// Copyright 2022 Google LLC
//
// This source code is licensed under the BSD-style license found in the
// LICENSE file in the root directory of this source tree.

#include <xnnpack/assembly.h>

# void xnn_f16_igemm_minmax_ukernel_4x16__aarch64_neonfp16arith_ld32(
#     size_t mr,                         x0
#     size_t nc,                         x1
#     size_t kc,                         x2 / x0
#     size_t ks,                         x3 / x9
#     const void**restrict a,            x4
#     const void*restrict w,             x5
#     void*restrict c,                   x6
#     size_t cm_stride,                  x7
#     size_t cn_stride,                  [sp] -> x10
#     size_t a_offset,                   [sp + 8] -> x11
#     const void* zero,                  [sp + 16] -> x12
#     const xnn_f16_minmax_params params [sp + 24] -> (x8)

# d8-d15, x19-x30 need to be preserved if used. x18 is reserved by the OS.

# Register usage
# A0  x8 v0
# A1 x13 v1
# A2 x14 v2
# A3 x15 v3

# B   x5 v20 v21 v22 v23

# C0  x6 v24 v25
# C1 x16 v26 v27
# C2 x17 v28 v29
# C3  x7 v30 v31

# Clamp v4, v5

BEGIN_FUNCTION xnn_f16_igemm_minmax_ukernel_4x16__aarch64_neonfp16arith_ld32

        # Load cn_stride, a_offset
        LDP     x10, x11, [sp]

        # Load zero, params pointer
        LDP     x12, x8, [sp, 16]

        # Load params values
        LD2R    {v4.8h, v5.8h}, [x8]

        # Clamp C pointers
        CMP     x0, 2                   // if mr < 2
        ADD     x16, x6, x7             // c1 = c0 + cm_stride
        CSEL    x16, x6, x16, LO        //   c1 = c0
        ADD     x17, x16, x7            // c2 = c1 + cm_stride
                                        // if mr <= 2
        CSEL    x17, x16, x17, LS       //   c2 = c1
        CMP     x0, 4                   // if mr < 4
        ADD     x7, x17, x7             // c3 = c2 + cm_stride
        CSEL    x7, x17, x7, LO         //   c3 = c2

0:
        # Load initial bias from w into accumulators
        LDR     q24, [x5], 16
        LDR     q25, [x5], 16
        MOV     v26.16b, v24.16b
        MOV     v28.16b, v24.16b
        MOV     v30.16b, v24.16b
        MOV     v27.16b, v25.16b
        MOV     v29.16b, v25.16b
        MOV     v31.16b, v25.16b

        MOV     x9, x3                  // p = ks

1:
        # Load next 4 A pointers
        LDP     x8, x13, [x4], 16
        LDP     x14, x15, [x4], 16

        CMP     x8, x12                 // if a0 == zero
        ADD     x8, x8, x11             // a0 += a_offset
        CSEL    x8, x12, x8, EQ         //   a0 = zero, else += a0 + a_offset
        CMP     x13, x12                // if a1 == zero
        ADD     x13, x13, x11           // a1 += a_offset
        CSEL    x13, x12, x13, EQ       //   a1 = zero, else += a1 + a_offset
        CMP     x14, x12                // if a2 == zero
        ADD     x14, x14, x11           // a2 += a_offset
        CSEL    x14, x12, x14, EQ       //   a2 = zero, else += a2 + a_offset
        CMP     x15, x12                // if a3 == zero
        ADD     x15, x15, x11           // a3 += a_offset
        CSEL    x15, x12, x15, EQ       //   a3 = zero, else += a3 + a_offset

        # Is there at least 2 halffloats (4 bytes)?
        SUBS    x0, x2, 4               // k = kc - 4
        B.LO    4f

       .p2align 3
        # Main loop - 2 halffloats of A (4 bytes)
2:
        LDR     s0,  [x8], 4
        LDR     q20, [x5], 16
        LDR     q21, [x5], 16
        LDR     s1, [x13], 4
        LDR     s2, [x14], 4
        LDR     s3, [x15], 4
        LDR     q22, [x5], 16
        LDR     q23, [x5], 16
        SUBS    x0, x0, 4
        FMLA    v24.8h, v20.8h, v0.h[0]
        FMLA    v25.8h, v21.8h, v0.h[0]
        FMLA    v26.8h, v20.8h, v1.h[0]
        FMLA    v27.8h, v21.8h, v1.h[0]
        FMLA    v28.8h, v20.8h, v2.h[0]
        FMLA    v29.8h, v21.8h, v2.h[0]
        FMLA    v30.8h, v20.8h, v3.h[0]
        FMLA    v31.8h, v21.8h, v3.h[0]

