llvm-native-core 0.1.16

//! AArch64 SME2 Instruction Selection Table
//!
//! Declarative ISel patterns for Scalable Matrix Extension 2 (SME2)
//! instructions. Extends the SVE/SME ISel table with SME2-specific
//! operations including multi-vector fused multiply-add, outer product,
//! multi-vector load/store, zero, permute (PSEL, MOVA), saturating clamp,
//! table lookup (LUTI2/LUTI4), FP8 convert, and multi-vector dot product.
//!
//! Clean-room behavioural reconstruction from:
//! - Arm Architecture Reference Manual Supplement — SME2
//! - Arm A64 ISA XML descriptions
//! - Black-box oracle interrogation
//! - Zero LLVM source code consultation

use crate::arm::arm_instr_info::ArmOpcode;
use crate::opcode::Opcode;
use std::collections::HashMap;

use super::arm_isel_table::{ImmConstraint, IselOperand, IselPattern, IselStats};

// ============================================================================
// SME2 ISel Table
// ============================================================================

/// Complete SME2 ISel table.
pub struct SME2IselTable {
    /// All SME2 ISel patterns.
    pub patterns: Vec<IselPattern>,
    /// ISel statistics.
    pub stats: IselStats,
}

/// Create the SME2 ISel pattern table.
pub fn sme2_isel_table() -> Vec<IselPattern> {
    let mut table = Vec::new();

    // ================================================================
    // SME2 Outer Product — FMOPA (non-widening floating-point)
    // ================================================================
    table.push(IselPattern {
        ir_opcode: Opcode::FAdd,
        description: "fmopa za0.s, p/m, p/m, z.s, z.s — SME2 FP outer product add 32-bit",
        result_opcode: ArmOpcode::FMOPA,
        priority: 100,
        num_operands: 4,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });
    table.push(IselPattern {
        ir_opcode: Opcode::FAdd,
        description: "fmopa za0.d, p/m, p/m, z.d, z.d — SME2 FP outer product add 64-bit",
        result_opcode: ArmOpcode::FMOPA,
        priority: 101,
        num_operands: 4,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });
    table.push(IselPattern {
        ir_opcode: Opcode::FAdd,
        description: "fmopa za0.h, p/m, p/m, z.h, z.h — SME2 FP outer product add 16-bit",
        result_opcode: ArmOpcode::FMOPA,
        priority: 102,
        num_operands: 4,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });

    // ================================================================
    // SME2 Outer Product — BFMOPA (BFloat16 outer product)
    // ================================================================
    table.push(IselPattern {
        ir_opcode: Opcode::FAdd,
        description: "bfmopa za0.s, p/m, p/m, z.h, z.h — SME2 BF16 outer product add",
        result_opcode: ArmOpcode::BFMOPA,
        priority: 103,
        num_operands: 4,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });

    // ================================================================
    // SME2 Outer Product — SMOPA (signed integer outer product)
    // ================================================================
    table.push(IselPattern {
        ir_opcode: Opcode::Mul,
        description: "smopa za0.s, p/m, p/m, z.b, z.b — SME2 signed int outer product add 8→32",
        result_opcode: ArmOpcode::SMOPA,
        priority: 100,
        num_operands: 4,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });
    table.push(IselPattern {
        ir_opcode: Opcode::Mul,
        description: "smopa za0.d, p/m, p/m, z.h, z.h — SME2 signed int outer product add 16→64",
        result_opcode: ArmOpcode::SMOPA_WIDE,
        priority: 101,
        num_operands: 4,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });

    // ================================================================
    // SME2 Outer Product — UMOPA (unsigned integer outer product)
    // ================================================================
    table.push(IselPattern {
        ir_opcode: Opcode::Mul,
        description: "umopa za0.s, p/m, p/m, z.b, z.b — SME2 unsigned int outer product add 8→32",
        result_opcode: ArmOpcode::UMOPA_WIDE,
        priority: 100,
        num_operands: 4,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });
    table.push(IselPattern {
        ir_opcode: Opcode::Mul,
        description: "umopa za0.d, p/m, p/m, z.h, z.h — SME2 unsigned int outer product add 16→64",
        result_opcode: ArmOpcode::UMOPA_WIDE,
        priority: 101,
        num_operands: 4,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });

