modfl.c revision 25c28e83beb90e7c80452a7c818c5e6f73a07dc8
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25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * Copyright 2011 Nexenta Systems, Inc. All rights reserved.
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * Copyright 2006 Sun Microsystems, Inc. All rights reserved.
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * Use is subject to license terms.
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis__modfl(long double x, long double *iptr) {
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis unsigned i[4];
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis long double q;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis if (hx >= 0x406f0000) { /* x is NaN, infinite, or integral */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis if (hx < 0x7fff0000 || (hx == 0x7fff0000 &&
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis /* split x at the binary point */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis yy.i[0] = xx.i[0] & ~((1 << (0x400f - (hx >> 16))) - 1);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis yy.i[1] = xx.i[1] & ~((1 << (0x402f - (hx >> 16))) - 1);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis yy.i[2] = xx.i[2] & ~((1 << (0x404f - (hx >> 16))) - 1);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis yy.i[3] = xx.i[3] & ~((1 << (0x406f - (hx >> 16))) - 1);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * we could implement the following more efficiently than by using
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * software emulation of fsubq, but we'll do it this way for now
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * (and hope hardware support becomes commonplace)
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis xx.i[0] = (xx.i[0] & ~0x80000000) | s; /* keep sign of x */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis__modfl(long double x, long double *iptr) {
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis unsigned i[3];
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis long double e;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * It might be faster to use one of the x86 fpops instead of
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * the following.
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis if (hx >= 0x403e) { /* x is NaN, infinite, or integral */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis /* split x at the binary point */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis yy.i[1] = xx.i[1] & ~((1 << (0x401e - hx)) - 1);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis yy.i[0] = xx.i[0] & ~((1 << (0x403e - hx)) - 1);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis xx.i[2] = (xx.i[2] & ~0x8000) | s; /* keep sign of x */