/*
 * Copyright (c) 2017-2018 ARM Limited.
 *
 * SPDX-License-Identifier: MIT
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to
 * deal in the Software without restriction, including without limitation the
 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
 * sell copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */
#if defined(__aarch64__) && defined(__ARM_FEATURE_FP16_SCALAR_ARITHMETIC)

#include <arm_neon.h>

#include "../../asmlib.hpp"

// Kernel implementation.
//
// Assume that "Apanel" points to a chunk of A blocks (each size 8xK) in read-order.
// Assume that "Bpanel" points to a chunk of B blocks (each size 12xK) in read-order.
// Assume that "Cpanel" points to a chunk of C output blocks (each size
// 12x8), the chunks being arranged in a row major fashion.
//
// Note that the intent of this is that either ablocks or bblocks will be 1
// - this construction allows the output loop to proceed in either order.

namespace arm_gemm
{
void a64_hgemm_asimd_24x8(const __fp16 *Apanel, const __fp16 *Bpanel, __fp16 *Cpanel, int ablocks, int bblocks, int K)
{
    const __fp16 *a_ptr = Apanel;
    __fp16       *c_ptr = Cpanel;

    for(int yb = 0; yb < ablocks; yb++)
    {
        const __fp16 *a_ptr0 = a_ptr;
        const __fp16 *b_ptr  = Bpanel;

        for(int xb = 0; xb < bblocks; xb++)
        {
            a_ptr = a_ptr0;
            // Fix up for odd lengths - set a flag if K is odd, but make
            // sure we round up the iteration count.
            int oddk = (K & 1);
            int k    = ((K + 1) / 2) - 1;

            register float16x8_t a0 asm("v0");
            register float16x8_t a0a asm("v1");
            register float16x8_t b0 asm("v2");
            register float16x8_t b1 asm("v3");
            register float16x8_t b2 asm("v4");
            register float16x8_t b0a asm("v5");
            register float16x8_t b1a asm("v6");
            register float16x8_t b2a asm("v7");

            __asm __volatile(
                ".arch    armv8.2-a+fp16\n"
                // Initialize result registers, load initial operands, prime prefetches.
                "movi    v8.8h, #0x0\n"
                "ldr    %q[a0], [%[a_ptr]]\n"
                "movi    v9.8h, #0x0\n"
                "ldr    %q[b0], [%[b_ptr]]\n"
                "movi    v10.8h, #0x0\n"
                "ldr    %q[b1], [%[b_ptr], #16]\n"
                "movi    v11.8h, #0x0\n"
                "ldr    %q[b2], [%[b_ptr], #32]\n"
                "movi    v12.8h, #0x0\n"
                "ldr    %q[b0a], [%[b_ptr], #48]\n"
                "movi    v13.8h, #0x0\n"
                "ldr    %q[b1a], [%[b_ptr], #64]\n"
                "movi    v14.8h, #0x0\n" ASM_PREFETCH("[%[b_ptr], #64]") "movi    v15.8h, #0x0\n" ASM_PREFETCH("[%[b_ptr], #128]") "movi    v16.8h, #0x0\n" ASM_PREFETCH("[%[a_ptr], #64]") "movi    v17.8h, #0x0\n"
                ASM_PREFETCH("[%[b_ptr], #192]") "movi    v18.8h, #0x0\n" ASM_PREFETCH("[%[b_ptr], #256]") "movi    v19.8h, #0x0\n" ASM_PREFETCH("[%[b_ptr], #320]")
                "movi    v20.8h, #0x0\n"
                "movi    v21.8h, #0x0\n"
                "movi    v22.8h, #0x0\n"
                "movi    v23.8h, #0x0\n"
                "movi    v24.8h, #0x0\n"
                "movi    v25.8h, #0x0\n"
                "movi    v26.8h, #0x0\n"
                "movi    v27.8h, #0x0\n"
                "movi    v28.8h, #0x0\n"
                "movi    v29.8h, #0x0\n"
                "movi    v30.8h, #0x0\n"
                "movi    v31.8h, #0x0\n"

