//
// x86-64 AVX2 stub: clamp-kernel-v1
// Clamp kernel — saturating bound
// Equation clamp: y_i = min(max(x_i, lo), hi)
//

.intel_syntax noprefix
.text
.globl clamp_avx2
.p2align 4

clamp_avx2:
    push rbp
    mov rbp, rsp
    // rdi = input ptr, rsi = output ptr, edx = n

    // AVX2 registers: ymm x 16
    vxorps ymm0, ymm0, ymm0
    vxorps ymm1, ymm1, ymm1
    vxorps ymm2, ymm2, ymm2
    vxorps ymm3, ymm3, ymm3

    // Phase 1: compare_lo
    // Clamp below by lo
    // Invariant: tmp_i = max(x_i, lo)

    // Phase 2: compare_hi
    // Clamp above by hi
    // Invariant: y_i = min(tmp_i, hi)

    // Phase 3: store
    // Write result
    // Invariant: lo ≤ y_i ≤ hi

    // Proof obligations:
    //   [bound] Output in [lo, hi]
    //   [monotonicity] Order preservation
    //   [idempotency] Idempotent application
    //   [equivalence] SIMD matches scalar

    pop rbp
    ret
