inst.isle

;; Instruction formats.
(type MInst
      (enum
       ;; A no-op of zero size.
       (Nop0)

       ;; A no-op that is one instruction large.
       (Nop4)

       ;; An ALU operation with two register sources and a register destination.
       (AluRRR
        (alu_op ALUOp)
        (size OperandSize)
        (rd WritableReg)
        (rn Reg)
        (rm Reg))

       ;; An ALU operation with three register sources and a register destination.
       (AluRRRR
        (alu_op ALUOp3)
        (size OperandSize)
        (rd WritableReg)
        (rn Reg)
        (rm Reg)
        (ra Reg))

       ;; An ALU operation with a register source and an immediate-12 source, and a register
       ;; destination.
       (AluRRImm12
        (alu_op ALUOp)
        (size OperandSize)
        (rd WritableReg)
        (rn Reg)
        (imm12 Imm12))

       ;; An ALU operation with a register source and an immediate-logic source, and a register destination.
       (AluRRImmLogic
        (alu_op ALUOp)
        (size OperandSize)
        (rd WritableReg)
        (rn Reg)
        (imml ImmLogic))

       ;; An ALU operation with a register source and an immediate-shiftamt source, and a register destination.
       (AluRRImmShift
        (alu_op ALUOp)
        (size OperandSize)
        (rd WritableReg)
        (rn Reg)
        (immshift ImmShift))

       ;; An ALU operation with two register sources, one of which can be shifted, and a register
       ;; destination.
       (AluRRRShift
        (alu_op ALUOp)
        (size OperandSize)
        (rd WritableReg)
        (rn Reg)
        (rm Reg)
        (shiftop ShiftOpAndAmt))

       ;; An ALU operation with two register sources, one of which can be {zero,sign}-extended and
       ;; shifted, and a register destination.
       (AluRRRExtend
        (alu_op ALUOp)
        (size OperandSize)
        (rd WritableReg)
        (rn Reg)
        (rm Reg)
        (extendop ExtendOp))

       ;; A bit op instruction with a single register source.
       (BitRR
        (op BitOp)
        (size OperandSize)
        (rd WritableReg)
        (rn Reg))

       ;; An unsigned (zero-extending) 8-bit load.
       (ULoad8
        (rd WritableReg)
        (mem AMode)
        (flags MemFlags))

       ;; A signed (sign-extending) 8-bit load.
       (SLoad8
        (rd WritableReg)
        (mem AMode)
        (flags MemFlags))

       ;; An unsigned (zero-extending) 16-bit load.
       (ULoad16
        (rd WritableReg)
        (mem AMode)
        (flags MemFlags))

       ;; A signed (sign-extending) 16-bit load.
       (SLoad16
        (rd WritableReg)
        (mem AMode)
        (flags MemFlags))

       ;; An unsigned (zero-extending) 32-bit load.
       (ULoad32
        (rd WritableReg)
        (mem AMode)
        (flags MemFlags))

       ;; A signed (sign-extending) 32-bit load.
       (SLoad32
        (rd WritableReg)
        (mem AMode)
        (flags MemFlags))

       ;; A 64-bit load.
       (ULoad64
        (rd WritableReg)
        (mem AMode)
        (flags MemFlags))

       ;; An 8-bit store.
       (Store8
        (rd Reg)
        (mem AMode)
        (flags MemFlags))

       ;; A 16-bit store.
       (Store16
        (rd Reg)
        (mem AMode)
        (flags MemFlags))

       ;; A 32-bit store.
       (Store32
        (rd Reg)
        (mem AMode)
        (flags MemFlags))

       ;; A 64-bit store.
       (Store64
        (rd Reg)
        (mem AMode)
        (flags MemFlags))

       ;; A store of a pair of registers.
       (StoreP64
        (rt Reg)
        (rt2 Reg)
        (mem PairAMode)
        (flags MemFlags))

       ;; A load of a pair of registers.
       (LoadP64
        (rt WritableReg)
        (rt2 WritableReg)
        (mem PairAMode)
        (flags MemFlags))

       ;; A MOV instruction. These are encoded as ORR's (AluRRR form).
       ;; The 32-bit version zeroes the top 32 bits of the
       ;; destination, which is effectively an alias for an unsigned
       ;; 32-to-64-bit extension.
       (Mov
        (size OperandSize)
        (rd WritableReg)
        (rm Reg))

       ;; A MOV[Z,N,K] with a 16-bit immediate.
       (MovWide
        (op MoveWideOp)
        (rd WritableReg)
        (imm MoveWideConst)
        (size OperandSize))

       ;; A sign- or zero-extend operation.
       (Extend
        (rd WritableReg)
        (rn Reg)
        (signed bool)
        (from_bits u8)
        (to_bits u8))

       ;; A conditional-select operation.
       (CSel
        (rd WritableReg)
        (cond Cond)
        (rn Reg)
        (rm Reg))

       ;; A conditional-set operation.
       (CSet
        (rd WritableReg)
        (cond Cond))

       ;; A conditional-set-mask operation.
       (CSetm
        (rd WritableReg)
        (cond Cond))

       ;; A conditional comparison with an immediate.
       (CCmpImm
        (size OperandSize)
        (rn Reg)
        (imm UImm5)
        (nzcv NZCV)
        (cond Cond))

       ;; A synthetic insn, which is a load-linked store-conditional loop, that has the overall
       ;; effect of atomically modifying a memory location in a particular way.  Because we have
       ;; no way to explain to the regalloc about earlyclobber registers, this instruction has
       ;; completely fixed operand registers, and we rely on the RA's coalescing to remove copies
       ;; in the surrounding code to the extent it can. Load- and store-exclusive instructions,
       ;; with acquire-release semantics, are used to access memory. The operand conventions are:
       ;;
       ;; x25   (rd) address
       ;; x26   (rd) second operand for `op`
       ;; x27   (wr) old value
       ;; x24   (wr) scratch reg; value afterwards has no meaning
       ;; x28   (wr) scratch reg; value afterwards has no meaning
       (AtomicRMWLoop
        (ty Type) ;; I8, I16, I32 or I64
        (op AtomicRMWLoopOp))

       ;; Similar to AtomicRMWLoop, a compare-and-swap operation implemented using a load-linked
       ;; store-conditional loop, with acquire-release semantics.
       ;; Note that the operand conventions, although very similar to AtomicRMWLoop, are different:
       ;;
       ;; x25   (rd) address
       ;; x26   (rd) expected value
       ;; x28   (rd) replacement value
       ;; x27   (wr) old value
       ;; x24   (wr) scratch reg; value afterwards has no meaning
       (AtomicCASLoop
        (ty Type) ;; I8, I16, I32 or I64
        )

       ;; An atomic read-modify-write operation. These instructions require the
       ;; Large System Extension (LSE) ISA support (FEAT_LSE). The instructions have
       ;; acquire-release semantics.
       (AtomicRMW
         (op AtomicRMWOp)
         (rs Reg)
         (rt WritableReg)
         (rn Reg)
         (ty Type))

       ;; An atomic compare-and-swap operation. These instructions require the
       ;; Large System Extension (LSE) ISA support (FEAT_LSE). The instructions have
       ;; acquire-release semantics.
       (AtomicCAS
         (rs WritableReg)
         (rt Reg)
         (rn Reg)
         (ty Type))

       ;; Read `access_ty` bits from address `rt`, either 8, 16, 32 or 64-bits, and put
       ;; it in `rn`, optionally zero-extending to fill a word or double word result.
       ;; This instruction is sequentially consistent.
       (LoadAcquire
        (access_ty Type) ;; I8, I16, I32 or I64
        (rt WritableReg)
        (rn Reg))

       ;; Write the lowest `ty` bits of `rt` to address `rn`.
       ;; This instruction is sequentially consistent.
       (StoreRelease
        (access_ty Type) ;; I8, I16, I32 or I64
        (rt Reg)
        (rn Reg))

       ;; A memory fence.  This must provide ordering to ensure that, at a minimum, neither loads
       ;; nor stores may move forwards or backwards across the fence.  Currently emitted as "dmb
       ;; ish".  This instruction is sequentially consistent.
       (Fence)

       ;; FPU move. Note that this is distinct from a vector-register
       ;; move; moving just 64 bits seems to be significantly faster.
       (FpuMove64
        (rd WritableReg)
        (rn Reg))

       ;; Vector register move.
       (FpuMove128
        (rd WritableReg)
        (rn Reg))

       ;; Move to scalar from a vector element.
       (FpuMoveFromVec
        (rd WritableReg)
        (rn Reg)
        (idx u8)
        (size VectorSize))

       ;; Zero-extend a SIMD & FP scalar to the full width of a vector register.
       ;; 16-bit scalars require half-precision floating-point support (FEAT_FP16).
       (FpuExtend
        (rd WritableReg)
        (rn Reg)
        (size ScalarSize))

       ;; 1-op FPU instruction.
       (FpuRR
        (fpu_op FPUOp1)
        (size ScalarSize)
        (rd WritableReg)
        (rn Reg))

       ;; 2-op FPU instruction.
       (FpuRRR
        (fpu_op FPUOp2)
        (size ScalarSize)
        (rd WritableReg)
        (rn Reg)
        (rm Reg))

       (FpuRRI
        (fpu_op FPUOpRI)
        (rd WritableReg)
        (rn Reg))

       ;; 3-op FPU instruction.
       (FpuRRRR
        (fpu_op FPUOp3)
        (rd WritableReg)
        (rn Reg)
        (rm Reg)
        (ra Reg))

       ;; FPU comparison.
       (FpuCmp
        (size ScalarSize)
        (rn Reg)
        (rm Reg))

       ;; Floating-point load, single-precision (32 bit).
       (FpuLoad32
        (rd WritableReg)
        (mem AMode)
        (flags MemFlags))

       ;; Floating-point store, single-precision (32 bit).
       (FpuStore32
        (rd Reg)
        (mem AMode)
        (flags MemFlags))

