasm_ins.args
op_stack_size_before = len(op_stack)
if DEBUG:
print(f"#@@ {opc.name}", args, len(op_stack))
if opc.kind is wasm_opc.OPC_KIND.CONST:
# breaks for floats
# breaks for floats
kind = OPC_TYPE_TO_CWERG_TYPE[opc.op_type]
dst = GetOpReg(fun, kind, len(op_stack))
bbls[-1].AddIns(ir.Ins(o.MOV, [dst, ir.Const(kind, args[0])]))
op_stack.append(dst)
elif opc is wasm_opc.NOP:
pass
elif opc is wasm_opc.DROP:
op_stack.pop(-1)
elif opc is wasm_opc.LOCAL_GET:
loc = GetLocalReg(fun, int(args[0]))
dst = GetOpReg(fun, loc.kind, len(op_stack))
bbls[-1].AddIns(ir.Ins(o.MOV, [dst, loc]))
op_stack.append(dst)
elif opc is wasm_opc.LOCAL_SET:
op = op_stack.pop(-1)
bbls[-1].AddIns(ir.Ins(o.MOV,
[GetLocalReg(fun, int(args[0])), op]))
elif opc is wasm_opc.LOCAL_TEE:
op = op_stack[-1] # no pop!
bbls[-1].AddIns(ir.Ins(o.MOV,
[GetLocalReg(fun, int(args[0])), op]))
elif opc is wasm_opc.GLOBAL_GET:
var_index = int(args[0])
var: wasm.Glob = mod.sections.get(
wasm.SECTION_ID.GLOBAL).items[var_index]
dst = GetOpReg(fun,
WASM_TYPE_TO_CWERG_TYPE[var.global_type.value_type],
len(op_stack))
var_mem = unit.GetMem(f"global_vars_{var_index}")
bbls[-1].AddIns(ir.Ins(o.LD_MEM, [dst, var_mem, ZERO]))
op_stack.append(dst)
elif opc is wasm_opc.GLOBAL_SET:
op = op_stack.pop(-1)
var_index = int(args[0])
var_mem = unit.GetMem(f"global_vars_{var_index}")
bbls[-1].AddIns(ir.Ins(o.ST_MEM, [var_mem, ZERO, op]))
elif opc.kind is wasm_opc.OPC_KIND.ALU:
if wasm_opc.FLAGS.UNARY in opc.flags:
opcode, arg_factory = WASM_ALU1_TO_CWERG[opc.basename]
op = op_stack.pop(-1)
dst = GetOpReg(fun, op.kind, len(op_stack))
bbls[-1].AddIns(ir.Ins(opcode, [dst] + arg_factory(op)))
op_stack.append(dst)
else:
op2 = op_stack.pop(-1)
op1 = op_stack.pop(-1)
dst = GetOpReg(fun, op1.kind, len(op_stack))
alu = WASM_ALU_TO_CWERG[opc.basename]
if wasm_opc.FLAGS.UNSIGNED in opc.flags:
tmp1 = GetOpReg(fun, ToUnsigned(op1.kind),
op_stack_size_before + 1)
tmp2 = GetOpReg(fun, ToUnsigned(op1.kind),
op_stack_size_before + 2)
tmp3 = GetOpReg(fun, ToUnsigned(op1.kind),
op_stack_size_before + 3)
bbls[-1].AddIns(ir.Ins(o.CONV, [tmp1, op1]))
bbls[-1].AddIns(ir.Ins(o.CONV, [tmp2, op2]))
if isinstance(alu, o.Opcode):
bbls[-1].AddIns(ir.Ins(alu, [tmp3, tmp1, tmp2]))
else:
alu(tmp3, tmp1, tmp2, bbls[-1])
bbls[-1].AddIns(ir.Ins(o.CONV, [dst, tmp3]))
else:
if isinstance(alu, o.Opcode):
bbls[-1].AddIns(ir.Ins(alu, [dst, op1, op2]))
else:
alu(dst, op1, op2, bbls[-1])
op_stack.append(dst)
elif opc.kind is wasm_opc.OPC_KIND.CONV:
conv, dst_unsigned, src_unsigned = WASM_CONV_TO_CWERG[opc.name]
op = op_stack.pop(-1)
dst = GetOpReg(fun, OPC_TYPE_TO_CWERG_TYPE[opc.op_type],
len(op_stack))
if src_unsigned:
tmp = GetOpReg(fun, ToUnsigned(op.kind),
op_stack_size_before + 1)
bbls[-1].AddIns(ir.Ins(o.CONV, [tmp, op]))
op = tmp
if dst_unsigned:
tmp = GetOpReg(fun, ToUnsigned(dst.kind),
op_stack_size_before + 1)
dst, tmp = tmp, dst