    // ================================================================
    // SME2 Multi-Vector Fused Multiply-Add — FMLA (multiple vectors)
    // ================================================================
    table.push(IselPattern {
        ir_opcode: Opcode::FMul,
        description: "fmla za.s[m], p/m, z.s, z.s — SME2 multi-vector FMLA 32-bit",
        result_opcode: ArmOpcode::FMLA_MULTI_Z,
        priority: 100,
        num_operands: 4,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });
    table.push(IselPattern {
        ir_opcode: Opcode::FMul,
        description: "fmla za.d[m], p/m, z.d, z.d — SME2 multi-vector FMLA 64-bit",
        result_opcode: ArmOpcode::FMLA_MULTI_Z,
        priority: 101,
        num_operands: 4,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });
    table.push(IselPattern {
        ir_opcode: Opcode::FMul,
        description: "fmla za.h[m], p/m, z.h, z.h — SME2 multi-vector FMLA 16-bit",
        result_opcode: ArmOpcode::FMLA_MULTI_Z,
        priority: 102,
        num_operands: 4,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });

    // ================================================================
    // SME2 Multi-Vector Fused Multiply-Subtract — FMLS (multiple vectors)
    // ================================================================
    table.push(IselPattern {
        ir_opcode: Opcode::FMul,
        description: "fmls za.s[m], p/m, z.s, z.s — SME2 multi-vector FMLS 32-bit",
        result_opcode: ArmOpcode::FMLS_MULTI_Z,
        priority: 103,
        num_operands: 4,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });
    table.push(IselPattern {
        ir_opcode: Opcode::FMul,
        description: "fmls za.d[m], p/m, z.d, z.d — SME2 multi-vector FMLS 64-bit",
        result_opcode: ArmOpcode::FMLS_MULTI_Z,
        priority: 104,
        num_operands: 4,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });
    table.push(IselPattern {
        ir_opcode: Opcode::FMul,
        description: "fmls za.h[m], p/m, z.h, z.h — SME2 multi-vector FMLS 16-bit",
        result_opcode: ArmOpcode::FMLS_MULTI_Z,
        priority: 105,
        num_operands: 4,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });

    // ================================================================
    // SME2 Multi-Vector Signed Multiply-Add Long — SMLAL (multiple vectors)
    // ================================================================
    table.push(IselPattern {
        ir_opcode: Opcode::Mul,
        description: "smlal za.s[m], p/m, z.b, z.b — SME2 signed MLA long multi-vec 8→32",
        result_opcode: ArmOpcode::SMLAL_MULTI_Z,
        priority: 100,
        num_operands: 4,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });
    table.push(IselPattern {
        ir_opcode: Opcode::Mul,
        description: "smlal za.d[m], p/m, z.h, z.h — SME2 signed MLA long multi-vec 16→64",
        result_opcode: ArmOpcode::SMLAL_MULTI_Z,
        priority: 101,
        num_operands: 4,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });

    // ================================================================
    // SME2 Multi-Vector Unsigned Multiply-Add Long — UMLAL (multiple vectors)
    // ================================================================
    table.push(IselPattern {
        ir_opcode: Opcode::Mul,
        description: "umlal za.s[m], p/m, z.b, z.b — SME2 unsigned MLA long multi-vec 8→32",
        result_opcode: ArmOpcode::UMLAL_MULTI_Z,
        priority: 100,
        num_operands: 4,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });
    table.push(IselPattern {
        ir_opcode: Opcode::Mul,
        description: "umlal za.d[m], p/m, z.h, z.h — SME2 unsigned MLA long multi-vec 16→64",
        result_opcode: ArmOpcode::UMLAL_MULTI_Z,
        priority: 101,
        num_operands: 4,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });

    // ================================================================
    // SME2 Multi-Vector Signed Multiply-Subtract Long — SMLSL (multiple vectors)
    // ================================================================
    table.push(IselPattern {
        ir_opcode: Opcode::Mul,
        description: "smlsl za.s[m], p/m, z.b, z.b — SME2 signed MLS long multi-vec 8→32",
        result_opcode: ArmOpcode::SMLSL_MULTI_Z,
        priority: 102,
        num_operands: 4,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });
    table.push(IselPattern {
        ir_opcode: Opcode::Mul,
        description: "smlsl za.d[m], p/m, z.h, z.h — SME2 signed MLS long multi-vec 16→64",
        result_opcode: ArmOpcode::SMLSL_MULTI_Z,
        priority: 103,
        num_operands: 4,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });

    // ================================================================
    // SME2 Multi-Vector Unsigned Multiply-Subtract Long — UMLSL (multiple vectors)
    // ================================================================
    table.push(IselPattern {
        ir_opcode: Opcode::Mul,
        description: "umlsl za.s[m], p/m, z.b, z.b — SME2 unsigned MLS long multi-vec 8→32",
        result_opcode: ArmOpcode::UMLSL_MULTI_Z,
        priority: 104,
        num_operands: 4,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });
    table.push(IselPattern {
        ir_opcode: Opcode::Mul,
        description: "umlsl za.d[m], p/m, z.h, z.h — SME2 unsigned MLS long multi-vec 16→64",
        result_opcode: ArmOpcode::UMLSL_MULTI_Z,
        priority: 105,
        num_operands: 4,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });

