Manuel Drehwald

@wsmoses a potential fix is this: https://github.com/rust-lang/enzyme/pull/21 (or the EnzymeAD/Enzyme equivalent)

We need to teach Enzyme to recognize ``` fn main( ) { %5 = load ptr %MPI_SUM %6 = call diffe_test_mpi_call(..., %5) } test_mpi_call(... ptr %5) { %7 = call...

Given that this has a test that passes at least in release mode, can we merge this (and maybe create an issue with further TODOs, to make sure the progress...

As a small note, I wouldn't recommend building rustc anymore, rustc is providing dist(ributable) builds. Enzyme could download those, rm libenzyme.so and replace it by one that was just build...

@wsmoses ``` [100%] Linking CXX shared library libEnzyme-15.dylib Undefined symbols for architecture x86_64: "_compress2", referenced from: llvm::compression::zlib::compress(llvm::ArrayRef, llvm::SmallVectorImpl&, int) in libLLVMSupport.a[38](Compression.cpp.o) "_compressBound", referenced from: llvm::compression::zlib::compress(llvm::ArrayRef, llvm::SmallVectorImpl&, int) in libLLVMSupport.a[38](Compression.cpp.o) "_crc32",...

llvm-reduced (still reproduces): [mwe1.ll.txt](https://github.com/user-attachments/files/20140515/mwe1.ll.txt)

@wsmoses reduced with ``` #!/bin/bash /home/manuel/prog/rust-master/build/x86_64-unknown-linux-gnu/llvm/build/bin/opt $1 -load-pass-plugin=/home/manuel/prog/rust-master/build/x86_64-unknown-linux-gnu/enzyme/build/Enzyme/LLVMEnzyme-20.so -passes="enzyme" \ |& grep "llvm::ScalarEvolution::LoopGuards::collectFromBlock" ``` ``` target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128" target triple = "x86_64-unknown-linux-gnu" define double @_ZN5case15a_f6417hd8c151c742c277cfE(ptr %0, double %1, double...

Also there is at least a 4th bug, but I think that one is on the rust side, where we at times pass the wrong llvm_dir (in cases like PGO...

[out.ll.txt](https://github.com/user-attachments/files/20029663/out.ll.txt)

@wsmoses I don't understand how the julia build environment differs, especially the last commit was just a guess (since I don't know why zlib was previously commented out). However, it...