bbls[-1].AddIns(ir.Ins(conv, [dst, op]))
if dst_unsigned:
bbls[-1].AddIns(ir.Ins(o.CONV, [tmp, dst]))
dst = tmp
op_stack.append(dst)
elif opc.kind is wasm_opc.OPC_KIND.BITCAST:
assert opc.name in SUPPORTED_BITCAST
op = op_stack.pop(-1)
dst = GetOpReg(fun, OPC_TYPE_TO_CWERG_TYPE[opc.op_type],
len(op_stack))
bbls[-1].AddIns(ir.Ins(o.BITCAST, [dst, op]))
op_stack.append(dst)
elif opc.kind is wasm_opc.OPC_KIND.CMP:
# this always works because of the sentinel: "end"
succ = wasm_fun.impl.expr.instructions[n + 1]
if succ.opcode not in {
wasm_opc.IF, wasm_opc.BR_IF, wasm_opc.SELECT
}:
cmp, res1, res2, op1, op2, unsigned = MakeCompare(
opc, op_stack)
if unsigned:
tmp1 = GetOpReg(fun, ToUnsigned(op1.kind),
op_stack_size_before + 1)
tmp2 = GetOpReg(fun, ToUnsigned(op1.kind),
op_stack_size_before + 2)
bbls[-1].AddIns(ir.Ins(o.CONV, [tmp1, op1]))
bbls[-1].AddIns(ir.Ins(o.CONV, [tmp2, op2]))
op1 = tmp1
op2 = tmp2
dst = GetOpReg(fun, o.DK.S32, len(op_stack))
bbls[-1].AddIns(ir.Ins(cmp, [dst, res1, res2, op1, op2]))
op_stack.append(dst)
elif opc is wasm_opc.LOOP or opc is wasm_opc.BLOCK:
block_stack.append(
MakeBlock(bbl_count, opc, args, fun, op_stack, mod))
bbl_count += 1
bbls.append(block_stack[-1].start_bbl)
elif opc is wasm_opc.IF:
# note we do set the new bbl right away because we add some instructions to the old one
# this always works because the stack cannot be empty at this point
pred = wasm_fun.impl.expr.instructions[n - 1].opcode
br, op1, op2, unsigned = MakeBranch(pred, op_stack, True)
if unsigned:
tmp1 = GetOpReg(fun, ToUnsigned(op1.kind),
op_stack_size_before + 1)
tmp2 = GetOpReg(fun, ToUnsigned(op1.kind),
op_stack_size_before + 2)
bbls[-1].AddIns(ir.Ins(o.CONV, [tmp1, op1]))
bbls[-1].AddIns(ir.Ins(o.CONV, [tmp2, op2]))
op1 = tmp1
op2 = tmp2
block_stack.append(
MakeBlock(bbl_count, opc, args, fun, op_stack, mod))
# assert len(block_stack[-1].param_types) == 0
bbl_count += 1
bbls[-1].AddIns(ir.Ins(br, [op1, op2, block_stack[-1].else_bbl]))
bbls.append(block_stack[-1].start_bbl)
elif opc is wasm_opc.ELSE:
block = block_stack[-1]
assert block.opcode is wasm_opc.IF
block.FinalizeIf(op_stack, bbls[-1], fun, last_opc
in {wasm_opc.UNREACHABLE, wasm_opc.BR})
if DEBUG:
print(f"#@@ AFTER STACK RESTORE", len(op_stack))
op_stack = op_stack[0:block.stack_start]
bbls[-1].AddIns(ir.Ins(o.BRA, [block.end_bbl]))
assert block.else_bbl is not None
bbls.append(block.else_bbl)
block.else_bbl = None
elif opc is wasm_opc.END:
if block_stack:
block = block_stack.pop(-1)
block.FinalizeEnd(
op_stack, bbls[-1], fun, last_opc
in {wasm_opc.UNREACHABLE, wasm_opc.BR})
if block.else_bbl:
bbls.append(block.else_bbl)
bbls.append(block.end_bbl)
else:
# end of function
assert n + 1 == len(wasm_fun.impl.expr.instructions)
pred = wasm_fun.impl.expr.instructions[n - 1].opcode
if pred not in {
wasm_opc.RETURN, wasm_opc.UNREACHABLE, wasm_opc.BR
}:
for x in reversed(fun.output_types):
op = op_stack.pop(-1)
