64-bit

问题 I'm currently learning Haskell using the project Euler problems as my playground. I was astound by how slow my Haskell programs turned out to be compared to similar programs written in other languages. I'm wondering if I've forseen something, or if this is the kind of performance penalties one has to expect when using Haskell. The following program in inspired by Problem 331, but I've changed it before posting so I don't spoil anything for other people. It computes the arc length of a

问题 I am using a neat table view controller called SKSTableView in my project which allows each table row to have a number of sub rows. This code works perfectly in 32bit mode but when I run it on my iPhone 5S or in the Simulator in 4-inch 64bit mode, when you tap on a row to get the sub rows it crashes. I do not have any knowledge of the differences of 64bit and 32bit iOS systems. I would love to understand what it happening here. You will notice that the *SubRowObjectKey is set to void- the

问题 I'm porting my application from 32 bit to 64 bit. Currently, the code compiles under both architectures, but the results are different. For various reasons, I'm using floats instead of doubles. I assume that there is some implicit upconverting from float to double happening on one machine and not the other. Is there a way to control for this, or specific gotchas I should be looking for? edited to add: 32 bit platform gcc (GCC) 4.1.2 20070925 (Red Hat 4.1.2-33) Dual-Core AMD Opteron(tm)

问题 I finally decided to post a question here after some time spent trying to figure out this problem. A few days ago I posted this same question on sqlite forum but that website is currently not available . http://sqlite.phxsoftware.com/forums/t/2669.aspx So, here is the question: I have 64-bit computer with 64-bit OS. A co-worker has 64-bit computer with 32-bit OS. We develop a web application that brings a lot of data from server and keeps it in memory SQLite database, so everything can run

问题 Obviously, a 64-bit processor has a 64-bit address space, so you have more than 4 GB of RAM at your disposal. Does compiling the same program as 64-bit and running on a 64-bit CPU have any other advantages that might actually benefit programs that aren't enormous memory hogs? I'm asking about CPUs in general, and Intel-compatible CPUs in particular. 回答1: There's a great article on Wikipedia about the differences and benefits of 64bit Intel/AMD cpus over their 32 bit versions. It should have

问题 After following the instructions in INSTALL.W64 I have two problems: The code is still written to the "out32" folder. I need to be able to link to both 32-bit and 64-bit versions of the library on my workstation, so I don't want the 64-bit versions to clobber the 32-bit libs. The output is still 32-bit! This means that I get "unresolved external symbol" errors when trying to link to the libraries from an x64 app. 回答1: To compile the static libraries (both release and debug), this is what you

问题 On Linux systems (either 32- or 64-bit), what is the size of pid_t , uid_t , and gid_t ? 回答1: #include <stdio.h> #include <sys/types.h> int main() { printf("pid_t: %zu\n", sizeof(pid_t)); printf("uid_t: %zu\n", sizeof(uid_t)); printf("gid_t: %zu\n", sizeof(gid_t)); } EDIT: Per popular request (and because, realistically, 99% of the people coming to this question are going to be running x86 or x86_64)... On an i686 and x86_64 (so, 32-bit and 64-bit) processor running Linux >= 3.0.0, the answer

问题 I am looking for a way of performing a bitwise AND on a 64 bit integer in JavaScript. JavaScript will cast all of its double values into signed 32-bit integers to do the bitwise operations (details here). 回答1: Javascript represents all numbers as 64-bit double precision IEEE 754 floating point numbers (see the ECMAscript spec, section 8.5.) All positive integers up to 2^53 can be encoded precisely. Larger integers get their least significant bits clipped. This leaves the question of how can

问题 I am looking for a way of performing a bitwise AND on a 64 bit integer in JavaScript. JavaScript will cast all of its double values into signed 32-bit integers to do the bitwise operations (details here). 回答1: Javascript represents all numbers as 64-bit double precision IEEE 754 floating point numbers (see the ECMAscript spec, section 8.5.) All positive integers up to 2^53 can be encoded precisely. Larger integers get their least significant bits clipped. This leaves the question of how can

问题 I've just received and read a newsletter from Google Play mentioning that from next year on, the store "will require that new apps and app updates with native libraries provide 64-bit versions in addition to their 32-bit versions". For those who haven't read it yet, it states: 64-bit support requirement in 2019 Platform support for 64-bit architectures was introduced in Android 5.0. Today, over 40% of Android devices coming online have 64-bit support, while still maintaining 32-bit