pragma

问题 I understand how #pragma unroll works, but if I have the following example: __global__ void test_kernel( const float* B, const float* C, float* A_out) { int j = threadIdx.x + blockIdx.x * blockDim.x; if (j < array_size) { #pragma unroll for (int i = 0; i < LIMIT; i++) { A_out[i] = B[i] + C[i]; } } } I want to determine the optimal value for LIMIT in the kernel above which will be launched with x number of threads and y number of blocks. The LIMIT can be anywhere from 2 to 1<<20 . Since 1

问题 Using SQLite3 with the following schema: CREATE TABLE Customers(ID INTEGER PRIMARY KEY, Company TEXT NOT NULL UNIQUE, Country TEXT NOT NULL, City TEXT NOT NULL); CREATE TABLE Orders(ID INTEGER PRIMARY KEY, CustomerID INTEGER NOT NULL, FOREIGN KEY(CustomerID) REFERENCES Customers(ID) ON DELETE RESTRICT ON UPDATE RESTRICT); and issuing this command: PRAGMA foreign_key_list(Orders); results in the following output: 0|0|Customers|CustomerID|ID|RESTRICT|RESTRICT|NONE As the documentation says

问题 This MCVE: #include <stdio.h> #include <time.h> #define MAX_LENGTH_DATETIME 25 template <typename T> char * convertUnixTimeToChar( time_t unixTime, T ) { (void) unixTime; #pragma message "2nd parameter in convertUnixTimeToChar() must be of type <char [MAX_LENGTH_DATETIME]>." exit(1); }; template<size_t N> char * convertUnixTimeToChar( time_t unixTime, char (&destination) [N] ) { if ( N < MAX_LENGTH_DATETIME ) { printf( "Overflow in convertUnixTimeToChar(): destination size [%ld] must be at

问题 I'm attempting to perform a link of previously generated .obj files (using the latest version of MSVC). When those .obj's were created, the source code specified: #pragma comment(lib, ...) As such, the linker is attempting to link against static libraries specified in the source. Is there a way to instruct the linker to ignore these libraries, so I can specify my own? e.g., if a piece of source did the following: #pragma comment(lib, foo.lib) At link time, I'd like the linker to ignore 'foo

问题 I want to know how much time each thread is using in the for loop. I want time_taken to be private for each thread so they can append their own time there. Best cast i would like the total time for each thread, instead of the time for each iteration in the while-loop. double time_taken = 0.0; while(delta >= epsilon) { delta = 0.0; double wtime = omp_get_wtime(); #pragma omp parallel for reduction(+:delta) for (i = 0; i < workSize; i++) { #do some work and change delta } time_taken += omp_get

问题 This question already has answers here : Closed 8 years ago . Possible Duplicates: C/C++ pragma in define macro Conditional “pragma omp” How can I use an OpenMP pragmas inside a macro definition? E.g. #define A() { \ ...a lot of code... \ #pragma omp for \ for(..) \ ..do_for.. \ ...another a lot of code \ } 回答1: As it was answered here Conditional "pragma omp" C99 has the _Pragma keyword that allows you to place what otherwise would be #pragma inside macros. Something like #define OMP_PARA

问题 Xcode is reporting the following warning: "SpriteKit Texture Atlas Generator Warning Splitting 'images.atlas' into 2 texture atlases due to input texture dimensions." Although I will modified my images in the future to avoid SpriteKit from generating this warning, I would like to temporarily suppress this warning using some pragma directives. Does anyone know the warning flag to use to suppress this warning using code like the following? #pragma clang diagnostic push #pragma clang diagnostic

问题 Can anyone supply me with simple working examples which illustrate the use of pragmas in Ada 2005 ? I understand that pragmas are used to priorities processes, just that I have not come across working examples ! Much appreciated ! 回答1: A search of comp.lang.ada for recent discussions about priorities has several interesting examples. This one seems particularly apropos to your question. Addendum: Two other exemplary sources are the Rationale for Ada 95 and Rationale for Ada 2005 回答2: An Ada

问题 This is similar to How do I show the value of a #define at compile-time?. Chris Barry's answer is not working for me: #ifdef __GNUC__ #define GCC_VERSION (__GNUC__ * 10000 + __GNUC_MINOR__ * 100 + __GNUC_PATCHLEVEL__) #endif ... #define XSTR(x) STR(x) #define STR(x) #x #pragma message "The value of GCC_VERSION: " XSTR(GCC_VERSION) Results in: $ rm -f dlltest.o && make dlltest.o g++ -DNDEBUG -g2 -O2 -march=native -pipe -c dlltest.cpp dlltest.cpp:13:80: note: #pragma message: The value of GCC

问题 Here is what I am doing in my DatabaseHelper class. public DatabaseHelper(Context context) { super(context, DATABASENAME, null, VERSION); context.openOrCreateDatabase(DATABASENAME, context.MODE_PRIVATE, null); } @Override public void onCreate(SQLiteDatabase db) { String queryProductsAllData = "CREATE TABLE `"+TABLE_PRODUCTS+"` (\n" + "\t`"+COLUMN_BRANDID +"`\tINTEGER,\n" + "\t`"+COLUMN_PRODUCTID +"`\tINTEGER,\n" + "\t`"+COLUMN_PRODUCTCODE +"`\tINTEGER,\n" + "\t`"+COLUMN_PIECESINCASE +"`