[PATCH 2/3] RISC-V: drop stray INSN_ALIAS flags

[Nelson Chu]

Thanks, this patch fixes the problem when dumping fence.tso, zip and
unzip with -Mno-aliases.  Please commit this one when you think it's
time.

* Before applying this patch,

% cat tmp.s
zip a0, a1
unzip a0, a1
fence.tso
% riscv64-unknown-elf-as -march=rv32i_zbkb tmp.s -o tmp.o
% riscv64-unknown-elf-objdump -d tmp.o

tmp.o:     file format elf32-littleriscv


Disassembly of section .text:

00000000 <.text>:
   0: 08f59513          zip a0,a1
   4: 08f5d513          unzip a0,a1
   8: 8330000f          fence.tso
% riscv64-unknown-elf-objdump -d -Mno-aliases tmp.o

tmp.o:     file format elf32-littleriscv

Disassembly of section .text:

00000000 <.text>:
   0: 08f59513          .4byte 0x8f59513
   4: 08f5d513          .4byte 0x8f5d513
   8: 8330000f          .4byte 0x8330000f

* After applying this patch, I get the right result for -Mno-aliases,

% riscv64-unknown-elf-objdump -d -Mno-aliases tmp.o

tmp.o:     file format elf32-littleriscv

Disassembly of section .text:

00000000 <.text>:
   0: 08f59513          zip a0,a1
   4: 08f5d513          unzip a0,a1
   8: 8330000f          fence.tso

