6476168: (fmt) Inconsistency formatting subnormal doubles with hexadecimal conversion

Summary: Update specification to match implementation.
Reviewed-by: darcy
Contributed-by: NBrian Burkhalter <brian.burkhalter@oracle.com>

src/share/classes/java/util/Formatter.java

@@ -626,12 +626,11 @@ import sun.misc.FormattedFloatingDecimal;
  * <p> For general argument types, the precision is the maximum number of
  * characters to be written to the output.
  *
- * <p> For the floating-point conversions {@code 'e'}, {@code 'E'}, and
- * {@code 'f'} the precision is the number of digits after the decimal
- * separator.  If the conversion is {@code 'g'} or {@code 'G'}, then the
+ * <p> For the floating-point conversions {@code 'a'}, {@code 'A'}, {@code 'e'},
+ * {@code 'E'}, and {@code 'f'} the precision is the number of digits after the
+ * radix point.  If the conversion is {@code 'g'} or {@code 'G'}, then the
  * precision is the total number of digits in the resulting magnitude after
- * rounding.  If the conversion is {@code 'a'} or {@code 'A'}, then the
- * precision must not be specified.
+ * rounding.
  *
  * <p> For character, integral, and date/time argument types and the percent
  * and line separator conversions, the precision is not applicable; if a
@@ -1297,14 +1296,21 @@ import sun.misc.FormattedFloatingDecimal;
  *     of the significand as a fraction.  The exponent is represented by
  *     {@code 'p'} (<tt>'&#92;u0070'</tt>) followed by a decimal string of the
  *     unbiased exponent as if produced by invoking {@link
- *     Integer#toString(int) Integer.toString} on the exponent value.
+ *     Integer#toString(int) Integer.toString} on the exponent value.  If the
+ *     precision is specified, the value is rounded to the given number of
+ *     hexadecimal digits.
  *
  *     <li> If <i>m</i> is a {@code double} value with a subnormal
- *     representation then the significand is represented by the characters
- *     {@code '0x0.'} followed by the hexadecimal representation of the rest
- *     of the significand as a fraction.  The exponent is represented by
- *     {@code 'p-1022'}.  Note that there must be at least one nonzero digit
- *     in a subnormal significand.
+ *     representation then, unless the precision is specified to be in the range
+ *     1 through 12, inclusive, the significand is represented by the characters
+ *     {@code '0x0.'} followed by the hexadecimal representation of the rest of
+ *     the significand as a fraction, and the exponent represented by
+ *     {@code 'p-1022'}.  If the precision is in the interval
+ *     [1,&nbsp;12], the subnormal value is normalized such that it
+ *     begins with the characters {@code '0x1.'}, rounded to the number of
+ *     hexadecimal digits of precision, and the exponent adjusted
+ *     accordingly.  Note that there must be at least one nonzero digit in a
+ *     subnormal significand.
  *
  *     </ul>
  *
@@ -1367,7 +1373,7 @@ import sun.misc.FormattedFloatingDecimal;
  * {@code 1}.
  *
  * <p> If the conversion is {@code 'a'} or {@code 'A'}, then the precision
- * is the number of hexadecimal digits after the decimal separator.  If the
+ * is the number of hexadecimal digits after the radix point.  If the
  * precision is not provided, then all of the digits as returned by {@link
  * Double#toHexString(double)} will be output.
  *