                // Skip loop if we are doing zero iterations of it.
                "cbz    %w[k], 4f\n"

                "1:\n"
                "fmla     v8.8h , %[b0].8h, %[a0].h[0]\n"
                "fmla      v9.8h , %[b0].8h, %[a0].h[1]\n"
                "ldr    %q[a0a], [%[a_ptr], #16]\n"
                "fmla    v10.8h, %[b0].8h, %[a0].h[2]\n"
                "fmla    v11.8h, %[b0].8h, %[a0].h[3]\n"
                "ldr    %q[b2a], [%[b_ptr], #80]\n"
                "fmla     v12.8h, %[b0].8h, %[a0].h[4]\n"
                "fmla    v13.8h, %[b0].8h, %[a0].h[5]\n"
                "fmla    v14.8h, %[b0].8h, %[a0].h[6]\n"
                "fmla    v15.8h, %[b0].8h, %[a0].h[7]\n"
                "ldr    %q[b0], [%[b_ptr], #96]\n"

                "fmla    v16.8h, %[b1].8h, %[a0].h[0]\n"
                "fmla    v17.8h, %[b1].8h, %[a0].h[1]\n" ASM_PREFETCH("[%[a_ptr], #128]")
                "fmla    v18.8h, %[b1].8h, %[a0].h[2]\n"
                "fmla    v19.8h, %[b1].8h, %[a0].h[3]\n"
                "add    %[b_ptr], %[b_ptr], #96\n"
                "fmla    v20.8h, %[b1].8h, %[a0].h[4]\n"
                "fmla    v21.8h, %[b1].8h, %[a0].h[5]\n"
                "fmla    v22.8h, %[b1].8h, %[a0].h[6]\n"
                "fmla    v23.8h, %[b1].8h, %[a0].h[7]\n"
                "ldr    %q[b1], [%[b_ptr], #16]\n"

                "fmla    v24.8h, %[b2].8h, %[a0].h[0]\n"
                "fmla    v25.8h, %[b2].8h, %[a0].h[1]\n" ASM_PREFETCH("[%[b_ptr], #288]")
                "fmla    v26.8h, %[b2].8h, %[a0].h[2]\n"
                "fmla    v27.8h, %[b2].8h, %[a0].h[3]\n"
                "fmla    v28.8h, %[b2].8h, %[a0].h[4]\n"
                "fmla    v29.8h, %[b2].8h, %[a0].h[5]\n"
                "fmla    v30.8h, %[b2].8h, %[a0].h[6]\n"
                "fmla    v31.8h, %[b2].8h, %[a0].h[7]\n"
                "ldr    %q[a0], [%[a_ptr], #32]\n"

                "fmla     v8.8h , %[b0a].8h, %[a0a].h[0]\n"
                "fmla    v9.8h , %[b0a].8h, %[a0a].h[1]\n"
                "ldr    %q[b2], [%[b_ptr], #32]\n"
                "fmla    v10.8h, %[b0a].8h, %[a0a].h[2]\n"
                "fmla    v11.8h, %[b0a].8h, %[a0a].h[3]\n"
                "fmla     v12.8h, %[b0a].8h, %[a0a].h[4]\n"
                "fmla    v13.8h, %[b0a].8h, %[a0a].h[5]\n"
                "fmla    v14.8h, %[b0a].8h, %[a0a].h[6]\n"
                "fmla    v15.8h, %[b0a].8h, %[a0a].h[7]\n"
                "ldr    %q[b0a], [%[b_ptr], #48]\n"

