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llvm-mirror/lib/Target/BPF/BPF.td
Jiong Wang 1bc276c3c4 [BPF] add code-gen support for JMP32 instructions
JMP32 instructions has been added to eBPF ISA. They are 32-bit variants of
existing BPF conditional jump instructions, but the comparison happens on
low 32-bit sub-register only, therefore some unnecessary extensions could
be saved.

JMP32 instructions will only be available for -mcpu=v3. Host probe hook has
been updated accordingly.

JMP32 instructions will only be enabled in code-gen when -mattr=+alu32
enabled, meaning compiling the program using sub-register mode.

For JMP32 encoding, it is a new instruction class, and is using the
reserved eBPF class number 0x6.

This patch has been tested by compiling and running kernel bpf selftests
with JMP32 enabled.

Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
llvm-svn: 353384
2019-02-07 10:43:09 +00:00

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1.6 KiB
TableGen

//===-- BPF.td - Describe the BPF Target Machine -----------*- tablegen -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
include "llvm/Target/Target.td"
include "BPFRegisterInfo.td"
include "BPFCallingConv.td"
include "BPFInstrInfo.td"
def BPFInstrInfo : InstrInfo;
class Proc<string Name, list<SubtargetFeature> Features>
: Processor<Name, NoItineraries, Features>;
def : Proc<"generic", []>;
def : Proc<"v1", []>;
def : Proc<"v2", []>;
def : Proc<"v3", []>;
def : Proc<"probe", []>;
def DummyFeature : SubtargetFeature<"dummy", "isDummyMode",
"true", "unused feature">;
def ALU32 : SubtargetFeature<"alu32", "HasAlu32", "true",
"Enable ALU32 instructions">;
def DwarfRIS: SubtargetFeature<"dwarfris", "UseDwarfRIS", "true",
"Disable MCAsmInfo DwarfUsesRelocationsAcrossSections">;
def BPFInstPrinter : AsmWriter {
string AsmWriterClassName = "InstPrinter";
bit isMCAsmWriter = 1;
}
def BPFAsmParser : AsmParser {
bit HasMnemonicFirst = 0;
}
def BPFAsmParserVariant : AsmParserVariant {
int Variant = 0;
string Name = "BPF";
string BreakCharacters = ".";
string TokenizingCharacters = "#()[]=:.<>!+*";
}
def BPF : Target {
let InstructionSet = BPFInstrInfo;
let AssemblyWriters = [BPFInstPrinter];
let AssemblyParsers = [BPFAsmParser];
let AssemblyParserVariants = [BPFAsmParserVariant];
}