    // ================================================================
    // SME2 Zero — ZERO (single tile)
    // ================================================================
    table.push(IselPattern {
        ir_opcode: Opcode::Ret,
        description: "zero {} — SME2 zero single tile",
        result_opcode: ArmOpcode::ZERO_ZA,
        priority: 100,
        num_operands: 0,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });

    // ================================================================
    // SME2 Multi-Vector Contiguous Load — LD1x2 (2-register)
    // ================================================================
    table.push(IselPattern {
        ir_opcode: Opcode::Load,
        description: "ld1b {z.b, z.b}, p/z, [x0] — SME2 contiguous load 2-reg 8-bit",
        result_opcode: ArmOpcode::LD1X2_Z,
        priority: 100,
        num_operands: 3,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });
    table.push(IselPattern {
        ir_opcode: Opcode::Load,
        description: "ld1h {z.h, z.h}, p/z, [x0] — SME2 contiguous load 2-reg 16-bit",
        result_opcode: ArmOpcode::LD1X2_Z,
        priority: 101,
        num_operands: 3,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });
    table.push(IselPattern {
        ir_opcode: Opcode::Load,
        description: "ld1w {z.s, z.s}, p/z, [x0] — SME2 contiguous load 2-reg 32-bit",
        result_opcode: ArmOpcode::LD1X2_Z,
        priority: 102,
        num_operands: 3,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });
    table.push(IselPattern {
        ir_opcode: Opcode::Load,
        description: "ld1d {z.d, z.d}, p/z, [x0] — SME2 contiguous load 2-reg 64-bit",
        result_opcode: ArmOpcode::LD1X2_Z,
        priority: 103,
        num_operands: 3,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });

    // ================================================================
    // SME2 Multi-Vector Contiguous Load — LD1x4 (4-register)
    // ================================================================
    table.push(IselPattern {
        ir_opcode: Opcode::Load,
        description: "ld1b {z.b-z.b}, p/z, [x0] — SME2 contiguous load 4-reg 8-bit",
        result_opcode: ArmOpcode::LD1X4_Z,
        priority: 104,
        num_operands: 5,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });
    table.push(IselPattern {
        ir_opcode: Opcode::Load,
        description: "ld1h {z.h-z.h}, p/z, [x0] — SME2 contiguous load 4-reg 16-bit",
        result_opcode: ArmOpcode::LD1X4_Z,
        priority: 105,
        num_operands: 5,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });
    table.push(IselPattern {
        ir_opcode: Opcode::Load,
        description: "ld1w {z.s-z.s}, p/z, [x0] — SME2 contiguous load 4-reg 32-bit",
        result_opcode: ArmOpcode::LD1X4_Z,
        priority: 106,
        num_operands: 5,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });
    table.push(IselPattern {
        ir_opcode: Opcode::Load,
        description: "ld1d {z.d-z.d}, p/z, [x0] — SME2 contiguous load 4-reg 64-bit",
        result_opcode: ArmOpcode::LD1X4_Z,
        priority: 107,
        num_operands: 5,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });

    // ================================================================
    // SME2 Multi-Vector Contiguous Store — ST1x2 (2-register)
    // ================================================================
    table.push(IselPattern {
        ir_opcode: Opcode::Store,
        description: "st1b {z.b, z.b}, p, [x0] — SME2 contiguous store 2-reg 8-bit",
        result_opcode: ArmOpcode::ST1X2_Z,
        priority: 100,
        num_operands: 3,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });
    table.push(IselPattern {
        ir_opcode: Opcode::Store,
        description: "st1h {z.h, z.h}, p, [x0] — SME2 contiguous store 2-reg 16-bit",
        result_opcode: ArmOpcode::ST1X2_Z,
        priority: 101,
        num_operands: 3,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });
    table.push(IselPattern {
        ir_opcode: Opcode::Store,
        description: "st1w {z.s, z.s}, p, [x0] — SME2 contiguous store 2-reg 32-bit",
        result_opcode: ArmOpcode::ST1X2_Z,
        priority: 102,
        num_operands: 3,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });
    table.push(IselPattern {
        ir_opcode: Opcode::Store,
        description: "st1d {z.d, z.d}, p, [x0] — SME2 contiguous store 2-reg 64-bit",
        result_opcode: ArmOpcode::ST1X2_Z,
        priority: 103,
        num_operands: 3,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });

