Integrated: 8342103: C2 compiler support for Float16 type and associated scalar operations

[Jatin Bhateja]

On Sun, 15 Dec 2024 18:05:02 GMT, Jatin Bhateja <jbhateja at openjdk.org> wrote:

> Hi All,
> 
> This patch adds C2 compiler support for various Float16 operations added by [PR#22128](https://github.com/openjdk/jdk/pull/22128)
> 
> Following is the summary of changes included with this patch:-
> 
> 1. Detection of various Float16 operations through inline expansion or pattern folding idealizations.
> 2. Float16 operations like add, sub, mul, div, max, and min are inferred through pattern folding idealization.
> 3. Float16 SQRT and FMA operation are inferred through inline expansion and their corresponding entry points are defined in the newly added Float16Math class.
>       -    These intrinsics receive unwrapped short arguments encoding IEEE 754 binary16 values.
> 5. New specialized IR nodes for Float16 operations, associated idealizations, and constant folding routines.
> 6. New Ideal type for constant and non-constant Float16 IR nodes. Please refer to [FAQs ](https://github.com/openjdk/jdk/pull/22754#issuecomment-2543982577)for more details.
> 7. Since Float16 uses short as its storage type, hence raw FP16 values are always loaded into general purpose register, but FP16 ISA generally operates over floating point registers, thus the compiler injects reinterpretation IR before and after Float16 operation nodes to move short value to floating point register and vice versa.
> 8. New idealization routines to optimize redundant reinterpretation chains. HF2S + S2HF = HF
> 9. X86  backend implementation for all supported intrinsics.
> 10. Functional and Performance validation tests.
> 
> Kindly review the patch and share your feedback.
> 
> Best Regards,
> Jatin

This pull request has now been integrated.

Changeset: 4b463ee7
Author:    Jatin Bhateja <jbhateja at openjdk.org>
URL:       https://git.openjdk.org/jdk/commit/4b463ee70eceb94fdfbffa5c49dd58dcc6a6c890
Stats:     2855 lines in 56 files changed: 2788 ins; 0 del; 67 mod

8342103: C2 compiler support for Float16 type and associated scalar operations

Co-authored-by: Paul Sandoz <psandoz at openjdk.org>
Co-authored-by: Bhavana Kilambi <bkilambi at openjdk.org>
Co-authored-by: Joe Darcy <darcy at openjdk.org>
Co-authored-by: Raffaello Giulietti <rgiulietti at openjdk.org>
Reviewed-by: psandoz, epeter, sviswanathan

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PR: https://git.openjdk.org/jdk/pull/22754