assert op.kind == x, f"outputs: {fun.output_types} mismatch {op.kind} vs {x}"
bbls[-1].AddIns(ir.Ins(o.PUSHARG, [op]))
bbls[-1].AddIns(ir.Ins(o.RET, []))
elif opc is wasm_opc.CALL:
wasm_callee = mod.functions[int(wasm_ins.args[0])]
callee = unit.GetFun(wasm_callee.name)
assert callee, f"unknown fun: {wasm_callee.name}"
EmitCall(fun, bbls[-1], ir.Ins(o.BSR, [callee]), op_stack,
mem_base, callee)
elif opc is wasm_opc.CALL_INDIRECT:
assert isinstance(args[1], wasm.TableIdx), f"{type(args[1])}"
assert int(args[1]) == 0, f"only one table supported"
assert isinstance(args[0], wasm.TypeIdx), f"{type(args[0])}"
type_sec = mod.sections.get(wasm.SECTION_ID.TYPE)
func_type: wasm.FunctionType = type_sec.items[int(args[0])]
arguments = [addr_type] + TranslateTypeList(func_type.args)
returns = TranslateTypeList(func_type.rets)
# print (f"# @@@@ CALL INDIRECT {returns} <- {arguments} [{int(args[0])}] {func_type}")
signature = FindFunWithSignature(unit, arguments, returns)
table_reg = GetOpReg(fun, addr_type, len(op_stack))
code_type = o.DK.C32 if addr_type is o.DK.A32 else o.DK.C64
fun_reg = GetOpReg(fun, code_type, len(op_stack) + 1)
index = op_stack.pop(-1)
assert index.kind is o.DK.S32
bbls[-1].AddIns(
ir.Ins(o.MUL, [
index, index,
ir.Const(o.DK.U32,
code_type.bitwidth() // 8)
]))
bbls[-1].AddIns(ir.Ins(o.LEA_MEM, [table_reg, global_table, ZERO]))
bbls[-1].AddIns(ir.Ins(o.LD, [fun_reg, table_reg, index]))
EmitCall(fun, bbls[-1], ir.Ins(o.JSR, [fun_reg, signature]),
op_stack, mem_base, signature)
elif opc is wasm_opc.RETURN:
for x in reversed(fun.output_types):
op = op_stack.pop(-1)
assert op.kind == x, f"outputs: {fun.output_types} mismatch {op.kind} vs {x}"
bbls[-1].AddIns(ir.Ins(o.PUSHARG, [op]))
bbls[-1].AddIns(ir.Ins(o.RET, []))
elif opc is wasm_opc.BR:
assert isinstance(args[0], wasm.LabelIdx)
block = GetTargetBlock(block_stack, args[0])
target = block.start_bbl
if block.opcode is not wasm_opc.LOOP:
target = block.end_bbl
block.FinalizeResultsCopy(op_stack, bbls[-1], fun)
bbls[-1].AddIns(ir.Ins(o.BRA, [target]))
elif opc is wasm_opc.BR_IF:
assert isinstance(args[0], wasm.LabelIdx)
pred = wasm_fun.impl.expr.instructions[n - 1].opcode
br, op1, op2, unsigned = MakeBranch(pred, op_stack, False)
if unsigned:
tmp1 = GetOpReg(fun, ToUnsigned(op1.kind),
op_stack_size_before + 1)
tmp2 = GetOpReg(fun, ToUnsigned(op1.kind),
op_stack_size_before + 2)
bbls[-1].AddIns(ir.Ins(o.CONV, [tmp1, op1]))
bbls[-1].AddIns(ir.Ins(o.CONV, [tmp2, op2]))
op1 = tmp1
op2 = tmp2
block = GetTargetBlock(block_stack, args[0])
target = block.start_bbl
if block.opcode is not wasm_opc.LOOP:
target = block.end_bbl
block.FinalizeResultsCopy(op_stack, bbls[-1], fun)
bbls[-1].AddIns(ir.Ins(br, [op1, op2, target]))
elif opc is wasm_opc.SELECT:
pred = wasm_fun.impl.expr.instructions[n - 1].opcode
br, op1, op2, unsigned = MakeBranch(pred, op_stack, False)
val_f = op_stack.pop(-1)
