RFR: 8348561: Add aarch64 intrinsics for ML-DSA [v5]

[Andrew Haley]

On Mon, 24 Feb 2025 17:11:24 GMT, Andrew Dinn <adinn at openjdk.org> wrote:

>> I have tried that, but the python script (actually the as command that it started) threw error messages:
>> 
>> aarch64ops.s:338:24: error: index must be a multiple of 8 in range [0, 32760].
>>         prfm    PLDL1KEEP, [x15, 43]
>>                                  ^
>> aarch64ops.s:357:20: error: expected 'sxtx' 'uxtx' or 'lsl' with optional integer in range [0, 4]
>>         sub     x1, x10, x23, sxth #2
>>                               ^
>> aarch64ops.s:359:20: error: expected 'sxtx' 'uxtx' or 'lsl' with optional integer in range [0, 4]
>>         add     x11, x21, x5, uxtb #3
>>                               ^
>> aarch64ops.s:360:22: error: expected 'sxtx' 'uxtx' or 'lsl' with optional integer in range [0, 4]
>>         adds    x11, x17, x17, uxtw #1
>>                                ^
>> aarch64ops.s:361:20: error: expected 'sxtx' 'uxtx' or 'lsl' with optional integer in range [0, 4]
>>         sub     x11, x0, x15, uxtb #1
>>                               ^
>> aarch64ops.s:362:19: error: expected 'sxtx' 'uxtx' or 'lsl' with optional integer in range [0, 4]
>>         subs    x7, x1, x0, sxth #2
>>                             ^
>> This is without any modifications from what is in the master branch currently.
>
> @ferakocz This also really needs addressing before committing the patch. Perhaps @theRealAph can advise on how to circumvent the problems you found when trying to update the python script?

> You might have to use an assembler from the latest binutils build (if the system default isn't the latest) and add the path to the assembler in the "AS" variable. Also you can run it something like - `python aarch64-asmtest.py | expand > asmtest.out.h`. Please let me know if you still face problems.

People have been running this script for a decade now.

Let's look at just one of these:


aarch64ops.s:357:20: error: expected 'sxtx' 'uxtx' or 'lsl' with optional integer in range [0, 4]
sub x1, x10, x23, sxth #2


>From the AArch64 manual:

SUB (extended register)
SUB <Xd|SP>, <Xn|SP>, <R><m>{, <extend> {#<amount>}}

 It thinks this is a SUB (shifted register), bit it's really a SUB (extended register).


fedora:aarch64 $ cat t.s
sub x1, x10, x23, sxth #2
fedora:aarch64 $ as t.s
fedora:aarch64 $ objdump -D a.out
Disassembly of section .text:

0000000000000000 <.text>:
   0:	cb37a941 	sub	x1, x10, w23, sxth #2


So perhaps binutils expects w23 here, not x23. But the manual (ARM DDI 0487K.a) says x23 should be just fine, and, what's more, gives the x form preferred status.

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PR Review Comment: https://git.openjdk.org/jdk/pull/23300#discussion_r1969374124