Problem I am studying high performance matrix multiplication algorithms such as OpenBLAS or GotoBLAS and I am trying to reproduce some of the results. This question deals with the inner kernel of a matrix multiplication algorithm. Specifically, I am looking at computing C += AB , where A and B are 2x2 matrices of type double at the peak speed of my CPU. There are two ways to do this. One wa
问题 我正在研究高性能的矩阵乘法算法，如OpenBLAS或GotoBLAS，我正试图重现一些结果。 这个问题涉及矩阵乘法算法的内核。 具体来说，我在计算C += AB ，其中A和B是我的CPU的峰值速度下的double类型的2×2矩阵。 有两种方法可以做到这一点。 一种方法是使用SIMD指令。 第二种方法是使用SIMD寄存器在汇编中直接编码。 迄今为止我所看到的 所有相关论文，当然网页，我的电脑上很多很多的SO Q＆作为处理对象（举不胜举）
I started work on a JmDNS bindings for Xamarin.Android. I managed to get the binding to build but I can not reference it from within my code. https://github.com/ytn3rd/monodroid-bindings/tree/master/JmDNS First issue I had was there was no IDNSListener class to reference. So I added a partial interface in there for it. I have the function it needs void updateRecord(DNSCache dnsCache, long n
我开始为Xamarin.Android开发一个JmDNS绑定。 我设法让绑定生成，但我不能从我的代码中引用它。 https://github.com/ytn3rd/monodroid-bindings/tree/master/JmDNS 我遇到的第一个问题是没有IDNSListener类可供参考。 所以我在那里添加了一个部分接口。 我有它需要的函数void updateRecord（DNSCache dnsCache，现在长，DNSEntry记录）; 注释掉，因为它会抱怨无法引用DNSCache或DNSEntry。 （我相信我删除了DNSCache，这
This question already has an answer here: What's the difference between passing by reference vs. passing by value? 18 answers In increment(char *c) you create a new pointer c which is pointing to the same object p does, but they are not the same, they are just pointing to the same thing. If you increment one, the other one stays the same. If you want to increment the pointer p you nee
这个问题在这里已经有了答案： 传递引用与价值传递之间有什么区别？ 18个答案 在increment(char *c)您创建了一个指向同一个对象p的新指针c ，但它们并不相同，它们只是指向相同的东西。 如果你增加一个，另一个保持不变。 如果你想增加指针p你需要一个指向这个指针的指针，把它传递给你的函数，并改变p而不是本地副本。
This question already has an answer here: What's the difference between passing by reference vs. passing by value? 18 answers In your function a is passed by value not by reference, so the x value will no tb e changed. While b is passed by reference, so value of y is changed.
这个问题在这里已经有了答案： 传递引用与价值传递之间有什么区别？ 18个答案 在你的函数中，按值传递而不是通过引用，所以x值不会被改变。 虽然b通过引用传递，所以y的值被改变。
This question already has an answer here: What's the difference between passing by reference vs. passing by value? 18 answers With the exception of arrays and functions (see below), C always passes arguments `by value': a copy of the value of each argument is passed to the function; the function cannot modify the actual argument passed to it: void foo(int j) { j = 0; /* modifie
这个问题在这里已经有了答案： 传递引用与价值传递之间有什么区别？ 18个答案 除了数组和函数（见下文）之外，C总是通过`value'传递参数：每个参数值的一个副本被传递给函数; 该函数不能修改传递给它的实际参数： void foo(int j) { j = 0; /* modifies the copy of the argument received by the function */ } int main(void) { int k=10; foo(k); /* k still equals 10 */ } 如果你想要一个函数来
This question already has an answer here: What's the difference between passing by reference vs. passing by value? 18 answers Pass by value creates a copy of the argument. It is this copy that is changed in the function void add(int x){ x = x+1; } Thus the change you make is made to the copy and not the variable in your main scope (that you are expecting to see changed). If you w
这个问题在这里已经有了答案： 传递引用与价值传递之间有什么区别？ 18个答案 按值传递会创建参数的副本。 这是在该功能中更改的副本 void add(int x){ x = x+1; } 因此，您所做的更改是针对副本而不是main范围中的变量（您期望看到更改）。 如果您想通过将参数作为参数传递来更改函数中的变量，则不能通过值传递。 你可以改变你的函数来传递像这样的指针 void add(int* x){ *x = *x + 1; } 并将整数的地址传
This question already has an answer here: What's the difference between passing by reference vs. passing by value? 18 answers There is no pass by reference in C, it's always pass by value. C developers can emulate pass by reference, by passing the pointers to a variable and the accessing it using dereferencing within the function. Something like the following, which sets a variabl
这个问题在这里已经有了答案： 传递引用与价值传递之间有什么区别？ 18个答案 在C中没有通过引用的传递，它总是按值传递。 C开发人员可以通过引用来模拟传递，方法是将指针传递给变量，并使用函数中的取消引用对其进行访问。 如下所示，它将变量设置为42 ： static void changeTo42 (int *pXyzzy) { *pXyzzy = 42; } : int x = 0; changeTo42 (&x); 与C ++真正的通过引用相比，你不必沉迷于指针（特别是指向指
In the latest edition of JavaSpecialists newsletter, the author mentions a piece of code that is un-compilable in Java public class A1 { Character aChar = 'u000d'; } Try compile it, and you will get an error, such as: A1.java:2: illegal line end in character literal Character aChar = 'u000d'; ^ Why an equivalent piece of c# code does not show su
在最新版本的Java专业人员通讯中，作者提到了一段在Java中不可编译的代码 public class A1 { Character aChar = 'u000d'; } 尝试编译它，你会得到一个错误，如： A1.java:2: illegal line end in character literal Character aChar = 'u000d'; ^ 为什么一个等效的c＃代码块不显示这样的问题？ public class CharacterFixture { char aChar = 'u000d'; } 我错过了什么
I'm used to // to mark a single line comment from Java and Visual Studio and was surprised that this does not exist for Ansi-C. Using /* my comment */ is quite annoying. Is there any other way to mark a single line comment when using Ansi-C? ANSI-C，不，但目前的C99标准允许它们。 You could also write a macro: #define COMMENT(x) int main() { COMMENT(Hi there) return 0; } Other tha
我习惯于//标记来自Java和Visual Studio的单行注释，并且对Ansi-C不存在这一点感到惊讶。 使用/* my comment */很烦人。 使用Ansi-C时，是否有其他方式可以标记单行注释？ ANSI-C，不，但目前的C99标准允许它们。 你也可以编写一个宏： #define COMMENT(x) int main() { COMMENT(Hi there) return 0; } 除此之外，在ANSI C中没有什么明显的 - 你注意到/* */ style在ANSI C 89中是无效的 好 ... ANSI C是C99;
When you have server-side code (ie some ApiController ) and your functions are asynchronous - so they return Task<SomeObject> - is it considered best practice that any time you await functions that you call ConfigureAwait(false) ? I had read that it is more performant since it doesn't have to switch thread contexts back to the original thread context. However, with ASP.NET Web Api, i
当你有服务器端代码（例如一些ApiController ）和你的函数是异步的 - 所以它们返回Task<SomeObject> - 当你等待函数调用ConfigureAwait(false) ，是否认为是最佳做法？ 我读过它是更高性能的，因为它不必将线程上下文切换回原始线程上下文。 但是，对于ASP.NET Web Api，如果您的请求进入一个线程，并且您在等待某个函数并调用ConfigureAwait(false) ，当您返回ApiController函数的最终结果时可能会将您置于不同的线程