1 Reply Latest reply on Apr 28, 2011 5:33 PM by fswehosky

    DC misses on register only instructions

      DC misses on register only instructions

      Hi, there, apology for this seemingly entry level question.

      The issue: CodeAnalyst reports that some instructions have many DC misses, even though these instructions have no main memory access at all. Both operands are XMM registers. For example, "mulps %xmm0 %xmm1"

      How should I interpret this?


      Thanks ahead


        • DC misses on register only instructions

          Hello Ben,

          That's a good question, so no apologies are needed. 

          Are you using the Event-based profiling?  With the event profiling, the accuracy of the instructions that actually triggered the interrupt is limited to any of the micro-ops that were executing in parallel.  It may be that an instruction preceeding or following the reported instruction actually triggered it.

          I recommend using the Instruction-based sampling (IBS) Ops profiling to capture precise DC miss information.

          I hope this helps.