                "fmla    v16.8h, %[b1a].8h, %[a0a].h[0]\n"
                "fmla    v17.8h, %[b1a].8h, %[a0a].h[1]\n" ASM_PREFETCH("[%[b_ptr], #352]")
                "fmla    v18.8h, %[b1a].8h, %[a0a].h[2]\n"
                "fmla    v19.8h, %[b1a].8h, %[a0a].h[3]\n"
                "fmla    v20.8h, %[b1a].8h, %[a0a].h[4]\n"
                "fmla    v21.8h, %[b1a].8h, %[a0a].h[5]\n"
                "fmla    v22.8h, %[b1a].8h, %[a0a].h[6]\n"
                "fmla    v23.8h, %[b1a].8h, %[a0a].h[7]\n"
                "ldr    %q[b1a], [%[b_ptr], #64]\n"

                "fmla    v24.8h, %[b2a].8h, %[a0a].h[0]\n"
                "fmla    v25.8h, %[b2a].8h, %[a0a].h[1]\n"
                "add    %[a_ptr], %[a_ptr], #32\n"
                "fmla    v26.8h, %[b2a].8h, %[a0a].h[2]\n"
                "fmla    v27.8h, %[b2a].8h, %[a0a].h[3]\n"
                "fmla    v28.8h, %[b2a].8h, %[a0a].h[4]\n"
                "fmla    v29.8h, %[b2a].8h, %[a0a].h[5]\n"
                "subs    %w[k], %w[k], #1\n"
                "fmla    v30.8h, %[b2a].8h, %[a0a].h[6]\n"
                "fmla    v31.8h, %[b2a].8h, %[a0a].h[7]\n"

                "bne    1b\n"
                "4:\n"

                // Jump to odd tail if necessary.
                "cbnz    %w[oddk], 2f\n"

                // Even tail.
                "fmla     v8.8h , %[b0].8h, %[a0].h[0]\n"
                "fmla   v9.8h , %[b0].8h, %[a0].h[1]\n"
                "ldr    %q[a0a], [%[a_ptr], #16]\n"
                "fmla    v10.8h, %[b0].8h, %[a0].h[2]\n"
                "fmla    v11.8h, %[b0].8h, %[a0].h[3]\n"
                "ldr    %q[b2a], [%[b_ptr], #80]\n"
                "fmla     v12.8h, %[b0].8h, %[a0].h[4]\n"
                "fmla   v13.8h, %[b0].8h, %[a0].h[5]\n"
                "fmla    v14.8h, %[b0].8h, %[a0].h[6]\n"
                "fmla    v15.8h, %[b0].8h, %[a0].h[7]\n"

                "fmla    v16.8h, %[b1].8h, %[a0].h[0]\n"
                "fmla    v17.8h, %[b1].8h, %[a0].h[1]\n"
                "add    %[b_ptr], %[b_ptr], #96\n"
                "fmla    v18.8h, %[b1].8h, %[a0].h[2]\n"
                "fmla    v19.8h, %[b1].8h, %[a0].h[3]\n"
                "fmla    v20.8h, %[b1].8h, %[a0].h[4]\n"
                "fmla    v21.8h, %[b1].8h, %[a0].h[5]\n"
                "add    %[a_ptr], %[a_ptr], #32\n"
                "fmla    v22.8h, %[b1].8h, %[a0].h[6]\n"
                "fmla    v23.8h, %[b1].8h, %[a0].h[7]\n"

                "fmla    v24.8h, %[b2].8h, %[a0].h[0]\n"
                "fmla    v25.8h, %[b2].8h, %[a0].h[1]\n"
                "fmla    v26.8h, %[b2].8h, %[a0].h[2]\n"
                "fmla    v27.8h, %[b2].8h, %[a0].h[3]\n"
                "fmla    v28.8h, %[b2].8h, %[a0].h[4]\n"
                "fmla    v29.8h, %[b2].8h, %[a0].h[5]\n"
                "fmla    v30.8h, %[b2].8h, %[a0].h[6]\n"
                "fmla    v31.8h, %[b2].8h, %[a0].h[7]\n"

