// Copyright 2019 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_f32_gemm${"inc" if INC else ""}_ukernel_6x8__aarch64_neonfma_ld64(
#     size_t mr,                x0
#     size_t nc,                x1
#     size_t kc,                x2 / x0
#     const uint8_t*restrict a, x3
#     size_t a_stride,          x4
#     const void*restrict w,    x5
#     uint8_t*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_f32_output_params params[restrict static 1])  [sp + 16] -> x8
$else:
  #     const union xnn_f32_output_params params[restrict static 1])  [sp + 8] -> x8

# d8-d15 need to be preserved if used.
# x19-30 need to be preserved if used.

# A pointers
#  x3 a0
#  x9 a1
# x10 a2
# x11 a3
# x12 a4
#  x4 a5

# C pointers
#  x6 c0
# x16 c1
# x17 c2
# x18 c3
# x13 c4
#  x7 c5

# Vector register usage
# A0   v0
# A1   v1
# A2   v2
# A3   v3
# A4   v4
# A5   v5
# B   v16 v17 v18 v19
# C   v20 v21
# C   v22 v23
# C   v24 v25
# C   v26 v27
# C   v28 v29
# C   v30 v31
# Clamp v6 v7
# unused A   v8 v9 v10 v11
# unused B   v12 v13 v14 v15

BEGIN_FUNCTION xnn_f32_gemm${"inc" if INC else ""}_ukernel_6x8__aarch64_neonfma_ld64

        # Clamp A and C pointers
        CMP x0, 2                // if mr < 2
        ADD x9, x3, x4           // a1 = a0 + a_stride
        ADD x16, x6, x7          // c1 = c0 + cm_stride
        CSEL x9, x3, x9, LO      //   a1 = a0
        CSEL x16, x6, x16, LO    //   c1 = c0

        ADD x10, x9, x4          // a2 = a1 + a_stride
        ADD x17, x16, x7         // c2 = c1 + cm_stride
                                 // if mr <= 2
        CSEL x10, x9, x10, LS    //   a2 = a1
        CSEL x17, x16, x17, LS   //   c2 = c1

        CMP x0, 4                // if mr < 4
        ADD x11, x10, x4         // a3 = a2 + a_stride
        ADD x18, x17, x7         // c3 = c2 + cm_stride
        CSEL x11, x10, x11, LO   //   a3 = a2
        CSEL x18, x17, x18, LO   //   c3 = c2

        ADD x12, x11, x4         // a4 = a3 + a_stride
        ADD x13, x18, x7         // c4 = c3 + cm_stride
                                 // if mr <= 5
        CSEL x12, x11, x12, LS   //   a4 = a3
        CSEL x13, x18, x13, LS   //   c4 = c3

        $if INC:
          # Load acc, params pointer
          LDP x15, x8, [sp, 8]
        $else:
          # Load params pointer
          LDR x8, [sp, 8]

        CMP x0, 6                // if mr < 6
        ADD x4, x12, x4          // a5 = a4 + a_stride
        ADD x7, x13, x7          // c5 = c4 + cm_stride
        CSEL x4, x12, x4, LO     //   a5 = a4
        CSEL x7, x13, x7, LO     //   c5 = c4

        # Load clamping_params values
        LD2R {v6.4s, v7.4s}, [x8]

        # Load cn_stride
        LDR x14, [sp]

0:
        $if INC:
          # Load initial accumulators
          LDP q20, q21, [x15], 32
          LDP q22, q23, [x15], 32
          LDP q24, q25, [x15], 32
          LDP q26, q27, [x15], 32
          LDP q28, q29, [x15], 32
          LDP q30, q31, [x15], 32
          PRFM PLDL1KEEP, [x5, 0]  // Prefetch B
          PRFM PLDL1KEEP, [x5, 64]
          PRFM PLDL1KEEP, [x5, 128]
          PRFM PLDL1KEEP, [x5, 192]
          PRFM PLDL1KEEP,  [x3]    // Prefetch A
          PRFM PLDL1KEEP,  [x9]
          PRFM PLDL1KEEP, [x10]
          PRFM PLDL1KEEP, [x11]
          PRFM PLDL1KEEP, [x12]
          PRFM PLDL1KEEP,  [x4]
        $else:
          # Load initial bias from w into accumulators
          LDP q20, q21, [x5], 32
          MOV v22.16b, v20.16b
          PRFM PLDL1KEEP, [x5, 0]  // Prefetch B
          MOV v23.16b, v21.16b
          PRFM PLDL1KEEP, [x5, 64]
          MOV v24.16b, v20.16b
          PRFM PLDL1KEEP, [x5, 128]
          MOV v25.16b, v21.16b
          PRFM PLDL1KEEP, [x5, 192]
          MOV v26.16b, v20.16b
          PRFM PLDL1KEEP,  [x3]    // Prefetch A
          MOV v27.16b, v21.16b
          PRFM PLDL1KEEP,  [x9]
          MOV v28.16b, v20.16b
          PRFM PLDL1KEEP, [x10]
          MOV v29.16b, v21.16b
          PRFM PLDL1KEEP, [x11]
          MOV v30.16b, v20.16b
          PRFM PLDL1KEEP, [x12]
          MOV v31.16b, v21.16b
          PRFM PLDL1KEEP,  [x4]

