Regenerating BPF target using the maintainer mode emits:
.../opcodes/bpf-opc.c:57:11: error: conversion from ‘long unsigned int’ to ‘unsigned int’ changes value from ‘18446744073709486335’ to ‘4294902015’ [-Werror=overflow]
  57 |   64, 64, 0xffffffffffff00ff, { { F (F_IMM32) }, { F (F_OFFSET16) }, { F (F_SRCLE) }, { F (F_OP_CODE) }, { F (F_DSTLE) }, { F (F_OP_SRC) }, { F (F_OP_CLASS) }, { 0 } }

The use of a narrow size to handle the mask CGEN in instruction format
is causing this error.  Additionally eBPF `call' instructions
constructed by expressions using symbols (BPF_PSEUDO_CALL) emits
annotations in `src' field of the instruction, used to identify BPF
target endianness.

cpu/
	* bpf.cpu (define-call-insn): Remove `src' field from
	instruction mask.

include/
	*opcode/cge.h (CGEN_IFMT): Adjust mask bit width.

opcodes/
	* bpf-opc.c: Regenerate.

Add gas and opcodes support for two xBPF-exclusive ALU operations:
SDIV (signed division) and SMOD (signed modulo), and add tests for
them in gas.

cpu/
	* bpf.cpu (insn-op-code-alu): Add SDIV and SMOD.
	(define-alu-insn-bin, daib): Take ISAs as an argument.
	(define-alu-instructions): Update calls to daib pmacro with
	ISAs; add sdiv and smod.

gas/
	* testsuite/gas/bpf/alu-xbpf.d: New file.
	* testsuite/gas/bpf/alu-xbpf.s: Likewise.
	* testsuite/gas/bpf/alu32-xbpf.d: Likewise.
	* testsuite/gas/bpf/alu32-xbpf.d: Likewise.
	* testuiste/gas/bpf/bpf.exp: Run new tests.

opcodes/
	* bpf-desc.c: Regenerate.
	* bpf-desc.h: Likewise.
	* bpf-opc.c: Likewise.
	* bpf-opc.h: Likewise.

The div and mod eBPF instructions are unsigned, but the semantic
specification for the simulator incorrectly used signed operators.
Correct them to unsigned versions, and correct the ALU tests in
the simulator (which incorrectly assumed signed semantics).

Tested in bpf-unknown-none.

cpu/ChangeLog:
2020-09-08  David Faust  <david.faust@oracle.com>

	* bpf.cpu (define-alu-instructions): Correct semantic operators
	for div, mod to unsigned versions.

sim/ChangeLog:
2020-09-08  David Faust  <david.faust@oracle.com>

	* bpf/sem-be.c: Regenerate.
	* bpf/sem-le.c: Likewise.

sim/testsuite/ChangeLog:
2020-09-08  David Faust  <david.faust@oracle.com>

	* sim/bpf/alu.s: Correct div and mod tests.
	* sim/bpf/alu32.s: Likewise.

This patch adds support for xBPF, another ISA targetting the BPF
virtual architecture. For now, the primary difference between eBPF
and xBPF is that xBPF supports indirect calls through the
'call %reg' form of the call instruction.

bfd/
	* archures.c (bfd_mach_xbpf): Define.
	* bfd-in2.h: Regenerate.
	* cpu-bpf.c (bfd_xbpf_arch) New.
	(bfd_bpf_arch) Update next in list field to point to xbpf arch.

cpu/
	* bpf.cpu (arch bpf): Add xbpf mach and isas.
	(define-xbpf-isa) New pmacro.
	(all-isas) Add xbpfle,xbpfbe.
	(endian-isas): New pmacro.
	(mach xbpf): New.
	(model xbpf-def): Likewise.
	(h-gpr): Add xbpf mach.
	(f-dstle, f-srcle, dstle, srcle): Add xbpfle isa.
	(f-dstbe, f-srcbe, dstbe, srcbe): Add xbpfbe isa.
	(define-alu-insn-un): Use new endian-isas pmacro.
	(define-alu-insn-bin, define-alu-insn-mov): Likewise.
	(define-endian-insn, define-lddw): Likewise.
	(dlind, dxli, dxsi, dsti): Likewise.
	(define-cond-jump-insn, define-call-insn): Likewise.
	(define-atomic-insns): Likewise.

gas/
	* config/tc-bpf.c: Add option -mxbpf to select xbpf isa.
	* testsuite/gas/bpf/indcall-1.d: New file.
	* testsuite/gas/bpf/indcall-1.s: Likewise.
	* testsuite/gas/bpf/indcall-bad-1.l: Likewise.
	* testsuite/gas/bpf/indcall-bad-1.s: Likewise.
	* testsuite/gas/bpf/bpf.exp: Run new tests.

opcodes/
	* bpf-desc.c: Regenerate.
	* bpf-desc.h: Likewise.
	* bpf-opc.c: Likewise.
	* bpf-opc.h: Likewise.
	* disassemble.c (disassemble_init_for_target): Set bits for xBPF
	ISA when appropriate.