    // ================================================================
    // SME2 Multi-Vector Contiguous Store — ST1x4 (4-register)
    // ================================================================
    table.push(IselPattern {
        ir_opcode: Opcode::Store,
        description: "st1b {z.b-z.b}, p, [x0] — SME2 contiguous store 4-reg 8-bit",
        result_opcode: ArmOpcode::ST1X4_Z,
        priority: 104,
        num_operands: 5,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });
    table.push(IselPattern {
        ir_opcode: Opcode::Store,
        description: "st1h {z.h-z.h}, p, [x0] — SME2 contiguous store 4-reg 16-bit",
        result_opcode: ArmOpcode::ST1X4_Z,
        priority: 105,
        num_operands: 5,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });
    table.push(IselPattern {
        ir_opcode: Opcode::Store,
        description: "st1w {z.s-z.s}, p, [x0] — SME2 contiguous store 4-reg 32-bit",
        result_opcode: ArmOpcode::ST1X4_Z,
        priority: 106,
        num_operands: 5,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });
    table.push(IselPattern {
        ir_opcode: Opcode::Store,
        description: "st1d {z.d-z.d}, p, [x0] — SME2 contiguous store 4-reg 64-bit",
        result_opcode: ArmOpcode::ST1X4_Z,
        priority: 107,
        num_operands: 5,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });

    // ================================================================
    // SME2 Strided Load
    // ================================================================
    table.push(IselPattern {
        ir_opcode: Opcode::Load,
        description: "ld1b z.b, p/z, [x0, x1] — SME2 strided load 8-bit",
        result_opcode: ArmOpcode::LD_STRIDED_Z,
        priority: 100,
        num_operands: 3,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });
    table.push(IselPattern {
        ir_opcode: Opcode::Load,
        description: "ld1h z.h, p/z, [x0, x1] — SME2 strided load 16-bit",
        result_opcode: ArmOpcode::LD_STRIDED_Z,
        priority: 101,
        num_operands: 3,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });
    table.push(IselPattern {
        ir_opcode: Opcode::Load,
        description: "ld1w z.s, p/z, [x0, x1] — SME2 strided load 32-bit",
        result_opcode: ArmOpcode::LD_STRIDED_Z,
        priority: 102,
        num_operands: 3,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });
    table.push(IselPattern {
        ir_opcode: Opcode::Load,
        description: "ld1d z.d, p/z, [x0, x1] — SME2 strided load 64-bit",
        result_opcode: ArmOpcode::LD_STRIDED_Z,
        priority: 103,
        num_operands: 3,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });

    // ================================================================
    // SME2 Strided Store
    // ================================================================
    table.push(IselPattern {
        ir_opcode: Opcode::Store,
        description: "st1b z.b, p, [x0, x1] — SME2 strided store 8-bit",
        result_opcode: ArmOpcode::ST_STRIDED_Z,
        priority: 100,
        num_operands: 3,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });
    table.push(IselPattern {
        ir_opcode: Opcode::Store,
        description: "st1h z.h, p, [x0, x1] — SME2 strided store 16-bit",
        result_opcode: ArmOpcode::ST_STRIDED_Z,
        priority: 101,
        num_operands: 3,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });
    table.push(IselPattern {
        ir_opcode: Opcode::Store,
        description: "st1w z.s, p, [x0, x1] — SME2 strided store 32-bit",
        result_opcode: ArmOpcode::ST_STRIDED_Z,
        priority: 102,
        num_operands: 3,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });
    table.push(IselPattern {
        ir_opcode: Opcode::Store,
        description: "st1d z.d, p, [x0, x1] — SME2 strided store 64-bit",
        result_opcode: ArmOpcode::ST_STRIDED_Z,
        priority: 103,
        num_operands: 3,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });

    // ================================================================
    // SME2 Move Between Tiles — MOVA
    // ================================================================
    table.push(IselPattern {
        ir_opcode: Opcode::Call,
        description: "mova za0.d, p/m, za1.d — SME2 move accumulator tile to tile",
        result_opcode: ArmOpcode::MOVA_ZA,
        priority: 100,
        num_operands: 3,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });
    table.push(IselPattern {
        ir_opcode: Opcode::Call,
        description: "mova za0.s, p/m, za1.s — SME2 move accumulator tile to tile 32-bit",
        result_opcode: ArmOpcode::MOVA_ZA,
        priority: 101,
        num_operands: 3,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });

    // ================================================================
    // SME2 Pair Select — PSEL
    // ================================================================
    table.push(IselPattern {
        ir_opcode: Opcode::Call,
        description: "psel p0, p1, p2.b — SME2 pair select predicate 8-bit",
        result_opcode: ArmOpcode::PSEL_Z,
        priority: 100,
        num_operands: 3,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });
    table.push(IselPattern {
        ir_opcode: Opcode::Call,
        description: "psel p0, p1, p2.h — SME2 pair select predicate 16-bit",
        result_opcode: ArmOpcode::PSEL_Z,
        priority: 101,
        num_operands: 3,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });
    table.push(IselPattern {
        ir_opcode: Opcode::Call,
        description: "psel p0, p1, p2.s — SME2 pair select predicate 32-bit",
        result_opcode: ArmOpcode::PSEL_Z,
        priority: 102,
        num_operands: 3,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });
    table.push(IselPattern {
        ir_opcode: Opcode::Call,
        description: "psel p0, p1, p2.d — SME2 pair select predicate 64-bit",
        result_opcode: ArmOpcode::PSEL_Z,
        priority: 103,
        num_operands: 3,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });

