Minimal Enzyme Example (No ImpactX)

Author: ax3l

src/main.cpp

@@ -17,9 +17,22 @@
 #   include <mpi.h>
 #endif
 
+#include <stdio.h>
+extern double __enzyme_autodiff(void*, double);
+double square(double x) {
+    return x * x;
+}
+double dsquare(double x) {
+    // This returns the derivative of square or 2 * x
+    return __enzyme_autodiff((void*) square, x);
+}
+
 
 int main(int argc, char* argv[])
 {
+    for(double i=1; i<5; i++)
+        printf("square(%f)=%f, dsquare(%f)=%f", i, square(i), i, dsquare(i));
+
 #if defined(AMREX_USE_MPI)
     AMREX_ALWAYS_ASSERT(MPI_SUCCESS == MPI_Init(&argc, &argv));
 #endif