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Fixes to support encoding/decoding
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@wallento
wallento committed Jul 13, 2020
1 parent 6f866e8 commit 5ee305f
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Showing 2 changed files with 62 additions and 66 deletions.
2 changes: 1 addition & 1 deletion riscvmodel/insn.py
View file
Expand Up @@ -290,7 +290,7 @@ def execute(self, model: Model):
pass


@isa("ecall", RV32I, opcode=0b1110011, funct3=0b000, imm=0b000000000000)
@isa("ecall", RV32I, opcode=0b1110011, funct3=0b000, imm=0b000000000000, rd=0b00000, rs1=0b00000)
class InstructionECALL(InstructionIType):
def execute(self, model: Model):
model.environment.call(model.state)
Expand Down
126 changes: 61 additions & 65 deletions riscvmodel/isa.py
View file
Expand Up @@ -15,8 +15,8 @@
from .types import Immediate, Register
from .variant import RV32I

Field = namedtuple("Field", ["name", "base", "size", "description", "static", "value"])
Field.__new__.__defaults__ = (None, None, None, None, False, None)
Field = namedtuple("Field", ["name", "base", "size", "offset", "description", "static", "value"])
Field.__new__.__defaults__ = (None, None, None, 0, None, False, None)

class Instruction(metaclass=ABCMeta):
"""
Expand Down Expand Up @@ -58,7 +58,14 @@ def set_field(cls, field, word, value):
fname = "field_{}".format(field)
base = getattr(cls, fname).base
size = getattr(cls, fname).size
return word | ((value & (2**size - 1)) << base)
if not isinstance(base, list):
base = [base]
size = [size]
off = 0
for part in range(len(base)):
word |= (((value >> off) & (2**size[part] - 1)) << base[part])
off += size[part]
return word

@classmethod
def get_fields(cls):
Expand Down Expand Up @@ -131,7 +138,7 @@ def encode(self) -> int:
"""
word = 0
for field in self.get_fields():
if field.static:
if field.value is not None:
word = self.set_field(field.name, word, field.value)
else:
value = getattr(self, field.name)
Expand Down Expand Up @@ -207,8 +214,8 @@ class InstructionRType(InstructionFunct3Type, InstructionFunct7Type, metaclass=A
asm_arg_signature = "<rd>, <rs1>, <rs2>"

field_rd = Field(name="rd", base=7, size=5, description="")
field_rs1 = Field(name="rd", base=15, size=5, description="")
field_rs2 = Field(name="rd", base=20, size=5, description="")
field_rs1 = Field(name="rs1", base=15, size=5, description="")
field_rs2 = Field(name="rs2", base=20, size=5, description="")

def __init__(self, rd: int = None, rs1: int = None, rs2: int = None):
super(InstructionRType, self).__init__()
Expand All @@ -217,8 +224,8 @@ def __init__(self, rd: int = None, rs1: int = None, rs2: int = None):
self.rs1 = rs1
self.rs2 = rs2

def ops_from_string(self, ops):
(self.rd, self.rs1, self.rs2) = [int(op[1:]) for op in ops.split(",")]
def ops_from_list(self, ops):
(self.rd, self.rs1, self.rs2) = [int(op[1:]) for op in ops]

def randomize(self, variant: Variant):
self.rd = randrange(0, variant.xlen)
Expand Down Expand Up @@ -268,7 +275,7 @@ class InstructionIType(InstructionFunct3Type, metaclass=ABCMeta):

field_rd = Field(name="rd", base=7, size=5, description="")
field_rs1 = Field(name="rs1", base=15, size=5, description="")
field_imm = Field(name="imm", base=20, size=5, description="")
field_imm = Field(name="imm", base=20, size=12, description="")

def __init__(self, rd: int = None, rs1: int = None, imm: int = None):
super(InstructionIType, self).__init__()
Expand All @@ -279,9 +286,15 @@ def __init__(self, rd: int = None, rs1: int = None, imm: int = None):
self.imm.set(imm)

