Integrated: 8282414: x86: Enhance the assembler to generate more compact instructions

[Quan Anh Mai]

On Sat, 26 Feb 2022 05:51:54 GMT, Quan Anh Mai <duke at openjdk.java.net> wrote:

> Hi, this patch enhances the x86 assembler to emit more compact code for some popular instructions.
> 
> For common arithmetic instructions against immediates, if the immediate requires more than 1 byte to encode, we can still shave off 1 byte if the register operand is rax.
> 
> For test instruction, since the operation does not write the result, we can downgrade a long to an int and an int to a byte instruction if the immediate is positive and encodable using a smaller amount of bytes.
> 
> Thank you very much.

This pull request has now been integrated.

Changeset: bacfaa3e
Author:    Quan Anh Mai <anhmdq99 at gmail.com>
Committer: Sandhya Viswanathan <sviswanathan at openjdk.org>
URL:       https://git.openjdk.java.net/jdk/commit/bacfaa3ee16882563200ef3b3df4441b33664451
Stats:     92 lines in 3 files changed: 69 ins; 11 del; 12 mod

8282414: x86: Enhance the assembler to generate more compact instructions

Reviewed-by: thartmann, sviswanathan

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

PR: https://git.openjdk.java.net/jdk/pull/7628