                "fmla     v8.8h , %[b0a].8h, %[a0a].h[0]\n"
                "fmla    v16.8h, %[b1a].8h, %[a0a].h[0]\n"
                "str    q8, [%[c_ptr]]\n"
                "fmla    v24.8h, %[b2a].8h, %[a0a].h[0]\n"
                "str    q16, [%[c_ptr], #16]\n"

                "fmla      v9.8h , %[b0a].8h, %[a0a].h[1]\n"
                "str    q24, [%[c_ptr], #32]\n"
                "fmla    v17.8h, %[b1a].8h, %[a0a].h[1]\n"
                "str    q9, [%[c_ptr], #48]\n"
                "fmla    v25.8h, %[b2a].8h, %[a0a].h[1]\n"
                "str    q17, [%[c_ptr], #64]\n"

                "fmla    v10.8h, %[b0a].8h, %[a0a].h[2]\n"
                "str    q25, [%[c_ptr], #80]\n"
                "fmla    v18.8h, %[b1a].8h, %[a0a].h[2]\n"
                "str    q10, [%[c_ptr], #96]\n"
                "fmla    v26.8h, %[b2a].8h, %[a0a].h[2]\n"
                "str    q18, [%[c_ptr], #112]\n"

                "fmla    v11.8h, %[b0a].8h, %[a0a].h[3]\n"
                "str    q26, [%[c_ptr], #128]\n"
                "fmla    v19.8h, %[b1a].8h, %[a0a].h[3]\n"
                "str    q11, [%[c_ptr], #144]\n"
                "fmla    v27.8h, %[b2a].8h, %[a0a].h[3]\n"
                "str    q19, [%[c_ptr], #160]\n"

                "fmla     v12.8h, %[b0a].8h, %[a0a].h[4]\n"
                "str    q27, [%[c_ptr], #176]\n"
                "fmla    v20.8h, %[b1a].8h, %[a0a].h[4]\n"
                "str    q12, [%[c_ptr], #192]\n"
                "fmla    v28.8h, %[b2a].8h, %[a0a].h[4]\n"
                "str    q20, [%[c_ptr], #208]\n"

                "fmla      v13.8h, %[b0a].8h, %[a0a].h[5]\n"
                "str    q28, [%[c_ptr], #224]\n"
                "fmla    v21.8h, %[b1a].8h, %[a0a].h[5]\n"
                "str    q13, [%[c_ptr], #240]\n"
                "fmla    v29.8h, %[b2a].8h, %[a0a].h[5]\n"
                "str    q21, [%[c_ptr], #256]\n"

                "fmla    v14.8h, %[b0a].8h, %[a0a].h[6]\n"
                "str    q29, [%[c_ptr], #272]\n"
                "fmla    v22.8h, %[b1a].8h, %[a0a].h[6]\n"
                "str    q14, [%[c_ptr], #288]\n"
                "fmla    v30.8h, %[b2a].8h, %[a0a].h[6]\n"
                "str    q22, [%[c_ptr], #304]\n"

                "fmla    v15.8h, %[b0a].8h, %[a0a].h[7]\n"
                "str    q30, [%[c_ptr], #320]\n"
                "fmla    v23.8h, %[b1a].8h, %[a0a].h[7]\n"
                "str    q15, [%[c_ptr], #336]\n"
                "fmla    v31.8h, %[b2a].8h, %[a0a].h[7]\n"
                "b    3f\n"

                // Odd tail
                "2:\n"
                "fmla     v8.8h , %[b0].8h, %[a0].h[0]\n"
                "add    %[b_ptr], %[b_ptr], #48\n"
                "fmla    v16.8h, %[b1].8h, %[a0].h[0]\n"
                "add    %[a_ptr], %[a_ptr], #16\n"
                "str    q8, [%[c_ptr]]\n"
                "fmla    v24.8h, %[b2].8h, %[a0].h[0]\n"
                "str    q16, [%[c_ptr], #16]\n"

