#include "PurifyIndexMath.h"
#include "IRMutator.h"
#include "IROperator.h"
#include "Simplify.h"

namespace Halide {
namespace Internal {

namespace {

class PurifyIndexMath : public IRMutator {
 using IRMutator::visit;

 Expr visit(const Call *op) override {
 if (op->is_intrinsic(Call::signed_integer_overflow)) {
 // This should only occur for values that are evaluated
 // but never actually used (e.g. on select branches that
 // are unreachable). Just replace it with zero.
 return make_zero(op->type);
 } else {
 return IRMutator::visit(op);
 }
 }
};

} // namespace

Expr purify_index_math(const Expr &s) {
 return PurifyIndexMath().mutate(s);
}

} // namespace Internal
} // namespace Halide