[PATCH] AArch64: add GAS support for UDF instruction

[Alex Coplan]

> -----Original Message-----
> From: Binutils <binutils-bounces@sourceware.org> On Behalf Of Alex Coplan
> Sent: 29 April 2020 16:02
> To: Tamar Christina <Tamar.Christina@arm.com>; binutils@sourceware.org
> Cc: Richard Earnshaw <Richard.Earnshaw@arm.com>; nd <nd@arm.com>; Marcus
> Shawcroft <Marcus.Shawcroft@arm.com>
> Subject: RE: [PATCH] AArch64: add GAS support for UDF instruction
> 
> Hi Tamar,
> 
> > -----Original Message-----
> > From: Tamar Christina <Tamar.Christina@arm.com>
> > Sent: 29 April 2020 08:44
> > To: Alex Coplan <Alex.Coplan@arm.com>; binutils@sourceware.org
> > Cc: nd <nd@arm.com>
> > Subject: RE: [PATCH] AArch64: add GAS support for UDF instruction
> >
> > Hi Alex,
> >
> > I'm not a maintainer so can't approve your patch but please add a
> > regression test to check something other than immediate 0.
> 
> So my original patch introduced testsuite/gas/aarch64/udf.{s,d} which
> tests a
> couple of different immediates. However, as your comment below reveals,
> it would
> have been a good idea to test some error cases as well, so I've added
> testsuite/gas/aarch64/udf-invalid.{s,l,d} to that end.
> 
> >
> > Also your new field encoder isn't handing when the immediate is out of
> > range correctly:
> >
> > > printf "udf 0xEFFFC\n" | ./gas/as-new && ./binutils/objdump -d a.out
> |
> > > tail -1
> >
> >    0:   0000fffc        udf     #65532
> >
> > Shows it's silently truncating the immediate rather than raising an out
> > of range error.
> 
> Good catch. The attached diff should fix this issue.
> 
> >
> > PS: When submitting a patch also CC the maintainers for the area you're
> > submitting for.
> 
> Noted. Is the updated patch OK for master?
> 
> >
> > Thanks,
> > Tamar
> 
> Thanks,
> Alex

I forgot to include the updated ChangeLog. Here it is:

binutils/ChangeLog:

2020-04-27  Alex Coplan  <alex.coplan@arm.com>

        * testsuite/binutils-all/aarch64/in-order-all.d: Update to use new
          disassembly.
        * testsuite/binutils-all/aarch64/out-of-order-all.d: Likewise.

ld/ChangeLog:

2020-04-28  Alex Coplan  <alex.coplan@arm.com>

        * testsuite/ld-aarch64/erratum843419_tls_ie.d: Use udf in disassembly.
        * testsuite/ld-aarch64/farcall-b-section.d: Likewise.
        * testsuite/ld-aarch64/farcall-back.d: Likewise.
        * testsuite/ld-aarch64/farcall-bl-section.d: Likewise.

gas/ChangeLog:

2020-04-27  Alex Coplan  <alex.coplan@arm.com>

        * config/tc-aarch64.c (fix_insn): Implement for AARCH64_OPND_UNDEFINED.
          (parse_operands): Implement for AARCH64_OPND_UNDEFINED.
        * testsuite/gas/aarch64/udf.s: New.
        * testsuite/gas/aarch64/udf.d: New.
        * testsuite/gas/aarch64/udf-invalid.s: New.
        * testsuite/gas/aarch64/udf-invalid.l: New.
        * testsuite/gas/aarch64/udf-invalid.d: New.

include/ChangeLog:

2020-04-27  Alex Coplan  <alex.coplan@arm.com>

        * opcode/aarch64.h (enum aarch64_opnd): Add AARCH64_OPND_UNDEFINED.

opcodes/ChangeLog:

2020-04-27  Alex Coplan  <alex.coplan@arm.com>

        * aarch64-opc.h (enum aarch64_field_kind): Add FLD_imm16_2.
        * aarch64-opc.c (fields): Add entry for FLD_imm16_2.
          (operand_general_constraint_met_p): validate AARCH64_OPND_UNDEFINED.
        * aarch64-tbl.h (aarch64_opcode_table): Add udf instruction, entry for
          FLD_imm16_2.
        * aarch64-asm-2.c: Regenerated.
        * aarch64-dis-2.c: Regenerated.
        * aarch64-opc-2.c: Regenerated.