                "fmla      v9.8h , %[b0].8h, %[a0].h[1]\n"
                "str    q24, [%[c_ptr], #32]\n"
                "fmla    v17.8h, %[b1].8h, %[a0].h[1]\n"
                "str    q9, [%[c_ptr], #48]\n"
                "fmla    v25.8h, %[b2].8h, %[a0].h[1]\n"
                "str    q17, [%[c_ptr], #64]\n"

                "fmla    v10.8h, %[b0].8h, %[a0].h[2]\n"
                "str    q25, [%[c_ptr], #80]\n"
                "fmla    v18.8h, %[b1].8h, %[a0].h[2]\n"
                "str    q10, [%[c_ptr], #96]\n"
                "fmla    v26.8h, %[b2].8h, %[a0].h[2]\n"
                "str    q18, [%[c_ptr], #112]\n"

                "fmla    v11.8h, %[b0].8h, %[a0].h[3]\n"
                "str    q26, [%[c_ptr], #128]\n"
                "fmla    v19.8h, %[b1].8h, %[a0].h[3]\n"
                "str    q11, [%[c_ptr], #144]\n"
                "fmla    v27.8h, %[b2].8h, %[a0].h[3]\n"
                "str    q19, [%[c_ptr], #160]\n"

                "fmla     v12.8h, %[b0].8h, %[a0].h[4]\n"
                "str    q27, [%[c_ptr], #176]\n"
                "fmla    v20.8h, %[b1].8h, %[a0].h[4]\n"
                "str    q12, [%[c_ptr], #192]\n"
                "fmla    v28.8h, %[b2].8h, %[a0].h[4]\n"
                "str    q20, [%[c_ptr], #208]\n"

                "fmla      v13.8h, %[b0].8h, %[a0].h[5]\n"
                "str    q28, [%[c_ptr], #224]\n"
                "fmla    v21.8h, %[b1].8h, %[a0].h[5]\n"
                "str    q13, [%[c_ptr], #240]\n"
                "fmla    v29.8h, %[b2].8h, %[a0].h[5]\n"
                "str    q21, [%[c_ptr], #256]\n"

                "fmla    v14.8h, %[b0].8h, %[a0].h[6]\n"
                "str    q29, [%[c_ptr], #272]\n"
                "fmla    v22.8h, %[b1].8h, %[a0].h[6]\n"
                "str    q14, [%[c_ptr], #288]\n"
                "fmla    v30.8h, %[b2].8h, %[a0].h[6]\n"
                "str    q22, [%[c_ptr], #304]\n"

                "fmla    v15.8h, %[b0].8h, %[a0].h[7]\n"
                "str    q30, [%[c_ptr], #320]\n"
                "fmla    v23.8h, %[b1].8h, %[a0].h[7]\n"
                "str    q15, [%[c_ptr], #336]\n"
                "fmla    v31.8h, %[b2].8h, %[a0].h[7]\n"

                "3:\n"
                "str    q23, [%[c_ptr], #352]\n"
                "str    q31, [%[c_ptr], #368]\n"
                "add    %[c_ptr], %[c_ptr], #384\n"
                :
                [a_ptr] "+r"(a_ptr), [b_ptr] "+r"(b_ptr), [c_ptr] "+r"(c_ptr),
                [a0] "+w"(a0), [a0a] "+w"(a0a),
                [b0] "+w"(b0), [b1] "+w"(b1), [b2] "+w"(b2), [k] "+r"(k),
                [b0a] "+w"(b0a), [b1a] "+w"(b1a), [b2a] "+w"(b2a)
                : [oddk] "r"(oddk)
                : "x20", "x21", "v8", "v9", "v10", "v11", "v12", "v13", "v14", "v15", "v16", "v17", "v18",
                "v19", "v20", "v21", "v22", "v23", "v24", "v25", "v26", "v27", "v28", "v29", "v30", "v31", "cc");
        }
    }
}

} // namespace arm_gemm

#endif // __aarch64__ && __ARM_FEATURE_FP16_SCALAR_ARITHMETIC