266 * <td>{@code 0x0.0000000000001p-1022}</td>
267 * </table>
268 * @param d the {@code double} to be converted.
269 * @return a hex string representation of the argument.
270 * @since 1.5
271 * @author Joseph D. Darcy
272 */
273 public static String toHexString(double d) {
274 /*
275 * Modeled after the "a" conversion specifier in C99, section
276 * 7.19.6.1; however, the output of this method is more
277 * tightly specified.
278 */
279 if (!FpUtils.isFinite(d) )
280 // For infinity and NaN, use the decimal output.
281 return Double.toString(d);
282 else {
283 // Initialized to maximum size of output.
284 StringBuffer answer = new StringBuffer(24);
285
286 if (FpUtils.rawCopySign(1.0, d) == -1.0) // value is negative,
287 answer.append("-"); // so append sign info
288
289 answer.append("0x");
290
291 d = Math.abs(d);
292
293 if(d == 0.0) {
294 answer.append("0.0p0");
295 }
296 else {
297 boolean subnormal = (d < DoubleConsts.MIN_NORMAL);
298
299 // Isolate significand bits and OR in a high-order bit
300 // so that the string representation has a known
301 // length.
302 long signifBits = (Double.doubleToLongBits(d)
303 & DoubleConsts.SIGNIF_BIT_MASK) |
304 0x1000000000000000L;
305
306 // Subnormal values have a 0 implicit bit; normal
307 // values have a 1 implicit bit.
308 answer.append(subnormal ? "0." : "1.");
309
310 // Isolate the low-order 13 digits of the hex
311 // representation. If all the digits are zero,
312 // replace with a single 0; otherwise, remove all
313 // trailing zeros.
314 String signif = Long.toHexString(signifBits).substring(3,16);
315 answer.append(signif.equals("0000000000000") ? // 13 zeros
316 "0":
317 signif.replaceFirst("0{1,12}$", ""));
318
319 // If the value is subnormal, use the E_min exponent
320 // value for double; otherwise, extract and report d's
321 // exponent (the representation of a subnormal uses
322 // E_min -1).
323 answer.append("p" + (subnormal ?
324 DoubleConsts.MIN_EXPONENT:
325 FpUtils.getExponent(d) ));
326 }
327 return answer.toString();
328 }
329 }
330
331 /**
332 * Returns a {@code Double} object holding the
333 * {@code double} value represented by the argument string
334 * {@code s}.
335 *
336 * <p>If {@code s} is {@code null}, then a
337 * {@code NullPointerException} is thrown.
338 *
339 * <p>Leading and trailing whitespace characters in {@code s}
340 * are ignored. Whitespace is removed as if by the {@link
341 * String#trim} method; that is, both ASCII space and control
342 * characters are removed. The rest of {@code s} should
343 * constitute a <i>FloatValue</i> as described by the lexical
344 * syntax rules:
345 *
|
266 * <td>{@code 0x0.0000000000001p-1022}</td>
267 * </table>
268 * @param d the {@code double} to be converted.
269 * @return a hex string representation of the argument.
270 * @since 1.5
271 * @author Joseph D. Darcy
272 */
273 public static String toHexString(double d) {
274 /*
275 * Modeled after the "a" conversion specifier in C99, section
276 * 7.19.6.1; however, the output of this method is more
277 * tightly specified.
278 */
279 if (!FpUtils.isFinite(d) )
280 // For infinity and NaN, use the decimal output.
281 return Double.toString(d);
282 else {
283 // Initialized to maximum size of output.
284 StringBuffer answer = new StringBuffer(24);
285
286 if (Math.copySign(1.0, d) == -1.0) // value is negative,
287 answer.append("-"); // so append sign info
288
289 answer.append("0x");
290
291 d = Math.abs(d);
292
293 if(d == 0.0) {
294 answer.append("0.0p0");
295 }
296 else {
297 boolean subnormal = (d < DoubleConsts.MIN_NORMAL);
298
299 // Isolate significand bits and OR in a high-order bit
300 // so that the string representation has a known
301 // length.
302 long signifBits = (Double.doubleToLongBits(d)
303 & DoubleConsts.SIGNIF_BIT_MASK) |
304 0x1000000000000000L;
305
306 // Subnormal values have a 0 implicit bit; normal
307 // values have a 1 implicit bit.
308 answer.append(subnormal ? "0." : "1.");
309
310 // Isolate the low-order 13 digits of the hex
311 // representation. If all the digits are zero,
312 // replace with a single 0; otherwise, remove all
313 // trailing zeros.
314 String signif = Long.toHexString(signifBits).substring(3,16);
315 answer.append(signif.equals("0000000000000") ? // 13 zeros
316 "0":
317 signif.replaceFirst("0{1,12}$", ""));
318
319 // If the value is subnormal, use the E_min exponent
320 // value for double; otherwise, extract and report d's
321 // exponent (the representation of a subnormal uses
322 // E_min -1).
323 answer.append("p" + (subnormal ?
324 DoubleConsts.MIN_EXPONENT:
325 Math.getExponent(d) ));
326 }
327 return answer.toString();
328 }
329 }
330
331 /**
332 * Returns a {@code Double} object holding the
333 * {@code double} value represented by the argument string
334 * {@code s}.
335 *
336 * <p>If {@code s} is {@code null}, then a
337 * {@code NullPointerException} is thrown.
338 *
339 * <p>Leading and trailing whitespace characters in {@code s}
340 * are ignored. Whitespace is removed as if by the {@link
341 * String#trim} method; that is, both ASCII space and control
342 * characters are removed. The rest of {@code s} should
343 * constitute a <i>FloatValue</i> as described by the lexical
344 * syntax rules:
345 *
|