Re: [PATCH v6 1/4] gas, aarch64: Add AdvSIMD lut extension

[Saurabh Jha <saurabh.jha@arm.com>]

On 5/23/2024 4:15 PM, Richard Earnshaw (lists) wrote:
> On 23/05/2024 14:50, Saurabh Jha wrote:
>>
>> Introduces instructions for the Advanced SIMD lut extension for AArch64. They are documented in the following links:
>> * luti2: https://developer.arm.com/documentation/ddi0602/2024-03/SIMD-FP-Instructions/LUTI2--Lookup-table-read-with-2-bit-indices-?lang=en
>> * luti4: https://developer.arm.com/documentation/ddi0602/2024-03/SIMD-FP-Instructions/LUTI4--Lookup-table-read-with-4-bit-indices-?lang=en
>>
>> These instructions needed definition of some new operands. We will first
>> discuss operands for the third operand of the instructions and then
>> discuss a vector register list operand needed for the second operand.
>>
>> The third operands are vectors with bit indices and without type
>> qualifiers. They are called Em_INDEX1_14, Em_INDEX2_13, and Em_INDEX3_12
>> and they have 1 bit, 2 bit, and 3 bit indices respectively. For these
>> new operands, we defined new parsing case branch and a new instruction
>> class. The lsb and width of these operands are the same as many existing
>> but the convention is to give different names to fields that serve
>> different purpose so we introduced new fields in aarch64-opc.c and
>> aarch64-opc.h for these new operands.
>>
>> For the second operand of these instructions, we introduced a new
>> operand called LVn_LUT. This represents a vector register list with
>> stride 1. We defined new inserter and extractor for this new operand and
>> it is encoded in FLD_Rn. We are enforcing the number of registers in the
>> reglist using opcode flag rather than operand flag as this is what other
>> SIMD vector register list operands are doing. The disassembly also uses
>> opcode flag to print the correct number of registers.
>> ---
>> Hi,
>>
>> Regression tested for aarch64-none-elf and found no regressions.
>>
>> Ok for binutils-master? I don't have commit access so can someone please commit on my behalf?
> 
> I was about to apply this when I realized that you haven't added anything to the manual or the NEWS file as we could customarily do for a new feature.  Could you update the patch for that please?
> 
> R.
> 

Yes, thanks for pointing it out. Fixed here: 
https://sourceware.org/pipermail/binutils/2024-May/134334.html
>>
>> Regards,
>> Saurabh
>> ---
>>   gas/config/tc-aarch64.c                       |  67 ++++++
>>   gas/testsuite/gas/aarch64/advsimd-lut-bad.d   |   3 +
>>   gas/testsuite/gas/aarch64/advsimd-lut-bad.l   |  25 +++
>>   .../gas/aarch64/advsimd-lut-illegal.d         |   3 +
>>   .../gas/aarch64/advsimd-lut-illegal.l         | 208 ++++++++++++++++++
>>   .../gas/aarch64/advsimd-lut-illegal.s         | 128 +++++++++++
>>   gas/testsuite/gas/aarch64/advsimd-lut.d       |  32 +++
>>   gas/testsuite/gas/aarch64/advsimd-lut.s       |  29 +++
>>   include/opcode/aarch64.h                      |   9 +-
>>   opcodes/aarch64-asm.c                         |  32 +++
>>   opcodes/aarch64-asm.h                         |   1 +
>>   opcodes/aarch64-dis.c                         |  15 ++
>>   opcodes/aarch64-dis.h                         |   1 +
>>   opcodes/aarch64-opc.c                         |  23 ++
>>   opcodes/aarch64-opc.h                         |   2 +
>>   opcodes/aarch64-tbl.h                         |  38 +++-
>>   16 files changed, 614 insertions(+), 2 deletions(-)
>>   create mode 100644 gas/testsuite/gas/aarch64/advsimd-lut-bad.d
>>   create mode 100644 gas/testsuite/gas/aarch64/advsimd-lut-bad.l
>>   create mode 100644 gas/testsuite/gas/aarch64/advsimd-lut-illegal.d
>>   create mode 100644 gas/testsuite/gas/aarch64/advsimd-lut-illegal.l
>>   create mode 100644 gas/testsuite/gas/aarch64/advsimd-lut-illegal.s
>>   create mode 100644 gas/testsuite/gas/aarch64/advsimd-lut.d
>>   create mode 100644 gas/testsuite/gas/aarch64/advsimd-lut.s
>>
>