text: // 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;
  }
  