Perf.Time

tick uses the rdtsc chipset to measure time performance of a computation.

The measurement unit is one oscillation of the chip crystal as measured by the rdtsc instruction which inspects the TSC register.

For reference, a computer with a frequency of 2 GHz means that one cycle is equivalent to 0.5 nanoseconds.

Documentation

tick_ :: IO Cycles

tick_ measures the number of cycles it takes to read the rdtsc chip twice: the difference is then how long it took to read the clock the second time.

warmup :: Int -> IO ()

Warm up the register, to avoid a high first measurement. Without a warmup, one or more larger values can occur at the start of a measurement spree, and often are in the zone of an L2 miss.

tick :: (a -> b) -> a -> IO (Cycles, b)

tick f a

• strictly evaluates f and a to WHNF
• starts the cycle counter
• strictly evaluates f a to WHNF
• stops the cycle counter
• returns (number of cycles, f a)

tickWHNF :: (a -> b) -> a -> IO (Cycles, b)

tickWHNF f a

• starts the cycle counter
• strictly evaluates f a to WHNF (this may also kick off thunk evaluation in f or a which will also be captured in the cycle count)
• stops the cycle counter
• returns (number of cycles, f a)

tickLazy :: (a -> b) -> a -> IO (Cycles, b)

tickLazy f a

• starts the cycle counter
• lazily evaluates f a
• stops the cycle counter
• returns (number of cycles, f a)

tickForce :: (NFData a, NFData b) => (a -> b) -> a -> IO (Cycles, b)

tickForce f a

• deeply evaluates f and a,
• starts the cycle counter
• deeply evaluates f a
• stops the cycle counter
• returns (number of cycles, f a)

tickForceArgs :: NFData a => (a -> b) -> a -> IO (Cycles, b)

tickForceArgs f a

• deeply evaluates f and a,
• starts the cycle counter
• strictly evaluates f a to WHNF
• stops the cycle counter
• returns (number of cycles, f a)

tickIO :: IO a -> IO (Cycles, a)

measures an IO a

ticks :: Int -> (a -> b) -> a -> IO ([Cycles], b)

n measurements of a tick

returns a list of Cycles and the last evaluated f a

ticksIO :: Int -> IO a -> IO ([Cycles], a)

n measurements of a tickIO

returns an IO tuple; list of Cycles and the last evaluated f a

newtype Cycles

Clock count.

Constructors

Cycles

Fields

• word :: Word64

Instances

Enum Cycles

Defined in Perf.Time

Methods

succ :: Cycles -> Cycles

pred :: Cycles -> Cycles

toEnum :: Int -> Cycles

fromEnum :: Cycles -> Int

enumFrom :: Cycles -> [Cycles]

enumFromThen :: Cycles -> Cycles -> [Cycles]

enumFromTo :: Cycles -> Cycles -> [Cycles]

enumFromThenTo :: Cycles -> Cycles -> Cycles -> [Cycles]

Eq Cycles

Defined in Perf.Time

Methods

(==) :: Cycles -> Cycles -> Bool

(/=) :: Cycles -> Cycles -> Bool

Integral Cycles

Defined in Perf.Time

Methods

quot :: Cycles -> Cycles -> Cycles

rem :: Cycles -> Cycles -> Cycles

div :: Cycles -> Cycles -> Cycles

mod :: Cycles -> Cycles -> Cycles

quotRem :: Cycles -> Cycles -> (Cycles, Cycles)

divMod :: Cycles -> Cycles -> (Cycles, Cycles)

toInteger :: Cycles -> Integer

Num Cycles

Defined in Perf.Time

Methods

(+) :: Cycles -> Cycles -> Cycles

(-) :: Cycles -> Cycles -> Cycles

(*) :: Cycles -> Cycles -> Cycles

negate :: Cycles -> Cycles

abs :: Cycles -> Cycles

signum :: Cycles -> Cycles

fromInteger :: Integer -> Cycles

Ord Cycles

Defined in Perf.Time

Methods

compare :: Cycles -> Cycles -> Ordering

(<) :: Cycles -> Cycles -> Bool

(<=) :: Cycles -> Cycles -> Bool

(>) :: Cycles -> Cycles -> Bool

(>=) :: Cycles -> Cycles -> Bool

max :: Cycles -> Cycles -> Cycles

min :: Cycles -> Cycles -> Cycles

Read Cycles

Defined in Perf.Time

Methods

readsPrec :: Int -> ReadS Cycles

readList :: ReadS [Cycles]

readPrec :: ReadPrec Cycles

readListPrec :: ReadPrec [Cycles]

Real Cycles

Defined in Perf.Time

Methods

toRational :: Cycles -> Rational

Show Cycles

Defined in Perf.Time

Methods

showsPrec :: Int -> Cycles -> ShowS

show :: Cycles -> String

showList :: [Cycles] -> ShowS

Semigroup Cycles

Defined in Perf.Time

Methods

(<>) :: Cycles -> Cycles -> Cycles

sconcat :: NonEmpty Cycles -> Cycles

stimes :: Integral b => b -> Cycles -> Cycles

Monoid Cycles

Defined in Perf.Time

Methods

mempty :: Cycles

mappend :: Cycles -> Cycles -> Cycles

mconcat :: [Cycles] -> Cycles

cputime :: StepMeasure IO Integer

a measure using getCPUTime from System.CPUTime (unit is picoseconds)

clocktime :: StepMeasure IO Double

a measure using getCurrentTime (unit is seconds)

time :: Measure IO Cycles

tick as a Measure

times :: Int -> Measure IO [Cycles]

tick as a multi-Measure

stepTime :: StepMeasure IO Cycles

tick as a StepMeasure