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THE FEUTEX TOOLKIT

Branch Misprediction Cost

Estimate added cycles per instruction from branch frequency and misprediction penalty.

Developer workspace● Runs in your browser
01 Your input
02 Your result
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FormulaAdded CPI = branch/100*miss/100*penalty; Estimated CPI = base+branch/100*miss/100*penalty

Made for real tasks

  • Estimate added cycles per instruction from branch frequency and misprediction penalty.
Explore step-by-step workflows →

Worked example

Inputs

Instructions that are branches
20 %
Branch misprediction share
5 %
Effective penalty
15 cycles
Baseline CPI
1 cycles/instruction

Expected results

Added CPI
0.15 cycles/instruction
Estimated CPI
1.15 cycles/instruction

Load the example in the workspace to reproduce these results. Display rounding does not change the underlying calculation.

How to use this tool

  1. Enter instructions that are branches, branch misprediction share, effective penalty, baseline cpi in the displayed units.
  2. Calculate the scenario, then compare it with measurements before changing a system.

Try this example

{
  "branch": 20,
  "miss": 5,
  "penalty": 15,
  "base": 1
}

Accuracy and scope

Additive effective penalty model; overlapping stalls and prediction correlation excluded.

Is my data uploaded?

This tool runs locally in your browser. Input and output are not sent to a processing server. Copy or download your result before leaving the page.