test/java/util/Formatter/Basic-X.java.template

@@ -1319,10 +1319,8 @@ public class Basic$Type$ extends Basic {
              Math.nextDown(DoubleConsts.MIN_NORMAL));
         test("%.1a", "0x1.0p-1022",
              Math.nextDown(DoubleConsts.MIN_NORMAL));
-        test("%.11a", "0x1.ffffffffffep-1023",
-             Double.parseDouble("0x0.fffffffffffp-1022"));
-        test("%.1a", "0x1.0p-1022",
-             Double.parseDouble("0x0.fffffffffffp-1022"));
+        test("%.11a", "0x1.ffffffffffep-1023", 0x0.fffffffffffp-1022);
+        test("%.1a", "0x1.0p-1022", 0x0.fffffffffffp-1022);
         test("%.30a", "0x0.000000000000100000000000000000p-1022", Double.MIN_VALUE);
         test("%.13a", "0x0.0000000000001p-1022", Double.MIN_VALUE);
         test("%.11a", "0x1.00000000000p-1074", Double.MIN_VALUE);
@@ -1336,19 +1334,50 @@ public class Basic$Type$ extends Basic {
         test("%.13a", "0x1.fffffffffffffp1023", Double.MAX_VALUE);
         test("%.11a", "0x1.00000000000p1024", Double.MAX_VALUE);
         test("%.1a", "0x1.0p1024", Double.MAX_VALUE);
-        test("%.11a", "0x1.18000000000p0", Double.parseDouble("0x1.18p0"));
-        test("%.1a", "0x1.2p0", Double.parseDouble("0x1.18p0"));
-
-        test("%.11a", "0x1.18000000000p0",
-             Double.parseDouble("0x1.180000000001p0"));
-        test("%.1a", "0x1.2p0",
-             Double.parseDouble("0x1.180000000001p0"));
-        test("%.11a", "0x1.28000000000p0", Double.parseDouble("0x1.28p0"));
-        test("%.1a", "0x1.2p0", Double.parseDouble("0x1.28p0"));
-
-        test("%.11a", "0x1.28000000000p0",
-             Double.parseDouble("0x1.280000000001p0"));
-        test("%.1a", "0x1.3p0", Double.parseDouble("0x1.280000000001p0"));
+        test("%.11a", "0x1.18000000000p0", 0x1.18p0);
+        test("%.1a", "0x1.2p0", 0x1.18p0);
+
+        test("%.11a", "0x1.18000000000p0", 0x1.180000000001p0);
+        test("%.1a", "0x1.2p0", 0x1.180000000001p0);
+        test("%.11a", "0x1.28000000000p0", 0x1.28p0);
+        test("%.1a", "0x1.2p0", 0x1.28p0);
+
+        test("%.11a", "0x1.28000000000p0", 0x1.280000000001p0);
+        test("%.1a", "0x1.3p0", 0x1.280000000001p0);
+
+        test("%a", "0x0.123p-1022", 0x0.123p-1022);
+        test("%1.3a", "0x1.230p-1026", 0x0.123p-1022);
+        test("%1.12a", "0x1.230000000000p-1026", 0x0.123p-1022);
+        test("%1.15a", "0x0.123000000000000p-1022", 0x0.123p-1022);
+        test("%1.5a", "0x1.00000p-1074", 0x0.0000000000001p-1022);
+        test("%1.7a", "0x1.0000000p-1022", 0x0.fffffffffffffp-1022);
+
+        test("%1.6a", "0x1.230000p-1026", 0x0.123000057p-1022);
+        test("%1.7a", "0x1.2300005p-1026", 0x0.123000057p-1022);
+        test("%1.8a", "0x1.23000057p-1026", 0x0.123000057p-1022);
+        test("%1.9a", "0x1.230000570p-1026", 0x0.123000057p-1022);
+
+        test("%1.6a", "0x1.230000p-1026", 0x0.123000058p-1022);
+        test("%1.7a", "0x1.2300006p-1026", 0x0.123000058p-1022);
+        test("%1.8a", "0x1.23000058p-1026", 0x0.123000058p-1022);
+        test("%1.9a", "0x1.230000580p-1026", 0x0.123000058p-1022);
+
+        test("%1.6a", "0x1.230000p-1026", 0x0.123000059p-1022);
+        test("%1.7a", "0x1.2300006p-1026", 0x0.123000059p-1022);
+        test("%1.8a", "0x1.23000059p-1026", 0x0.123000059p-1022);
+        test("%1.9a", "0x1.230000590p-1026", 0x0.123000059p-1022);
+
+        test("%1.4a", "0x1.0000p-1022", Math.nextDown(Double.MIN_NORMAL));
+
+        test("%a", "0x1.fffffffffffffp1023", Double.MAX_VALUE);
+        test("%1.1a", "0x1.0p1024", Double.MAX_VALUE);
+        test("%1.2a", "0x1.00p1024", Double.MAX_VALUE);
+        test("%1.6a", "0x1.000000p1024", Double.MAX_VALUE);
+        test("%1.9a", "0x1.000000000p1024", Double.MAX_VALUE);
+        test("%1.11a", "0x1.00000000000p1024", Double.MAX_VALUE);
+        test("%1.12a", "0x1.000000000000p1024", Double.MAX_VALUE);
+        test("%1.13a", "0x1.fffffffffffffp1023", Double.MAX_VALUE);
+
 #end[double]
 
         //---------------------------------------------------------------------

test/java/util/Formatter/Basic.java

@@ -25,7 +25,7 @@
  * @summary Unit test for formatter
  * @bug 4906370 4962433 4973103 4989961 5005818 5031150 4970931 4989491 5002937
  *      5005104 5007745 5061412 5055180 5066788 5088703 6317248 6318369 6320122
- *      6344623 6369500 6534606 6282094 6286592 6476425 5063507 6469160
+ *      6344623 6369500 6534606 6282094 6286592 6476425 5063507 6469160 6476168
  *
  * @run shell/timeout=240 Basic.sh
  */

