[Tack-devel] Accessing to unaligned data in records/structures

[Carl E. C. <cec...@ya...>]

Greetings,              I am slowly working on the em instruction testsuite, and I am a bit stuck, when trying to test LOI from the below code, I get a bad pointer error in the interpreter at LOI 2, because the address is not aligned. Hence my question, how do you access the second field of this structure? What happens in pascal if the record is declared as packed, or is this just a problem associated with the interpreter?


/* Unaligned structure containing the data to read. */ 
struct01
    rom    255I1
    rom -32767I2
    rom 2147483647I4
#if EM_WSIZE >= 4    
    rom 9223372036854775807I8
#endif
    
    exp $_m_a_i_n
    pro $_m_a_i_n, 0
    
    /* Unaligned structure access */
    
1    
    lae    struct01+1            /* stack address of structure */
    loi    2                    /* stack data from structure    */
    loc    -32767
    cmi    EM_WSIZE            /* check if value is what is expected. */
    zeq *2

    ldc __LINE__
    cal $fail
    asp 4    
    
Thanks for all your help,Carl