64-bit

问题 For a hobby project I'm working on, I need to emulate certain 64-bit integer operations on a x86 CPU, and it needs to be fast . Currently, I'm doing this via MMX instructions, but that's really a pain to work with, because I have to flush the fp register state all the time (and because most MMX instructions deal with signed integers, and I need unsigned behavior). So I'm wondering if the SSE/optimization gurus here on SO can come up with a better implementation using SSE. The operations I

问题 Here is the C++ program compiled by up-to-date Cygwin64 (gcc/x86_84-pc-cygwin/9.3.0): extern "C" __declspec(dllimport) void foo(void); int main(void) { foo(); return 0; } with commandline: g++ -o mre.exe mre.cc /f/temp/simpledll/x64/Debug/simpledll.lib For SimpleDLL I created a new Windows C++ DLL using VS Community 2019, switched to x64 target, disabled PCH, and added simpledll.cpp: extern "C" __declspec(dllexport) void foo(void); void foo(void) { MessageBoxA(NULL, "In simpledll foo", "Title

问题 Here is the C++ program compiled by up-to-date Cygwin64 (gcc/x86_84-pc-cygwin/9.3.0): extern "C" __declspec(dllimport) void foo(void); int main(void) { foo(); return 0; } with commandline: g++ -o mre.exe mre.cc /f/temp/simpledll/x64/Debug/simpledll.lib For SimpleDLL I created a new Windows C++ DLL using VS Community 2019, switched to x64 target, disabled PCH, and added simpledll.cpp: extern "C" __declspec(dllexport) void foo(void); void foo(void) { MessageBoxA(NULL, "In simpledll foo", "Title

问题 Here is the C++ program compiled by up-to-date Cygwin64 (gcc/x86_84-pc-cygwin/9.3.0): extern "C" __declspec(dllimport) void foo(void); int main(void) { foo(); return 0; } with commandline: g++ -o mre.exe mre.cc /f/temp/simpledll/x64/Debug/simpledll.lib For SimpleDLL I created a new Windows C++ DLL using VS Community 2019, switched to x64 target, disabled PCH, and added simpledll.cpp: extern "C" __declspec(dllexport) void foo(void); void foo(void) { MessageBoxA(NULL, "In simpledll foo", "Title

问题 I'm attempting to make an x64 build of a project with Visual Studio 2005. It's currently failing with linker error C1905, 'Front end and back end not compatible (must target same processor).' From what I gather, this is essentially saying that my x64 build is attempting to link with x86 modules. Unfortunately, this project links with a lot of different libraries. I'm not sure which is the one causing the problem. Is there any way to get more information out of Visual Studio? 回答1: First, check

问题 What I want: To add a network namespace option to execsnoop bcc tool to trace only the logs with specified network namespace just like we have filter PID option in many other bcc tools. For eg: execsnoop -N "ns_id" I am using linux kernel structures to retrieve namespace id net = task->nsproxy->net_ns; and need to assign the retrieved ns to data.netns which is u32 int. What I am doing: int syscall__execve(struct pt_regs *ctx, const char __user *filename, const char __user *const __user *_

问题 I want to create a binary on MacOS Catalina (64 bit) with a data segment that can be made executable (see here for details) but is not executable from the start. I make my binary with gcc -nostdlib -segprot __DATA rwx rw- .... I also created an object file with gcc and then called ld directly. The ld version is $ ld -v @(#)PROGRAM:ld PROJECT:ld64-530 BUILD 18:57:17 Dec 13 2019 configured to support archs: armv6 armv7 armv7s arm64 arm64e arm64_32 i386 x86_64 x86_64h armv6m armv7k armv7m

问题 I want to create a binary on MacOS Catalina (64 bit) with a data segment that can be made executable (see here for details) but is not executable from the start. I make my binary with gcc -nostdlib -segprot __DATA rwx rw- .... I also created an object file with gcc and then called ld directly. The ld version is $ ld -v @(#)PROGRAM:ld PROJECT:ld64-530 BUILD 18:57:17 Dec 13 2019 configured to support archs: armv6 armv7 armv7s arm64 arm64e arm64_32 i386 x86_64 x86_64h armv6m armv7k armv7m

问题 How does the JVM handle a primitive "long", which is 64bits, on a 32bit processor? Can it utilise mulitple cores in parallel when on a Multi-Core 32bit machine? How much slower are 64bit operations on a 32bit machine? 回答1: It may use multiple cores to run different threads, but it does not use them in parallel for 64 bit calculations. A 64 bit long is basically stored as two 32 bit ints. In order to add them, two additions are needed, keeping track of the carry bit. Multiplication is kind of

问题 I load the odbccp32.dll from System32 and even tried to use from SysWow64 . I use SQLConfigDataSource function to configure my System DSN for specified Driver. This function successfully configure drivers which are 32-bit, but does not do the same for 64-bit drivers. Does this dll only works for drivers which are 32-bit? When I ran ODBC Administrator tool (64-bit) I am able to see the 64-bit drivers and add them manually to System DSN, but I cannot do this using this DLL . 回答1: Only 64-bit