diff options
Diffstat (limited to 'vendor/github.com/cilium/ebpf/asm/alu.go')
-rw-r--r-- | vendor/github.com/cilium/ebpf/asm/alu.go | 149 |
1 files changed, 149 insertions, 0 deletions
diff --git a/vendor/github.com/cilium/ebpf/asm/alu.go b/vendor/github.com/cilium/ebpf/asm/alu.go new file mode 100644 index 000000000..70ccc4d15 --- /dev/null +++ b/vendor/github.com/cilium/ebpf/asm/alu.go @@ -0,0 +1,149 @@ +package asm + +//go:generate stringer -output alu_string.go -type=Source,Endianness,ALUOp + +// Source of ALU / ALU64 / Branch operations +// +// msb lsb +// +----+-+---+ +// |op |S|cls| +// +----+-+---+ +type Source uint8 + +const sourceMask OpCode = 0x08 + +// Source bitmask +const ( + // InvalidSource is returned by getters when invoked + // on non ALU / branch OpCodes. + InvalidSource Source = 0xff + // ImmSource src is from constant + ImmSource Source = 0x00 + // RegSource src is from register + RegSource Source = 0x08 +) + +// The Endianness of a byte swap instruction. +type Endianness uint8 + +const endianMask = sourceMask + +// Endian flags +const ( + InvalidEndian Endianness = 0xff + // Convert to little endian + LE Endianness = 0x00 + // Convert to big endian + BE Endianness = 0x08 +) + +// ALUOp are ALU / ALU64 operations +// +// msb lsb +// +----+-+---+ +// |OP |s|cls| +// +----+-+---+ +type ALUOp uint8 + +const aluMask OpCode = 0xf0 + +const ( + // InvalidALUOp is returned by getters when invoked + // on non ALU OpCodes + InvalidALUOp ALUOp = 0xff + // Add - addition + Add ALUOp = 0x00 + // Sub - subtraction + Sub ALUOp = 0x10 + // Mul - multiplication + Mul ALUOp = 0x20 + // Div - division + Div ALUOp = 0x30 + // Or - bitwise or + Or ALUOp = 0x40 + // And - bitwise and + And ALUOp = 0x50 + // LSh - bitwise shift left + LSh ALUOp = 0x60 + // RSh - bitwise shift right + RSh ALUOp = 0x70 + // Neg - sign/unsign signing bit + Neg ALUOp = 0x80 + // Mod - modulo + Mod ALUOp = 0x90 + // Xor - bitwise xor + Xor ALUOp = 0xa0 + // Mov - move value from one place to another + Mov ALUOp = 0xb0 + // ArSh - arithmatic shift + ArSh ALUOp = 0xc0 + // Swap - endian conversions + Swap ALUOp = 0xd0 +) + +// HostTo converts from host to another endianness. +func HostTo(endian Endianness, dst Register, size Size) Instruction { + var imm int64 + switch size { + case Half: + imm = 16 + case Word: + imm = 32 + case DWord: + imm = 64 + default: + return Instruction{OpCode: InvalidOpCode} + } + + return Instruction{ + OpCode: OpCode(ALUClass).SetALUOp(Swap).SetSource(Source(endian)), + Dst: dst, + Constant: imm, + } +} + +// Op returns the OpCode for an ALU operation with a given source. +func (op ALUOp) Op(source Source) OpCode { + return OpCode(ALU64Class).SetALUOp(op).SetSource(source) +} + +// Reg emits `dst (op) src`. +func (op ALUOp) Reg(dst, src Register) Instruction { + return Instruction{ + OpCode: op.Op(RegSource), + Dst: dst, + Src: src, + } +} + +// Imm emits `dst (op) value`. +func (op ALUOp) Imm(dst Register, value int32) Instruction { + return Instruction{ + OpCode: op.Op(ImmSource), + Dst: dst, + Constant: int64(value), + } +} + +// Op32 returns the OpCode for a 32-bit ALU operation with a given source. +func (op ALUOp) Op32(source Source) OpCode { + return OpCode(ALUClass).SetALUOp(op).SetSource(source) +} + +// Reg32 emits `dst (op) src`, zeroing the upper 32 bit of dst. +func (op ALUOp) Reg32(dst, src Register) Instruction { + return Instruction{ + OpCode: op.Op32(RegSource), + Dst: dst, + Src: src, + } +} + +// Imm32 emits `dst (op) value`, zeroing the upper 32 bit of dst. +func (op ALUOp) Imm32(dst Register, value int32) Instruction { + return Instruction{ + OpCode: op.Op32(ImmSource), + Dst: dst, + Constant: int64(value), + } +} |