[riscv-port-jdk11u:riscv-port] RFR: 8293524: RISC-V: Use macro-assembler functions as appropriate

[Gui Cao]

On Fri, 27 Sep 2024 03:03:41 GMT, Dingli Zhang <dzhang at openjdk.org> wrote:

> Please review this backport to riscv-port-jdk11u.
> Backport of [JDK-8293524](https://bugs.openjdk.org/browse/JDK-8293524).
> The original patch cannot be directly applied because jdk11u has no [JDK-8241436 ](https://bugs.openjdk.org/browse/JDK-8241436 ) and [JDK-8229258](https://bugs.openjdk.org/browse/JDK-8229258) . Also jdk11u does not have generate_bigIntegerLeftShift and generate_bigIntegerRightShift functions.
> 
> Testing:
> - Tier1 passed without new failure on lp4a (release).

Why is li(result, 1); converted to mv(result, -1);?

src/hotspot/cpu/riscv/macroAssembler_riscv.cpp line 2258:

> 2256: 
> 2257:   // Success
> 2258:   mv(result, -1);

why is -1?

src/hotspot/cpu/riscv/macroAssembler_riscv.cpp line 2284:

> 2282:   // equal, succeed
> 2283:   if (result_as_bool) {
> 2284:     mv(result, -1);

and here.

src/hotspot/cpu/riscv/macroAssembler_riscv.cpp line 2313:

> 2311: 
> 2312:   // Success
> 2313:   mv(result, -1);

and here.

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PR Review: https://git.openjdk.org/riscv-port-jdk11u/pull/34#pullrequestreview-2353513033
PR Review Comment: https://git.openjdk.org/riscv-port-jdk11u/pull/34#discussion_r1791271129
PR Review Comment: https://git.openjdk.org/riscv-port-jdk11u/pull/34#discussion_r1791272039
PR Review Comment: https://git.openjdk.org/riscv-port-jdk11u/pull/34#discussion_r1791272298