On Fri, 13 Sep 2024 16:20:28 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: > > Documentation change suggerstion from Paul src/jdk.incubator.vector/share/classes/jdk/incubator/vector/VectorOperators.java line 589: > 587: * @see VectorMath#minUnsigned(int, int) (int, int) > 588: */ > 589: public static final Associative UMIN = assoc("UMIN", "umin", > VectorSupport.VECTOR_OP_UMIN, VO_NOFP+VO_ASSOC); We should rename the existing unsigned compare operators to use the same naming scheme i.e., s/UNSIGNED_LT/ULT etc. ------------- PR Review Comment: https://git.openjdk.org/jdk/pull/20507#discussion_r1759558844