        # Is there at least 2 floats (8 bytes) for main loop?
        SUBS x0, x2, 8  // k = kc - 8
        B.LO 2f

        # Main loop - 2 floats of A (8 bytes)
        # 24 FMA + 6 LD64 A + 2 LDP B
1:
        LDR   d0,  [x3], 8
        LDP  q16,  q17, [x5], 32
        LDR   d1,  [x9], 8
        LDR   d2, [x10], 8
        LDR   d3, [x11], 8
        LDR   d4, [x12], 8
        LDR   d5,  [x4], 8
        FMLA v20.4s, v16.4s,  v0.s[0]
        FMLA v22.4s, v16.4s,  v1.s[0]
        FMLA v24.4s, v16.4s,  v2.s[0]
        FMLA v26.4s, v16.4s,  v3.s[0]
        LDP  q18,  q19, [x5], 32
        FMLA v28.4s, v16.4s,  v4.s[0]
        FMLA v30.4s, v16.4s,  v5.s[0]
        FMLA v21.4s, v17.4s,  v0.s[0]
        FMLA v23.4s, v17.4s,  v1.s[0]
        FMLA v25.4s, v17.4s,  v2.s[0]
        FMLA v27.4s, v17.4s,  v3.s[0]
        FMLA v29.4s, v17.4s,  v4.s[0]
        FMLA v31.4s, v17.4s,  v5.s[0]

        FMLA v20.4s, v18.4s,  v0.s[1]
        FMLA v22.4s, v18.4s,  v1.s[1]
        FMLA v24.4s, v18.4s,  v2.s[1]
        FMLA v26.4s, v18.4s,  v3.s[1]
        FMLA v28.4s, v18.4s,  v4.s[1]
        FMLA v30.4s, v18.4s,  v5.s[1]
        FMLA v21.4s, v19.4s,  v0.s[1]
        FMLA v23.4s, v19.4s,  v1.s[1]
        FMLA v25.4s, v19.4s,  v2.s[1]
        FMLA v27.4s, v19.4s,  v3.s[1]
        SUBS x0, x0, 8
        FMLA v29.4s, v19.4s,  v4.s[1]
        FMLA v31.4s, v19.4s,  v5.s[1]
        B.HS 1b

2:
        # Is there a remainder?- 1 floats of A (4 bytes)
        TBNZ x0, 2, 4f
3:
        # Clamp
        FMIN v20.4s, v20.4s, v6.4s
        FMIN v21.4s, v21.4s, v6.4s
        FMIN v22.4s, v22.4s, v6.4s
        FMIN v23.4s, v23.4s, v6.4s
        FMIN v24.4s, v24.4s, v6.4s
        FMIN v25.4s, v25.4s, v6.4s
        FMIN v26.4s, v26.4s, v6.4s
        FMIN v27.4s, v27.4s, v6.4s
        FMIN v28.4s, v28.4s, v6.4s
        FMIN v29.4s, v29.4s, v6.4s
        FMIN v30.4s, v30.4s, v6.4s
        FMIN v31.4s, v31.4s, v6.4s
        FMAX v20.4s, v20.4s, v7.4s
        FMAX v21.4s, v21.4s, v7.4s
        FMAX v22.4s, v22.4s, v7.4s
        FMAX v23.4s, v23.4s, v7.4s
        FMAX v24.4s, v24.4s, v7.4s
        FMAX v25.4s, v25.4s, v7.4s
        FMAX v26.4s, v26.4s, v7.4s
        FMAX v27.4s, v27.4s, v7.4s
        FMAX v28.4s, v28.4s, v7.4s
        FMAX v29.4s, v29.4s, v7.4s
        FMAX v30.4s, v30.4s, v7.4s
        FMAX v31.4s, v31.4s, v7.4s