test/java/util/Formatter/BasicDouble.java

@@ -1319,10 +1319,8 @@ public class BasicDouble extends Basic {
              Math.nextDown(DoubleConsts.MIN_NORMAL));
         test("%.1a", "0x1.0p-1022",
              Math.nextDown(DoubleConsts.MIN_NORMAL));
-        test("%.11a", "0x1.ffffffffffep-1023",
-             Double.parseDouble("0x0.fffffffffffp-1022"));
-        test("%.1a", "0x1.0p-1022",
-             Double.parseDouble("0x0.fffffffffffp-1022"));
+        test("%.11a", "0x1.ffffffffffep-1023", 0x0.fffffffffffp-1022);
+        test("%.1a", "0x1.0p-1022", 0x0.fffffffffffp-1022);
         test("%.30a", "0x0.000000000000100000000000000000p-1022", Double.MIN_VALUE);
         test("%.13a", "0x0.0000000000001p-1022", Double.MIN_VALUE);
         test("%.11a", "0x1.00000000000p-1074", Double.MIN_VALUE);
@@ -1336,19 +1334,50 @@ public class BasicDouble extends Basic {
         test("%.13a", "0x1.fffffffffffffp1023", Double.MAX_VALUE);
         test("%.11a", "0x1.00000000000p1024", Double.MAX_VALUE);
         test("%.1a", "0x1.0p1024", Double.MAX_VALUE);
-        test("%.11a", "0x1.18000000000p0", Double.parseDouble("0x1.18p0"));
-        test("%.1a", "0x1.2p0", Double.parseDouble("0x1.18p0"));
-
-        test("%.11a", "0x1.18000000000p0",
-             Double.parseDouble("0x1.180000000001p0"));
-        test("%.1a", "0x1.2p0",
-             Double.parseDouble("0x1.180000000001p0"));
-        test("%.11a", "0x1.28000000000p0", Double.parseDouble("0x1.28p0"));
-        test("%.1a", "0x1.2p0", Double.parseDouble("0x1.28p0"));
-
-        test("%.11a", "0x1.28000000000p0",
-             Double.parseDouble("0x1.280000000001p0"));
-        test("%.1a", "0x1.3p0", Double.parseDouble("0x1.280000000001p0"));
+        test("%.11a", "0x1.18000000000p0", 0x1.18p0);
+        test("%.1a", "0x1.2p0", 0x1.18p0);
+
+        test("%.11a", "0x1.18000000000p0", 0x1.180000000001p0);
+        test("%.1a", "0x1.2p0", 0x1.180000000001p0);
+        test("%.11a", "0x1.28000000000p0", 0x1.28p0);
+        test("%.1a", "0x1.2p0", 0x1.28p0);
+
+        test("%.11a", "0x1.28000000000p0", 0x1.280000000001p0);
+        test("%.1a", "0x1.3p0", 0x1.280000000001p0);
+
+        test("%a", "0x0.123p-1022", 0x0.123p-1022);
+        test("%1.3a", "0x1.230p-1026", 0x0.123p-1022);
+        test("%1.12a", "0x1.230000000000p-1026", 0x0.123p-1022);
+        test("%1.15a", "0x0.123000000000000p-1022", 0x0.123p-1022);
+        test("%1.5a", "0x1.00000p-1074", 0x0.0000000000001p-1022);
+        test("%1.7a", "0x1.0000000p-1022", 0x0.fffffffffffffp-1022);
+
+        test("%1.6a", "0x1.230000p-1026", 0x0.123000057p-1022);
+        test("%1.7a", "0x1.2300005p-1026", 0x0.123000057p-1022);
+        test("%1.8a", "0x1.23000057p-1026", 0x0.123000057p-1022);
+        test("%1.9a", "0x1.230000570p-1026", 0x0.123000057p-1022);
+
+        test("%1.6a", "0x1.230000p-1026", 0x0.123000058p-1022);
+        test("%1.7a", "0x1.2300006p-1026", 0x0.123000058p-1022);
+        test("%1.8a", "0x1.23000058p-1026", 0x0.123000058p-1022);
+        test("%1.9a", "0x1.230000580p-1026", 0x0.123000058p-1022);
+
+        test("%1.6a", "0x1.230000p-1026", 0x0.123000059p-1022);
+        test("%1.7a", "0x1.2300006p-1026", 0x0.123000059p-1022);
+        test("%1.8a", "0x1.23000059p-1026", 0x0.123000059p-1022);
+        test("%1.9a", "0x1.230000590p-1026", 0x0.123000059p-1022);
+
+        test("%1.4a", "0x1.0000p-1022", Math.nextDown(Double.MIN_NORMAL));
+
+        test("%a", "0x1.fffffffffffffp1023", Double.MAX_VALUE);
+        test("%1.1a", "0x1.0p1024", Double.MAX_VALUE);
+        test("%1.2a", "0x1.00p1024", Double.MAX_VALUE);
+        test("%1.6a", "0x1.000000p1024", Double.MAX_VALUE);
+        test("%1.9a", "0x1.000000000p1024", Double.MAX_VALUE);
+        test("%1.11a", "0x1.00000000000p1024", Double.MAX_VALUE);
+        test("%1.12a", "0x1.000000000000p1024", Double.MAX_VALUE);
+        test("%1.13a", "0x1.fffffffffffffp1023", Double.MAX_VALUE);
+
 
 
         //---------------------------------------------------------------------