enzyme/test/Integration/ReverseMode/smallrealloc.c

// RUN: %clang -std=c11 -O0 %s -S -emit-llvm -o - | %opt - %OPloadEnzyme %enzyme -S | %lli - 
// RUN: %clang -std=c11 -O1 %s -S -emit-llvm -o - | %opt - %OPloadEnzyme %enzyme -S | %lli - 
// RUN: %clang -std=c11 -O2 %s -S -emit-llvm -o - | %opt - %OPloadEnzyme %enzyme -S | %lli - 
// RUN: %clang -std=c11 -O3 %s -S -emit-llvm -o - | %opt - %OPloadEnzyme %enzyme -S | %lli - 
// RUN: %clang -std=c11 -O0 %s -S -emit-llvm -o - | %opt - %OPloadEnzyme %enzyme -enzyme-inline=1 -S | %lli - 
// RUN: %clang -std=c11 -O1 %s -S -emit-llvm -o - | %opt - %OPloadEnzyme %enzyme -enzyme-inline=1 -S | %lli - 
// RUN: %clang -std=c11 -O2 %s -S -emit-llvm -o - | %opt - %OPloadEnzyme %enzyme -enzyme-inline=1 -S | %lli - 
// RUN: %clang -std=c11 -O3 %s -S -emit-llvm -o - | %opt - %OPloadEnzyme %enzyme -enzyme-inline=1 -S | %lli - 

#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <assert.h>

#include "../test_utils.h"


float __enzyme_autodiff(void*, float);

float foo(float inp) {
  float* x = (float*)malloc(1*sizeof(float));
  x[0] = inp;
  float* y = (float*)realloc(x, 2*sizeof(float));
  y[1] = y[0] + inp;
  float res = y[1];
  free(y);
  return res;
}


int main(int argc, char** argv) {
  float inp = 3.0f;
  float res = __enzyme_autodiff(foo, inp);

  printf("hello! inp=%f, res=%f\n", inp, res);
  APPROX_EQ(res, 2.0f, 1e-10);

  return 0;
}