enzyme/test/Integration/ReverseMode/virtualshadow2.cpp

// RUN: %clang++ -std=c++11 -fno-exceptions -ffast-math -O0 %s -S -emit-llvm -o - | %opt - %OPloadEnzyme %enzyme -S | %lli -
// RUN: %clang++ -std=c++11 -fno-exceptions -ffast-math -O1 %s -S -emit-llvm -o - | %opt - %OPloadEnzyme %enzyme -S | %lli -
// RUN: %clang++ -std=c++11 -fno-exceptions -ffast-math -O2 %s -S -emit-llvm -o - | %opt - %OPloadEnzyme %enzyme -S | %lli -
// RUN: %clang++ -std=c++11 -fno-exceptions -ffast-math -O3 %s -S -emit-llvm -o - | %opt - %OPloadEnzyme %enzyme -S | %lli -
// RUN: %clang++ -std=c++11 -fno-exceptions -ffast-math -O0 %s -S -emit-llvm -o - | %opt - %OPloadEnzyme %enzyme -enzyme-inline=1 -S | %lli -
// RUN: %clang++ -std=c++11 -fno-exceptions -ffast-math -O1 %s -S -emit-llvm -o - | %opt - %OPloadEnzyme %enzyme -enzyme-inline=1 -S | %lli -
// RUN: %clang++ -std=c++11 -fno-exceptions -ffast-math -O2 %s -S -emit-llvm -o - | %opt - %OPloadEnzyme %enzyme -enzyme-inline=1 -S | %lli -
// RUN: %clang++ -std=c++11 -fno-exceptions -ffast-math -O3 %s -S -emit-llvm -o - | %opt - %OPloadEnzyme %enzyme -enzyme-inline=1 -S | %lli -

#include <stdio.h>
#include "../test_utils.h"

struct S {
   double (*fn)(double);
   double val;
};

double square(double x){ return x * x; }

double foo(struct S* s) {
  return square(s->val);
}


void primal() {
  struct S s;
  s.fn = square;
  s.val = 3.0;
  printf("%f\n", foo(&s));
}

void* __enzyme_virtualreverse(void*);
void __enzyme_autodiff(void*, void*, void*);
void reverse() {
  struct S s;
  s.fn = square;
  s.val = 3.0;
  struct S d_s;
  d_s.fn = (double (*)(double))__enzyme_virtualreverse((void*)square);
  d_s.val = 0.0;
  __enzyme_autodiff((void*)foo, &s, &d_s);
  printf("shadow res=%f\n", d_s.val);
  APPROX_EQ(d_s.val, 6.0, 1e-7);
}

int main() {
    primal();
    reverse();
}