// Copyright 2020 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_gemm${"inc" if INC else ""}_minmax_ukernel_4x16__aarch64_neonfp16arith_ld64(
#     size_t mr,                x0
#     size_t nc,                x1
#     size_t kc,                x2 / x0
#     const void*restrict a,    x3
#     size_t a_stride,          x4
#     const void*restrict w,    x5
#     void*restrict c,          x6
#     size_t cm_stride,         x7
#     size_t cn_stride,         [sp] -> x14
$if INC:
  #     const float*restrict acc,  [sp + 8] -> x15
  #     const union xnn_f16_minmax_params params[restrict XNN_MIN_ELEMENTS(1)])  [sp + 16] -> (x8)
$else:
  #     const union xnn_f16_minmax_params params[restrict XNN_MIN_ELEMENTS(1)])  [sp + 8] -> (x8)

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

# Register usage
# A0  x3 v0
# A1 x11 v1
# A2 x12 v2
# A3  x4 v3

# B   x5 v20 v21 v22 v23 v16 v17 v18 v19

# C0  x6 v24 v25
# C1  x9 v26 v27
# C2 x10 v28 v29
# C3  x7 v30 v31

# Clamp v4, v5

BEGIN_FUNCTION xnn_f16_gemm${"inc" if INC else ""}_minmax_ukernel_4x16__aarch64_neonfp16arith_ld64

        $if INC:
          # Load cn_stride, acc
          LDP     x14, x15, [sp]
          # Load params pointer
          LDR     x8, [sp, 16]
        $else:
          # Load cn_stride, params pointer
          LDP     x14, x8, [sp]

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

        # Clamp A and C pointers
        CMP     x0, 2                   // if mr < 2
        ADD     x11, x3, x4             // a1 = a0 + a_stride
        ADD     x9, x6, x7              // c1 = c0 + cm_stride
        CSEL    x11, x3, x11, LO        //   a1 = a0
        CSEL    x9, x6, x9, LO          //   c1 = c0

        ADD     x12, x11, x4            // a2 = a1 + a_stride
        ADD     x10, x9, x7             // c2 = c1 + cm_stride
                                        // if mr <= 2
        CSEL    x12, x11, x12, LS       //   a2 = a1
        CSEL    x10, x9, x10, LS        //   c2 = c1

        CMP     x0, 4                   // if mr < 4
        ADD     x4, x12, x4             // a3 = a2 + a_stride
        ADD     x7, x10, x7             // c3 = c2 + cm_stride
        CSEL    x4, x12, x4, LO         //   a3 = a2
        CSEL    x7, x10, x7, LO         //   c3 = c2

0:
        $if INC:
          # Load initial accumulators
          LDP     q24, q25, [x15], 32
          LDP     q26, q27, [x15], 32
          LDP     q28, q29, [x15], 32
          LDP     q30, q31, [x15], 32
        $else:
          # 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

        # Is there at least 2 halffloats (4 bytes)?
        SUBS    x0, x2, 8               // k = kc - 8
        B.LO    3f

       .p2align 3
        # Main loop - 4 halffloats of A (8 bytes)
1:
        LDR     d0,  [x3], 8
        LDR     q20, [x5], 16
        LDR     q21, [x5], 16
        LDR     d1, [x11], 8
        LDR     d2, [x12], 8
        LDR     d3,  [x4], 8
        LDR     q22, [x5], 16
        LDR     q23, [x5], 16
        LDR     q16, [x5], 16
        LDR     q17, [x5], 16
        LDR     q18, [x5], 16
        LDR     q19, [x5], 16
        SUBS    x0, x0, 8
        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]

        FMLA    v24.8h, v16.8h, v0.h[2]
        FMLA    v25.8h, v17.8h, v0.h[2]
        FMLA    v26.8h, v16.8h, v1.h[2]
        FMLA    v27.8h, v17.8h, v1.h[2]
        FMLA    v28.8h, v16.8h, v2.h[2]
        FMLA    v29.8h, v17.8h, v2.h[2]
        FMLA    v30.8h, v16.8h, v3.h[2]
        FMLA    v31.8h, v17.8h, v3.h[2]
        FMLA    v24.8h, v18.8h, v0.h[3]
        FMLA    v25.8h, v19.8h, v0.h[3]
        FMLA    v26.8h, v18.8h, v1.h[3]
        FMLA    v27.8h, v19.8h, v1.h[3]
        FMLA    v28.8h, v18.8h, v2.h[3]
        FMLA    v29.8h, v19.8h, v2.h[3]
        FMLA    v30.8h, v18.8h, v3.h[3]
        FMLA    v31.8h, v19.8h, v3.h[3]
        B.HS    1b