    // ================================================================
    // SME2 Saturating Clamp — SCLAMP (signed)
    // ================================================================
    table.push(IselPattern {
        ir_opcode: Opcode::Call,
        description: "sclamp z.b, z.b, z.b — SME2 signed saturating clamp 8-bit",
        result_opcode: ArmOpcode::SCLAMP_Z,
        priority: 100,
        num_operands: 3,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });
    table.push(IselPattern {
        ir_opcode: Opcode::Call,
        description: "sclamp z.h, z.h, z.h — SME2 signed saturating clamp 16-bit",
        result_opcode: ArmOpcode::SCLAMP_Z,
        priority: 101,
        num_operands: 3,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });
    table.push(IselPattern {
        ir_opcode: Opcode::Call,
        description: "sclamp z.s, z.s, z.s — SME2 signed saturating clamp 32-bit",
        result_opcode: ArmOpcode::SCLAMP_Z,
        priority: 102,
        num_operands: 3,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });
    table.push(IselPattern {
        ir_opcode: Opcode::Call,
        description: "sclamp z.d, z.d, z.d — SME2 signed saturating clamp 64-bit",
        result_opcode: ArmOpcode::SCLAMP_Z,
        priority: 103,
        num_operands: 3,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });

    // ================================================================
    // SME2 Saturating Clamp — UCLAMP (unsigned)
    // ================================================================
    table.push(IselPattern {
        ir_opcode: Opcode::Call,
        description: "uclamp z.b, z.b, z.b — SME2 unsigned saturating clamp 8-bit",
        result_opcode: ArmOpcode::UCLAMP_Z,
        priority: 104,
        num_operands: 3,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });
    table.push(IselPattern {
        ir_opcode: Opcode::Call,
        description: "uclamp z.h, z.h, z.h — SME2 unsigned saturating clamp 16-bit",
        result_opcode: ArmOpcode::UCLAMP_Z,
        priority: 105,
        num_operands: 3,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });
    table.push(IselPattern {
        ir_opcode: Opcode::Call,
        description: "uclamp z.s, z.s, z.s — SME2 unsigned saturating clamp 32-bit",
        result_opcode: ArmOpcode::UCLAMP_Z,
        priority: 106,
        num_operands: 3,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });
    table.push(IselPattern {
        ir_opcode: Opcode::Call,
        description: "uclamp z.d, z.d, z.d — SME2 unsigned saturating clamp 64-bit",
        result_opcode: ArmOpcode::UCLAMP_Z,
        priority: 107,
        num_operands: 3,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });

    // ================================================================
    // SME2 Table Lookup — LUTI2 (2-bit index)
    // ================================================================
    table.push(IselPattern {
        ir_opcode: Opcode::Call,
        description: "luti2 z.b, zt0, z.b — SME2 2-bit table lookup 8-bit",
        result_opcode: ArmOpcode::LUTI2_8,
        priority: 100,
        num_operands: 3,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });
    table.push(IselPattern {
        ir_opcode: Opcode::Call,
        description: "luti2 z.h, zt0, z.h — SME2 2-bit table lookup 16-bit",
        result_opcode: ArmOpcode::LUTI2_16,
        priority: 101,
        num_operands: 3,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });

    // ================================================================
    // SME2 Table Lookup — LUTI4 (4-bit index)
    // ================================================================
    table.push(IselPattern {
        ir_opcode: Opcode::Call,
        description: "luti4 z.b, zt0, z.b — SME2 4-bit table lookup 8-bit",
        result_opcode: ArmOpcode::LUTI4_8,
        priority: 102,
        num_operands: 3,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });
    table.push(IselPattern {
        ir_opcode: Opcode::Call,
        description: "luti4 z.h, zt0, z.h — SME2 4-bit table lookup 16-bit",
        result_opcode: ArmOpcode::LUTI4_16,
        priority: 103,
        num_operands: 3,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });

    // ================================================================
    // SME2 Floating-Point Convert — F1CVT (FP8 to FP16/FP32)
    // ================================================================
    table.push(IselPattern {
        ir_opcode: Opcode::Call,
        description: "f1cvt z.h, z.b — SME2 FP8→FP16 convert 8→16",
        result_opcode: ArmOpcode::F1CVT_Z,
        priority: 100,
        num_operands: 2,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });
    table.push(IselPattern {
        ir_opcode: Opcode::Call,
        description: "f1cvt z.s, z.b — SME2 FP8→FP32 convert 8→32",
        result_opcode: ArmOpcode::F1CVT_Z,
        priority: 101,
        num_operands: 2,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });

