/*
 * 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.
 */

// Build on AArch64 where either FP16_KERNELS is set or FP16 is explicitly supported.
#if defined(__aarch64__) && (defined(FP16_KERNELS) || defined(__ARM_FEATURE_FP16_VECTOR_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 24xK) in read-order.
// Assume that "Cpanel" points to a chunk of C output blocks (each size
// 24x8), 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 (
                // Enable FP16 instruction support (but only if it's not already on).
#ifndef __ARM_FEATURE_FP16_VECTOR_ARITHMETIC
                ".arch	armv8.2-a+fp16\n"
#endif
                // 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__ && (FP16_KERNELS || __ARM_FEATURE_FP16_VECTOR_ARITHMETIC)