enzyme/test/Integration/ForwardMode/customfwd.c

// This should work on LLVM 7, 8, 9, however in CI the version of clang installed on Ubuntu 18.04 cannot load
// a clang plugin properly without segfaulting on exit. This is fine on Ubuntu 20.04 or later LLVM versions...
// RUN: if [ %llvmver -ge 10 ]; then %clang -std=c11 -O0 %s -S -emit-llvm -o - %loadClangEnzyme | %lli - ; fi
// RUN: if [ %llvmver -ge 10 ]; then %clang -std=c11 -O1 %s -S -emit-llvm -o - %loadClangEnzyme | %lli - ; fi
// RUN: if [ %llvmver -ge 10 ]; then %clang -std=c11 -O2 %s -S -emit-llvm -o - %loadClangEnzyme | %lli - ; fi
// RUN: if [ %llvmver -ge 10 ]; then %clang -std=c11 -O3 %s -S -emit-llvm -o - %loadClangEnzyme | %lli - ; fi
// RUN: if [ %llvmver -ge 10 ]; then %clang -std=c11 -O0 %s -S -emit-llvm -o - %loadClangEnzyme -mllvm -enzyme-inline=1 -S | %lli - ; fi
// RUN: if [ %llvmver -ge 10 ]; then %clang -std=c11 -O1 %s -S -emit-llvm -o - %loadClangEnzyme -mllvm -enzyme-inline=1 -S | %lli - ; fi
// RUN: if [ %llvmver -ge 10 ]; then %clang -std=c11 -O2 %s -S -emit-llvm -o - %loadClangEnzyme -mllvm -enzyme-inline=1 -S | %lli - ; fi
// RUN: if [ %llvmver -ge 10 ]; then %clang -std=c11 -O3 %s -S -emit-llvm -o - %loadClangEnzyme -mllvm -enzyme-inline=1 -S | %lli - ; fi
// RUN: if [ %llvmver -ge 12 ]; then %clang -std=c11 -O0 %s -S -emit-llvm -o - %newLoadClangEnzyme | %lli - ; fi
// RUN: if [ %llvmver -ge 12 ]; then %clang -std=c11 -O1 %s -S -emit-llvm -o - %newLoadClangEnzyme | %lli - ; fi
// RUN: if [ %llvmver -ge 12 ]; then %clang -std=c11 -O2 %s -S -emit-llvm -o - %newLoadClangEnzyme | %lli - ; fi
// RUN: if [ %llvmver -ge 12 ]; then %clang -std=c11 -O3 %s -S -emit-llvm -o - %newLoadClangEnzyme | %lli - ; fi
// RUN: if [ %llvmver -ge 12 ]; then %clang -std=c11 -O0 %s -S -emit-llvm -o - %newLoadClangEnzyme -mllvm -enzyme-inline=1 -S | %lli - ; fi
// RUN: if [ %llvmver -ge 12 ]; then %clang -std=c11 -O1 %s -S -emit-llvm -o - %newLoadClangEnzyme -mllvm -enzyme-inline=1 -S | %lli - ; fi
// RUN: if [ %llvmver -ge 12 ]; then %clang -std=c11 -O2 %s -S -emit-llvm -o - %newLoadClangEnzyme -mllvm -enzyme-inline=1 -S | %lli - ; fi
// RUN: if [ %llvmver -ge 12 ]; then %clang -std=c11 -O3 %s -S -emit-llvm -o - %newLoadClangEnzyme -mllvm -enzyme-inline=1 -S | %lli - ; fi

#include "../test_utils.h"

double __enzyme_fwddiff(void*, ...);

__attribute__((noinline))
void square_(const double* src, double* dest) {
    *dest = *src * *src;
}

int derivative = 0;
void derivative_square_(const double* src, const double *d_src, const double* dest, double* d_dest) {
    derivative++;
    // intentionally incorrect for debugging
    *d_dest = 100; 
}

void* __enzyme_register_derivative_square[] = {
    (void*)square_,
    (void*)derivative_square_,
};


double square(double x) {
    double y;
    square_(&x, &y);
    return y;
}

double dsquare(double x) {
    return __enzyme_fwddiff((void*)square, x, 1.0);
}


int main() {
    double res = dsquare(3.0);
    printf("res=%f derivative=%d\n", res, derivative);
    APPROX_EQ(res, 100.0, 1e-10);
    APPROX_EQ(derivative, 1.0, 1e-10);
}