> 
> > -----Original Message-----
> > From: Tamar Christina <Tamar.Christina@arm.com>
> > Sent: 29 April 2020 08:44
> > To: Alex Coplan <Alex.Coplan@arm.com>; binutils@sourceware.org
> > Cc: nd <nd@arm.com>
> > Subject: RE: [PATCH] AArch64: add GAS support for UDF instruction
> >
> > Hi Alex,
> >
> > I'm not a maintainer so can't approve your patch but please add a
> > regression test to check something other than immediate 0.
> >
> > Also your new field encoder isn't handing when the immediate is out of
> > range correctly:
> >
> > > printf "udf 0xEFFFC\n" | ./gas/as-new && ./binutils/objdump -d a.out
> |
> > > tail -1
> >
> >    0:   0000fffc        udf     #65532
> >
> > Shows it's silently truncating the immediate rather than raising an out
> > of range error.
> >
> > PS: When submitting a patch also CC the maintainers for the area you're
> > submitting for.
> >
> > Thanks,
> > Tamar
> >
> > > -----Original Message-----
> > > From: Binutils <binutils-bounces@sourceware.org> On Behalf Of Alex
> > > Coplan
> > > Sent: Tuesday, April 28, 2020 11:42 AM
> > > To: binutils@sourceware.org
> > > Cc: nd <nd@arm.com>
> > > Subject: [PATCH] AArch64: add GAS support for UDF instruction
> > >
> > > Hello,
> > >
> > > The attached patch adds support to the AArch64 assembler for the UDF
> > > instruction, see https://developer.arm.com/docs/ddi0596/a/a64-base-
> > > instructions-alphabetic-order/udf-permanently-undefined
> > >
> > > Note that the files marked regenerated are not included in the patch
> > > in order to keep the size of the patch down: these will need to be
> > > regenerated before commit.
> > >
> > > Testing:
> > >  - New regression test added: fails before and passes after the
> patch.
> > >  - Bootstrap and regression on aarch64-linux.
> > >
> > > Ok for master? If so, I will need a maintainer to regenerate the
> > > generated files and commit the patch as I don't have commit access.
> > >
> > > Thanks,
> > > Alex
> > >
> > > ---
> > >
> > > binutils/ChangeLog:
> > >
> > > 2020-04-27  Alex Coplan  <alex.coplan@arm.com>
> > >
> > >         * testsuite/binutils-all/aarch64/in-order-all.d: Update to
> use
> > new
> > >           disassembly.
> > >         * testsuite/binutils-all/aarch64/out-of-order-all.d:
> Likewise.
> > >
> > > ld/ChangeLog:
> > >
> > > 2020-04-28  Alex Coplan  <alex.coplan@arm.com>
> > >
> > >         * testsuite/ld-aarch64/erratum843419_tls_ie.d: Use udf in
> > disassembly.
> > >         * testsuite/ld-aarch64/farcall-b-section.d: Likewise.
> > >         * testsuite/ld-aarch64/farcall-back.d: Likewise.
> > >         * testsuite/ld-aarch64/farcall-bl-section.d: Likewise.
> > >
> > > gas/ChangeLog:
> > >
> > > 2020-04-27  Alex Coplan  <alex.coplan@arm.com>
> > >
> > >         * config/tc-aarch64.c (fix_insn): Implement for
> > > AARCH64_OPND_UNDEFINED.
> > >         * config/tc-aarch64.c (parse_operands): Likewise.
> > >         * testsuite/gas/aarch64/udf.s: New.
> > >         * testsuite/gas/aarch64/udf.d: New.
> > >
> > > include/ChangeLog:
> > >
> > > 2020-04-27  Alex Coplan  <alex.coplan@arm.com>
> > >
> > >         * opcode/aarch64.h (enum aarch64_opnd): Add
> > > AARCH64_OPND_UNDEFINED.
> > >
> > > opcodes/ChangeLog:
> > >
> > > 2020-04-27  Alex Coplan  <alex.coplan@arm.com>
> > >
> > >         * aarch64-opc.h (enum aarch64_field_kind): Add FLD_imm16_2.
> > >         * aarch64-opc.c (fields): Add entry for FLD_imm16_2.
> > >         * aarch64-tbl.h (aarch64_opcode_table): Add udf instruction,
> > entry for
> > >           FLD_imm16_2.
> > >         * aarch64-asm-2.c: Regenerated.
> > >         * aarch64-dis-2.c: Regenerated.
> > >         * aarch64-opc-2.c: Regenerated.