RFR: 8273346: Expand library mappings to IEEE 754 operations

[Raffaello Giulietti]

On Wed, 25 May 2022 00:19:41 GMT, Joe Darcy <darcy at openjdk.org> wrote:

> Generally add apiNote's to map from Java library methods to particular IEEE 754 operations. For now, I only added such notes to java.lang.Math and not java.lang.StrictMath.

src/java.base/share/classes/java/lang/Math.java line 771:

> 769:      * This method corresponds to the convertToIntegerTiesToEven
> 770:      * operation defined in IEEE 754.
> 771:      *

IEEE `convertToIntegerTiesToEven` rounds ties to the even integer.
The method's spec, however, requires ties to round toward positive infinity.
Unfortunately, IEEE 754 doesn't offer a `convertToIntegerTiesToPositive`

src/java.base/share/classes/java/lang/Math.java line 824:

> 822:      * This method corresponds to the convertToIntegerTiesToEven
> 823:      * operation defined in IEEE 754.
> 824:      *

see comment for `round(float)`

src/java.base/share/classes/java/math/RoundingMode.java line 49:

> 47:  * exponent range of {@code BigDecimal}, the mathematical result will
> 48:  * be exactly representable in the result precision or fall between
> 49:  * two representable values. In the case of falling between two

Perhaps better would be
`two adjacent representable values.`

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PR: https://git.openjdk.java.net/jdk/pull/8876