/*
 * Copyright (C) 2020 Linux Studio Plugins Project <https://lsp-plug.in/>
 *           (C) 2020 Vladimir Sadovnikov <sadko4u@gmail.com>
 *
 * This file is part of lsp-dsp-lib
 * Created on: 31 мар. 2020 г.
 *
 * lsp-dsp-lib is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * any later version.
 *
 * lsp-dsp-lib is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with lsp-dsp-lib. If not, see <https://www.gnu.org/licenses/>.
 */

#ifndef PRIVATE_DSP_ARCH_X86_SSE_FASTCONV_APPLY_H_
#define PRIVATE_DSP_ARCH_X86_SSE_FASTCONV_APPLY_H_

#ifndef PRIVATE_DSP_ARCH_X86_SSE_IMPL
    #error "This header should not be included directly"
#endif /* PRIVATE_DSP_ARCH_X86_SSE_IMPL */

namespace lsp
{
    namespace sse
    {
        static inline void fastconv_apply_internal(float *tmp, const float *c1, const float *c2, size_t rank)
        {
            size_t items    = size_t(1) << (rank + 1);

            ARCH_X86_ASM
            (
                __ASM_EMIT("1:")

                // Load data
                __ASM_EMIT("movups      0x00(%[c1]), %%xmm0")       /* xmm0 = r0 r1 r2 r3 */
                __ASM_EMIT("movups      0x10(%[c1]), %%xmm2")       /* xmm1 = i0 i1 i2 i3 */
                __ASM_EMIT("movups      0x20(%[c1]), %%xmm4")
                __ASM_EMIT("movups      0x30(%[c1]), %%xmm6")

                // Do complex multiplication
                // xmm0 = r0 r1 r2 r3
                // xmm2 = i0 i1 i2 i3
                // xmm4 = r4 r5 r6 r7
                // xmm6 = i4 i5 i6 i7
                __ASM_EMIT("movups      0x00(%[c2]), %%xmm1")       /* xmm1 = rc0 rc1 rc2 rc3 */
                __ASM_EMIT("movups      0x10(%[c2]), %%xmm3")       /* xmm3 = ic0 ic1 ic2 ic3 */
                __ASM_EMIT("movaps      %%xmm1, %%xmm5")            /* xmm5 = rc0 rc1 rc2 rc3 */
                __ASM_EMIT("movaps      %%xmm3, %%xmm7")            /* xmm7 = ic0 ic1 ic2 ic3 */
                __ASM_EMIT("mulps       %%xmm0, %%xmm1")            /* xmm1 = rc0*r0 rc1*r1 rc2*r2 rc3*r3 */
                __ASM_EMIT("mulps       %%xmm2, %%xmm7")            /* xmm7 = ic0*i0 ic1*i1 ic2*i2 ic3*i3 */
                __ASM_EMIT("mulps       %%xmm0, %%xmm3")            /* xmm3 = ic0*r0 ic1*r1 ic2*r2 ic3*r3 */
                __ASM_EMIT("mulps       %%xmm2, %%xmm5")            /* xmm5 = rc0*i0 rc1*i1 rc2*i2 rc3*i3 */
                __ASM_EMIT("subps       %%xmm7, %%xmm1")            /* xmm1 = rc0*r0-ic0*i0 rc1*r1-ic1*i1 rc2*r2-ic2*i2 rc3*r3-ic3*i3 */
                __ASM_EMIT("addps       %%xmm5, %%xmm3")            /* xmm3 = ic0*r0+rc0*i0 ic1*r1+rc1*i1 ic2*r2+rc2*i2 ic3*r3+rc3*i3 */

                __ASM_EMIT("movups      0x20(%[c2]), %%xmm0")       /* xmm0 = rc4 rc5 rc6 rc7 */
                __ASM_EMIT("movups      0x30(%[c2]), %%xmm2")       /* xmm2 = ic4 ic5 ic6 ic7 */
                __ASM_EMIT("movaps      %%xmm0, %%xmm5")            /* xmm5 = rc4 rc5 rc6 rc7 */
                __ASM_EMIT("movaps      %%xmm2, %%xmm7")            /* xmm7 = ic4 ic5 ic6 ic7 */
                __ASM_EMIT("mulps       %%xmm4, %%xmm5")            /* xmm5 = rc4*r4 rc5*r5 rc6*r6 rc7*r7 */
                __ASM_EMIT("mulps       %%xmm6, %%xmm2")            /* xmm2 = ic4*i4 ic5*i5 ic6*i6 ic7*i7 */
                __ASM_EMIT("mulps       %%xmm4, %%xmm7")            /* xmm7 = ic4*r4 ic5*r5 ic6*r6 ic7*r7 */
                __ASM_EMIT("mulps       %%xmm6, %%xmm0")            /* xmm0 = rc4*i4 rc5*i5 rc6*i6 rc7*i7 */
                __ASM_EMIT("subps       %%xmm2, %%xmm5")            /* xmm5 = rc4*r4-ic4*i4 rc5*r5-ic5*i5 rc6*r6-ic6*i6 rc7*r7-ic7*i7 */
                __ASM_EMIT("addps       %%xmm0, %%xmm7")            /* xmm7 = ic4*r4+rc4*i4 ic5*r5+rc5*i5 ic6*r6+rc6*i6 ic7*r7+rc7*i7 */

