177ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao/* This file is distributed under the University of Illinois Open Source 277ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao * License. See LICENSE.TXT for details. 377ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao */ 477ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao 577ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao/* long double __gcc_qdiv(long double x, long double y); 677ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao * This file implements the PowerPC 128-bit double-double division operation. 777ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao * This implementation is shamelessly cribbed from Apple's DDRT, circa 1993(!) 877ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao */ 977ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao 1077ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao#include "DD.h" 1177ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao 1277ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liaolong double __gcc_qdiv(long double a, long double b) 1377ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao{ 1477ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao static const uint32_t infinityHi = UINT32_C(0x7ff00000); 1577ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao DD dst = { .ld = a }, src = { .ld = b }; 1677ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao 1777ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao register double x = dst.s.hi, x1 = dst.s.lo, 1877ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao y = src.s.hi, y1 = src.s.lo; 1977ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao 2077ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao double yHi, yLo, qHi, qLo; 2177ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao double yq, tmp, q; 2277ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao 2377ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao q = x / y; 2477ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao 2577ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao /* Detect special cases */ 2677ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao if (q == 0.0) { 2777ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao dst.s.hi = q; 2877ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao dst.s.lo = 0.0; 2977ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao return dst.ld; 3077ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao } 3177ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao 3277ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao const doublebits qBits = { .d = q }; 3377ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao if (((uint32_t)(qBits.x >> 32) & infinityHi) == infinityHi) { 3477ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao dst.s.hi = q; 3577ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao dst.s.lo = 0.0; 3677ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao return dst.ld; 3777ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao } 3877ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao 3977ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao yHi = high26bits(y); 4077ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao qHi = high26bits(q); 4177ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao 4277ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao yq = y * q; 4377ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao yLo = y - yHi; 4477ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao qLo = q - qHi; 4577ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao 4677ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao tmp = LOWORDER(yq, yHi, yLo, qHi, qLo); 4777ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao tmp = (x - yq) - tmp; 4877ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao tmp = ((tmp + x1) - y1 * q) / y; 4977ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao x = q + tmp; 5077ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao 5177ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao dst.s.lo = (q - x) + tmp; 5277ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao dst.s.hi = x; 5377ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao 5477ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao return dst.ld; 5577ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao} 56