Support APX GPR32 with rex2 prefix

APX uses the REX2 prefix to support EGPR for map0 and map1 of legacy
instructions. We added the NoEgpr flag in i386-gen.c for instructions
that do not support EGPR.

gas/ChangeLog:

2023-12-28  Lingling Kong <lingling.kong@intel.com>
	    H.J. Lu  <hongjiu.lu@intel.com>
	    Lili Cui <lili.cui@intel.com>
	    Lin Hu   <lin1.hu@intel.com>

	* config/tc-i386.c
	(enum i386_error): Add unsupported_EGPR_for_addressing
	and invalid_pseudo_prefix.
	(struct _i386_insn): Add rex2 and rex2_encoding for
	gpr32.
	(cpu_arch): Add apx_f.
	(is_cpu): Ditto.
	(register_number): Handle RegRex2 for gpr32.
	(is_apx_rex2_encoding): New func. Test rex2 prefix encoding.
	(build_rex2_prefix): New func. Build legacy insn in
	opcode 0/1 use gpr32 with rex2 prefix.
	(establish_rex): Handle rex2 and rex2_encoding.
	(optimize_encoding): Handel add r16-r31 for registers.
	(md_assemble): Handle apx encoding.
	(parse_insn): Handle Prefix_REX2.
	(check_EgprOperands): New func. Check if Egprs operands
	are valid for the instruction
	(match_template):  Handle Egpr operands check.
	(set_rex_rex2):  New func. set i.rex and i.rex2.
	(build_modrm_byte): Ditto.
	(output_insn): Handle rex2 2-byte prefix output.
	(check_register): Handle check egpr illegal without
	target apx, 64-bit mode and with rex_prefix.
	* doc/c-i386.texi: Document .apx.
	* testsuite/gas/i386/ilp32/x86-64-opcode-inval-intel.d: D5 valid
	in 64-bit mode.
	* testsuite/gas/i386/ilp32/x86-64-opcode-inval.d: Ditto.
	* testsuite/gas/i386/rex-bad: Adjust rex testcase.
	* testsuite/gas/i386/x86-64-opcode-inval-intel.d: Ditto.
	* testsuite/gas/i386/x86-64-opcode-inval.d: Ditto.
	* testsuite/gas/i386/x86-64-opcode-inval.s: Ditto.
	* testsuite/gas/i386/x86-64-pseudos-bad.l: Add illegal rex2 test.
	* testsuite/gas/i386/x86-64-pseudos-bad.s: Ditto.
	* testsuite/gas/i386/x86-64-pseudos.d: Add rex2 test.
	* testsuite/gas/i386/x86-64-pseudos.s: Ditto.
	* testsuite/gas/i386/x86-64.exp: Run APX tests.
	* testsuite/gas/i386/x86-64-apx-egpr-inval.l: New test.
	* testsuite/gas/i386/x86-64-apx-egpr-inval.s: New test.
	* testsuite/gas/i386/x86-64-apx-rex2.d: New test.
	* testsuite/gas/i386/x86-64-apx-rex2.s: New test.

include/ChangeLog:

	* opcode/i386.h (REX2_OPCODE): New.
	(REX2_M): Ditto.

opcodes/ChangeLog:

	* i386-dis.c (struct instr_info): Add erex for gpr32.
	Add last_erex_prefix for rex2 prefix.
	(REX2_M): Extend for gpr32.
	(PREFIX_REX2): Ditto.
	(PREFIX_REX2_ILLEGAL): Ditto.
	(ckprefix): Ditto.
	(prefix_name): Ditto.
	(print_insn): Ditto.
	(print_register): Ditto.
	(OP_E_memory): Ditto.
	(OP_REG): Ditto.
	(OP_EX): Ditto.
	* i386-gen.c (rex2_disallowed): Some instructions are not allowed rex2 prefix.
	(process_i386_opcode_modifier): Set NoEgpr for VEX and some special instructions.
	(output_i386_opcode): Handle if_entry_needs_special_handle.
	* i386-init.h : Regenerated.
	* i386-mnem.h : Regenerated.
	* i386-opc.h (enum i386_cpu): Add CpuAPX_F.
	(NoEgpr): New.
	(Prefix_NoOptimize): Ditto.
	(Prefix_REX2): Ditto.
	(RegRex2): Ditto.
	* i386-opc.tbl: Add rex2 prefix.
	* i386-reg.tbl: Add egprs (r16-r31).
	* i386-tbl.h: Regenerated.

1 files changed, 6 insertions, 1 deletions

diff --git a/gas/doc/c-i386.texi b/gas/doc/c-i386.texi
index 03ee980..21f48c9 100644
--- a/gas/doc/c-i386.texi
+++ b/gas/doc/c-i386.texi
@@ -217,6 +217,7 @@ accept various extension mnemonics.  For example,
 @code{avx10.1/256},
 @code{avx10.1/128},
 @code{user_msr},
+@code{apx_f},
 @code{amx_int8},
 @code{amx_bf16},
 @code{amx_fp16},
@@ -984,6 +985,10 @@ instructions (x86-64 only).  Note that this differs from the @samp{rex}
 prefix which generates REX prefix unconditionally.
 
 @item
+@samp{@{rex2@}} -- prefer REX2 prefix for integer and legacy vector
+instructions (APX_F only).
+
+@item
 @samp{@{nooptimize@}} -- disable instruction size optimization.
 @end itemize
 
@@ -1663,7 +1668,7 @@ supported on the CPU specified.  The choices for @var{cpu_type} are:
 @item @samp{.lwp} @tab @samp{.fma4} @tab @samp{.xop} @tab @samp{.cx16}
 @item @samp{.padlock} @tab @samp{.clzero} @tab @samp{.mwaitx} @tab @samp{.rdpru}
 @item @samp{.mcommit} @tab @samp{.sev_es} @tab @samp{.snp} @tab @samp{.invlpgb}
-@item @samp{.tlbsync}
+@item @samp{.tlbsync} @tab @samp{.apx_f}
 @end multitable
 
 Apart from the warning, there are only two other effects on