       ;; Floating-point load, double-precision (64 bit).
       (FpuLoad64
        (rd WritableReg)
        (mem AMode)
        (flags MemFlags))

       ;; Floating-point store, double-precision (64 bit).
       (FpuStore64
        (rd Reg)
        (mem AMode)
        (flags MemFlags))

       ;; Floating-point/vector load, 128 bit.
       (FpuLoad128
        (rd WritableReg)
        (mem AMode)
        (flags MemFlags))

       ;; Floating-point/vector store, 128 bit.
       (FpuStore128
        (rd Reg)
        (mem AMode)
        (flags MemFlags))

       ;; A load of a pair of floating-point registers, double precision (64-bit).
       (FpuLoadP64
        (rt WritableReg)
        (rt2 WritableReg)
        (mem PairAMode)
        (flags MemFlags))

       ;; A store of a pair of floating-point registers, double precision (64-bit).
       (FpuStoreP64
        (rt Reg)
        (rt2 Reg)
        (mem PairAMode)
        (flags MemFlags))

       ;; A load of a pair of floating-point registers, 128-bit.
       (FpuLoadP128
        (rt WritableReg)
        (rt2 WritableReg)
        (mem PairAMode)
        (flags MemFlags))

       ;; A store of a pair of floating-point registers, 128-bit.
       (FpuStoreP128
        (rt Reg)
        (rt2 Reg)
        (mem PairAMode)
        (flags MemFlags))

       (LoadFpuConst64
        (rd WritableReg)
        (const_data u64))

       (LoadFpuConst128
        (rd WritableReg)
        (const_data u128))

       ;; Conversion: FP -> integer.
       (FpuToInt
        (op FpuToIntOp)
        (rd WritableReg)
        (rn Reg))

       ;; Conversion: integer -> FP.
       (IntToFpu
        (op IntToFpuOp)
        (rd WritableReg)
        (rn Reg))

       ;; FP conditional select, 32 bit.
       (FpuCSel32
        (rd WritableReg)
        (rn Reg)
        (rm Reg)
        (cond Cond))

       ;; FP conditional select, 64 bit.
       (FpuCSel64
        (rd WritableReg)
        (rn Reg)
        (rm Reg)
        (cond Cond))

       ;; Round to integer.
       (FpuRound
        (op FpuRoundMode)
        (rd WritableReg)
        (rn Reg))

       ;; Move from a GPR to a vector register.  The scalar value is parked in the lowest lane
       ;; of the destination, and all other lanes are zeroed out.  Currently only 32- and 64-bit
       ;; transactions are supported.
       (MovToFpu
        (rd WritableReg)
        (rn Reg)
        (size ScalarSize))

       ;; Loads a floating-point immediate.
       (FpuMoveFPImm
        (rd WritableReg)
        (imm ASIMDFPModImm)
        (size ScalarSize))

       ;; Move to a vector element from a GPR.
       (MovToVec
        (rd WritableReg)
        (rn Reg)
        (idx u8)
        (size VectorSize))

       ;; Unsigned move from a vector element to a GPR.
       (MovFromVec
        (rd WritableReg)
        (rn Reg)
        (idx u8)
        (size VectorSize))

       ;; Signed move from a vector element to a GPR.
       (MovFromVecSigned
        (rd WritableReg)
        (rn Reg)
        (idx u8)
        (size VectorSize)
        (scalar_size OperandSize))

       ;; Duplicate general-purpose register to vector.
       (VecDup
        (rd WritableReg)
        (rn Reg)
        (size VectorSize))

       ;; Duplicate scalar to vector.
       (VecDupFromFpu
        (rd WritableReg)
        (rn Reg)
        (size VectorSize))

       ;; Duplicate FP immediate to vector.
       (VecDupFPImm
        (rd WritableReg)
        (imm ASIMDFPModImm)
        (size VectorSize))

       ;; Duplicate immediate to vector.
       (VecDupImm
        (rd WritableReg)
        (imm ASIMDMovModImm)
        (invert bool)
        (size VectorSize))

       ;; Vector extend.
       (VecExtend
        (t VecExtendOp)
        (rd WritableReg)
        (rn Reg)
        (high_half bool))

       ;; Move vector element to another vector element.
       (VecMovElement
        (rd WritableReg)
        (rn Reg)
        (dest_idx u8)
        (src_idx u8)
        (size VectorSize))

       ;; Vector widening operation.
       (VecRRLong
        (op VecRRLongOp)
        (rd WritableReg)
        (rn Reg)
        (high_half bool))

       ;; Vector narrowing operation.
       (VecRRNarrow
        (op VecRRNarrowOp)
        (rd WritableReg)
        (rn Reg)
        (high_half bool))

       ;; 1-operand vector instruction that operates on a pair of elements.
       (VecRRPair
        (op VecPairOp)
        (rd WritableReg)
        (rn Reg))

       ;; 2-operand vector instruction that produces a result with twice the
       ;; lane width and half the number of lanes.
       (VecRRRLong
        (alu_op VecRRRLongOp)
        (rd WritableReg)
        (rn Reg)
        (rm Reg)
        (high_half bool))

       ;; 1-operand vector instruction that extends elements of the input
       ;; register and operates on a pair of elements. The output lane width
       ;; is double that of the input.
       (VecRRPairLong
        (op VecRRPairLongOp)
        (rd WritableReg)
        (rn Reg))

       ;; A vector ALU op.
       (VecRRR
        (alu_op VecALUOp)
        (rd WritableReg)
        (rn Reg)
        (rm Reg)
        (size VectorSize))

       ;; Vector two register miscellaneous instruction.
       (VecMisc
        (op VecMisc2)
        (rd WritableReg)
        (rn Reg)
        (size VectorSize))

       ;; Vector instruction across lanes.
       (VecLanes
        (op VecLanesOp)
        (rd WritableReg)
        (rn Reg)
        (size VectorSize))

       ;; Vector shift by immediate Shift Left (immediate), Unsigned Shift Right (immediate)
       ;; Signed Shift Right (immediate).  These are somewhat unusual in that, for right shifts,
       ;; the allowed range of `imm` values is 1 to lane-size-in-bits, inclusive.  A zero
       ;; right-shift cannot be encoded.  Left shifts are "normal", though, having valid `imm`
       ;; values from 0 to lane-size-in-bits - 1 inclusive.
       (VecShiftImm
        (op VecShiftImmOp)
        (rd WritableReg)
        (rn Reg)
        (size VectorSize)
        (imm u8))

       ;; Vector extract - create a new vector, being the concatenation of the lowest `imm4` bytes
       ;; of `rm` followed by the uppermost `16 - imm4` bytes of `rn`.
       (VecExtract
        (rd WritableReg)
        (rn Reg)
        (rm Reg)
        (imm4 u8))

       ;; Table vector lookup - single register table. The table consists of 8-bit elements and is
       ;; stored in `rn`, while `rm` contains 8-bit element indices. `is_extension` specifies whether
       ;; to emit a TBX or a TBL instruction, i.e. whether to leave the elements in the destination
       ;; vector that correspond to out-of-range indices (greater than 15) unmodified or to set them
       ;; to 0.
       (VecTbl
        (rd WritableReg)
        (rn Reg)
        (rm Reg)
        (is_extension bool))

       ;; Table vector lookup - two register table. The table consists of 8-bit elements and is
       ;; stored in `rn` and `rn2`, while `rm` contains 8-bit element indices. `is_extension`
       ;; specifies whether to emit a TBX or a TBL instruction, i.e. whether to leave the elements in
       ;; the destination vector that correspond to out-of-range indices (greater than 31) unmodified
       ;; or to set them to 0. The table registers `rn` and `rn2` must have consecutive numbers
       ;; modulo 32, that is v31 and v0 (in that order) are consecutive registers.
       (VecTbl2
        (rd WritableReg)
        (rn Reg)
        (rn2 Reg)
        (rm Reg)
        (is_extension bool))

       ;; Load an element and replicate to all lanes of a vector.
       (VecLoadReplicate
        (rd WritableReg)
        (rn Reg)
        (size VectorSize))

       ;; Vector conditional select, 128 bit.  A synthetic instruction, which generates a 4-insn
       ;; control-flow diamond.
       (VecCSel
        (rd WritableReg)
        (rn Reg)
        (rm Reg)
        (cond Cond))

       ;; Move to the NZCV flags (actually a `MSR NZCV, Xn` insn).
       (MovToNZCV
        (rn Reg))

       ;; Move from the NZCV flags (actually a `MRS Xn, NZCV` insn).
       (MovFromNZCV
        (rd WritableReg))

       ;; A machine call instruction. N.B.: this allows only a +/- 128MB offset (it uses a relocation
       ;; of type `Reloc::Arm64Call`); if the destination distance is not `RelocDistance::Near`, the
       ;; code should use a `LoadExtName` / `CallInd` sequence instead, allowing an arbitrary 64-bit
       ;; target.
       (Call
        (info BoxCallInfo))

       ;; A machine indirect-call instruction.
       (CallInd
        (info BoxCallIndInfo))

       ;; ---- branches (exactly one must appear at end of BB) ----

       ;; A machine return instruction.
       (Ret
        (rets VecReg))

       ;; A placeholder instruction, generating no code, meaning that a function epilogue must be
       ;; inserted there.
       (EpiloguePlaceholder)

       ;; An unconditional branch.
       (Jump
        (dest BranchTarget))

       ;; A conditional branch. Contains two targets; at emission time, both are emitted, but
       ;; the MachBuffer knows to truncate the trailing branch if fallthrough. We optimize the
       ;; choice of taken/not_taken (inverting the branch polarity as needed) based on the
       ;; fallthrough at the time of lowering.
       (CondBr
        (taken BranchTarget)
        (not_taken BranchTarget)
        (kind CondBrKind))

       ;; A conditional trap: execute a `udf` if the condition is true. This is
       ;; one VCode instruction because it uses embedded control flow; it is
       ;; logically a single-in, single-out region, but needs to appear as one
       ;; unit to the register allocator.
       ;;
       ;; The `CondBrKind` gives the conditional-branch condition that will
       ;; *execute* the embedded `Inst`. (In the emitted code, we use the inverse
       ;; of this condition in a branch that skips the trap instruction.)
       (TrapIf
        (kind CondBrKind)
        (trap_code TrapCode))

