| 348 | } |
| 349 | |
| 350 | BasicDecimal128 Divide(int64_t context, const BasicDecimalScalar128& x, |
| 351 | const BasicDecimalScalar128& y, int32_t out_precision, |
| 352 | int32_t out_scale, bool* overflow) { |
| 353 | if (y.value() == 0) { |
| 354 | const char* err_msg = "DIVIDE: divide by zero error (decimal)"; |
| 355 | gdv_fn_context_set_error_msg(context, err_msg); |
| 356 | return 0; |
| 357 | } |
| 358 | |
| 359 | // scale up to the output scale, and do an integer division. |
| 360 | int32_t delta_scale = out_scale + y.scale() - x.scale(); |
| 361 | DCHECK_GE(delta_scale, 0); |
| 362 | |
| 363 | BasicDecimal128 result; |
| 364 | auto num_bits_required_after_scaling = MaxBitsRequiredAfterScaling(x, delta_scale); |
| 365 | if (num_bits_required_after_scaling <= 127) { |
| 366 | // fast-path. The dividend fits in 128-bit after scaling too. |
| 367 | *overflow = false; |
| 368 | |
| 369 | // do the division. |
| 370 | auto x_scaled = CheckAndIncreaseScale(x.value(), delta_scale); |
| 371 | BasicDecimal128 remainder; |
| 372 | auto status = x_scaled.Divide(y.value(), &result, &remainder); |
| 373 | DCHECK_EQ(status, arrow::DecimalStatus::kSuccess); |
| 374 | |
| 375 | // round-up |
| 376 | if (BasicDecimal128::Abs(2 * remainder) >= BasicDecimal128::Abs(y.value())) { |
| 377 | result += (x.value().Sign() ^ y.value().Sign()) + 1; |
| 378 | } |
| 379 | } else { |
| 380 | // convert to 256-bit and do the divide. |
| 381 | *overflow = delta_scale > 38 && num_bits_required_after_scaling > 255; |
| 382 | if (!*overflow) { |
| 383 | int64_t result_high; |
| 384 | uint64_t result_low; |
| 385 | |
| 386 | gdv_xlarge_scale_up_and_divide(x.value().high_bits(), x.value().low_bits(), |
| 387 | y.value().high_bits(), y.value().low_bits(), |
| 388 | delta_scale, &result_high, &result_low, overflow); |
| 389 | result = BasicDecimal128(result_high, result_low); |
| 390 | } |
| 391 | } |
| 392 | return result; |
| 393 | } |
| 394 | |
| 395 | BasicDecimal128 Mod(int64_t context, const BasicDecimalScalar128& x, |
| 396 | const BasicDecimalScalar128& y, int32_t out_precision, |