def ops_from_list(self, ops):
if len(ops) == 0: # ecall
return
self.rd = int(ops[0][1:])
self.rs1 = int(ops[1][1:])
self.imm.set(int(ops[2]))
if ops[1][0] == "x":
self.rs1 = int(ops[1][1:])
self.imm.set(int(ops[2], 0))
else: # Load
self.rs1 = int(ops[2][1:])
self.imm.set(int(ops[1], 0))

def randomize(self, variant: Variant):
self.rd = randrange(0, variant.xlen)
Expand All @@ -300,12 +313,6 @@ def __str__(self) -> str:
return "{} x{}, x{}, {}".format(self.mnemonic, self.rd, self.rs1,
self.imm)

def __eq__(self, other) -> bool:
if not super().__eq__(other):
return False
return self.rd == other.rd and self.rs1 == other.rs1 and self.imm == other.imm


class InstructionILType(InstructionIType, metaclass=ABCMeta):
"""
I-type instruction specialization for stores. The produce a different
Expand Down Expand Up @@ -335,21 +342,24 @@ class InstructionISType(InstructionFunct3Type,InstructionFunct7Type, metaclass=A
:type imm: int
"""

isa_format_id = "IS"

field_rd = Field(name="rd", base=7, size=5, description="")
field_rs1 = Field(name="rs1", base=15, size=5, description="")
field_shamt = Field(name="shamt", base=20, size=5, description="")

asm_arg_signature = "<rd>, <rs1>, <shamt>"

def __init__(self, rd: int = None, rs1: int = None, shamt: int = None):
super(InstructionISType, self).__init__()
self.rd = rd
self.rs1 = rs1
self.shamt = Immediate(bits=5, init=shamt)

def ops_from_string(self, ops):
ops = ops.split(",")
def ops_from_list(self, ops):
self.rd = int(ops[0][1:])
self.rs1 = int(ops[1][1:])
self.shamt.set(int(ops[2]))
self.shamt.set(int(ops[2], 0))

def randomize(self, variant: Variant):
self.rd = randrange(0, variant.xlen)
Expand Down Expand Up @@ -383,17 +393,25 @@ class InstructionSType(InstructionFunct3Type, metaclass=ABCMeta):
:param imm: Offset of store, for calculation of address relative to rs1
:type imm: int
"""

isa_format_id = "S"

field_rs1 = Field(name="rs1", base=15, size=5, description="")
field_rs2 = Field(name="rs2", base=20, size=5, description="")
field_imm = Field(name="imm", base=[7, 25], size=[5, 7], description="")

asm_arg_signature = "<rs2>, <imm>(<rs1>)"

def __init__(self, rs1: int = None, rs2: int = None, imm: int = None):
super(InstructionSType, self).__init__()
self.rs1 = rs1
self.rs2 = rs2
self.imm = Immediate(bits=12, signed=True, init=imm)

def ops_from_string(self, ops):
ops = ops.split(",")
self.rs1 = int(ops[0][1:])
self.rs2 = int(ops[1][ops[1].find("(") + 2:-1])
self.imm.set(int(ops[1][0:ops[1].find("(")]))
def ops_from_list(self, ops):
self.rs1 = int(ops[2][1:])
self.rs2 = int(ops[0][1:])
self.imm.set(int(ops[1], 0))

def randomize(self, variant: Variant):
self.rs1 = randrange(0, variant.xlen)
Expand All @@ -411,12 +429,6 @@ def __str__(self):
return "{} x{}, {}(x{})".format(self.mnemonic, self.rs2, self.imm,
self.rs1)

def __eq__(self, other):
if not super().__eq__(other):
return False
return self.rs1 == other.rs1 and self.rs2 == other.rs2 and self.imm == other.imm


class InstructionBType(InstructionFunct3Type, metaclass=ABCMeta):
"""
B-type instructions encode branches. Branches have two source registers that
Expand All @@ -430,35 +442,31 @@ class InstructionBType(InstructionFunct3Type, metaclass=ABCMeta):
16-bit aligned)
:type imm: int
"""