       ;; An indirect branch through a register, augmented with set of all
       ;; possible successors.
       (IndirectBr
        (rn Reg)
        (targets VecMachLabel))

       ;; A "break" instruction, used for e.g. traps and debug breakpoints.
       (Brk)

       ;; An instruction guaranteed to always be undefined and to trigger an illegal instruction at
       ;; runtime.
       (Udf
        (trap_code TrapCode))

       ;; Compute the address (using a PC-relative offset) of a memory location, using the `ADR`
       ;; instruction. Note that we take a simple offset, not a `MemLabel`, here, because `Adr` is
       ;; only used for now in fixed lowering sequences with hardcoded offsets. In the future we may
       ;; need full `MemLabel` support.
       (Adr
        (rd WritableReg)
        ;; Offset in range -2^20 .. 2^20.
        (off i32))

       ;; Raw 32-bit word, used for inline constants and jump-table entries.
       (Word4
        (data u32))

       ;; Raw 64-bit word, used for inline constants.
       (Word8
        (data u64))

       ;; Jump-table sequence, as one compound instruction (see note in lower_inst.rs for rationale).
       (JTSequence
        (info BoxJTSequenceInfo)
        (ridx Reg)
        (rtmp1 WritableReg)
        (rtmp2 WritableReg))

       ;; Load an inline symbol reference.
       (LoadExtName
        (rd WritableReg)
        (name BoxExternalName)
        (offset i64))

       ;; Load address referenced by `mem` into `rd`.
       (LoadAddr
        (rd WritableReg)
        (mem AMode))

       ;; Marker, no-op in generated code: SP "virtual offset" is adjusted. This
       ;; controls how AMode::NominalSPOffset args are lowered.
       (VirtualSPOffsetAdj
        (offset i64))

       ;; Meta-insn, no-op in generated code: emit constant/branch veneer island
       ;; at this point (with a guard jump around it) if less than the needed
       ;; space is available before the next branch deadline. See the `MachBuffer`
       ;; implementation in `machinst/buffer.rs` for the overall algorithm. In
       ;; brief, we retain a set of "pending/unresolved label references" from
       ;; branches as we scan forward through instructions to emit machine code;
       ;; if we notice we're about to go out of range on an unresolved reference,
       ;; we stop, emit a bunch of "veneers" (branches in a form that has a longer
       ;; range, e.g. a 26-bit-offset unconditional jump), and point the original
       ;; label references to those. This is an "island" because it comes in the
       ;; middle of the code.
       ;;
       ;; This meta-instruction is a necessary part of the logic that determines
       ;; where to place islands. Ordinarily, we want to place them between basic
       ;; blocks, so we compute the worst-case size of each block, and emit the
       ;; island before starting a block if we would exceed a deadline before the
       ;; end of the block. However, some sequences (such as an inline jumptable)
       ;; are variable-length and not accounted for by this logic; so these
       ;; lowered sequences include an `EmitIsland` to trigger island generation
       ;; where necessary.
       (EmitIsland
        ;; The needed space before the next deadline.
        (needed_space CodeOffset))

       ;; A call to the `ElfTlsGetAddr` libcall. Returns address of TLS symbol in x0.
       (ElfTlsGetAddr
        (symbol ExternalName))

       ;; An unwind pseudo-instruction.
       (Unwind
        (inst UnwindInst))

       ;; A dummy use, useful to keep a value alive.
       (DummyUse
        (reg Reg))))

;; An ALU operation. This can be paired with several instruction formats
;; below (see `Inst`) in any combination.
(type ALUOp
  (enum
    (Add)
    (Sub)
    (Orr)
    (OrrNot)
    (And)
    (AndS)
    (AndNot)
    ;; XOR (AArch64 calls this "EOR")
    (Eor)
    ;; XNOR (AArch64 calls this "EOR-NOT")
    (EorNot)
    ;; Add, setting flags
    (AddS)
    ;; Sub, setting flags
    (SubS)
    ;; Signed multiply, high-word result
    (SMulH)
    ;; Unsigned multiply, high-word result
    (UMulH)
    (SDiv)
    (UDiv)
    (RotR)
    (Lsr)
    (Asr)
    (Lsl)
    ;; Add with carry
    (Adc)
    ;; Add with carry, settings flags
    (AdcS)
    ;; Subtract with carry
    (Sbc)
    ;; Subtract with carry, settings flags
    (SbcS)
))

;; An ALU operation with three arguments.
(type ALUOp3
  (enum
    ;; Multiply-add
    (MAdd)
    ;; Multiply-sub
    (MSub)
))

(type MoveWideOp
  (enum
    (MovZ)
    (MovN)
    (MovK)
))

(type UImm5 (primitive UImm5))
(type Imm12 (primitive Imm12))
(type ImmLogic (primitive ImmLogic))
(type ImmShift (primitive ImmShift))
(type ShiftOpAndAmt (primitive ShiftOpAndAmt))
(type MoveWideConst (primitive MoveWideConst))
(type NZCV (primitive NZCV))
(type ASIMDFPModImm (primitive ASIMDFPModImm))
(type ASIMDMovModImm (primitive ASIMDMovModImm))

(type BoxCallInfo (primitive BoxCallInfo))
(type BoxCallIndInfo (primitive BoxCallIndInfo))
(type CondBrKind (primitive CondBrKind))
(type BranchTarget (primitive BranchTarget))
(type BoxJTSequenceInfo (primitive BoxJTSequenceInfo))
(type CodeOffset (primitive CodeOffset))

(type ExtendOp extern
  (enum
    (UXTB)
    (UXTH)
    (UXTW)
    (UXTX)
    (SXTB)
    (SXTH)
    (SXTW)
    (SXTX)
))

;; An operation on the bits of a register. This can be paired with several instruction formats
;; below (see `Inst`) in any combination.
(type BitOp
  (enum
    ;; Bit reverse
    (RBit)
    (Clz)
    (Cls)
))

(type AMode extern (enum))
(type PairAMode extern (enum))
(type FPUOpRI extern (enum))

(type OperandSize extern
      (enum Size32
            Size64))

;; Helper for calculating the `OperandSize` corresponding to a type
(decl operand_size (Type) OperandSize)
(rule (operand_size (fits_in_32 _ty)) (OperandSize.Size32))
(rule (operand_size (fits_in_64 _ty)) (OperandSize.Size64))

(type ScalarSize extern
      (enum Size8
            Size16
            Size32
            Size64
            Size128))

(type Cond extern
  (enum
    (Eq)
    (Ne)
    (Hs)
    (Lo)
    (Mi)
    (Pl)
    (Vs)
    (Vc)
    (Hi)
    (Ls)
    (Ge)
    (Lt)
    (Gt)
    (Le)
    (Al)
    (Nv)
))

(type VectorSize extern
  (enum
    (Size8x8)
    (Size8x16)
    (Size16x4)
    (Size16x8)
    (Size32x2)
    (Size32x4)
    (Size64x2)
))

;; Helper for calculating the `VectorSize` corresponding to a type
(decl vector_size (Type) VectorSize)
(rule (vector_size (multi_lane 8 16)) (VectorSize.Size8x16))
(rule (vector_size (multi_lane 16 8)) (VectorSize.Size16x8))
(rule (vector_size (multi_lane 32 4)) (VectorSize.Size32x4))
(rule (vector_size (multi_lane 64 2)) (VectorSize.Size64x2))

;; A floating-point unit (FPU) operation with one arg.
(type FPUOp1
  (enum
    (Abs)
    (Neg)
    (Sqrt)
    (Cvt32To64)
    (Cvt64To32)
))

;; A floating-point unit (FPU) operation with two args.
(type FPUOp2
  (enum
    (Add)
    (Sub)
    (Mul)
    (Div)
    (Max)
    (Min)
))

;; A floating-point unit (FPU) operation with three args.
(type FPUOp3
  (enum
    (MAdd32)
    (MAdd64)
))

;; A conversion from an FP to an integer value.
(type FpuToIntOp
  (enum
    (F32ToU32)
    (F32ToI32)
    (F32ToU64)
    (F32ToI64)
    (F64ToU32)
    (F64ToI32)
    (F64ToU64)
    (F64ToI64)
))

;; A conversion from an integer to an FP value.
(type IntToFpuOp
  (enum
    (U32ToF32)
    (I32ToF32)
    (U32ToF64)
    (I32ToF64)
    (U64ToF32)
    (I64ToF32)
    (U64ToF64)
    (I64ToF64)
))

;; Modes for FP rounding ops: round down (floor) or up (ceil), or toward zero (trunc), or to
;; nearest, and for 32- or 64-bit FP values.
(type FpuRoundMode
  (enum
    (Minus32)
    (Minus64)
    (Plus32)
    (Plus64)
    (Zero32)
    (Zero64)
    (Nearest32)
    (Nearest64)
))

;; Type of vector element extensions.
(type VecExtendOp
  (enum
    ;; Signed extension of 8-bit elements
    (Sxtl8)
    ;; Signed extension of 16-bit elements
    (Sxtl16)
    ;; Signed extension of 32-bit elements
    (Sxtl32)
    ;; Unsigned extension of 8-bit elements
    (Uxtl8)
    ;; Unsigned extension of 16-bit elements
    (Uxtl16)
    ;; Unsigned extension of 32-bit elements
    (Uxtl32)
))