Thanks
Nelson

On Tue, Sep 13, 2022 at 9:03 PM Jan Beulich <jbeulich@suse.com> wrote:
>
> FENCE.TSO isn't an alias. ZIP and UNZIP in the long run likely are, but
> presently they aren't. This fixes disassembly of these insns with
> -Mno-aliases.
>
> --- /dev/null
> +++ b/gas/testsuite/gas/riscv/fence-tso-na.d
> @@ -0,0 +1,12 @@
> +#as: -march=rv32ic
> +#source: fence-tso.s
> +#objdump: -dr -Mno-aliases
> +
> +.*:[   ]+file format .*
> +
> +
> +Disassembly of section .text:
> +
> +0+000 <target>:
> +[      ]+[0-9a-f]+:[   ]+8330000f[     ]+fence.tso
> +#pass
> --- /dev/null
> +++ b/gas/testsuite/gas/riscv/zbkb-32-na.d
> @@ -0,0 +1,23 @@
> +#as: -march=rv32i_zbkb
> +#source: zbkb-32.s
> +#objdump: -d -Mno-aliases
> +
> +.*:[   ]+file format .*
> +
> +
> +Disassembly of section .text:
> +
> +0+000 <target>:
> +[      ]+[0-9a-f]+:[   ]+60c5d533[     ]+ror[  ]+a0,a1,a2
> +[      ]+[0-9a-f]+:[   ]+60c59533[     ]+rol[  ]+a0,a1,a2
> +[      ]+[0-9a-f]+:[   ]+6025d513[     ]+rori[         ]+a0,a1,0x2
> +[      ]+[0-9a-f]+:[   ]+40c5f533[     ]+andn[         ]+a0,a1,a2
> +[      ]+[0-9a-f]+:[   ]+40c5e533[     ]+orn[  ]+a0,a1,a2
> +[      ]+[0-9a-f]+:[   ]+40c5c533[     ]+xnor[         ]+a0,a1,a2
> +[      ]+[0-9a-f]+:[   ]+08c5c533[     ]+pack[         ]+a0,a1,a2
> +[      ]+[0-9a-f]+:[   ]+08c5f533[     ]+packh[        ]+a0,a1,a2
> +[      ]+[0-9a-f]+:[   ]+68755513[     ]+brev8[        ]+a0,a0
> +[      ]+[0-9a-f]+:[   ]+69855513[     ]+rev8[         ]+a0,a0
> +[      ]+[0-9a-f]+:[   ]+08f51513[     ]+zip[  ]+a0,a0
> +[      ]+[0-9a-f]+:[   ]+08f55513[     ]+unzip[        ]+a0,a0
> +#pass
> --- a/opcodes/riscv-opc.c
> +++ b/opcodes/riscv-opc.c
> @@ -421,7 +421,7 @@ const struct riscv_opcode riscv_opcodes[
>  {"fence",       0, INSN_CLASS_I, "",          MATCH_FENCE|MASK_PRED|MASK_SUCC, MASK_FENCE|MASK_RD|MASK_RS1|MASK_IMM, match_opcode, INSN_ALIAS },
>  {"fence",       0, INSN_CLASS_I, "P,Q",       MATCH_FENCE, MASK_FENCE|MASK_RD|MASK_RS1|(MASK_IMM & ~MASK_PRED & ~MASK_SUCC), match_opcode, 0 },
>  {"fence.i",     0, INSN_CLASS_ZIFENCEI, "",   MATCH_FENCE_I, MASK_FENCE|MASK_RD|MASK_RS1|MASK_IMM, match_opcode, 0 },
> -{"fence.tso",   0, INSN_CLASS_I, "",          MATCH_FENCE_TSO, MASK_FENCE_TSO|MASK_RD|MASK_RS1, match_opcode, INSN_ALIAS },
> +{"fence.tso",   0, INSN_CLASS_I, "",          MATCH_FENCE_TSO, MASK_FENCE_TSO|MASK_RD|MASK_RS1, match_opcode, 0 },
>  {"rdcycle",     0, INSN_CLASS_I, "d",         MATCH_RDCYCLE, MASK_RDCYCLE, match_opcode, INSN_ALIAS },
>  {"rdinstret",   0, INSN_CLASS_I, "d",         MATCH_RDINSTRET, MASK_RDINSTRET, match_opcode, INSN_ALIAS },
>  {"rdtime",      0, INSN_CLASS_I, "d",         MATCH_RDTIME, MASK_RDTIME, match_opcode, INSN_ALIAS },
> @@ -942,8 +942,8 @@ const struct riscv_opcode riscv_opcodes[
>  {"cpopw",     64, INSN_CLASS_ZBB,  "d,s",   MATCH_CPOPW, MASK_CPOPW, match_opcode, 0 },
>  {"brev8",     32, INSN_CLASS_ZBKB,  "d,s",      MATCH_GREVI | MATCH_SHAMT_BREV8, MASK_GREVI | MASK_SHAMT, match_opcode, 0 },
>  {"brev8",     64, INSN_CLASS_ZBKB,  "d,s",      MATCH_GREVI | MATCH_SHAMT_BREV8, MASK_GREVI | MASK_SHAMT, match_opcode, 0 },
> -{"zip",       32, INSN_CLASS_ZBKB,  "d,s",      MATCH_SHFLI|MATCH_SHAMT_ZIP_32, MASK_SHFLI|MASK_SHAMT, match_opcode, INSN_ALIAS },
> -{"unzip",     32, INSN_CLASS_ZBKB,  "d,s",      MATCH_UNSHFLI|MATCH_SHAMT_ZIP_32, MASK_UNSHFLI|MASK_SHAMT, match_opcode, INSN_ALIAS },
> +{"zip",       32, INSN_CLASS_ZBKB,  "d,s",      MATCH_SHFLI|MATCH_SHAMT_ZIP_32, MASK_SHFLI|MASK_SHAMT, match_opcode, 0 },
> +{"unzip",     32, INSN_CLASS_ZBKB,  "d,s",      MATCH_UNSHFLI|MATCH_SHAMT_ZIP_32, MASK_UNSHFLI|MASK_SHAMT, match_opcode, 0 },
>  {"pack",       0, INSN_CLASS_ZBKB,  "d,s,t",    MATCH_PACK, MASK_PACK, match_opcode, 0 },
>  {"packh",      0, INSN_CLASS_ZBKB,  "d,s,t",    MATCH_PACKH, MASK_PACKH, match_opcode, 0 },
>  {"packw",     64, INSN_CLASS_ZBKB,  "d,s,t",    MATCH_PACKW, MASK_PACKW, match_opcode, 0 },
>