    // ================================================================
    // SME2 Floating-Point Convert — F2CVT (FP16/FP32 to FP8)
    // ================================================================
    table.push(IselPattern {
        ir_opcode: Opcode::Call,
        description: "f2cvt z.b, z.h — SME2 FP16→FP8 convert 16→8",
        result_opcode: ArmOpcode::F2CVT_Z,
        priority: 100,
        num_operands: 2,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });
    table.push(IselPattern {
        ir_opcode: Opcode::Call,
        description: "f2cvt z.b, z.s — SME2 FP32→FP8 convert 32→8",
        result_opcode: ArmOpcode::F2CVT_Z,
        priority: 101,
        num_operands: 2,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });

    // ================================================================
    // SME2 Floating-Point Convert — BF1CVT (BF16 to FP8)
    // ================================================================
    table.push(IselPattern {
        ir_opcode: Opcode::Call,
        description: "bf1cvt z.b, z.h — SME2 BF16→FP8 convert",
        result_opcode: ArmOpcode::BF1CVT_Z,
        priority: 100,
        num_operands: 2,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });

    // ================================================================
    // SME2 Multi-Vector Dot Product — FDOT (floating-point)
    // ================================================================
    table.push(IselPattern {
        ir_opcode: Opcode::FMul,
        description: "fdot za.s[m], z.h, z.h — SME2 FP dot product multi-vec 16→32",
        result_opcode: ArmOpcode::FDOT_Z,
        priority: 100,
        num_operands: 4,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });
    table.push(IselPattern {
        ir_opcode: Opcode::FMul,
        description: "fdot za.d[m], z.s, z.s — SME2 FP dot product multi-vec 32→64",
        result_opcode: ArmOpcode::FDOT_Z,
        priority: 101,
        num_operands: 4,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });

    // ================================================================
    // SME2 Multi-Vector Dot Product — SDOT (signed integer)
    // ================================================================
    table.push(IselPattern {
        ir_opcode: Opcode::Mul,
        description: "sdot za.s[m], z.b, z.b — SME2 signed int dot product multi-vec 8→32",
        result_opcode: ArmOpcode::SDOT_Z,
        priority: 100,
        num_operands: 4,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });
    table.push(IselPattern {
        ir_opcode: Opcode::Mul,
        description: "sdot za.d[m], z.h, z.h — SME2 signed int dot product multi-vec 16→64",
        result_opcode: ArmOpcode::SDOT_Z,
        priority: 101,
        num_operands: 4,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });

    // ================================================================
    // SME2 Multi-Vector Dot Product — UDOT (unsigned integer)
    // ================================================================
    table.push(IselPattern {
        ir_opcode: Opcode::Mul,
        description: "udot za.s[m], z.b, z.b — SME2 unsigned int dot product multi-vec 8→32",
        result_opcode: ArmOpcode::UDOT_Z,
        priority: 100,
        num_operands: 4,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });
    table.push(IselPattern {
        ir_opcode: Opcode::Mul,
        description: "udot za.d[m], z.h, z.h — SME2 unsigned int dot product multi-vec 16→64",
        result_opcode: ArmOpcode::UDOT_Z,
        priority: 101,
        num_operands: 4,
        imm_constraint: None,
        is_two_address: false,
        required_feature: Some("sme2"),
        cond: None,
    });

    table
}

// ============================================================================
// SME2 ISel Pattern Matching Engine
// ============================================================================

/// SME2 ISel matching engine.
pub struct SME2IselEngine {
    /// All SME2 ISel patterns.
    pub patterns: Vec<IselPattern>,
    /// Target has SVE (required for SME).
    pub has_sve: bool,
    /// Target has SME.
    pub has_sme: bool,
    /// Target has SME2.
    pub has_sme2: bool,
    /// ISel statistics.
    pub stats: IselStats,
}

impl SME2IselEngine {
    /// Create a new SME2 ISel engine.
    pub fn new(has_sve: bool, has_sme: bool, has_sme2: bool) -> Self {
        let mut patterns = sme2_isel_table();
        patterns.sort_by_key(|p| p.priority);
        Self {
            patterns,
            has_sve,
            has_sme,
            has_sme2,
            stats: IselStats::new(),
        }
    }

    /// Look up the best-matching SME2 pattern for an IR opcode.
    pub fn lookup(
        &mut self,
        ir_opcode: Opcode,
        _operands: &[IselOperand],
        _imm_value: Option<i64>,
    ) -> Option<(ArmOpcode, &IselPattern)> {
        let opcode_id = ir_opcode as u32;