;; A vector ALU operation.
(type VecALUOp
  (enum
    ;; Signed saturating add
    (Sqadd)
    ;; Unsigned saturating add
    (Uqadd)
    ;; Signed saturating subtract
    (Sqsub)
    ;; Unsigned saturating subtract
    (Uqsub)
    ;; Compare bitwise equal
    (Cmeq)
    ;; Compare signed greater than or equal
    (Cmge)
    ;; Compare signed greater than
    (Cmgt)
    ;; Compare unsigned higher
    (Cmhs)
    ;; Compare unsigned higher or same
    (Cmhi)
    ;; Floating-point compare equal
    (Fcmeq)
    ;; Floating-point compare greater than
    (Fcmgt)
    ;; Floating-point compare greater than or equal
    (Fcmge)
    ;; Bitwise and
    (And)
    ;; Bitwise bit clear
    (Bic)
    ;; Bitwise inclusive or
    (Orr)
    ;; Bitwise exclusive or
    (Eor)
    ;; Bitwise select
    (Bsl)
    ;; Unsigned maximum pairwise
    (Umaxp)
    ;; Add
    (Add)
    ;; Subtract
    (Sub)
    ;; Multiply
    (Mul)
    ;; Signed shift left
    (Sshl)
    ;; Unsigned shift left
    (Ushl)
    ;; Unsigned minimum
    (Umin)
    ;; Signed minimum
    (Smin)
    ;; Unsigned maximum
    (Umax)
    ;; Signed maximum
    (Smax)
    ;; Unsigned rounding halving add
    (Urhadd)
    ;; Floating-point add
    (Fadd)
    ;; Floating-point subtract
    (Fsub)
    ;; Floating-point divide
    (Fdiv)
    ;; Floating-point maximum
    (Fmax)
    ;; Floating-point minimum
    (Fmin)
    ;; Floating-point multiply
    (Fmul)
    ;; Add pairwise
    (Addp)
    ;; Zip vectors (primary) [meaning, high halves]
    (Zip1)
    ;; Signed saturating rounding doubling multiply returning high half
    (Sqrdmulh)
))

;; A Vector miscellaneous operation with two registers.
(type VecMisc2
  (enum
    ;; Bitwise NOT
    (Not)
    ;; Negate
    (Neg)
    ;; Absolute value
    (Abs)
    ;; Floating-point absolute value
    (Fabs)
    ;; Floating-point negate
    (Fneg)
    ;; Floating-point square root
    (Fsqrt)
    ;; Reverse elements in 64-bit doublewords
    (Rev64)
    ;; Floating-point convert to signed integer, rounding toward zero
    (Fcvtzs)
    ;; Floating-point convert to unsigned integer, rounding toward zero
    (Fcvtzu)
    ;; Signed integer convert to floating-point
    (Scvtf)
    ;; Unsigned integer convert to floating-point
    (Ucvtf)
    ;; Floating point round to integral, rounding towards nearest
    (Frintn)
    ;; Floating point round to integral, rounding towards zero
    (Frintz)
    ;; Floating point round to integral, rounding towards minus infinity
    (Frintm)
    ;; Floating point round to integral, rounding towards plus infinity
    (Frintp)
    ;; Population count per byte
    (Cnt)
    ;; Compare bitwise equal to 0
    (Cmeq0)
    ;; Compare signed greater than or equal to 0
    (Cmge0)
    ;; Compare signed greater than 0
    (Cmgt0)
    ;; Compare signed less than or equal to 0
    (Cmle0)
    ;; Compare signed less than 0
    (Cmlt0)
    ;; Floating point compare equal to 0
    (Fcmeq0)
    ;; Floating point compare greater than or equal to 0
    (Fcmge0)
    ;; Floating point compare greater than 0
    (Fcmgt0)
    ;; Floating point compare less than or equal to 0
    (Fcmle0)
    ;; Floating point compare less than 0
    (Fcmlt0)
))

;; A vector widening operation with one argument.
(type VecRRLongOp
  (enum
    ;; Floating-point convert to higher precision long, 16-bit elements
    (Fcvtl16)
    ;; Floating-point convert to higher precision long, 32-bit elements
    (Fcvtl32)
    ;; Shift left long (by element size), 8-bit elements
    (Shll8)
    ;; Shift left long (by element size), 16-bit elements
    (Shll16)
    ;; Shift left long (by element size), 32-bit elements
    (Shll32)
))

;; A vector narrowing operation with one argument.
(type VecRRNarrowOp
  (enum
    ;; Extract narrow, 16-bit elements
    (Xtn16)
    ;; Extract narrow, 32-bit elements
    (Xtn32)
    ;; Extract narrow, 64-bit elements
    (Xtn64)
    ;; Signed saturating extract narrow, 16-bit elements
    (Sqxtn16)
    ;; Signed saturating extract narrow, 32-bit elements
    (Sqxtn32)
    ;; Signed saturating extract narrow, 64-bit elements
    (Sqxtn64)
    ;; Signed saturating extract unsigned narrow, 16-bit elements
    (Sqxtun16)
    ;; Signed saturating extract unsigned narrow, 32-bit elements
    (Sqxtun32)
    ;; Signed saturating extract unsigned narrow, 64-bit elements
    (Sqxtun64)
    ;; Unsigned saturating extract narrow, 16-bit elements
    (Uqxtn16)
    ;; Unsigned saturating extract narrow, 32-bit elements
    (Uqxtn32)
    ;; Unsigned saturating extract narrow, 64-bit elements
    (Uqxtn64)
    ;; Floating-point convert to lower precision narrow, 32-bit elements
    (Fcvtn32)
    ;; Floating-point convert to lower precision narrow, 64-bit elements
    (Fcvtn64)
))

(type VecRRRLongOp
  (enum
    ;; Signed multiply long.
    (Smull8)
    (Smull16)
    (Smull32)
    ;; Unsigned multiply long.
    (Umull8)
    (Umull16)
    (Umull32)
    ;; Unsigned multiply add long
    (Umlal8)
    (Umlal16)
    (Umlal32)
))

;; A vector operation on a pair of elements with one register.
(type VecPairOp
  (enum
    ;; Add pair of elements
    (Addp)
))

;; 1-operand vector instruction that extends elements of the input register
;; and operates on a pair of elements.
(type VecRRPairLongOp
  (enum
    ;; Sign extend and add pair of elements
    (Saddlp8)
    (Saddlp16)
    ;; Unsigned extend and add pair of elements
    (Uaddlp8)
    (Uaddlp16)
))

;; An operation across the lanes of vectors.
(type VecLanesOp
  (enum
    ;; Integer addition across a vector
    (Addv)
    ;; Unsigned minimum across a vector
    (Uminv)
))

;; A shift-by-immediate operation on each lane of a vector.
(type VecShiftImmOp
  (enum
    ;; Unsigned shift left
    (Shl)
    ;; Unsigned shift right
    (Ushr)
    ;; Signed shift right
    (Sshr)
))

;; Atomic read-modify-write operations with acquire-release semantics
(type AtomicRMWOp
  (enum
    (Add)
    (Clr)
    (Eor)
    (Set)
    (Smax)
    (Smin)
    (Umax)
    (Umin)
    (Swp)
))

;; Atomic read-modify-write operations, with acquire-release semantics,
;; implemented with a loop.
(type AtomicRMWLoopOp
  (enum
    (Add)
    (Sub)
    (And)
    (Nand)
    (Eor)
    (Orr)
    (Smax)
    (Smin)
    (Umax)
    (Umin)
    (Xchg)
))

;; Extractors for target features ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(decl use_lse () Inst)
(extern extractor use_lse use_lse)

;; Extractor helpers for various immmediate constants ;;;;;;;;;;;;;;;;;;;;;;;;;;

(decl pure imm_logic_from_u64 (Type u64) ImmLogic)
(extern constructor imm_logic_from_u64 imm_logic_from_u64)

(decl pure imm_logic_from_imm64 (Type Imm64) ImmLogic)
(extern constructor imm_logic_from_imm64 imm_logic_from_imm64)

(decl pure imm_shift_from_imm64 (Type Imm64) ImmShift)
(extern constructor imm_shift_from_imm64 imm_shift_from_imm64)

(decl imm_shift_from_u8 (u8) ImmShift)
(extern constructor imm_shift_from_u8 imm_shift_from_u8)

(decl imm12_from_u64 (Imm12) u64)
(extern extractor imm12_from_u64 imm12_from_u64)

(decl u8_into_uimm5 (u8) UImm5)
(extern constructor u8_into_uimm5 u8_into_uimm5)

(decl u8_into_imm12 (u8) Imm12)
(extern constructor u8_into_imm12 u8_into_imm12)

(decl u64_into_imm_logic (Type u64) ImmLogic)
(extern constructor u64_into_imm_logic u64_into_imm_logic)

(decl imm12_from_negated_u64 (Imm12) u64)
(extern extractor imm12_from_negated_u64 imm12_from_negated_u64)

(decl pure lshl_from_imm64 (Type Imm64) ShiftOpAndAmt)
(extern constructor lshl_from_imm64 lshl_from_imm64)

(decl integral_ty (Type) Type)
(extern extractor integral_ty integral_ty)

(decl valid_atomic_transaction (Type) Type)
(extern extractor valid_atomic_transaction valid_atomic_transaction)

;; Helper to go directly from a `Value`, when it's an `iconst`, to an `Imm12`.
(decl imm12_from_value (Imm12) Value)
(extractor
  (imm12_from_value n)
  (iconst (u64_from_imm64 (imm12_from_u64 n))))

;; Same as `imm12_from_value`, but tries negating the constant value.
(decl imm12_from_negated_value (Imm12) Value)
(extractor
  (imm12_from_negated_value n)
  (iconst (u64_from_imm64 (imm12_from_negated_u64 n))))

;; Helper type to represent a value and an extend operation fused together.
(type ExtendedValue extern (enum))
(decl extended_value_from_value (ExtendedValue) Value)
(extern extractor extended_value_from_value extended_value_from_value)

;; Constructors used to poke at the fields of an `ExtendedValue`.
(decl put_extended_in_reg (ExtendedValue) Reg)
(extern constructor put_extended_in_reg put_extended_in_reg)
(decl get_extended_op (ExtendedValue) ExtendOp)
(extern constructor get_extended_op get_extended_op)

(decl nzcv (bool bool bool bool) NZCV)
(extern constructor nzcv nzcv)

(decl cond_br_zero (Reg) CondBrKind)
(extern constructor cond_br_zero cond_br_zero)

