Changes between Version 2 and Version 3 of Ticket #228, comment 2


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Timestamp:
06/22/2021 01:07:28 PM (5 years ago)
Author:
Gary Dixon

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  • Ticket #228, comment 2

    v2 v3  
    126126However, the asq instruction (which was executing when the Overflow Fault
    127127occurred) is performing signed arithmetic.  Since the sign-bit is ON in the
    128 Q register, a large negative quantity is being added to a smaller positive value.
    129 The result should be a negative value.  An Overflow fault is triggered because
    130 the Overflow Mask indicator (oflm) is NOT set in the Indicators recorded
     128Q register, a large negative quantity is being added to an unknown (probably
     129negative) value. The result must have been a very large negative value which
     130overflowed the negative end of the fixed bin(35) integer range.
     131The ovfl indicator is set in the Indicators; and an Overflow fault was triggered
     132because the Overflow Mask indicator (oflm) is NOT set in the Indicators recorded
    131133in the machine conditions. 
    132134}}}