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Slow LEA instruction

sid9559
Beginner
139 Views

Hello,

I am analying a code for Image processing and I find that the bottleneck is slow LEA instructions. can someone help me wth menthods to fix it??

Regards,

Siddharth

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2 Replies
Peter_W_Intel
Employee
139 Views
If LEA instructions with three operands (base, index, offset), there is pressure of using port 1 and port 3 to cause 3 cycles latency - especially in deep loop. I don't think it makes sense to modify (inline?) assembly code directly, recommend to use Intel(r) C/C++ compiler with advanced options, such as O2, xHost, etc. In source code level, you may review: 1. Reduce index access in loop, if possible 2. Consider data alignment 3. Reduce branch code in loop 4. No dependency between iterations of loop 5. Others I missed
sid9559
Beginner
138 Views
Hello Peter, Thanks for your response. I will take a look into your recomendations and see how I can optimize my code. Siddharth
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