Lib.Operands module

This file defines the base class Operand and its subclasses for different operands: Condition, DataLocation and Function.

The class DataLocation itself has subclasses: Register, Offset for address in memory, Immediate for constants and Temporary for location not yet allocated.

This file also define shortcuts for registers in RISCV.

class Lib.Operands.Operand[source]: Bases: object

class Lib.Operands.Condition(optype)[source]

Bases: Operand

Condition, i.e. comparison operand for a CondJump.

Example usage :

Condition(‘beq’) = branch if equal.
Condition(MiniCParser.LT) = branch if lower than.
…

The constructor’s argument shall be a string in the list all_ops, or a comparison operator in MiniCParser.LT, MiniCParser.GT, … (one of the keys in opdict).

A ‘negate’ method allows getting the negation of this condition.

negate() → Condition[source]: Return the opposite condition.

class Lib.Operands.Function(name: str)[source]

Bases: Operand

Operand for build-in function call.

class Lib.Operands.DataLocation[source]

Bases: Operand

A Data Location is either a register, a temporary or a place in memory (offset).

class Lib.Operands.Register(number: int)[source]

Bases: DataLocation

A (physical) register.

Lib.Operands.ZERO = zero: Zero register

Lib.Operands.RA = ra

Lib.Operands.SP = sp

Lib.Operands.GP: Register not used for this course

Lib.Operands.TP: Register not used for this course

Lib.Operands.A = (a0, a1, a2, a3, a4, a5, a6, a7)

Lib.Operands.S = (fp, s1, s2, s3, s4, s5, s6, s7, s8, s9, s10, s11)

Lib.Operands.T = (t0, t1, t2, t3, t4, t5, t6)

Lib.Operands.A0 = a0

Lib.Operands.A1 = a1

Lib.Operands.FP = fp: Frame Pointer = Saved register 0

Lib.Operands.GP_REGS = (s4, s5, s6, s7, s8, s9, s10, s11, t0, t1, t2, t3, t4, t5, t6): General purpose registers, usable for the allocator

class Lib.Operands.Offset(basereg: Register, offset: int)[source]

Bases: DataLocation

Offset = address in memory computed with base + offset.

get_offset() → int[source]: Return the value of the offset.

class Lib.Operands.Immediate(val)[source]

Bases: DataLocation

Immediate operand (integer).

class Lib.Operands.Temporary(number: int, pool: TemporaryPool)[source]

Bases: DataLocation

Temporary, a location that has not been allocated yet. It will later be mapped to a physical register (Register) or to a memory location (Offset).

get_alloced_loc() → DataLocation[source]: Return the DataLocation allocated to this Temporary.

class Lib.Operands.TemporaryPool[source]

Bases: object

Manage a pool of temporaries.

get_all_temps() → List[Temporary][source]: Return all the temporaries of the pool.

get_alloced_loc(t: Temporary) → DataLocation[source]: Get the actual DataLocation allocated for the temporary t.

add_tmp(t: Temporary)[source]: Add a temporary to the pool.

set_temp_allocation(allocation: Dict[Temporary, DataLocation]) → None[source]: Give a mapping from temporaries to actual registers. The argument allocation must be a dict from Temporary to DataLocation other than Temporary (typically Register or Offset). Typing enforces that keys are Temporary and values are Datalocation. We check the values are indeed not Temporary.

fresh_tmp() → Temporary[source]: Give a new fresh Temporary and add it to the pool.

class Lib.Operands.Renamer(pool: TemporaryPool)[source]

Bases: object

Manage a renaming of temporaries.

fresh(t: Temporary) → Temporary[source]: Give a fresh rename for a Temporary.

replace(t: Temporary) → Temporary[source]: Give the rename for a Temporary (which is itself if it is not renamed).

defined(t: Temporary) → bool[source]: True if the Temporary is renamed.

copy()[source]: Give a copy of the Renamer.