RFR: 8320646: RISC-V: C2 VectorCastHF2F

[Ludovic Henry]

On Sun, 4 Feb 2024 09:38:48 GMT, Hamlin Li <mli at openjdk.org> wrote:

> Hi,
> Can you review this patch to add instrinsics for VectorCastHF2F/VectorCastF2HF?
> Thanks!
> 
> ## Test
> 
> test/jdk/java/lang/Float/Binary16ConversionNaN.java
> test/jdk/java/lang/Float/Binary16Conversion.java
> 
> hotspot/jtreg/compiler/intrinsics/float16
> hotspot/jtreg/compiler/vectorization/TestFloatConversionsVectorjava
> hotspot/jtreg/compiler/vectorization/TestFloatConversionsVectorNaN.java

Changes requested by luhenry (Committer).

src/hotspot/cpu/riscv/assembler_riscv.hpp line 1617:

> 1615:   INSN(vadd_vi,   0b1010111, 0b011, 0b000000);
> 1616:   INSN(vrsub_vi,  0b1010111, 0b011, 0b000011);
> 1617:   INSN(vnsra_wi,  0b1010111, 0b011, 0b101101);

You can put it up with `vnsra_wx` in the "Vector Narrowing Integer Right Shift Instructions" at https://github.com/openjdk/jdk/pull/17698/files#diff-314214875276cd9a11ecdfd52b68403ded286710ba0820461b0b510506f61a33R1528

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PR Review: https://git.openjdk.org/jdk/pull/17698#pullrequestreview-1866369917
PR Review Comment: https://git.openjdk.org/jdk/pull/17698#discussion_r1480571940