C++: Add nomagic to Function::getParameter
#20854
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Pull Request Overview
This PR adds nomagic pragmas to two parameter-related predicates in the Function class to prevent inefficient join operations. The change addresses a performance issue where magic optimization was causing a join-on-index problem in Function::getParameter.
Key Changes
- Added
pragma[nomagic]toFunction::getParameter(int n)to prevent magic optimization from creating inefficient join patterns - Added
pragma[nomagic]toFunction::getAParameter()for consistency and to prevent similar performance issues
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jketema
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Nov 17, 2025
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jketema
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Looks sensible. I'm happy if DCA is happy.
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Sorry... I am that person who didn't have the log :-) My editor OOMed during the experiments and I think it wiped all the logs. |
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DCA was uneventful. At first I thought there was a large speedup, but then I realized it was on the macos project only 😭 |
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Magic was giving us the dreaded join-on-index in
Function::getParameter. Sadly, the person who was getting this issue didn't save an evaluator log for me, but they did manage to share this very useful screenshot 😅