Correct the type of the offset16 field to HI, and simplify memory
accesses which use it. Also update c-calls in semantics for a
few instructions.

cpu/ChangeLog:

2020-06-25 David Faust  <david.faust@oracle.com>

	* bpf.cpu (f-offset16): Change type from INT to HI.
	(dxli): Simplify memory access.
	(dxsi): Likewise.
	(define-endian-insn): Update c-call in semantics.
	(dlabs) Likewise.
	(dlind) Likewise.

cpu/ChangeLog:

2020-06-02  Jose E. Marchesi  <jose.marchesi@oracle.com>

	* bpf.cpu (define-bpf-isa): Set base-insn-bitsize to 64.
	* bpf.opc (bpf_print_insn): Do not set endian_code here.

gas/ChangeLog:

2020-06-04  Jose E. Marchesi  <jose.marchesi@oracle.com>

	* config/tc-bpf.c (md_begin): Pass CGEN_CPU_OPEN_INSN_ENDIAN to
	bpf_cgen_cpu_open.
	(md_assemble): Remove no longer needed hack.

opcodes/ChangeLog:

2020-06-04  Jose E. Marchesi  <jose.marchesi@oracle.com>

	* disassemble.c (disassemble_init_for_target): Set endian_code for
	bpf targets.
	* bpf-desc.c: Regenerate.
	* bpf-opc.c: Likewise.
	* bpf-dis.c: Likewise.

This patch adds semantic RTL descriptions to the eBPF instructions
defined in cpu/bpf.cpu.  It also contains a couple of minor
improvements.

Tested in bpf-unknown-none targets.
No regressions.

cpu/ChangeLog:

2020-05-28  Jose E. Marchesi  <jose.marchesi@oracle.com>
	    David Faust <david.faust@oracle.com>

	* bpf.cpu (define-alu-insn-un): Add definitions of semantics.
	(define-alu-insn-mov): Likewise.
	(daib): Likewise.
	(define-alu-instructions): Likewise.
	(define-endian-insn): Likewise.
	(define-lddw): Likewise.
	(dlabs): Likewise.
	(dlind): Likewise.
	(dxli): Likewise.
	(dxsi): Likewise.
	(dsti): Likewise.
	(define-ldstx-insns): Likewise.
	(define-st-insns): Likewise.
	(define-cond-jump-insn): Likewise.
	(dcji): Likewise.
	(define-condjump-insns): Likewise.
	(define-call-insn): Likewise.
	(ja): Likewise.
	("exit"): Likewise.
	(define-atomic-insns): Likewise.
	(sem-exchange-and-add): New macro.
	* bpf.cpu ("brkpt"): New instruction.
	(bpfbf): Set word-bitsize to 32 and insn-endian big.
	(h-gpr): Prefer r0 to `a' and r6 to `ctx'.
	(h-pc): Expand definition.
	* bpf.opc (bpf_print_insn): Set endian_code to BIG.

opcodes/ChangeLog:

2020-05-28  Jose E. Marchesi  <jose.marchesi@oracle.com>
	    David Faust <david.faust@oracle.com>

	* bpf-desc.c: Regenerate.
	* bpf-opc.h: Likewise.
	* bpf-opc.c: Likewise.
	* bpf-dis.c: Likewise.

Add support for the JMP32 class of eBPF instructions.

cpu/ChangeLog

	* bpf.cpu (define-cond-jump-insn): Renamed from djci.
	(dcji) New version with support for JMP32

gas/ChangeLog

	* testsuite/gas/bpf/bpf.exp: Run jump32 tests.
	* testsuite/gas/bpf/jump32.s: New file.
	* testsuite/gas/bpf/jump32.d: Likewise.

opcodes/ChangeLog

	* bpf-desc.c: Regenerate.
	* bpf-desc.h: Likewise.
	* bpf-opc.c: Regenerate.
	* bpf-opc.h: Likewise.