                // Do x4 reverse butterflies
                // xmm1 = r0 r1 r2 r3
                // xmm3 = i0 i1 i2 i3
                // xmm5 = r4 r5 r6 r7
                // xmm7 = i4 i5 i6 i7
                __ASM_EMIT("movaps      %%xmm1, %%xmm0")            /* xmm0 = r0 r1 r2 r3 */
                __ASM_EMIT("movaps      %%xmm5, %%xmm4")
                __ASM_EMIT("shufps      $0x88, %%xmm3, %%xmm0")     /* xmm0 = r0 r2 i0 i2 */
                __ASM_EMIT("shufps      $0x88, %%xmm7, %%xmm4")
                __ASM_EMIT("shufps      $0xdd, %%xmm3, %%xmm1")     /* xmm1 = r1 r3 i1 i3 */
                __ASM_EMIT("shufps      $0xdd, %%xmm7, %%xmm5")
                __ASM_EMIT("movaps      %%xmm0, %%xmm2")            /* xmm2 = r0 r2 i0 i2 */
                __ASM_EMIT("movaps      %%xmm4, %%xmm6")
                __ASM_EMIT("addps       %%xmm1, %%xmm0")            /* xmm0 = r0+r1 r2+r3 i0+i1 i2+i3 = r0k r2k i0k i2k */
                __ASM_EMIT("addps       %%xmm5, %%xmm4")
                __ASM_EMIT("subps       %%xmm1, %%xmm2")            /* xmm2 = r0-r1 r2-r3 i0-i1 i2-i3 = r1k r3k i1k i3k */
                __ASM_EMIT("subps       %%xmm5, %%xmm6")

                __ASM_EMIT("movaps      %%xmm0, %%xmm1")            /* xmm1 = r0k r2k i0k i2k */
                __ASM_EMIT("movaps      %%xmm4, %%xmm5")
                __ASM_EMIT("shufps      $0x88, %%xmm2, %%xmm0")     /* xmm0 = r0k i0k r1k i1k */
                __ASM_EMIT("shufps      $0x88, %%xmm6, %%xmm4")
                __ASM_EMIT("shufps      $0x7d, %%xmm2, %%xmm1")     /* xmm1 = r2k i2k i3k r3k */
                __ASM_EMIT("shufps      $0x7d, %%xmm6, %%xmm5")
                __ASM_EMIT("movaps      %%xmm0, %%xmm2")            /* xmm2 = r0k i0k r1k i1k */
                __ASM_EMIT("movaps      %%xmm4, %%xmm6")
                __ASM_EMIT("addps       %%xmm1, %%xmm0")            /* xmm0 = r0k+r2k i0k+i2k r1k+i3k i1k+r3k = d0 d4 d3 d5 */
                __ASM_EMIT("addps       %%xmm5, %%xmm4")
                __ASM_EMIT("subps       %%xmm1, %%xmm2")            /* xmm2 = r0k-r2k i0k-i2k r1k-i3k i1k-r3k = d2 d6 d1 d7  */
                __ASM_EMIT("subps       %%xmm5, %%xmm6")

                __ASM_EMIT("movaps      %%xmm0, %%xmm1")            /* xmm1 = d0 d4 d3 d5 */
                __ASM_EMIT("movaps      %%xmm4, %%xmm5")
                __ASM_EMIT("shufps      $0x88, %%xmm2, %%xmm0")     /* xmm0 = d0 d3 d2 d1 */
                __ASM_EMIT("shufps      $0x88, %%xmm6, %%xmm4")
                __ASM_EMIT("shufps      $0xdd, %%xmm2, %%xmm1")     /* xmm1 = d4 d5 d6 d7 */
                __ASM_EMIT("shufps      $0xdd, %%xmm6, %%xmm5")
                __ASM_EMIT("shufps      $0x6c, %%xmm0, %%xmm0")     /* xmm0 = d0 d1 d2 d3 */
                __ASM_EMIT("shufps      $0x6c, %%xmm4, %%xmm4")

                // Finally store result
                __ASM_EMIT("movups     %%xmm0, 0x00(%[tmp])")
                __ASM_EMIT("movups     %%xmm1, 0x10(%[tmp])")
                __ASM_EMIT("movups     %%xmm4, 0x20(%[tmp])")
                __ASM_EMIT("movups     %%xmm5, 0x30(%[tmp])")

                __ASM_EMIT("add         $0x40, %[tmp]")
                __ASM_EMIT("add         $0x40, %[c1]")
                __ASM_EMIT("add         $0x40, %[c2]")
                __ASM_EMIT("sub         $16, %[k]")
                __ASM_EMIT("jnz         1b")

                : [tmp] "+r" (tmp), [k] "+r" (items), [c1] "+r" (c1), [c2] "+r" (c2)
                :
                : "cc", "memory",
                  "%xmm0", "%xmm1", "%xmm2", "%xmm3",
                  "%xmm4", "%xmm5", "%xmm6", "%xmm7"
            );

        }
    }
}

#endif /* PRIVATE_DSP_ARCH_X86_SSE_FASTCONV_APPLY_H_ */