isa_format_id = "B"

field_rs1 = Field(name="rs1", base=15, size=5, description="")
field_rs2 = Field(name="rs2", base=20, size=5, description="")
field_imm = Field(name="imm", base=[7, 25], size=[5, 7], offset=1, description="")

asm_arg_signature = "<rs1>, <rs2>, <imm>"

def __init__(self, rs1: int = None, rs2: int = None, imm: int = None):
super(InstructionBType, self).__init__()
self.rs1 = rs1
self.rs2 = rs2
self.imm = Immediate(bits=13, signed=True, lsb0=True)
if imm is not None:
self.imm.set(imm)
self.imm = Immediate(bits=13, signed=True, lsb0=True, init=imm)

def ops_from_string(self, ops):
ops = ops.split(",")
def ops_from_list(self, ops):
self.rs1 = int(ops[0][1:])
self.rs2 = int(ops[1][1:])
self.imm.set(int(ops[2]))
self.imm.set(int(ops[2], 0))

def randomize(self, variant: Variant):
self.rs1 = randrange(0, variant.xlen)
self.rs2 = randrange(0, variant.xlen)
self.imm.randomize()

def decode(self, machinecode: int):
self.rs1 = (machinecode >> 15) & 0x1F
self.rs2 = (machinecode >> 20) & 0x1F
imm11 = (machinecode >> 7) & 0x1
imm1to4 = (machinecode >> 8) & 0xF
imm5to10 = (machinecode >> 25) & 0x3F
imm12 = (machinecode >> 31) & 0x1
self.imm.set_from_bits((imm12 << 12) | (imm11 << 11) | (imm5to10 << 5)
| (imm1to4 << 1))

def inopstr(self, model):
opstr = "{:>3}={}, ".format("x{}".format(self.rs1),
model.state.intreg[self.rs1])
Expand All @@ -470,12 +478,6 @@ def __str__(self):
return "{} x{}, x{}, .{:+}".format(self.mnemonic, self.rs1, self.rs2,
self.imm)

def __eq__(self, other):
if not super().__eq__(other):
return False
return self.rs1 == other.rs1 and self.rs2 == other.rs2 and self.imm == other.imm


class InstructionUType(Instruction, metaclass=ABCMeta):
"""
U-type instructions are used for constant formation and set the upper bits of a register.
Expand All @@ -485,15 +487,18 @@ class InstructionUType(Instruction, metaclass=ABCMeta):
:param imm: Immediate (20-bit, unsigned)
:type imm: int
"""

field_rd = Field(name="rd", base=7, size=5, description="")
field_imm = Field(name="imm", base=12, size=20, description="")

def __init__(self, rd: int = None, imm: int = None):
super(InstructionUType, self).__init__()
self.rd = rd # pylint: disable=invalid-name
self.imm = Immediate(bits=20, init=imm)

def ops_from_string(self, ops):
ops = ops.split(",")
def ops_from_list(self, ops):
self.rd = int(ops[0][1:])
self.imm.set(int(ops[1]))
self.imm.set(int(ops[1], 0))

def randomize(self, variant: Variant):
self.rd = randrange(0, variant.xlen)
Expand All @@ -506,11 +511,6 @@ def outopstr(self, model):
def __str__(self):
return "{} x{}, {}".format(self.mnemonic, self.rd, self.imm)

def __eq__(self, other):
if not super().__eq__(other):
return False
return self.rd == other.rd and self.imm == other.imm


class InstructionJType(Instruction, metaclass=ABCMeta):
"""
Expand Down Expand Up @@ -539,10 +539,6 @@ def outopstr(self, model):
def __str__(self):
return "{} x{}, .{:+}".format(self.mnemonic, self.rd, self.imm)

def __eq__(self, other):
if not super().__eq__(other):
return False
return self.rd == other.rd and self.imm == other.imm

class InstructionCType(Instruction, metaclass=ABCMeta):
"""
Expand Down

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