        # Is there a remainder- 1 to 3 halffloats of A (2 to 6 bytes)
        ANDS    x0, x0, 7
        B.NE    3f

2:
        # Clamp
        FMAX    v24.8h, v24.8h, v4.8h
        SUBS    x1, x1, 16
        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
        B.LO    5f

        $if INC:
          ST1     {v30.16b, v31.16b},  [x7], x14
          SUB     x3,  x3, x2             // a0 -= kc
          ST1     {v28.16b, v29.16b}, [x10], x14
          SUB     x11, x11, x2            // a1 -= kc
          ST1     {v26.16b, v27.16b},  [x9], x14
          SUB     x12, x12, x2            // a2 -= kc
          ST1     {v24.16b, v25.16b},  [x6], x14
          SUB     x4,  x4, x2             // a3 -= kc
        $else:
          ST1     {v24.16b, v25.16b},  [x6], x14
          SUB     x3,  x3, x2             // a0 -= kc
          ST1     {v26.16b, v27.16b},  [x9], x14
          SUB     x11, x11, x2            // a1 -= kc
          ST1     {v28.16b, v29.16b}, [x10], x14
          SUB     x12, x12, x2            // a2 -= kc
          ST1     {v30.16b, v31.16b},  [x7], x14
          SUB     x4,  x4, x2             // a3 -= kc

        B.HI    0b

        RET

        # Remainder- 1 to 3 halffloats of A (2 to 6 bytes)
3:
        TBZ     x0, 2, 4f
        LDR     s0,  [x3], 4
        LDR     q20, [x5], 16
        LDR     q21, [x5], 16
        LDR     s1, [x11], 4
        LDR     s2, [x12], 4
        LDR     s3,  [x4], 4
        LDR     q22, [x5], 16
        LDR     q23, [x5], 16
        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]
        TBZ     x0, 1, 2b

4:
        LDR     h0,  [x3], 2
        LDR     q20, [x5], 16
        LDR     q21, [x5], 16
        LDR     h1, [x11], 2
        LDR     h2, [x12], 2
        LDR     h3,  [x4], 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       2b


        # Store odd width
5:
        TBZ     x1, 3, 6f
        $if INC:
          STR     q30, [x7], 16
          MOV     v30.16b, v31.16b
          STR     q28, [x10], 16
          MOV     v28.16b, v29.16b
          STR     q26, [x9], 16
          MOV     v26.16b, v27.16b
          STR     q24, [x6], 16
          MOV     v24.16b, v25.16b
        $else:
          STR     q24, [x6], 16
          MOV     v24.16b, v25.16b
          STR     q26, [x9], 16
          MOV     v26.16b, v27.16b
          STR     q28, [x10], 16
          MOV     v28.16b, v29.16b
          STR     q30, [x7], 16
          MOV     v30.16b, v31.16b

6:
        TBZ     x1, 2, 7f
        $if INC:
          STR     d30, [x7], 8
          STR     d28, [x10], 8
          DUP     d30, v30.d[1]
          DUP     d28, v28.d[1]
          STR     d26, [x9], 8
          STR     d24, [x6], 8
          DUP     d26, v26.d[1]
          DUP     d24, v24.d[1]
        $else:
          STR     d24, [x6], 8
          STR     d26, [x9], 8
          DUP     d24, v24.d[1]
          DUP     d26, v26.d[1]
          STR     d28, [x10], 8
          STR     d30, [x7], 8
          DUP     d28, v28.d[1]
          DUP     d30, v30.d[1]

7:
        TBZ     x1, 1, 8f
        $if INC:
          STR     s30,  [x7], 4
          STR     s28, [x10], 4
          DUP     s30, v30.s[1]
          DUP     s28, v28.s[1]
          STR     s26,  [x9], 4
          STR     s24,  [x6], 4
          DUP     s26, v26.s[1]
          DUP     s24, v24.s[1]
        $else:
          STR     s24,  [x6], 4
          STR     s26,  [x9], 4
          DUP     s24, v24.s[1]
          DUP     s26, v26.s[1]
          STR     s28, [x10], 4
          STR     s30,  [x7], 4
          DUP     s28, v28.s[1]
          DUP     s30, v30.s[1]

8:
        TBZ     x1, 0, 9f
        $if INC:
          STR     h30,  [x7]
          STR     h28, [x10]
          STR     h26,  [x9]
          STR     h24,  [x6]
        $else:
          STR     h24,  [x6]
          STR     h26,  [x9]
          STR     h28, [x10]
          STR     h30,  [x7]
9:
        RET

END_FUNCTION xnn_f16_gemm${"inc" if INC else ""}_minmax_ukernel_4x16__aarch64_neonfp16arith_ld64

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