(decl cond_br_cond (Cond) CondBrKind)
(extern constructor cond_br_cond cond_br_cond)

;; Instruction creation helpers ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

;; Helper for creating the zero register.
(decl zero_reg () Reg)
(extern constructor zero_reg zero_reg)

(decl writable_zero_reg () WritableReg)
(extern constructor writable_zero_reg writable_zero_reg)

;; Helpers for getting a particular real register
(decl xreg (u8) Reg)
(extern constructor xreg xreg)

(decl writable_xreg (u8) WritableReg)
(extern constructor writable_xreg writable_xreg)

;; Helper for emitting `MInst.Mov64` instructions.
(decl mov64_to_real (u8 Reg) Reg)
(rule (mov64_to_real num src)
      (let ((dst WritableReg (writable_xreg num))
            (_ Unit (emit (MInst.Mov (operand_size $I64) dst src))))
        dst))

(decl mov64_from_real (u8) Reg)
(rule (mov64_from_real num)
      (let ((dst WritableReg (temp_writable_reg $I64))
            (_ Unit (emit (MInst.Mov (operand_size $I64) dst (xreg num)))))
        dst))

;; Helper for emitting `MInst.MovZ` instructions.
(decl movz (MoveWideConst OperandSize) Reg)
(rule (movz imm size)
      (let ((dst WritableReg (temp_writable_reg $I64))
            (_ Unit (emit (MInst.MovWide (MoveWideOp.MovZ) dst imm size))))
        dst))

;; Helper for emitting `MInst.MovN` instructions.
(decl movn (MoveWideConst OperandSize) Reg)
(rule (movn imm size)
      (let ((dst WritableReg (temp_writable_reg $I64))
            (_ Unit (emit (MInst.MovWide (MoveWideOp.MovN) dst imm size))))
        dst))

;; Helper for emitting `MInst.AluRRImmLogic` instructions.
(decl alu_rr_imm_logic (ALUOp Type Reg ImmLogic) Reg)
(rule (alu_rr_imm_logic op ty src imm)
      (let ((dst WritableReg (temp_writable_reg $I64))
            (_ Unit (emit (MInst.AluRRImmLogic op (operand_size ty) dst src imm))))
        dst))

;; Helper for emitting `MInst.AluRRImmShift` instructions.
(decl alu_rr_imm_shift (ALUOp Type Reg ImmShift) Reg)
(rule (alu_rr_imm_shift op ty src imm)
      (let ((dst WritableReg (temp_writable_reg $I64))
            (_ Unit (emit (MInst.AluRRImmShift op (operand_size ty) dst src imm))))
        dst))

;; Helper for emitting `MInst.AluRRR` instructions.
(decl alu_rrr (ALUOp Type Reg Reg) Reg)
(rule (alu_rrr op ty src1 src2)
      (let ((dst WritableReg (temp_writable_reg $I64))
            (_ Unit (emit (MInst.AluRRR op (operand_size ty) dst src1 src2))))
        dst))

;; Helper for emitting `MInst.VecRRR` instructions.
(decl vec_rrr (VecALUOp Reg Reg VectorSize) Reg)
(rule (vec_rrr op src1 src2 size)
      (let ((dst WritableReg (temp_writable_reg $I8X16))
            (_ Unit (emit (MInst.VecRRR op dst src1 src2 size))))
        dst))

;; Helper for emitting `MInst.VecLanes` instructions.
(decl vec_lanes (VecLanesOp Reg VectorSize) Reg)
(rule (vec_lanes op src size)
      (let ((dst WritableReg (temp_writable_reg $I8X16))
            (_ Unit (emit (MInst.VecLanes op dst src size))))
        dst))

;; Helper for emitting `MInst.VecDup` instructions.
(decl vec_dup (Reg VectorSize) Reg)
(rule (vec_dup src size)
      (let ((dst WritableReg (temp_writable_reg $I8X16))
            (_ Unit (emit (MInst.VecDup dst src size))))
        dst))

;; Helper for emitting `MInst.AluRRImm12` instructions.
(decl alu_rr_imm12 (ALUOp Type Reg Imm12) Reg)
(rule (alu_rr_imm12 op ty src imm)
      (let ((dst WritableReg (temp_writable_reg $I64))
            (_ Unit (emit (MInst.AluRRImm12 op (operand_size ty) dst src imm))))
        dst))

;; Helper for emitting `MInst.AluRRRShift` instructions.
(decl alu_rrr_shift (ALUOp Type Reg Reg ShiftOpAndAmt) Reg)
(rule (alu_rrr_shift op ty src1 src2 shift)
      (let ((dst WritableReg (temp_writable_reg $I64))
            (_ Unit (emit (MInst.AluRRRShift op (operand_size ty) dst src1 src2 shift))))
        dst))

;; Helper for emitting `MInst.AluRRRExtend` instructions.
(decl alu_rrr_extend (ALUOp Type Reg Reg ExtendOp) Reg)
(rule (alu_rrr_extend op ty src1 src2 extend)
      (let ((dst WritableReg (temp_writable_reg $I64))
            (_ Unit (emit (MInst.AluRRRExtend op (operand_size ty) dst src1 src2 extend))))
        dst))

;; Same as `alu_rrr_extend`, but takes an `ExtendedValue` packed "pair" instead
;; of a `Reg` and an `ExtendOp`.
(decl alu_rr_extend_reg (ALUOp Type Reg ExtendedValue) Reg)
(rule (alu_rr_extend_reg op ty src1 extended_reg)
      (let ((src2 Reg (put_extended_in_reg extended_reg))
            (extend ExtendOp (get_extended_op extended_reg)))
        (alu_rrr_extend op ty src1 src2 extend)))

;; Helper for emitting `MInst.AluRRRR` instructions.
(decl alu_rrrr (ALUOp3 Type Reg Reg Reg) Reg)
(rule (alu_rrrr op ty src1 src2 src3)
      (let ((dst WritableReg (temp_writable_reg $I64))
            (_ Unit (emit (MInst.AluRRRR op (operand_size ty) dst src1 src2 src3))))
        dst))

;; Helper for emitting `MInst.BitRR` instructions.
(decl bit_rr (BitOp Type Reg) Reg)
(rule (bit_rr op ty src)
      (let ((dst WritableReg (temp_writable_reg $I64))
            (_ Unit (emit (MInst.BitRR op (operand_size ty) dst src))))
        dst))

;; Helper for emitting `adds` instructions.
(decl add_with_flags_paired (Type Reg Reg) ProducesFlags)
(rule (add_with_flags_paired ty src1 src2)
      (let ((dst WritableReg (temp_writable_reg $I64)))
        (ProducesFlags.ProducesFlagsReturnsResultWithConsumer
         (MInst.AluRRR (ALUOp.AddS) (operand_size ty) dst src1 src2)
         dst)))

;; Helper for emitting `adc` instructions.
(decl adc_paired (Type Reg Reg) ConsumesFlags)
(rule (adc_paired ty src1 src2)
      (let ((dst WritableReg (temp_writable_reg $I64)))
        (ConsumesFlags.ConsumesFlagsReturnsResultWithProducer
         (MInst.AluRRR (ALUOp.Adc) (operand_size ty) dst src1 src2)
         dst)))

;; Helper for emitting `subs` instructions.
(decl sub_with_flags_paired (Type Reg Reg) ProducesFlags)
(rule (sub_with_flags_paired ty src1 src2)
      (let ((dst WritableReg (temp_writable_reg $I64)))
        (ProducesFlags.ProducesFlagsReturnsResultWithConsumer
         (MInst.AluRRR (ALUOp.SubS) (operand_size ty) dst src1 src2)
         dst)))

(decl cmp64_imm (Reg Imm12) ProducesFlags)
(rule (cmp64_imm src1 src2)
      (ProducesFlags.ProducesFlagsSideEffect
       (MInst.AluRRImm12 (ALUOp.SubS) (OperandSize.Size64) (writable_zero_reg)
        src1 src2)))

;; Helper for emitting `sbc` instructions.
(decl sbc_paired (Type Reg Reg) ConsumesFlags)
(rule (sbc_paired ty src1 src2)
      (let ((dst WritableReg (temp_writable_reg $I64)))
        (ConsumesFlags.ConsumesFlagsReturnsResultWithProducer
         (MInst.AluRRR (ALUOp.Sbc) (operand_size ty) dst src1 src2)
         dst)))

;; Helper for emitting `MInst.VecMisc` instructions.
(decl vec_misc (VecMisc2 Reg VectorSize) Reg)
(rule (vec_misc op src size)
      (let ((dst WritableReg (temp_writable_reg $I8X16))
            (_ Unit (emit (MInst.VecMisc op dst src size))))
        dst))

;; Helper for emitting `MInst.VecRRRLong` instructions.
(decl vec_rrr_long (VecRRRLongOp Reg Reg bool) Reg)
(rule (vec_rrr_long op src1 src2 high_half)
      (let ((dst WritableReg (temp_writable_reg $I8X16))
            (_ Unit (emit (MInst.VecRRRLong op dst src1 src2 high_half))))
        dst))

;; Helper for emitting `MInst.VecRRRLong` instructions, but for variants
;; where the operation both reads and modifies the destination register.
;;
;; Currently this is only used for `VecRRRLongOp.Umlal*`
(decl vec_rrrr_long (VecRRRLongOp Reg Reg Reg bool) Reg)
(rule (vec_rrrr_long op src1 src2 src3 high_half)
      (let ((dst WritableReg (temp_writable_reg $I8X16))
            (_1 Unit (emit (MInst.FpuMove128 dst src1)))
            (_2 Unit (emit (MInst.VecRRRLong op dst src2 src3 high_half))))
        dst))

;; Helper for emitting `MInst.VecRRNarrow` instructions.
(decl vec_rr_narrow (VecRRNarrowOp Reg bool) Reg)
(rule (vec_rr_narrow op src high_half)
      (let ((dst WritableReg (temp_writable_reg $I8X16))
            (_ Unit (emit (MInst.VecRRNarrow op dst src high_half))))
        dst))