        FMLA    v24.8h, v22.8h, v0.h[1]
        FMLA    v25.8h, v23.8h, v0.h[1]
        FMLA    v26.8h, v22.8h, v1.h[1]
        FMLA    v27.8h, v23.8h, v1.h[1]
        FMLA    v28.8h, v22.8h, v2.h[1]
        FMLA    v29.8h, v23.8h, v2.h[1]
        FMLA    v30.8h, v22.8h, v3.h[1]
        FMLA    v31.8h, v23.8h, v3.h[1]
        B.HS    2b

        # Is there a remainder?- 1 halffloat of A (2 bytes)
        TBNZ    x0, 1, 4f

3:
        # ks loop
        SUBS    x9, x9, 32              // ks -= MR * sizeof(void*)
        B.HI    1b

        # Clamp
        FMAX    v24.8h, v24.8h, v4.8h
        FMAX    v25.8h, v25.8h, v4.8h
        FMAX    v26.8h, v26.8h, v4.8h
        FMAX    v27.8h, v27.8h, v4.8h
        FMAX    v28.8h, v28.8h, v4.8h
        FMAX    v29.8h, v29.8h, v4.8h
        FMAX    v30.8h, v30.8h, v4.8h
        FMAX    v31.8h, v31.8h, v4.8h
        FMIN    v24.8h, v24.8h, v5.8h
        FMIN    v25.8h, v25.8h, v5.8h
        FMIN    v26.8h, v26.8h, v5.8h
        FMIN    v27.8h, v27.8h, v5.8h
        FMIN    v28.8h, v28.8h, v5.8h
        FMIN    v29.8h, v29.8h, v5.8h
        FMIN    v30.8h, v30.8h, v5.8h
        FMIN    v31.8h, v31.8h, v5.8h

        # Store full 4 x 16
        SUBS    x1, x1, 16
        B.LO    5f

        STP     q30, q31,  [x7]
        ADD     x7,  x7, x10
        STP     q28, q29, [x17]
        ADD     x17, x17, x10
        STP     q26, q27, [x16]
        ADD     x16, x16, x10
        STP     q24, q25,  [x6]
        ADD     x6,  x6, x10

        SUB     x4, x4, x3              // a -= ks

        # nc loop
        B.HI    0b
        RET

        # Remainder- 1 halffloat of A
4:
        LDR     h0, [x8], 2
        LDR     q20, [x5], 16
        LDR     q21, [x5], 16
        LDR     h1, [x13], 2
        LDR     h2, [x14], 2
        LDR     h3, [x15], 2
        FMLA    v24.8h, v20.8h, v0.h[0]
        FMLA    v25.8h, v21.8h, v0.h[0]
        FMLA    v26.8h, v20.8h, v1.h[0]
        FMLA    v27.8h, v21.8h, v1.h[0]
        FMLA    v28.8h, v20.8h, v2.h[0]
        FMLA    v29.8h, v21.8h, v2.h[0]
        FMLA    v30.8h, v20.8h, v3.h[0]
        FMLA    v31.8h, v21.8h, v3.h[0]
        B       3b

        # Store odd width
5:
        TBZ     x1, 3, 6f
        STR     q30, [x7], 16
        MOV     v30.16b, v31.16b
        STR     q28, [x17], 16
        MOV     v28.16b, v29.16b
        STR     q26, [x16], 16
        MOV     v26.16b, v27.16b
        STR     q24, [x6], 16
        MOV     v24.16b, v25.16b

6:
        TBZ     x1, 2, 7f
        STR     d30, [x7], 8
        STR     d28, [x17], 8
        DUP     d30, v30.d[1]
        DUP     d28, v28.d[1]
        STR     d26, [x16], 8
        STR     d24, [x6], 8
        DUP     d26, v26.d[1]
        DUP     d24, v24.d[1]

7:
        TBZ     x1, 1, 8f
        STR     s30,  [x7], 4
        STR     s28, [x17], 4
        DUP     s30, v30.s[1]
        DUP     s28, v28.s[1]
        STR     s26, [x16], 4
        STR     s24,  [x6], 4
        DUP     s26, v26.s[1]
        DUP     s24, v24.s[1]
8:
        TBZ     x1, 0, 9f
        STR     h30,  [x7]
        STR     h28, [x17]
        STR     h26, [x16]
        STR     h24,  [x6]
9:
        RET

END_FUNCTION xnn_f16_igemm_minmax_ukernel_4x16__aarch64_neonfp16arith_ld32

#ifdef __ELF__
.section ".note.GNU-stack","",%progbits
#endif