This patch fixes the neg/neg32 BPF instructions, which have K (=0)
instead of X (=1) in their header source bit, despite operating on
registes.

cpu/ChangeLog:

2020-01-30  Jose E. Marchesi  <jose.marchesi@oracle.com>

	* bpf.cpu (define-alu-insn-un): The unary BPF instructions
	(neg and neg32) use OP_SRC_K even if they operate only in
	registers.

opcodes/ChangeLog:

2020-01-30  Jose E. Marchesi  <jose.marchesi@oracle.com>

	* bpf-opc.c: Regenerate.

gas/ChangeLog:

2020-01-30  Jose E. Marchesi  <jose.marchesi@oracle.com>

	* testsuite/gas/bpf/alu.d: Update expected opcode for `neg'.
	* testsuite/gas/bpf/alu-be.d: Likewise.
	* testsuite/gas/bpf/alu32.d: Likewise for `neg32'.
	* testsuite/gas/bpf/alu32-be.d: Likewise.

cpu/
	* bpf.cpu (f-imm64): Avoid signed overflow.
opcodes/
	* bpf-ibld.c: Regenerate.

2019-11-20  Jose E. Marchesi  <jose.marchesi@oracle.com>

	* bpf.cpu: Fix comment describing the 128-bit instruction format.

This patch changes the eBPF CPU description to prefer the register
names %r0 and %r6 instead of %a and %ctx when disassembling.  This
matches better with the current practice, vs. cBPF.

It also updates the GAS tests in order to reflect this change.
Tested in a x86_64 host.

cpu/ChangeLog:

2019-07-19  Jose E. Marchesi  <jose.marchesi@oracle.com>

	* bpf.cpu (h-gpr): when disassembling, use %r0 and %r6 instead of
	%a and %ctx.

opcodes/ChangeLog:

2019-07-19  Jose E. Marchesi  <jose.marchesi@oracle.com>

	* bpf-desc.c: Regenerated.

gas/ChangeLog:

2019-07-19  Jose E. Marchesi  <jose.marchesi@oracle.com>

	* testsuite/gas/bpf/alu.d: Use %r6 instead of %ctx.
	* testsuite/gas/bpf/lddw-be.d: Likewise.
	* testsuite/gas/bpf/lddw.d: Likewise.
	* testsuite/gas/bpf/alu-be.d: Likewise.
	* testsuite/gas/bpf/alu32.d: Likewise.

This patch fixes the eBPF CPU description in order to reflect the
right explicit arguments passed to the ldabs{b,h,w,dw} instructions,
updates the corresponding GAS tests, and updates the BPF section of
the GAS manual.

cpu/ChangeLog:

2019-07-15  Jose E. Marchesi  <jose.marchesi@oracle.com>

	* bpf.cpu (dlabs): New pmacro.
	(dlind): Likewise.

opcodes/ChangeLog:

2019-07-15  Jose E. Marchesi  <jose.marchesi@oracle.com>

	* bpf-desc.c: Regenerate.
	* bpf-opc.c: Likewise.
	* bpf-opc.h: Likewise.

gas/ChangeLog:

2019-07-15  Jose E. Marchesi  <jose.marchesi@oracle.com>

	* testsuite/gas/bpf/mem.s: ldabs instructions do not take a `src'
	register as an argument.
	* testsuite/gas/bpf/mem.d: Updated accordingly.
	* testsuite/gas/bpf/mem-be.d: Likewise.
	* doc/c-bpf.texi (BPF Opcodes): Update to reflect the correct
	explicit arguments to ldabs and ldind instructions.

The eBPF non-generic load instructions ldind{b,h,w,dw} and
ldabs{b,h,w,dw} do not take an explicit destination register as an
argument.  Instead, they put the loaded value in %r0, implicitly.

This patch fixes the CPU BPF description to not expect a 'dst'
argument in these arguments, regenerates the corresponding files in
opcodes, and updates the impacted GAS tests.

Tested in a x86-64 host.

cpu/ChangeLog:

2019-07-14  Jose E. Marchesi  <jose.marchesi@oracle.com>

	* bpf.cpu (dlsi): ldabs and ldind instructions do not take an
	explicit 'dst' argument.

opcodes/ChangeLog:

2019-07-14  Jose E. Marchesi  <jose.marchesi@oracle.com>

	* bpf-desc.c: Regenerate.
	* bpf-opc.c: Likewise.

gas/ChangeLog:

2019-07-14  Jose E. Marchesi  <jose.marchesi@oracle.com>

	* testsuite/gas/bpf/mem.s: Do not use explicit arguments for
	ldabs and ldind instructions.
	* testsuite/gas/bpf/mem.d: Updated accordingly.
	* testsuite/gas/bpf/mem-be.d: Likewise.

This patch adds a CPU description for the Linux kernel eBPF virtual
machine, plus supporting code for disassembler and assembler.

cpu/ChangeLog:

2019-05-23  Jose E. Marchesi  <jose.marchesi@oracle.com>

	* bpf.cpu: New file.
	* bpf.opc: Likewise.