;; Helper for emitting `MInst.VecRRLong` instructions.
(decl vec_rr_long (VecRRLongOp Reg bool) Reg)
(rule (vec_rr_long op src high_half)
      (let ((dst WritableReg (temp_writable_reg $I8X16))
            (_ Unit (emit (MInst.VecRRLong op dst src high_half))))
        dst))

;; Helper for emitting `MInst.MovToFpu` instructions.
(decl mov_to_fpu (Reg ScalarSize) Reg)
(rule (mov_to_fpu x size)
      (let ((dst WritableReg (temp_writable_reg $I8X16))
            (_ Unit (emit (MInst.MovToFpu dst x size))))
        dst))

;; Helper for emitting `MInst.MovToVec` instructions.
(decl mov_to_vec (Reg Reg u8 VectorSize) Reg)
(rule (mov_to_vec src1 src2 lane size)
      (let ((dst WritableReg (temp_writable_reg $I8X16))
            (_1 Unit (emit (MInst.FpuMove128 dst src1)))
            (_2 Unit (emit (MInst.MovToVec dst src2 lane size))))
        dst))

;; Helper for emitting `MInst.MovFromVec` instructions.
(decl mov_from_vec (Reg u8 VectorSize) Reg)
(rule (mov_from_vec rn idx size)
      (let ((dst WritableReg (temp_writable_reg $I64))
            (_ Unit (emit (MInst.MovFromVec dst rn idx size))))
        dst))

;; Helper for emitting `MInst.MovFromVecSigned` instructions.
(decl mov_from_vec_signed (Reg u8 VectorSize OperandSize) Reg)
(rule (mov_from_vec_signed rn idx size scalar_size)
      (let ((dst WritableReg (temp_writable_reg $I64))
            (_ Unit (emit (MInst.MovFromVecSigned dst rn idx size scalar_size))))
        dst))

;; Helper for emitting `MInst.Extend` instructions.
(decl extend (Reg bool u8 u8) Reg)
(rule (extend rn signed from_bits to_bits)
      (let ((dst WritableReg (temp_writable_reg $I64))
            (_ Unit (emit (MInst.Extend dst rn signed from_bits to_bits))))
        dst))

;; Helper for emitting `MInst.LoadAcquire` instructions.
(decl load_acquire (Type Reg) Reg)
(rule (load_acquire ty addr)
      (let ((dst WritableReg (temp_writable_reg $I64))
            (_ Unit (emit (MInst.LoadAcquire ty dst addr))))
        dst))

;; Helper for generating a `tst` instruction.
;;
;; Produces a `ProducesFlags` rather than a register or emitted instruction
;; which must be paired with `with_flags*` helpers.
(decl tst_imm (Type Reg ImmLogic) ProducesFlags)
(rule (tst_imm ty reg imm)
      (ProducesFlags.ProducesFlagsSideEffect
       (MInst.AluRRImmLogic (ALUOp.AndS)
                            (operand_size ty)
                            (writable_zero_reg)
                            reg
                            imm)))

;; Helper for generating a `CSel` instruction.
;;
;; Note that this doesn't actually emit anything, instead it produces a
;; `ConsumesFlags` instruction which must be consumed with `with_flags*`
;; helpers.
(decl csel (Cond Reg Reg) ConsumesFlags)
(rule (csel cond if_true if_false)
      (let ((dst WritableReg (temp_writable_reg $I64)))
        (ConsumesFlags.ConsumesFlagsReturnsReg
         (MInst.CSel dst cond if_true if_false)
         dst)))

;; Helpers for generating `add` instructions.

(decl add (Type Reg Reg) Reg)
(rule (add ty x y) (alu_rrr (ALUOp.Add) ty x y))

(decl add_imm (Type Reg Imm12) Reg)
(rule (add_imm ty x y) (alu_rr_imm12 (ALUOp.Add) ty x y))

(decl add_extend (Type Reg ExtendedValue) Reg)
(rule (add_extend ty x y) (alu_rr_extend_reg (ALUOp.Add) ty x y))

(decl add_shift (Type Reg Reg ShiftOpAndAmt) Reg)
(rule (add_shift ty x y z) (alu_rrr_shift (ALUOp.Add) ty x y z))

(decl add_vec (Reg Reg VectorSize) Reg)
(rule (add_vec x y size) (vec_rrr (VecALUOp.Add) x y size))

;; Helpers for generating `sub` instructions.

(decl sub (Type Reg Reg) Reg)
(rule (sub ty x y) (alu_rrr (ALUOp.Sub) ty x y))

(decl sub_imm (Type Reg Imm12) Reg)
(rule (sub_imm ty x y) (alu_rr_imm12 (ALUOp.Sub) ty x y))

(decl sub_extend (Type Reg ExtendedValue) Reg)
(rule (sub_extend ty x y) (alu_rr_extend_reg (ALUOp.Sub) ty x y))

(decl sub_shift (Type Reg Reg ShiftOpAndAmt) Reg)
(rule (sub_shift ty x y z) (alu_rrr_shift (ALUOp.Sub) ty x y z))

(decl sub_vec (Reg Reg VectorSize) Reg)
(rule (sub_vec x y size) (vec_rrr (VecALUOp.Sub) x y size))

;; Helpers for generating `madd` instructions.

(decl madd (Type Reg Reg Reg) Reg)
(rule (madd ty x y z) (alu_rrrr (ALUOp3.MAdd) ty x y z))

;; Helpers for generating `msub` instructions.

(decl msub (Type Reg Reg Reg) Reg)
(rule (msub ty x y z) (alu_rrrr (ALUOp3.MSub) ty x y z))

;; Helper for generating `uqadd` instructions.
(decl uqadd (Reg Reg VectorSize) Reg)
(rule (uqadd x y size) (vec_rrr (VecALUOp.Uqadd) x y size))

;; Helper for generating `sqadd` instructions.
(decl sqadd (Reg Reg VectorSize) Reg)
(rule (sqadd x y size) (vec_rrr (VecALUOp.Sqadd) x y size))

;; Helper for generating `uqsub` instructions.
(decl uqsub (Reg Reg VectorSize) Reg)
(rule (uqsub x y size) (vec_rrr (VecALUOp.Uqsub) x y size))

;; Helper for generating `sqsub` instructions.
(decl sqsub (Reg Reg VectorSize) Reg)
(rule (sqsub x y size) (vec_rrr (VecALUOp.Sqsub) x y size))

;; Helper for generating `umulh` instructions.
(decl umulh (Type Reg Reg) Reg)
(rule (umulh ty x y) (alu_rrr (ALUOp.UMulH) ty x y))

;; Helper for generating `smulh` instructions.
(decl smulh (Type Reg Reg) Reg)
(rule (smulh ty x y) (alu_rrr (ALUOp.SMulH) ty x y))

;; Helper for generating `mul` instructions.
(decl mul (Reg Reg VectorSize) Reg)
(rule (mul x y size) (vec_rrr (VecALUOp.Mul) x y size))

;; Helper for generating `neg` instructions.
(decl neg (Reg VectorSize) Reg)
(rule (neg x size) (vec_misc (VecMisc2.Neg) x size))

;; Helper for generating `rev64` instructions.
(decl rev64 (Reg VectorSize) Reg)
(rule (rev64 x size) (vec_misc (VecMisc2.Rev64) x size))

;; Helper for generating `xtn64` instructions.
(decl xtn64 (Reg bool) Reg)
(rule (xtn64 x high_half) (vec_rr_narrow (VecRRNarrowOp.Xtn64) x high_half))

;; Helper for generating `addp` instructions.
(decl addp (Reg Reg VectorSize) Reg)
(rule (addp x y size) (vec_rrr (VecALUOp.Addp) x y size))

;; Helper for generating `addv` instructions.
(decl addv (Reg VectorSize) Reg)
(rule (addv x size) (vec_lanes (VecLanesOp.Addv) x size))

;; Helper for generating `shll32` instructions.
(decl shll32 (Reg bool) Reg)
(rule (shll32 x high_half) (vec_rr_long (VecRRLongOp.Shll32) x high_half))

;; Helper for generating `umlal32` instructions.
(decl umlal32 (Reg Reg Reg bool) Reg)
(rule (umlal32 x y z high_half) (vec_rrrr_long (VecRRRLongOp.Umlal32) x y z high_half))

;; Helper for generating `smull8` instructions.
(decl smull8 (Reg Reg bool) Reg)
(rule (smull8 x y high_half) (vec_rrr_long (VecRRRLongOp.Smull8) x y high_half))

;; Helper for generating `umull8` instructions.
(decl umull8 (Reg Reg bool) Reg)
(rule (umull8 x y high_half) (vec_rrr_long (VecRRRLongOp.Umull8) x y high_half))

;; Helper for generating `smull16` instructions.
(decl smull16 (Reg Reg bool) Reg)
(rule (smull16 x y high_half) (vec_rrr_long (VecRRRLongOp.Smull16) x y high_half))

;; Helper for generating `umull16` instructions.
(decl umull16 (Reg Reg bool) Reg)
(rule (umull16 x y high_half) (vec_rrr_long (VecRRRLongOp.Umull16) x y high_half))

;; Helper for generating `smull32` instructions.
(decl smull32 (Reg Reg bool) Reg)
(rule (smull32 x y high_half) (vec_rrr_long (VecRRRLongOp.Smull32) x y high_half))

;; Helper for generating `umull32` instructions.
(decl umull32 (Reg Reg bool) Reg)
(rule (umull32 x y high_half) (vec_rrr_long (VecRRRLongOp.Umull32) x y high_half))

;; Helper for generating `asr` instructions.
(decl asr (Type Reg Reg) Reg)
(rule (asr ty x y) (alu_rrr (ALUOp.Asr) ty x y))

(decl asr_imm (Type Reg ImmShift) Reg)
(rule (asr_imm ty x imm) (alu_rr_imm_shift (ALUOp.Asr) ty x imm))

;; Helper for generating `lsr` instructions.
(decl lsr (Type Reg Reg) Reg)
(rule (lsr ty x y) (alu_rrr (ALUOp.Lsr) ty x y))

(decl lsr_imm (Type Reg ImmShift) Reg)
(rule (lsr_imm ty x imm) (alu_rr_imm_shift (ALUOp.Lsr) ty x imm))

;; Helper for generating `lsl` instructions.
(decl lsl (Type Reg Reg) Reg)
(rule (lsl ty x y) (alu_rrr (ALUOp.Lsl) ty x y))

(decl lsl_imm (Type Reg ImmShift) Reg)
(rule (lsl_imm ty x imm) (alu_rr_imm_shift (ALUOp.Lsl) ty x imm))

;; Helper for generating `udiv` instructions.
(decl a64_udiv (Type Reg Reg) Reg)
(rule (a64_udiv ty x y) (alu_rrr (ALUOp.UDiv) ty x y))

;; Helper for generating `sdiv` instructions.
(decl a64_sdiv (Type Reg Reg) Reg)
(rule (a64_sdiv ty x y) (alu_rrr (ALUOp.SDiv) ty x y))

;; Helper for generating `not` instructions.
(decl not (Reg VectorSize) Reg)
(rule (not x size) (vec_misc (VecMisc2.Not) x size))

;; Helpers for generating `orr_not` instructions.

