On Mon, 19 Aug 2024 07:19:30 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: > > Review comments resolutions. src/hotspot/share/opto/vectornode.hpp line 150: > 148: class SaturatingVectorNode : public VectorNode { > 149: private: > 150: bool _is_unsigned; Would it be better to make it a `const bool`? src/hotspot/share/opto/vectornode.hpp line 172: > 170: class SaturatingAddVBNode : public SaturatingVectorNode { > 171: public: > 172: SaturatingAddVBNode(Node* in1, Node* in2, const TypeVect* vt, bool > is_unsigned) : SaturatingVectorNode(in1,in2,vt,is_unsigned) {} Style: spaces after the commas in `SaturatingVectorNode(in1,in2,vt,is_unsigned)` ------------- PR Review Comment: https://git.openjdk.org/jdk/pull/20507#discussion_r1723459735 PR Review Comment: https://git.openjdk.org/jdk/pull/20507#discussion_r1723463554
