On Thu, 5 Sep 2024 08:34:36 GMT, Jatin Bhateja <jbhat...@openjdk.org> wrote:
>> Hi All, >> >> As per the discussion on panama-dev mailing list[1], patch adds the support >> following new vector operators. >> >> >> . SUADD : Saturating unsigned addition. >> . SADD : Saturating signed addition. >> . SUSUB : Saturating unsigned subtraction. >> . SSUB : Saturating signed subtraction. >> . UMAX : Unsigned max >> . UMIN : Unsigned min. >> >> >> New vector operators are applicable to only integral types since their >> values wraparound in over/underflowing scenarios after setting appropriate >> status flags. For floating point types, as per IEEE 754 specs there are >> multiple schemes to handler underflow, one of them is gradual underflow >> which transitions the value to subnormal range. Similarly, overflow >> implicitly saturates the floating-point value to an Infinite value. >> >> As the name suggests, these are saturating operations, i.e. the result of >> the computation is strictly capped by lower and upper bounds of the result >> type and is not wrapped around in underflowing or overflowing scenarios. >> >> Summary of changes: >> - Java side implementation of new vector operators. >> - Add new scalar saturating APIs for each of the above saturating vector >> operator in corresponding primitive box classes, fallback implementation of >> vector operators is based over it. >> - C2 compiler IR and inline expander changes. >> - Optimized x86 backend implementation for new vector operators and their >> predicated counterparts. >> - Extends existing VectorAPI Jtreg test suite to cover new operations. >> >> Kindly review and share your feedback. >> >> Best Regards, >> PS: Intrinsification and auto-vectorization of new core-lib API will be >> addressed separately in a follow-up patch. >> >> [1] https://mail.openjdk.org/pipermail/panama-dev/2024-May/020408.html > > Jatin Bhateja has updated the pull request incrementally with one additional > commit since the last revision: > > Some cleanups. Just a few quick remarks. src/hotspot/share/opto/vectornode.hpp line 188: > 186: }; > 187: > 188: Suprious newline, please remove Suggestion: src/jdk.incubator.vector/share/classes/jdk/incubator/vector/VectorMathUtils.java line 78: > 76: * @since 24 > 77: */ > 78: public static long addSaturating(long a, long b) { Are these public methods any Java dev could use? If so: do we have tests for them? ------------- Changes requested by epeter (Reviewer). PR Review: https://git.openjdk.org/jdk/pull/20507#pullrequestreview-2283248252 PR Review Comment: https://git.openjdk.org/jdk/pull/20507#discussion_r1745655940 PR Review Comment: https://git.openjdk.org/jdk/pull/20507#discussion_r1745665600