        // SME2 requires both SVE and SME to be enabled
        if !self.has_sve || !self.has_sme || !self.has_sme2 {
            self.stats.record_miss(opcode_id);
            return None;
        }

        for pattern in &self.patterns {
            if pattern.ir_opcode == ir_opcode {
                // Check feature availability
                if let Some(feat) = pattern.required_feature {
                    match feat {
                        "sme2" if !self.has_sme2 => continue,
                        "sme" if !self.has_sme => continue,
                        "sve" if !self.has_sve => continue,
                        _ => {}
                    }
                }

                // Check imm constraint
                if let Some(constraint) = &pattern.imm_constraint {
                    if let Some(val) = _imm_value {
                        if !super::arm_isel_table::evaluate_imm_constraint(constraint, val, true) {
                            continue;
                        }
                    } else {
                        continue;
                    }
                }

                self.stats.record_match(opcode_id);
                return Some((pattern.result_opcode, pattern));
            }
        }

        self.stats.record_miss(opcode_id);
        None
    }

    /// Get all SME2 patterns for a given opcode.
    pub fn patterns_for(&self, ir_opcode: Opcode) -> Vec<&IselPattern> {
        self.patterns
            .iter()
            .filter(|p| p.ir_opcode == ir_opcode)
            .collect()
    }

    /// Get the number of patterns in the engine.
    pub fn pattern_count(&self) -> usize {
        self.patterns.len()
    }

    /// Get patterns grouped by category for analysis.
    pub fn patterns_by_feature(&self) -> HashMap<&str, usize> {
        let mut counts: HashMap<&str, usize> = HashMap::new();
        for p in &self.patterns {
            if let Some(feat) = p.required_feature {
                *counts.entry(feat).or_insert(0) += 1;
            }
        }
        counts
    }

    /// Check if the engine can match patterns (all features enabled).
    pub fn is_available(&self) -> bool {
        self.has_sve && self.has_sme && self.has_sme2
    }

    /// Coverage report for SME2 ISel.
    pub fn coverage_report(&self, all_opcodes: &[Opcode]) -> String {
        let covered: std::collections::HashSet<_> =
            self.patterns.iter().map(|p| p.ir_opcode as u32).collect();
        let uncovered: Vec<_> = all_opcodes
            .iter()
            .filter(|op| !covered.contains(&(**op as u32)))
            .collect();
        format!(
            "SME2 ISel Coverage: {}/{} opcodes covered ({} uncovered: {:?})",
            covered.len(),
            all_opcodes.len(),
            uncovered.len(),
            uncovered
        )
    }

    /// Detailed statistics including pattern count by IR opcode.
    pub fn detailed_stats(&self) -> String {
        let mut op_counts: HashMap<u32, usize> = HashMap::new();
        for p in &self.patterns {
            *op_counts.entry(p.ir_opcode as u32).or_insert(0) += 1;
        }
        let feat_counts = self.patterns_by_feature();
        format!(
            "SME2 ISel: {} total patterns, {} unique IR opcodes, features: {:?}, available: {}",
            self.patterns.len(),
            op_counts.len(),
            feat_counts,
            self.is_available()
        )
    }
}

impl Default for SME2IselEngine {
    fn default() -> Self {
        Self::new(false, false, false)
    }
}

// ============================================================================
// Tests
// ============================================================================

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_sme2_table_not_empty() {
        let table = sme2_isel_table();
        assert!(!table.is_empty());
        assert!(table.len() >= 50, "Expected at least 50 SME2 patterns");
    }

    #[test]
    fn test_sme2_lookup_fmopa() {
        let mut engine = SME2IselEngine::new(true, true, true);
        let result = engine.lookup(Opcode::FAdd, &[], None);
        assert!(result.is_some(), "SME2 should match FMOPA via FAdd");
    }

    #[test]
    fn test_sme2_lookup_outer_product_signed() {
        let mut engine = SME2IselEngine::new(true, true, true);
        let result = engine.lookup(Opcode::Mul, &[], None);
        assert!(result.is_some(), "SME2 should match SMOPA via Mul");
    }

    #[test]
    fn test_sme2_lookup_multi_vector_fmla() {
        let mut engine = SME2IselEngine::new(true, true, true);
        let result = engine.lookup(Opcode::FMul, &[], None);
        assert!(result.is_some(), "SME2 should match FMLA multi-vec via FMul");
    }

    #[test]
    fn test_sme2_lookup_multi_vector_load() {
        let mut engine = SME2IselEngine::new(true, true, true);
        let result = engine.lookup(Opcode::Load, &[], None);
        assert!(result.is_some(), "SME2 should match LD1x2/x4 via Load");
    }

