Assertion `!subretused' failed when compiling simple example with custom derivatives.

[tthsqe12]

I don't see anything wrong with doing

extern double F(double);
extern double Fp(double);

__attribute__((noinline)) double f(double x) {return F(x);}
void f_aug(double x) { }
double f_rev(double x, double grad_out) {return grad_out*Fp(x);}
void* __enzyme_register_gradient_f[3] = { (void*)f, (void*)f_aug, (void*)f_rev };

void g(double x[5]) {
    x[2] = f(x[0] + x[1]);
}

template<typename ...T> void __enzyme_autodiff(void*, T...);

void g_auto(double x[5], double x_b[5]) {
    __enzyme_autodiff((void*)g, x, x_b);
}

but

Enzyme/enzyme/Enzyme/AdjointGenerator.h

Line 7257 in b2f1190

assert(!subretused);

fails here. My command line is nothing unusual (-O0 fails the same way)

0.	Program arguments: /home/pc/cpp/llvm-project-llvmorg-15.0.7/build/bin/clang++ -O3 -fno-exceptions tcustom.cpp -S -emit-llvm -o output.ll -fpass-plugin=/home/pc/cpp/git/Enzyme/enzyme/build/Enzyme/ClangEnzyme-15.so -Xclang -load -Xclang /home/pc/cpp/git/Enzyme/enzyme/build/Enzyme/ClangEnzyme-15.so

[wsmoses]

Ah your augmented primal should also return the original result of the function

[tthsqe12]

OK. Why this need not be done in Integration/ReverseMode/invsqrt.c? (This is where I learned about enzyme_register_gradient)