Safe Haskell	None
Language	GHC2021

Language.QBE.Simulator.Expression

Contents

Expression Abstraction
Conversion Functions,
Comparision

Description

This module provides a generic expression language used to describe arithmetic and logic operations on instruction operands in the abstract Simulator description of QBE semantics. Therefore, in addition to the Simulator monad, it is the central component for the abstract description of QBE's semantics.

Synopsis

class ValueRepr v where
- fromLit :: ExtType -> Word64 -> v
- fromFloat :: Float -> v
- fromDouble :: Double -> v
- toWord64 :: v -> Word64
- getType :: v -> ExtType
- floatToInt :: ExtType -> Bool -> v -> Maybe v
- intToFloat :: ExtType -> Bool -> v -> Maybe v
- extendFloat :: v -> Maybe v
- truncFloat :: v -> Maybe v
- extend :: ExtType -> Bool -> v -> Maybe v
- extract :: ExtType -> v -> Maybe v
- add :: v -> v -> Maybe v
- sub :: v -> v -> Maybe v
- mul :: v -> v -> Maybe v
- div :: v -> v -> Maybe v
- urem :: v -> v -> Maybe v
- srem :: v -> v -> Maybe v
- udiv :: v -> v -> Maybe v
- or :: v -> v -> Maybe v
- xor :: v -> v -> Maybe v
- and :: v -> v -> Maybe v
- neg :: v -> Maybe v
- sar :: v -> v -> Maybe v
- shr :: v -> v -> Maybe v
- shl :: v -> v -> Maybe v
- eq :: v -> v -> Maybe v
- ne :: v -> v -> Maybe v
- sle :: v -> v -> Maybe v
- slt :: v -> v -> Maybe v
- sge :: v -> v -> Maybe v
- sgt :: v -> v -> Maybe v
- ule :: v -> v -> Maybe v
- ult :: v -> v -> Maybe v
- uge :: v -> v -> Maybe v
- ugt :: v -> v -> Maybe v
- ord :: v -> v -> Maybe v
- unord :: v -> v -> Maybe v
fromString :: ValueRepr v => String -> [v]
toString :: ValueRepr v => [v] -> String
boolToValue :: ValueRepr v => Bool -> v
compareIntExpr :: ValueRepr v => IntCmpOp -> v -> v -> Maybe v
compareFloatExpr :: ValueRepr v => FloatCmpOp -> v -> v -> Maybe v

Expression Abstraction

class ValueRepr v where Source #

Generic expression abstraction operating on values of type ExtType. Values are either fixed-size bitvectors (8-, 16, 32-, or 64-bit) or single-precision or double-precision floating point values. The value type must be tracked internally by the ValueRepr instance. Operations on the value must return Nothing if the operation is performed on values of different types.

Minimal complete definition

fromLit, fromFloat, fromDouble, toWord64, getType, floatToInt, intToFloat, extendFloat, truncFloat, extend, extract, add, sub, mul, div, urem, srem, udiv, or, xor, and, neg, sar, shr, shl, eq, ne, sle, slt, sge, sgt, ule, ult, uge, ugt, ord

Methods

fromLit :: ExtType -> Word64 -> v Source #

Create a ValueRepr from an integer literal.

TODO: rename fromLit to fromInt

fromFloat :: Float -> v Source #

fromDouble :: Double -> v Source #

toWord64 :: v -> Word64 Source #

getType :: v -> ExtType Source #

floatToInt :: ExtType -> Bool -> v -> Maybe v Source #

intToFloat :: ExtType -> Bool -> v -> Maybe v Source #

extendFloat :: v -> Maybe v Source #

truncFloat :: v -> Maybe v Source #

extend :: ExtType -> Bool -> v -> Maybe v Source #

Extend a value to the given ExtType. The Bool is true if the value should be sign-extended, otherwise it is zero-extended. If the v is a float or if the current size exceeds (or is equal to) the size of ExtType, then Nothing is returned.

extract :: ExtType -> v -> Maybe v Source #

Extract the least significant bits of a v. The bits to extract are deduced from the given ExtType. Returns Nothing if the ExtType is a float type, if the value is a float, or if the size of ExtType exceeds the size of v.

add :: v -> v -> Maybe v Source #

Addition.

sub :: v -> v -> Maybe v Source #

Subtraction.

mul :: v -> v -> Maybe v Source #

Multiplication.

div :: v -> v -> Maybe v Source #

Unsigned division.

urem :: v -> v -> Maybe v Source #

Unsigned remainder.

srem :: v -> v -> Maybe v Source #

Signed remainder.

udiv :: v -> v -> Maybe v Source #

Unsigned division.

or :: v -> v -> Maybe v Source #

Bitwise or.

xor :: v -> v -> Maybe v Source #

Bitwise xor.

and :: v -> v -> Maybe v Source #

Bitwise and.

neg :: v -> Maybe v Source #

Unary negation.

sar :: v -> v -> Maybe v Source #

Arithmetic right shift, preserving the sign bit of the shifted value. Shift amount must always be a 32-bit value, the shifted value must be 32- or 64-bit.

shr :: v -> v -> Maybe v Source #

Logical shift right, filling the newly freed bits with zeroes. Shift amount must always be a 32-bit value, the shifted value must be 32- or 64-bit.

shl :: v -> v -> Maybe v Source #

Logical shift left, always fills the freed bits with zeroes. Shift amount must always be a 32-bit value, the shifted value must be 32- or 64-bit.

eq :: v -> v -> Maybe v Source #

Check for equality.

ne :: v -> v -> Maybe v Source #

Check if two values are not equal.

sle :: v -> v -> Maybe v Source #

Signed less than or equal to.

slt :: v -> v -> Maybe v Source #

Signed less than.