RFR: 8302976: C2 intrinsification of Float.floatToFloat16 and Float.float16ToFloat yields different result than the interpreter

Tue Mar 7 00:51:12 UTC 2023

On Tue, 7 Mar 2023 00:19:03 GMT, Sandhya Viswanathan <sviswanathan at openjdk.org> wrote:

> 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.

Correct, it is consistent.  Only optimization to calculate constant value during compile time is skipped. C2 will generate HW instruction for `ConvF2HF` node as if its input was not constant. That is it.

It is possible to add similar Stub routines  for AArch64 and RISC-V to be called from C2 but I am not expert in those platforms so I skipped them.

-------------

PR: https://git.openjdk.org/jdk/pull/12869