        # Store full 6 x 8
        CMP x1, 8
        B.LO 5f

        $if INC:
          ST1 {v30.16b, v31.16b},  [x7], x14
          SUB  x3,  x3, x2 // a0 -= kc
          ST1 {v28.16b, v29.16b}, [x13], x14
          SUB  x9,  x9, x2 // a1 -= kc
          ST1 {v26.16b, v27.16b}, [x18], x14
          SUB x10, x10, x2 // a2 -= kc
          ST1 {v24.16b, v25.16b}, [x17], x14
          SUB x11, x11, x2 // a3 -= kc
          ST1 {v22.16b, v23.16b}, [x16], x14
          SUB x12, x12, x2 // a4 -= kc
          ST1 {v20.16b, v21.16b},  [x6], x14
          SUB  x4,  x4, x2 // a5 -= kc
        $else:
          ST1 {v20.16b, v21.16b},  [x6], x14
          SUB  x3,  x3, x2 // a0 -= kc
          ST1 {v22.16b, v23.16b}, [x16], x14
          SUB  x9,  x9, x2 // a1 -= kc
          ST1 {v24.16b, v25.16b}, [x17], x14
          SUB x10, x10, x2 // a2 -= kc
          ST1 {v26.16b, v27.16b}, [x18], x14
          SUB x11, x11, x2 // a3 -= kc
          ST1 {v28.16b, v29.16b}, [x13], x14
          SUB x12, x12, x2 // a4 -= kc
          ST1 {v30.16b, v31.16b},  [x7], x14
          SUB  x4,  x4, x2 // a5 -= kc

        SUBS x1, x1, 8
        B.HI 0b

        RET

4:
        # Remainder- 1 floats of A (4 bytes)
        LDR   s0,  [x3], 4
        LDP  q16,  q17, [x5], 32
        LDR   s1,  [x9], 4
        LDR   s2, [x10], 4
        LDR   s3, [x11], 4
        LDR   s4, [x12], 4
        LDR   s5,  [x4], 4
        FMLA v20.4s, v16.4s,  v0.s[0]
        FMLA v22.4s, v16.4s,  v1.s[0]
        FMLA v24.4s, v16.4s,  v2.s[0]
        FMLA v26.4s, v16.4s,  v3.s[0]
        FMLA v28.4s, v16.4s,  v4.s[0]
        FMLA v30.4s, v16.4s,  v5.s[0]
        FMLA v21.4s, v17.4s,  v0.s[0]
        FMLA v23.4s, v17.4s,  v1.s[0]
        FMLA v25.4s, v17.4s,  v2.s[0]
        FMLA v27.4s, v17.4s,  v3.s[0]
        FMLA v29.4s, v17.4s,  v4.s[0]
        FMLA v31.4s, v17.4s,  v5.s[0]
        B 3b

        # Store odd width
5:
        TBZ x1, 2, 6f
        $if INC:
          STR q30,  [x7], 16
          MOV v30.16b, v31.16b
          STR q28, [x13], 16
          MOV v28.16b, v29.16b
          STR q26, [x18], 16
          MOV v26.16b, v27.16b
          STR q24, [x17], 16
          MOV v24.16b, v25.16b
          STR q22, [x16], 16
          MOV v22.16b, v23.16b
          STR q20,  [x6], 16
          MOV v20.16b, v21.16b
        $else:
          STR q20,  [x6], 16
          MOV v20.16b, v21.16b
          STR q22, [x16], 16
          MOV v22.16b, v23.16b
          STR q24, [x17], 16
          MOV v24.16b, v25.16b
          STR q26, [x18], 16
          MOV v26.16b, v27.16b
          STR q28, [x13], 16
          MOV v28.16b, v29.16b
          STR q30,  [x7], 16
          MOV v30.16b, v31.16b

6:
        TBZ x1, 1, 7f
        $if INC:
          STR d30,  [x7], 8
          DUP d30, v30.d[1]
          STR d28, [x13], 8
          DUP d28, v28.d[1]
          STR d26, [x18], 8
          DUP d26, v26.d[1]
          STR d24, [x17], 8
          DUP d24, v24.d[1]
          STR d22, [x16], 8
          DUP d22, v22.d[1]
          STR d20,  [x6], 8
          DUP d20, v20.d[1]
        $else:
          STR d20,  [x6], 8
          DUP d20, v20.d[1]
          STR d22, [x16], 8
          DUP d22, v22.d[1]
          STR d24, [x17], 8
          DUP d24, v24.d[1]
          STR d26, [x18], 8
          DUP d26, v26.d[1]
          STR d28, [x13], 8
          DUP d28, v28.d[1]
          STR d30,  [x7], 8
          DUP d30, v30.d[1]

7:
        TBZ x1, 0, 8f
        $if INC:
          STR s30,  [x7]
          STR s28, [x13]
          STR s26, [x18]
          STR s24, [x17]
          STR s22, [x16]
          STR s20,  [x6]
        $else:
          STR s20,  [x6]
          STR s22, [x16]
          STR s24, [x17]
          STR s26, [x18]
          STR s28, [x13]
          STR s30,  [x7]
8:
        RET

END_FUNCTION xnn_f32_gemm${"inc" if INC else ""}_ukernel_6x8__aarch64_neonfma__ld64

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