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

[Andrew Haley]

On Tue, 25 Feb 2025 11:15:39 GMT, Ferenc Rakoczi <duke at openjdk.org> wrote:

>>> 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.
>
> @theRealAlph, maybe we are not reading the same manual (ARM DDI 0487K.a). In my copy:
> SUB (extended register) is defined as
> SUB <Xd|SP>, <Xn|SP>, <R><m>{, <extend> {#<amount>}}
> and <R> should be W when <extend> is SXTH
> and the as I have enforces this: 
> 
> ferakocz at ferakocz-mac aarch64 % cat t.s  
> sub x1, x10, w23, sxth #2
> ferakocz at ferakocz-mac aarch64 % cat > t1.s
> sub x1, x10, x23, sxth #2
> ferakocz at ferakocz-mac aarch64 % cat t.s
> sub x1, x10, w23, sxth #2
> ferakocz at ferakocz-mac aarch64 % cat t1.s
> sub x1, x10, x23, sxth #2
> ferakocz at ferakocz-mac aarch64 % as --version
> Apple clang version 16.0.0 (clang-1600.0.26.6)
> Target: arm64-apple-darwin24.3.0
> Thread model: posix
> InstalledDir: /Library/Developer/CommandLineTools/usr/bin
> ferakocz at ferakocz-mac aarch64 % as t.s
> ferakocz at ferakocz-mac aarch64 % objdump -D t.o
> 
> t.o:	file format mach-o arm64
> 
> Disassembly of section __TEXT,__text:
> 
> 0000000000000000 <ltmp0>:
>        0: cb37a941     	sub	x1, x10, w23, sxth #2
> ferakocz at ferakocz-mac aarch64 % as t1.s
> t1.s:1:19: error: expected 'sxtx' 'uxtx' or 'lsl' with optional integer in range [0, 4]
> sub x1, x10, x23, sxth #2
>                     ^
> 
> I have not found the place in the manual where it allows/encourages the use of x<n> instead of w<n>, but I admit I haven't read through all of the 14568 pages.
> 
> So I'm stuck for now. What 'as' are you using?

> I have not found the place in the manual where it allows/encourages the use of x instead of w, but I admit I > haven't read through all of the 14568 pages.

Yes, you've got a point, but it's always worked. Is this a macos thing, maybe?

> So I'm stuck for now. What 'as' are you using?

Latest binutils, today. I checked it out half an hour ago.

GNU assembler (GNU Binutils) 2.44.50.20250225
Copyright (C) 2025 Free Software Foundation, Inc.

Try this:


diff --git a/test/hotspot/gtest/aarch64/aarch64-asmtest.py b/test/hotspot/gtest/aarch64/aarch64-asmtest.py
index 9c770632e25..b1674fff04d 100644
--- a/test/hotspot/gtest/aarch64/aarch64-asmtest.py
+++ b/test/hotspot/gtest/aarch64/aarch64-asmtest.py
@@ -476,8 +476,13 @@ class AddSubExtendedOp(ThreeRegInstruction):
                    + ", " + str(self.amount) + ");"))
 
     def astr(self):
-        return (super(AddSubExtendedOp, self).astr()
-                + (", " + AddSubExtendedOp.optNames[self.option]
+        prefix = self.asmRegPrefix
+        return (super(ThreeRegInstruction, self).astr()
+                + ('%s, %s, %s'
+                   % (self.reg[0].astr(prefix),
+                      self.reg[1].astr(prefix),
+                      self.reg[1].astr("w"))
+                + ", " + AddSubExtendedOp.optNames[self.option]
                    + " #" + str(self.amount)))
 
 class AddSubImmOp(TwoRegImmedInstruction):

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

PR Review Comment: https://git.openjdk.org/jdk/pull/23300#discussion_r1969760509