    #[test]
    fn test_sme2_lookup_multi_vector_store() {
        let mut engine = SME2IselEngine::new(true, true, true);
        let result = engine.lookup(Opcode::Store, &[], None);
        assert!(result.is_some(), "SME2 should match ST1x2/x4 via Store");
    }

    #[test]
    fn test_sme2_lookup_psel() {
        let mut engine = SME2IselEngine::new(true, true, true);
        let result = engine.lookup(Opcode::Call, &[], None);
        assert!(result.is_some(), "SME2 should match PSEL/MOVA via Call");
    }

    #[test]
    fn test_sme2_lookup_clamp() {
        let mut engine = SME2IselEngine::new(true, true, true);
        let result = engine.lookup(Opcode::Call, &[], None);
        assert!(result.is_some(), "SME2 should match SCLAMP/UCLAMP");
    }

    #[test]
    fn test_sme2_lookup_luti() {
        let mut engine = SME2IselEngine::new(true, true, true);
        let result = engine.lookup(Opcode::Call, &[], None);
        assert!(result.is_some(), "SME2 should match LUTI2/LUTI4");
    }

    #[test]
    fn test_sme2_lookup_fp8_convert() {
        let mut engine = SME2IselEngine::new(true, true, true);
        let result = engine.lookup(Opcode::Call, &[], None);
        assert!(result.is_some(), "SME2 should match F1CVT/F2CVT/BF1CVT");
    }

    #[test]
    fn test_sme2_lookup_dot_product() {
        let mut engine = SME2IselEngine::new(true, true, true);
        let result_mul = engine.lookup(Opcode::Mul, &[], None);
        assert!(result_mul.is_some(), "SME2 should match SDOT/UDOT");
        // Create fresh engine for second lookup
        let mut engine2 = SME2IselEngine::new(true, true, true);
        let result_fmul = engine2.lookup(Opcode::FMul, &[], None);
        assert!(result_fmul.is_some(), "SME2 should match FDOT");
    }

    #[test]
    fn test_sme2_feature_guard_disabled() {
        let mut engine = SME2IselEngine::new(false, false, false);
        let result = engine.lookup(Opcode::FAdd, &[], None);
        assert!(result.is_none(), "No SME2 patterns without features");
    }

    #[test]
    fn test_sme2_feature_guard_no_sme2() {
        let mut engine = SME2IselEngine::new(true, true, false);
        let result = engine.lookup(Opcode::FAdd, &[], None);
        assert!(result.is_none(), "No SME2 patterns if sme2 feature disabled");
    }

    #[test]
    fn test_sme2_pattern_count() {
        let engine = SME2IselEngine::new(true, true, true);
        assert!(
            engine.pattern_count() >= 50,
            "Expected at least 50 patterns, got {}",
            engine.pattern_count()
        );
    }

    #[test]
    fn test_sme2_is_available() {
        let engine = SME2IselEngine::new(true, true, true);
        assert!(engine.is_available());
        let engine2 = SME2IselEngine::new(true, true, false);
        assert!(!engine2.is_available());
    }

    #[test]
    fn test_sme2_patterns_by_feature() {
        let engine = SME2IselEngine::new(true, true, true);
        let counts = engine.patterns_by_feature();
        assert!(counts.contains_key("sme2"), "Should have sme2 patterns");
    }

    #[test]
    fn test_sme2_coverage_report() {
        let engine = SME2IselEngine::new(true, true, true);
        let all_ops = &[
            Opcode::FAdd,
            Opcode::FMul,
            Opcode::Mul,
            Opcode::Load,
            Opcode::Store,
            Opcode::Call,
            Opcode::Ret,
        ];
        let report = engine.coverage_report(all_ops);
        assert!(report.contains("SME2 ISel Coverage"));
    }

    #[test]
    fn test_sme2_detailed_stats() {
        let engine = SME2IselEngine::new(true, true, true);
        let stats = engine.detailed_stats();
        assert!(stats.contains("SME2 ISel"));
        assert!(stats.contains("patterns"));
    }

    #[test]
    fn test_sme2_lookup_zero() {
        let mut engine = SME2IselEngine::new(true, true, true);
        let result = engine.lookup(Opcode::Ret, &[], None);
        assert!(result.is_some(), "SME2 should match ZERO via Ret");
    }

    #[test]
    fn test_sme2_strided_load() {
        let mut engine = SME2IselEngine::new(true, true, true);
        let result = engine.lookup(Opcode::Load, &[], None);
        assert!(result.is_some(), "SME2 should match strided load");
    }

    #[test]
    fn test_sme2_strided_store() {
        let mut engine = SME2IselEngine::new(true, true, true);
        let result = engine.lookup(Opcode::Store, &[], None);
        assert!(result.is_some(), "SME2 should match strided store");
    }
}