On Mon, 25 Nov 2024 20:04:09 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/21490#issuecomment-2482867818)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 instructions >> generally operate over floating point registers, therefore compiler injectes >> 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 >> 6. Auto-vectorization of newly supported scalar operations. >> 7. X86 and AARCH64 backend implementation for all supported intrinsics. >> 9. Functional and Performance validation tests. >> >> Kindly review and share your feedback. >> >> Best Regards, >> Jatin > > Jatin Bhateja has updated the pull request incrementally with one additional > commit since the last revision: > > Review comments resolution > Another example where I asked if we have good tests: >  > > And the test you point to is this: >  > > It only covers a single constant `divisor = 8`. But what about divisors that > are out of the allowed range, or not powers of 2? How do we know that you > chose the bounds correctly, and are not off-by-1? And what about negative > divisors? >  Please refer to my detailed comments on divide by power of two transformation, test point specifically test division to multiplication transformation if divisor is POT. https://github.com/openjdk/jdk/pull/21490/files#diff-ff6734d21eacbbdeae65d3b11f5261cbb6158752a9ccf5fb13eb0d2e5eb3f414R829 https://github.com/openjdk/jdk/pull/21490/files#diff-ff6734d21eacbbdeae65d3b11f5261cbb6158752a9ccf5fb13eb0d2e5eb3f414R839 Hi @eme64 I can feel the reviewer's pain, I think adding one gtest makes sense here to test various newly added Type primitives like geth, is_nan etc and idioms being folded in newly added value transformation. ------------- PR Comment: https://git.openjdk.org/jdk/pull/21490#issuecomment-2499970345
