[riscv-port-jdk17u:riscv-port] RFR: 8307446: RISC-V: Improve performance of floating point to integer conversion

[Fei Yang]

On Mon, 22 May 2023 04:22:49 GMT, Feilong Jiang <fjiang at openjdk.org> wrote:

> Hi,
> please review this clean backport of [JDK-8307446](https://bugs.openjdk.org/browse/JDK-8307446).
> 
> JHM shows the same improvement on Unmatched board:
> 
> 
> Benchmark                     (size)   Mode  Cnt   Score   Error   Units
> --- baseline -----------------------------------------------------------
> FloatConversion.doubleToInt     2048  thrpt   15  30.270 ? 0.144  ops/ms
> FloatConversion.doubleToLong    2048  thrpt   15  29.831 ? 0.128  ops/ms
> FloatConversion.floatToInt      2048  thrpt   15  30.530 ? 0.031  ops/ms
> FloatConversion.floatToLong     2048  thrpt   15  30.189 ? 0.100  ops/ms
> --- optimized ----------------------------------------------------------
> FloatConversion.doubleToInt     2048  thrpt   15  66.051 ? 0.064  ops/ms
> FloatConversion.doubleToLong    2048  thrpt   15  66.095 ? 0.460  ops/ms
> FloatConversion.floatToInt      2048  thrpt   15  68.114 ? 0.072  ops/ms
> FloatConversion.floatToLong     2048  thrpt   15  68.482 ? 0.193  ops/ms

Marked as reviewed by fyang (Lead).

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PR Review: https://git.openjdk.org/riscv-port-jdk17u/pull/57#pullrequestreview-1438344676