[cfe-users] What option can make clang generate tail call IR?

[gamma_chen]

The following recursive example cannot generate "tail call". It generate "call" only. Anyone knows how to make "tail call"?

// clang -c 1.c -emit-llvm -o 1.bc
// llvm-dis 1.bc -o -


// File 1.c

int factorial(int x)
{
  x--;
  if (x <= 0)
    return 1;
  return x*factorial(x-1);
}

// output 
define i32 @factorial(i32 %x) #0 {
...
  %call = call i32 @factorial(i32 %sub)
..
}
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