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#include <stdio.h>

// Align structure members with 1-byte boundaries
#pragma pack(push, 1)
typedef struct {
    char a;   // 1 byte
    int b;    // 4 bytes
} PackedStruct;
#pragma pack(pop)

int main() {
    // Print size of the structure with no padding
    printf("Size of PackedStruct: %zu\n", sizeof(PackedStruct));
    return 0;
}

              
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#include <stdio.h>

// Suppress warning about unused static functions
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wunused-function"

// Normally triggers a warning, but it is now ignored
static void unused_helper() {
    printf("This helper is never called.\n");
}

#pragma GCC diagnostic pop

int main() {
    printf("No warnings about unused functions.\n");
    return 0;
}

              
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#include <stdio.h>

// Example function to call in a loop
void process(int i) {
    printf("Processing %d\n", i);
}

int main() {
    // Suggest loop unrolling to the compiler
    #pragma unroll 4
    for (int i = 0; i < 8; i++) {
        process(i);
    }
    return 0;
}