val_t = op_stack.pop(-1)
assert val_f.kind == val_t.kind
reg = GetOpReg(fun, val_f.kind, len(op_stack))
op_stack.append(reg)
bbls[-1].AddIns(ir.Ins(o.MOV, [reg, val_t]))
bbls.append(fun.AddBbl(ir.Bbl(f"select_{bbl_count}")))
bbl_count += 1
if unsigned:
tmp1 = GetOpReg(fun, ToUnsigned(op1.kind),
op_stack_size_before + 1)
tmp2 = GetOpReg(fun, ToUnsigned(op1.kind),
op_stack_size_before + 2)
bbls[-2].AddIns(ir.Ins(o.CONV, [tmp1, op1]))
bbls[-2].AddIns(ir.Ins(o.CONV, [tmp2, op2]))
op1 = tmp1
op2 = tmp2
bbls[-2].AddIns(ir.Ins(br, [op1, op2, bbls[-1]]))
bbls[-2].AddIns(ir.Ins(o.MOV, [reg, val_f]))
elif opc.kind is wasm_opc.OPC_KIND.STORE:
val = op_stack.pop(-1)
offset = op_stack.pop(-1)
if args[1] != 0:
tmp = GetOpReg(fun, offset.kind, len(op_stack))
bbls[-1].AddIns(
ir.Ins(o.ADD,
[tmp, offset,
ir.Const(offset.kind, args[1])]))
offset = tmp
dk_tmp = STORE_TO_CWERG_TYPE.get(opc.name)
if dk_tmp is not None:
tmp = GetOpReg(fun, dk_tmp, len(op_stack) + 1)
bbls[-1].AddIns(ir.Ins(o.CONV, [tmp, val]))
val = tmp
bbls[-1].AddIns(ir.Ins(o.ST, [mem_base, offset, val]))
elif opc.kind is wasm_opc.OPC_KIND.LOAD:
offset = op_stack.pop(-1)
if args[1] != 0:
tmp = GetOpReg(fun, offset.kind, len(op_stack))
bbls[-1].AddIns(
ir.Ins(o.ADD,
[tmp, offset,
ir.Const(offset.kind, args[1])]))
offset = tmp
dst = GetOpReg(fun, OPC_TYPE_TO_CWERG_TYPE[opc.op_type],
len(op_stack))
op_stack.append(dst)
dk_tmp = LOAD_TO_CWERG_TYPE.get(opc.basename)
if dk_tmp:
tmp = GetOpReg(fun, dk_tmp, len(op_stack))
bbls[-1].AddIns(ir.Ins(o.LD, [tmp, mem_base, offset]))
bbls[-1].AddIns(ir.Ins(o.CONV, [dst, tmp]))
else:
bbls[-1].AddIns(ir.Ins(o.LD, [dst, mem_base, offset]))
elif opc is wasm_opc.BR_TABLE:
bbl_tab = {
n: GetTargetBbl(block_stack, x)
for n, x in enumerate(args[0])
}
bbl_def = GetTargetBbl(block_stack, args[1])
op = op_stack.pop(-1)
tab_size = ir.Const(ToUnsigned(op.kind), len(bbl_tab))
jtb_count += 1
jtb = fun.AddJtb(
ir.Jtb(f"jtb_{jtb_count}", bbl_def, bbl_tab, tab_size.value))
reg_unsigned = GetOpReg(fun, ToUnsigned(op.kind), len(op_stack))
bbls[-1].AddIns(ir.Ins(o.CONV, [reg_unsigned, op]))
bbls[-1].AddIns(ir.Ins(o.BLE, [tab_size, reg_unsigned, bbl_def]))
bbls[-1].AddIns(ir.Ins(o.SWITCH, [reg_unsigned, jtb]))
elif opc is wasm_opc.UNREACHABLE:
bbls[-1].AddIns(ir.Ins(o.TRAP, []))
elif opc is wasm_opc.MEMORY_GROW or opc is wasm_opc.MEMORY_SIZE:
op = ZERO_S
if opc is wasm_opc.MEMORY_GROW:
op = op_stack.pop(-1)
bbls[-1].AddIns(ir.Ins(o.PUSHARG, [op]))
assert unit.GetFun("__memory_grow")
bbls[-1].AddIns(ir.Ins(o.BSR, [unit.GetFun("__memory_grow")]))
dst = GetOpReg(fun, o.DK.S32, len(op_stack))
bbls[-1].AddIns(ir.Ins(o.POPARG, [dst]))
op_stack.append(dst)
else:
assert False, f"unsupported opcode [{opc.name}]"
assert not op_stack, f"op_stack not empty in {fun.name}: {op_stack}"
assert not block_stack, f"block_stack not empty in {fun.name}: {block_stack}"
assert len(bbls) == len(fun.bbls)
fun.bbls = bbls
