On Sun, 15 Dec 2024 18:05:02 GMT, Jatin Bhateja <jbhat...@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 Can you quickly summarize what tests you have, and what they test? test/hotspot/jtreg/compiler/vectorization/TestFloat16VectorConvChain.java line 49: > 47: counts = {IRNode.VECTOR_CAST_HF2F, IRNode.VECTOR_SIZE_ANY, ">= > 1", IRNode.VECTOR_CAST_F2HF, IRNode.VECTOR_SIZE_ANY, " >= 1"}) > 48: @IR(applyIfCPUFeatureAnd = {"avx512_fp16", "false", "zvfh", "true"}, > 49: counts = {IRNode.VECTOR_CAST_HF2F, IRNode.VECTOR_SIZE_ANY, ">= > 1", IRNode.VECTOR_CAST_F2HF, IRNode.VECTOR_SIZE_ANY, " >= 1"}) Looks like this is having vector changes? And this is pre-existing: but why are we using `VECTOR_SIZE_ANY` here? Can we not know the vector size? Maybe we can introduce a new tag `max_float16` or `max_hf`. And do something like this: `IRNode.VECTOR_SIZE + "min(max_float, max_hf)", "> 0"` The downside with using `ANY` is that the exact size is not tested, and that might mean that the size is much smaller than ideal. ------------- PR Review: https://git.openjdk.org/jdk/pull/22754#pullrequestreview-2505332519 PR Review Comment: https://git.openjdk.org/jdk/pull/22754#discussion_r1886290546