(decl orr_not (Type Reg Reg) Reg)
(rule (orr_not ty x y) (alu_rrr (ALUOp.OrrNot) ty x y))

(decl orr_not_shift (Type Reg Reg ShiftOpAndAmt) Reg)
(rule (orr_not_shift ty x y shift) (alu_rrr_shift (ALUOp.OrrNot) ty x y shift))

;; Helpers for generating `orr` instructions.

(decl orr (Type Reg Reg) Reg)
(rule (orr ty x y) (alu_rrr (ALUOp.Orr) ty x y))

(decl orr_imm (Type Reg ImmLogic) Reg)
(rule (orr_imm ty x y) (alu_rr_imm_logic (ALUOp.Orr) ty x y))

(decl orr_vec (Reg Reg VectorSize) Reg)
(rule (orr_vec x y size) (vec_rrr (VecALUOp.Orr) x y size))

;; Helpers for generating `and` instructions.

(decl and_reg (Type Reg Reg) Reg)
(rule (and_reg ty x y) (alu_rrr (ALUOp.And) ty x y))

(decl and_imm (Type Reg ImmLogic) Reg)
(rule (and_imm ty x y) (alu_rr_imm_logic (ALUOp.And) ty x y))

(decl and_vec (Reg Reg VectorSize) Reg)
(rule (and_vec x y size) (vec_rrr (VecALUOp.And) x y size))

;; Helpers for generating `eor` instructions.
(decl eor_vec (Reg Reg VectorSize) Reg)
(rule (eor_vec x y size) (vec_rrr (VecALUOp.Eor) x y size))

;; Helpers for generating `bic` instructions.

(decl bic (Type Reg Reg) Reg)
(rule (bic ty x y) (alu_rrr (ALUOp.AndNot) ty x y))

(decl bic_vec (Reg Reg VectorSize) Reg)
(rule (bic_vec x y size) (vec_rrr (VecALUOp.Bic) x y size))

;; Helpers for generating `sshl` instructions.
(decl sshl (Reg Reg VectorSize) Reg)
(rule (sshl x y size) (vec_rrr (VecALUOp.Sshl) x y size))

;; Helpers for generating `ushl` instructions.
(decl ushl (Reg Reg VectorSize) Reg)
(rule (ushl x y size) (vec_rrr (VecALUOp.Ushl) x y size))

;; Helpers for generating `rotr` instructions.

(decl a64_rotr (Type Reg Reg) Reg)
(rule (a64_rotr ty x y) (alu_rrr (ALUOp.RotR) ty x y))

(decl a64_rotr_imm (Type Reg ImmShift) Reg)
(rule (a64_rotr_imm ty x y) (alu_rr_imm_shift (ALUOp.RotR) ty x y))

;; Helpers for generating `rbit` instructions.

(decl rbit (Type Reg) Reg)
(rule (rbit ty x) (bit_rr (BitOp.RBit) ty x))

;; Helpers for generating `clz` instructions.

(decl a64_clz (Type Reg) Reg)
(rule (a64_clz ty x) (bit_rr (BitOp.Clz) ty x))

;; Helpers for generating `cls` instructions.

(decl a64_cls (Type Reg) Reg)
(rule (a64_cls ty x) (bit_rr (BitOp.Cls) ty x))

;; Helpers for generating `eon` instructions.

(decl eon (Type Reg Reg) Reg)
(rule (eon ty x y) (alu_rrr (ALUOp.EorNot) ty x y))

;; Helpers for generating `cnt` instructions.

(decl vec_cnt (Reg VectorSize) Reg)
(rule (vec_cnt x size) (vec_misc (VecMisc2.Cnt) x size))

;; Helpers for generating a `bsl` instruction.

(decl bsl (Type Reg Reg Reg) Reg)
(rule (bsl ty c x y)
      (let ((dst WritableReg (temp_writable_reg ty))
            (_1 Unit (emit (MInst.FpuMove128 dst c)))
            (_2 Unit (emit (MInst.VecRRR (VecALUOp.Bsl) dst x y (vector_size ty)))))
        dst))

;; Immediate value helpers ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

;; Type of extension performed by an immediate helper
(type ImmExtend
  (enum
    (Sign)
    (Zero)))

;; Arguments:
;; * Immediate type
;; * Way to extend the immediate value to the full width of the destination
;;   register
;; * Immediate value - only the bits that fit within the type are used and
;;   extended, while the rest are ignored
;;
;; Note that, unlike the convention in the AArch64 backend, this helper leaves
;; all bits in the destination register in a defined state, i.e. smaller types
;; such as `I8` are either sign- or zero-extended.
(decl imm (Type ImmExtend u64) Reg)

;; Weird logical-instruction immediate in ORI using zero register; to simplify,
;; we only match when we are zero-extending the value.
(rule (imm (integral_ty ty) (ImmExtend.Zero) k)
      (if-let n (imm_logic_from_u64 ty k))
      (orr_imm ty (zero_reg) n))

(decl load_constant64_full (Type ImmExtend u64) Reg)
(extern constructor load_constant64_full load_constant64_full)

;; Fallback for integral 64-bit constants
(rule (imm (integral_ty ty) extend n)
      (load_constant64_full ty extend n))

;; Sign extension helpers ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

;; Place a `Value` into a register, sign extending it to 32-bits
(decl put_in_reg_sext32 (Value) Reg)
(rule (put_in_reg_sext32 val @ (value_type (fits_in_32 ty)))
      (extend val $true (ty_bits ty) 32))

;; 32/64-bit passthrough.
(rule (put_in_reg_sext32 val @ (value_type $I32)) val)
(rule (put_in_reg_sext32 val @ (value_type $I64)) val)

;; Place a `Value` into a register, zero extending it to 32-bits
(decl put_in_reg_zext32 (Value) Reg)
(rule (put_in_reg_zext32 val @ (value_type (fits_in_32 ty)))
      (extend val $false (ty_bits ty) 32))

;; 32/64-bit passthrough.
(rule (put_in_reg_zext32 val @ (value_type $I32)) val)
(rule (put_in_reg_zext32 val @ (value_type $I64)) val)

;; Place a `Value` into a register, sign extending it to 64-bits
(decl put_in_reg_sext64 (Value) Reg)
(rule (put_in_reg_sext64 val @ (value_type (fits_in_32 ty)))
      (extend val $true (ty_bits ty) 64))

;; 64-bit passthrough.
(rule (put_in_reg_sext64 val @ (value_type $I64)) val)

;; Place a `Value` into a register, zero extending it to 64-bits
(decl put_in_reg_zext64 (Value) Reg)
(rule (put_in_reg_zext64 val @ (value_type (fits_in_32 ty)))
      (extend val $false (ty_bits ty) 64))

;; 64-bit passthrough.
(rule (put_in_reg_zext64 val @ (value_type $I64)) val)

;; Misc instruction helpers ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

(decl trap_if_zero_divisor (Reg) Reg)
(rule (trap_if_zero_divisor reg)
      (let ((_ Unit (emit (MInst.TrapIf (cond_br_zero reg) (trap_code_division_by_zero)))))
        reg))

(decl size_from_ty (Type) OperandSize)
(rule (size_from_ty (fits_in_32 _ty)) (OperandSize.Size32))
(rule (size_from_ty $I64) (OperandSize.Size64))

;; Check for signed overflow. The only case is min_value / -1.
;; The following checks must be done in 32-bit or 64-bit, depending
;; on the input type.
(decl trap_if_div_overflow (Type Reg Reg) Reg)
(rule (trap_if_div_overflow ty x y)
      (let (
          ;; Check RHS is -1.
          (_1 Unit (emit (MInst.AluRRImm12 (ALUOp.AddS) (operand_size ty) (writable_zero_reg) y (u8_into_imm12 1))))

          ;; Check LHS is min_value, by subtracting 1 and branching if
          ;; there is overflow.
          (_2 Unit (emit (MInst.CCmpImm (size_from_ty ty)
                                        x
                                        (u8_into_uimm5 1)
                                        (nzcv $false $false $false $false)
                                        (Cond.Eq))))
          (_3 Unit (emit (MInst.TrapIf (cond_br_cond (Cond.Vs))
                                      (trap_code_integer_overflow))))
        )
        x))

;; An atomic load that can be sunk into another operation.
(type SinkableAtomicLoad extern (enum))

;; Extract a `SinkableAtomicLoad` that works with `Reg` from a value
;; operand.
(decl sinkable_atomic_load (SinkableAtomicLoad) Value)
(extern extractor sinkable_atomic_load sinkable_atomic_load)

