Kotlin Language Features Related to Null Handling

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Any software engineer with a Java background would find the null handling features in the Kotlin language interesting. Let's summarize this topic with some examples. Nullable types: In Kotlin, types are non-nullable by default. If you want a variable to be able to hold a null value, you need to explicitly declare its type as nullable using the Type? syntax. For example, String? denotes a nullable string, while String represents a non-nullable string. Safe calls (?.): Kotlin introduces the safe call operator (?.) for handling nullable types. It allows you to safely invoke a method or access a property on a nullable object. If the object is null, the expression returns null instead of throwing a NullPointerException. Example: data class Person(val name: String, val age: Int, val address: String?) fun main() {     // Create a person with a nullable address     val person1 = Person("John Doe", 25, "123 Main Street")     val person2 = Person("Jane Doe", 30,...
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Running SPEC2000 binaries on SimpleScalar

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Fast-forwarding and limiting the instructions:

Example: fast-forward 1 million instructions and then execute 100 million instructions:

(under simple-sim3.0 directory)

./sim-outorder -max:inst 1000000000 tests/spec2000/164.gzip/gzip00.peak.ev6 input.source 60









sim-outorder 256.bzip2/bzip200.peak.ev6 input.source 58

 sim-outorder 164.gzip/gzip00.peak.ev6 input.source 60

 sim-outorder 164.gzip/gzip00.peak.ev6 2000000: input.source 60

 sim-outorder 2000000: 181.mcf/mcf00.peak.ev6 inp.in

sim-outorder 186.crafty/crafty00.peak.ev6 < crafty.in

sim-outorder 197.parser/parser00.peak.ev6 2.1.dict -batch < 197.parser/ref.in

sim-outorder x175.vpr/vpr00.peak.ev6 < x175.vpr/net.in

sim-outorder 183.equake/equake00.peak.ev6 < 183.equake/inp.in

sim-outorder _177.mesa/mesa00.peak.ev6 < _177.mesa/mesa.in

Percentage of instructions that are fetched from the same page:

int/bzip2: 99%
int/gzip:  99%
int/mcf: 95%
int/crafty: 99%
int/parser: 95%
int/x175.vpr: 95%
float/lukas: 97%
float/equake: %98
float/wupwise: %96
float/mesa: %99
float/art: %93
float/sixtrack: %99 


 [1] Zhao, L. E. I., et al. "A leakage efficient instruction tlb design for embedded processors." IEICE TRANSACTIONS on Information and Systems 94.8 (2011): 1565-1574.


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