| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| |
| // long double __gcc_qdiv(long double x, long double y); |
| // This file implements the PowerPC 128-bit double-double division operation. |
| // This implementation is shamelessly cribbed from Apple's DDRT, circa 1993(!) |
| |
| #include "DD.h" |
| |
| long double __gcc_qdiv(long double a, long double b) { |
| static const uint32_t infinityHi = UINT32_C(0x7ff00000); |
| DD dst = {.ld = a}, src = {.ld = b}; |
| |
| register double x = dst.s.hi, x1 = dst.s.lo, y = src.s.hi, y1 = src.s.lo; |
| |
| double yHi, yLo, qHi, qLo; |
| double yq, tmp, q; |
| |
| q = x / y; |
| |
| // Detect special cases |
| if (q == 0.0) { |
| dst.s.hi = q; |
| dst.s.lo = 0.0; |
| return dst.ld; |
| } |
| |
| const doublebits qBits = {.d = q}; |
| if (((uint32_t)(qBits.x >> 32) & infinityHi) == infinityHi) { |
| dst.s.hi = q; |
| dst.s.lo = 0.0; |
| return dst.ld; |
| } |
| |
| yHi = high26bits(y); |
| qHi = high26bits(q); |
| |
| yq = y * q; |
| yLo = y - yHi; |
| qLo = q - qHi; |
| |
| tmp = LOWORDER(yq, yHi, yLo, qHi, qLo); |
| tmp = (x - yq) - tmp; |
| tmp = ((tmp + x1) - y1 * q) / y; |
| x = q + tmp; |
| |
| dst.s.lo = (q - x) + tmp; |
| dst.s.hi = x; |
| |
| return dst.ld; |
| } |