;; Sink a `SinkableLoad` into a `Reg`.
;;
;; This is a side-effectful operation that notifies the context that the
;; instruction that produced the `SinkableAtomicLoad` has been sunk into another
;; instruction, and no longer needs to be lowered.
(decl sink_atomic_load (SinkableAtomicLoad) Reg)
(extern constructor sink_atomic_load sink_atomic_load)

;; Helper for generating either an `AluRRR`, `AluRRRShift`, or `AluRRImmLogic`
;; instruction depending on the input. Note that this requires that the `ALUOp`
;; specified is commutative.
(decl alu_rs_imm_logic_commutative (ALUOp Type Value Value) Reg)

;; Base case of operating on registers.
(rule (alu_rs_imm_logic_commutative op ty x y)
      (alu_rrr op ty x y))

;; Special cases for when one operand is a constant.
(rule (alu_rs_imm_logic_commutative op ty x (iconst k))
      (if-let imm (imm_logic_from_imm64 ty k))
      (alu_rr_imm_logic op ty x imm))
(rule (alu_rs_imm_logic_commutative op ty (iconst k) x)
      (if-let imm (imm_logic_from_imm64 ty k))
      (alu_rr_imm_logic op ty x imm))

;; Special cases for when one operand is shifted left by a constant.
(rule (alu_rs_imm_logic_commutative op ty x (ishl y (iconst k)))
      (if-let amt (lshl_from_imm64 ty k))
      (alu_rrr_shift op ty x y amt))
(rule (alu_rs_imm_logic_commutative op ty (ishl x (iconst k)) y)
      (if-let amt (lshl_from_imm64 ty k))
      (alu_rrr_shift op ty y x amt))

;; Same as `alu_rs_imm_logic_commutative` above, except that it doesn't require
;; that the operation is commutative.
(decl alu_rs_imm_logic (ALUOp Type Value Value) Reg)
(rule (alu_rs_imm_logic op ty x y)
      (alu_rrr op ty x y))
(rule (alu_rs_imm_logic op ty x (iconst k))
      (if-let imm (imm_logic_from_imm64 ty k))
      (alu_rr_imm_logic op ty x imm))
(rule (alu_rs_imm_logic op ty x (ishl y (iconst k)))
      (if-let amt (lshl_from_imm64 ty k))
      (alu_rrr_shift op ty x y amt))

;; Helper for generating i128 bitops which simply do the same operation to the
;; hi/lo registers.
;;
;; TODO: Support immlogic here
(decl i128_alu_bitop (ALUOp Type Value Value) ValueRegs)
(rule (i128_alu_bitop op ty x y)
      (let (
          (x_regs ValueRegs (put_in_regs x))
          (x_lo Reg (value_regs_get x_regs 0))
          (x_hi Reg (value_regs_get x_regs 1))
          (y_regs ValueRegs (put_in_regs y))
          (y_lo Reg (value_regs_get y_regs 0))
          (y_hi Reg (value_regs_get y_regs 1))
        )
        (value_regs
          (alu_rrr op ty x_lo y_lo)
          (alu_rrr op ty x_hi y_hi))))

;; Float vector compare helpers ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

;; Match 32 bit float 0 value
(decl zero_value_f32 (Ieee32) Ieee32)
(extern extractor zero_value_f32 zero_value_f32)

;; Match 64 bit float 0 value
(decl zero_value_f64 (Ieee64) Ieee64)
(extern extractor zero_value_f64 zero_value_f64)

;; Generate comparison to zero operator from input condition code
(decl float_cc_cmp_zero_to_vec_misc_op (FloatCC) VecMisc2)
(extern constructor float_cc_cmp_zero_to_vec_misc_op float_cc_cmp_zero_to_vec_misc_op)

(decl float_cc_cmp_zero_to_vec_misc_op_swap (FloatCC) VecMisc2)
(extern constructor float_cc_cmp_zero_to_vec_misc_op_swap float_cc_cmp_zero_to_vec_misc_op_swap)

;; Match valid generic compare to zero cases
(decl fcmp_zero_cond (FloatCC) FloatCC)
(extern extractor fcmp_zero_cond fcmp_zero_cond)

;; Match not equal compare to zero separately as it requires two output instructions
(decl fcmp_zero_cond_not_eq (FloatCC) FloatCC)
(extern extractor fcmp_zero_cond_not_eq fcmp_zero_cond_not_eq)

;; Helper for generating float compare to zero instructions where 2nd argument is zero
(decl float_cmp_zero (FloatCC Reg VectorSize) Reg)
(rule (float_cmp_zero cond rn size)
      (vec_misc (float_cc_cmp_zero_to_vec_misc_op cond) rn size))

;; Helper for generating float compare to zero instructions in case where 1st argument is zero
(decl float_cmp_zero_swap (FloatCC Reg VectorSize) Reg)
(rule (float_cmp_zero_swap cond rn size)
      (vec_misc (float_cc_cmp_zero_to_vec_misc_op_swap cond) rn size))

;; Helper for generating float compare equal to zero instruction
(decl fcmeq0 (Reg VectorSize) Reg)
(rule (fcmeq0 rn size)
      (vec_misc (VecMisc2.Fcmeq0) rn size))

;; Int vector compare helpers ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

;; Match integer 0 value
(decl zero_value (Imm64) Imm64)
(extern extractor zero_value zero_value)

;; Generate comparison to zero operator from input condition code
(decl int_cc_cmp_zero_to_vec_misc_op (IntCC) VecMisc2)
(extern constructor int_cc_cmp_zero_to_vec_misc_op int_cc_cmp_zero_to_vec_misc_op)

(decl int_cc_cmp_zero_to_vec_misc_op_swap (IntCC) VecMisc2)
(extern constructor int_cc_cmp_zero_to_vec_misc_op_swap int_cc_cmp_zero_to_vec_misc_op_swap)

;; Match valid generic compare to zero cases
(decl icmp_zero_cond (IntCC) IntCC)
(extern extractor icmp_zero_cond icmp_zero_cond)

;; Match not equal compare to zero separately as it requires two output instructions
(decl icmp_zero_cond_not_eq (IntCC) IntCC)
(extern extractor icmp_zero_cond_not_eq icmp_zero_cond_not_eq)

;; Helper for generating int compare to zero instructions where 2nd argument is zero
(decl int_cmp_zero (IntCC Reg VectorSize) Reg)
(rule (int_cmp_zero cond rn size)
      (vec_misc (int_cc_cmp_zero_to_vec_misc_op cond) rn size))

;; Helper for generating int compare to zero instructions in case where 1st argument is zero
(decl int_cmp_zero_swap (IntCC Reg VectorSize) Reg)
(rule (int_cmp_zero_swap cond rn size)
      (vec_misc (int_cc_cmp_zero_to_vec_misc_op_swap cond) rn size))

;; Helper for generating int compare equal to zero instruction
(decl cmeq0 (Reg VectorSize) Reg)
(rule (cmeq0 rn size)
      (vec_misc (VecMisc2.Cmeq0) rn size))

;; Helper for emitting `MInst.AtomicRMW` instructions.
(decl lse_atomic_rmw (AtomicRMWOp Value Reg Type) Reg)
(rule (lse_atomic_rmw op p r_arg2 ty)
      (let (
          (r_addr Reg p)
          (dst WritableReg (temp_writable_reg ty))
          (_ Unit (emit (MInst.AtomicRMW op r_arg2 dst r_addr ty)))
        )
        dst))

;; Helper for emitting `MInst.AtomicCAS` instructions.
(decl lse_atomic_cas (Reg Reg Reg Type) Reg)
(rule (lse_atomic_cas addr expect replace ty)
      (let (
            (dst WritableReg (temp_writable_reg ty))
            (_1 Unit (emit (MInst.Mov (operand_size ty) dst expect)))
            (_2 Unit (emit (MInst.AtomicCAS dst replace addr ty)))
          )
          dst))

;; Helper for emitting `MInst.AtomicRMWLoop` instructions.
;; - Make sure that both args are in virtual regs, since in effect
;; we have to do a parallel copy to get them safely to the AtomicRMW input
;; regs, and that's not guaranteed safe if either is in a real reg.
;; - Move the args to the preordained AtomicRMW input regs
;; - And finally, copy the preordained AtomicRMW output reg to its destination.
(decl atomic_rmw_loop (AtomicRMWLoopOp Value Value Type) Reg)
(rule (atomic_rmw_loop op p arg2 ty)
      (let (
          (v_addr Reg (ensure_in_vreg p $I64))
          (v_arg2 Reg (ensure_in_vreg arg2 $I64))
          (r_addr Reg (mov64_to_real 25 v_addr))
          (r_arg2 Reg (mov64_to_real 26 v_arg2))
          (_ Unit (emit (MInst.AtomicRMWLoop ty op)))
        )
        (mov64_from_real 27)))

;; Helper for emitting `MInst.AtomicCASLoop` instructions.
;; This is very similar to, but not identical to, the AtomicRmw case.  Note
;; that the AtomicCASLoop sequence does its own masking, so we don't need to worry
;; about zero-extending narrow (I8/I16/I32) values here.
;; Make sure that all three args are in virtual regs.  See corresponding comment
;; for `atomic_rmw_loop` above.
(decl atomic_cas_loop (Reg Reg Reg Type) Reg)
(rule (atomic_cas_loop addr expect replace ty)
      (let (
          (v_addr Reg (ensure_in_vreg addr $I64))
          (v_exp Reg (ensure_in_vreg expect $I64))
          (v_rep Reg (ensure_in_vreg replace $I64))
          ;; Move the args to the preordained AtomicCASLoop input regs
          (r_addr Reg (mov64_to_real 25 v_addr))
          (r_exp Reg (mov64_to_real 26 v_exp))
          (r_rep Reg (mov64_to_real 28 v_rep))
          ;; Now the AtomicCASLoop itself, implemented in the normal way, with a
          ;; load-exclusive, store-exclusive loop
          (_ Unit (emit (MInst.AtomicCASLoop ty)))
        )
        ;; And finally, copy the preordained AtomicCASLoop output reg to its destination.
        ;; Also, x24 and x28 are trashed.
        (mov64_from_real 27)))