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parseinstrs: Refactor mapping of opcode to Trie

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This commit is contained in:
Alexis Engelke
2021-01-23 13:16:05 +01:00
parent 13a2456458
commit dc399390a4
1 changed files with 23 additions and 32 deletions
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55
parseinstrs.py
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@@ -265,34 +265,6 @@ class Opcode(NamedTuple):
rexw=match.group("rexw"), rexw=match.group("rexw"),
) )
def for_trie(self):
opcode = []
opcode.append((EntryKind.TABLE_ROOT, [self.escape | self.vex << 2]))
if not self.extended:
opcode.append((EntryKind.TABLE256, [self.opc]))
else:
opcode.append((EntryKind.TABLE256, [self.opc + i for i in range(8)]))
if self.prefix:
if self.prefix == "NFx":
opcode.append((EntryKind.TABLE_PREFIX, [0, 1]))
else:
prefix_val = ["NP", "66", "F3", "F2"].index(self.prefix)
opcode.append((EntryKind.TABLE_PREFIX, [prefix_val]))
if self.opcext:
opcode.append((EntryKind.TABLE16, [((self.opcext - 0xc0) >> 3) | 8]))
opcode.append((EntryKind.TABLE8E, [self.opcext & 7]))
if self.modreg:
# TODO: optimize for /r and /m specifiers to reduce size
mod = {"m": [0], "r": [1<<3], "rm": [0, 1<<3]}[self.modreg[1]]
reg = [self.modreg[0]] if self.modreg[0] is not None else list(range(8))
opcode.append((EntryKind.TABLE16, [x + y for x in mod for y in reg]))
if self.vexl in ("0", "1") or self.rexw in ("0", "1"):
rexw = {"0": [0], "1": [1<<0], "IG": [0, 1<<0]}[self.rexw or "IG"]
vexl = {"0": [0], "1": [1<<1], "IG": [0, 1<<1]}[self.vexl or "IG"]
entries = list(map(sum, product(rexw, vexl)))
opcode.append((EntryKind.TABLE_VEX, entries))
return opcode
class Trie: class Trie:
KIND_ORDER = (EntryKind.TABLE_ROOT, EntryKind.TABLE256, KIND_ORDER = (EntryKind.TABLE_ROOT, EntryKind.TABLE256,
EntryKind.TABLE_PREFIX, EntryKind.TABLE16, EntryKind.TABLE_PREFIX, EntryKind.TABLE16,
@@ -316,10 +288,6 @@ class Trie:
self.kindmap[kind].append(len(self.trie) - 1) self.kindmap[kind].append(len(self.trie) - 1)
return len(self.trie) - 1 return len(self.trie) - 1
def _transform_opcode(self, opcode):
vals = {k: v for k, v in opcode.for_trie()}
return [vals.get(kind) for kind in self.KIND_ORDER]
def _clone(self, elem): def _clone(self, elem):
if not elem or elem[0].is_instr: if not elem or elem[0].is_instr:
return elem return elem
@@ -327,6 +295,29 @@ class Trie:
self.trie[new_num] = [self._clone(e) for e in self.trie[elem[1]]] self.trie[new_num] = [self._clone(e) for e in self.trie[elem[1]]]
return elem[0], new_num return elem[0], new_num
def _transform_opcode(self, opc):
troot = [opc.escape | opc.vex << 2]
t256 = [opc.opc + i for i in range(8 if opc.extended else 1)]
tprefix, t16, t8e, tvex = None, None, None, None
if opc.prefix == "NFx":
tprefix = [0, 1]
elif opc.prefix:
tprefix = [["NP", "66", "F3", "F2"].index(opc.prefix)]
if opc.opcext:
t16 = [((opc.opcext - 0xc0) >> 3) | 8]
t8e = [opc.opcext & 7]
elif opc.modreg:
# TODO: optimize for /r and /m specifiers to reduce size
mod = {"m": [0], "r": [1<<3], "rm": [0, 1<<3]}[opc.modreg[1]]
reg = [opc.modreg[0]] if opc.modreg[0] is not None else list(range(8))
t16 = [x + y for x in mod for y in reg]
if opc.vexl in ("0", "1") or opc.rexw in ("0", "1"):
rexw = {"0": [0], "1": [1<<0], "IG": [0, 1<<0]}[opc.rexw or "IG"]
vexl = {"0": [0], "1": [1<<1], "IG": [0, 1<<1]}[opc.vexl or "IG"]
tvex = list(map(sum, product(rexw, vexl)))
# Order must match KIND_ORDER.
return troot, t256, tprefix, t16, t8e, tvex
def add_opcode(self, opcode, descidx, root_idx, weak=False): def add_opcode(self, opcode, descidx, root_idx, weak=False):
opcode = self._transform_opcode(opcode) opcode = self._transform_opcode(opcode)
frontier = [(0, root_idx)] frontier = [(0, root_idx)]