Integrated: 8294492: RISC-V: Use li instead of patchable movptr at non-patchable callsites

[Xiaolin Zheng]

On Wed, 28 Sep 2022 06:28:53 GMT, Xiaolin Zheng <xlinzheng at openjdk.org> wrote:

> A cleanup which can also reduce some code size. The main purpose is to separate the current mixed movptr usages: movptr's semantics allow it to be used for fixed-length patchable addresses. In the current backend several callsites which are not patchable use movptr (6 instructions) as well, but that's unnecessary for we can use li(1~6 instructions) to substitute them.
> 
> This patch extracts the last 12-bit offset from the li(), a recursive function, to merge it into the rest "jalr/ld/sd..." that can accept a 12-bit offset as an operand, same as the movptr_with_offset before.
> 
> Originally some non-patchable callsites:
> 
> ;; 0x401ab1dc40
> 0x000000401372b324:   lui	t0,0x201
> 0x000000401372b328:   addi	t0,t0,-680 # 0x0000000000200d58
> 0x000000401372b32c:   slli	t0,t0,0xb
> 0x000000401372b32e:   addi	t0,t0,1905
> 0x000000401372b332:   slli	t0,t0,0x6
> 0x000000401372b334:   jalr	t0
> 
> Now:
> 
> 0x000000401b2bd9f4:   lui	t0,0x4003
> 0x000000401b2bd9f8:   addiw	t0,t0,-1275
> 0x000000401b2bd9fc:   slli	t0,t0,0xc
> 0x000000401b2bda00:   jalr	1080(t0) # 0x0000000004003438
> 
> Not so much, but the main purpose is to clarify the usage of movptr and li.
> 
> The first commit has gone through a hotspot tier1~tier4; the other ones are testing under a hotspot tier1.

This pull request has now been integrated.

Changeset: 1decdcee
Author:    Xiaolin Zheng <xlinzheng at openjdk.org>
Committer: Fei Yang <fyang at openjdk.org>
URL:       https://git.openjdk.org/jdk/commit/1decdcee71eae3344aaf2c0223d40a2b57a044b9
Stats:     103 lines in 8 files changed: 21 ins; 52 del; 30 mod

8294492: RISC-V: Use li instead of patchable movptr at non-patchable callsites

Reviewed-by: fyang

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PR: https://git.openjdk.org/jdk/pull/10462