Fix boxcox to return same result for same input in one batch (#162772)

Summary:
The SIMD path is using SLEEF version of `pow` which is slightly different from `std::pow`.  The fix is to use the same vectorized code (with partial load and store) for the trailing data as well to ensure consistency between results.

Rollback Plan:

Differential Revision: D82265247

Pull Request resolved: https://github.com/pytorch/pytorch/pull/162772
Approved by: https://github.com/swolchok
This commit is contained in:
Jimmy Lu
2025-09-13 03:57:35 +00:00
committed by PyTorch MergeBot
parent 66133b1ab7
commit 49d30f9a23

View File

@ -73,6 +73,19 @@ void box_cox_zero_lambda(
}
}
template <typename T>
at::vec::Vectorized<T> box_cox_nonzero_lambda_impl(
at::vec::Vectorized<T> data,
at::vec::Vectorized<T> lambda1,
at::vec::Vectorized<T> lambda2,
at::vec::Vectorized<T> k_eps) {
auto sum = data + lambda2;
auto max = at::vec::max(sum, k_eps);
auto lambda_over_1 = at::vec::fast_recieprocal(lambda1);
auto pow = max.pow(lambda1);
return at::vec::fmsub(pow, lambda_over_1, lambda_over_1);
}
template <typename T>
void box_cox_nonzero_lambda(
int64_t D,
@ -88,21 +101,18 @@ void box_cox_nonzero_lambda(
auto k_eps_vec = Vec(k_eps);
for(; j + VLEN < D; j += VLEN) {
auto data = Vec::loadu(data_ptr + j);
auto lambda2 = Vec::loadu(lambda2_ptr + j);
auto sum = data + lambda2;
auto max = at::vec::max(sum, k_eps_vec);
auto lambda1 = Vec::loadu(lambda1_ptr + j);
auto lambda_over_1 = at::vec::fast_recieprocal(lambda1);
auto pow = max.pow(lambda1);
auto res = at::vec::fmsub(pow, lambda_over_1, lambda_over_1);
auto lambda2 = Vec::loadu(lambda2_ptr + j);
auto res = box_cox_nonzero_lambda_impl(data, lambda1, lambda2, k_eps_vec);
res.store(out + j);
}
for ( ;j < D; ++j) {
auto sum = data_ptr[j] + lambda2_ptr[j];
auto max = std::max(sum, k_eps);
auto lambda_over_1 = at::vec::fast_recieprocal(lambda1_ptr[j]);
auto pow = std::pow(max, lambda1_ptr[j]);
out[j] = pow * lambda_over_1 - lambda_over_1;
if (j < D) {
auto remaining = D - j;
auto data = Vec::loadu(data_ptr + j, remaining);
auto lambda1 = Vec::loadu(lambda1_ptr + j, remaining);
auto lambda2 = Vec::loadu(lambda2_ptr + j, remaining);
auto res = box_cox_nonzero_lambda_impl(data, lambda1, lambda2, k_eps_vec);
res.store(out + j, remaining);
}
}
#else