RFR: 8287552: riscv: Fix comment typo in li64

[Fei Yang]

On Tue, 31 May 2022 07:59:21 GMT, Feilong Jiang <fjiang at openjdk.org> wrote:

> In riscv, 'imm[31:28]’ should be 'imm[31:20]' for '0x7ff' in the following two places:
> 
> src/hotspot/cpu/riscv/assembler_riscv.cpp:
> 
> 
> void Assembler::li64(Register Rd, int64_t imm) {
> // Load upper 32 bits. upper = imm[63:32], but if imm[31] == 1 or
> // (imm[31:28] == 0x7ff && imm[19] == 1), upper = imm[63:32] + 1.
> int64_t lower = imm & 0xffffffff;
> 
> 
> src/hotspot/cpu/riscv/macroAssembler_riscv.cpp:
> 
> 
>   // Load upper 32 bits. Upper = target[63:32], but if target[31] = 1 or (target[31:28] == 0x7ff && target[19] == 1),
>   // upper = target[63:32] + 1.
> 
> 
> This patch also unifies the immediate type in `movptr_with_offset` to `int64_t`.
> 
> Hotspot tier1 test on QEMU passed without new failures.

Looks fine.

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Marked as reviewed by fyang (Reviewer).

PR: https://git.openjdk.java.net/jdk/pull/8950