On Mon, 6 Mar 2023 23:54:44 GMT, Vladimir Kozlov <k...@openjdk.org> wrote:
>> Implemented `Float.floatToFloat16` and `Float.float16ToFloat` intrinsics in >> Interpreter and C1 compiler to produce the same results as C2 intrinsics on >> x64, Aarch64 and RISC-V - all platforms where C2 intrinsics for these Java >> methods were implemented originally. >> >> Replaced `SharedRuntime::f2hf()` and `hf2f()` C runtime functions with calls >> to runtime stubs which use the same HW instructions as C2 intrinsics. Only >> for 64-bit x64 because 32-bit x86 stub does not work: result is passed >> through FPU register and NaN values become different from C2 intrinsic. This >> runtime stub is only used to calculate constant values during C2 compilation >> and can be skipped. >> >> I added new tests based on Tobias's `TestAll.java` And copied >> `jdk/lang/Float/Binary16Conversion*.java` tests to run them with `-Xcomp` to >> make sure code is compiled by C1 or C2. I modified >> `Binary16ConversionNaN.java` to compare results from Interpreter, C1 and C2. >> >> Tested tier1-5, Xcomp, stress > > @fyang, please help to verify that new tests passed on RISC-V with these > changes and review these changes. Thanks! > > I tested x86 (64- and 32-bit) and AArch64. @vnkozlov Thanks a lot for taking this up. Is the following in the PR description still true: "Replaced SharedRuntime::f2hf() and hf2f() C runtime functions with calls to runtime stubs which use the same HW instructions as C2 intrinsics. Only for 64-bit x64 because 32-bit x86 stub does not work: result is passed through FPU register and NaN values become different from C2 intrinsic." >From the PR it looks to me that for x86_64 you have the changes in place for >SharedRuntime and the same result is produced across SharedRuntime, >interpreter, c1, and c2. For x86 32-bit also things are consistent across. Only the SharedRuntime optimization doesnt happen for x86 32bit as StubRoutines::hf2f() and StubRoutines::f2hf() are set as null. The fallback is handled correctly in interpreter, c1, and c2. ------------- PR: https://git.openjdk.org/jdk/pull/12869
