;;
;; Copyright (c) 2019, Intel Corporation
;;
;; Redistribution and use in source and binary forms, with or without
;; modification, are permitted provided that the following conditions are met:
;;
;;     * Redistributions of source code must retain the above copyright notice,
;;       this list of conditions and the following disclaimer.
;;     * Redistributions in binary form must reproduce the above copyright
;;       notice, this list of conditions and the following disclaimer in the
;;       documentation and/or other materials provided with the distribution.
;;     * Neither the name of Intel Corporation nor the names of its contributors
;;       may be used to endorse or promote products derived from this software
;;       without specific prior written permission.
;;
;; THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
;; AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
;; IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
;; DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
;; FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
;; DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
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;; CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
;; OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
;; OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
;;

%include "include/os.asm"

section .data
default rel
align 16
swap_mask:
db      0x03, 0x02, 0x01, 0x00, 0x07, 0x06, 0x05, 0x04
db      0x0b, 0x0a, 0x09, 0x08, 0x0f, 0x0e, 0x0d, 0x0c

section .text

; Function which XOR's 64 bytes of the input buffer with 64 bytes of the
; KeyStream, placing the result in the output buffer.
; KeyStream bytes must be swapped on 32 bit boundary before this operation
%macro xor_keystream 1
%define %%SIMDTYPE %1 ; "SSE" or "AVX"

%ifidn %%SIMDTYPE, AVX
        %define %%MOVDQU  vmovdqu
        %define %%MOVDQA  vmovdqa
        %define %%PXOR    vpxor
        %define %%PSHUFB  vpshufb
%else
        %define %%MOVDQU  movdqu
        %define %%MOVDQA  movdqa
        %define %%PXOR    pxor
        %define %%PSHUFB  pshufb
%endif
%ifdef LINUX
        %define	        %%pIn	rdi
        %define	        %%pOut	rsi
        %define	        %%pKS	rdx
%else
        %define	        %%pIn	rcx
        %define	        %%pOut	rdx
        %define	        %%pKS	r8

        mov             rax, rsp
        sub             rsp, 48
        and             rsp, ~15
        %%MOVDQA        [rsp], xmm6
        %%MOVDQA        [rsp + 16], xmm7
        %%MOVDQA        [rsp + 32], xmm8
%endif
        %define         XKEY0   xmm0
        %define         XKEY1   xmm1
        %define         XKEY2   xmm2
        %define         XKEY3   xmm3
        %define         XIN0    xmm4
        %define         XIN1    xmm5
        %define         XIN2    xmm6
        %define         XIN3    xmm7
        %define         XSHUF   xmm8

        %%MOVDQA        XSHUF, [rel swap_mask]
        %%MOVDQA        XKEY0, [%%pKS]
        %%MOVDQA        XKEY1, [%%pKS + 16]
        %%MOVDQA        XKEY2, [%%pKS + 32]
        %%MOVDQA        XKEY3, [%%pKS + 48]

        %%PSHUFB        XKEY0, XSHUF
        %%PSHUFB        XKEY1, XSHUF
        %%PSHUFB        XKEY2, XSHUF
        %%PSHUFB        XKEY3, XSHUF

        %%MOVDQU        XIN0, [%%pIn]
        %%MOVDQU        XIN1, [%%pIn + 16]
        %%MOVDQU        XIN2, [%%pIn + 32]
        %%MOVDQU        XIN3, [%%pIn + 48]

        %%PXOR          XKEY0, XIN0
        %%PXOR          XKEY1, XIN1
        %%PXOR          XKEY2, XIN2
        %%PXOR          XKEY3, XIN3

        %%MOVDQU        [%%pOut],      XKEY0
        %%MOVDQU        [%%pOut + 16], XKEY1
        %%MOVDQU        [%%pOut + 32], XKEY2
        %%MOVDQU        [%%pOut + 48], XKEY3

%ifndef LINUX
        %%MOVDQA        xmm6, [rsp]
        %%MOVDQA        xmm7, [rsp + 16]
        %%MOVDQA        xmm8, [rsp + 32]
        mov             rsp,rax
%endif
%endmacro

MKGLOBAL(asm_XorKeyStream64B_avx,function,internal)
asm_XorKeyStream64B_avx:
        xor_keystream AVX
        ret

MKGLOBAL(asm_XorKeyStream64B_sse,function,internal)
asm_XorKeyStream64B_sse:
        xor_keystream SSE
        ret

%ifdef LINUX
section .note.GNU-stack noalloc noexec nowrite progbits
%endif