Clang 15.0 make c++ code 5 times slower than Clang 14.3.1

Hi,

I am running Mac Intel I7 post 2020 with Sonoma and clang 15.0 .

The Clang 15.0 makes c++ code running 5 times slower than it was before upgrade from Ventura 13.6 and Clang 14.3.1

The other trouble is that Sonoma does not allow to revert to Clang 14.3.1 . I do not use Xcode only command line tools .

here my options :

g++ -std=c++17 -Ofast -march=native -funroll-loops -flto -DNDEBUG -o a prog.cpp

So what happened to C++ ?

Clang 15.0 make c++ code 5 times slower than Clang 14.3.1
 
 
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