/* Function acosf vectorized with SSE4.
   Copyright (C) 2021-2022 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library 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 2.1 of the License, or (at your option) any later version.

   The GNU C Library 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 the GNU C Library; if not, see
   https://www.gnu.org/licenses/.  */

/*
 * ALGORITHM DESCRIPTION:
 *
 *      SelMask = (|x| >= 0.5) ? 1 : 0;
 *      R = SelMask ? sqrt(0.5 - 0.5*|x|) : |x|
 *      acos(|x|) = SelMask ? 2*Poly(R) : (Pi/2 - Poly(R))
 *      acos(x) = sign(x) ? (Pi - acos(|x|)) : acos(|x|)
 *
 *
 */

/* Offsets for data table __svml_sacos_data_internal
 */
#define SgnBit                        	0
#define OneHalf                       	16
#define SmallNorm                     	32
#define MOne                          	48
#define Two                           	64
#define sqrt_coeff                    	80
#define poly_coeff                    	112
#define Pi2H                          	192
#define PiH                           	208

#include <sysdep.h>

        .text
	.section .text.sse4,"ax",@progbits
ENTRY(_ZGVbN4v_acosf_sse4)
        subq      $72, %rsp
        cfi_def_cfa_offset(80)

/* X<X^2 iff X<0 */
        movaps    %xmm0, %xmm14

/*
 * 2*sqrt(X) ~ Sh - Sl  (to 24+ bits)
 * SQ ~ 2*sqrt(X)
 */
        movups    __svml_sacos_data_internal(%rip), %xmm3
        movups    OneHalf+__svml_sacos_data_internal(%rip), %xmm5

/* x = -|arg| */
        movaps    %xmm3, %xmm4
        orps      %xmm0, %xmm4

/* Y = 0.5 + 0.5*(-x) */
        movaps    %xmm5, %xmm6
        mulps     %xmm4, %xmm6

/* x^2 */
        movaps    %xmm4, %xmm13
        mulps     %xmm4, %xmm13
        addps     %xmm6, %xmm5

/* SQ ~ 2*sqrt(Y) */
        rsqrtps   %xmm5, %xmm8
        minps     %xmm5, %xmm13
        movaps    %xmm5, %xmm2
        movaps    %xmm13, %xmm1
        cmpltps   SmallNorm+__svml_sacos_data_internal(%rip), %xmm2
        cmpnltps  %xmm5, %xmm1
        cmpltps   %xmm13, %xmm14
        addps     %xmm5, %xmm5
        andnps    %xmm8, %xmm2
        movaps    %xmm13, %xmm11
        movaps    %xmm2, %xmm9
        movaps    %xmm1, %xmm6
        mulps     %xmm2, %xmm9
        andnps    %xmm4, %xmm6
        mulps     %xmm5, %xmm2
        mulps     %xmm13, %xmm11
        mulps     %xmm9, %xmm5
        movups    sqrt_coeff+__svml_sacos_data_internal(%rip), %xmm10
        andps     %xmm0, %xmm3

/* polynomial */
        movups    poly_coeff+__svml_sacos_data_internal(%rip), %xmm12
        movaps    %xmm1, %xmm15
        mulps     %xmm13, %xmm12
        subps     Two+__svml_sacos_data_internal(%rip), %xmm5
        mulps     %xmm5, %xmm10
        addps     poly_coeff+16+__svml_sacos_data_internal(%rip), %xmm12
        mulps     %xmm2, %xmm5
        mulps     %xmm11, %xmm12
        addps     sqrt_coeff+16+__svml_sacos_data_internal(%rip), %xmm10
        mulps     %xmm5, %xmm10
        movups    poly_coeff+32+__svml_sacos_data_internal(%rip), %xmm5
        subps     %xmm10, %xmm2
        mulps     %xmm13, %xmm5
        movups    MOne+__svml_sacos_data_internal(%rip), %xmm7
        andps     %xmm1, %xmm2
        cmpnleps  %xmm4, %xmm7
        addps     poly_coeff+48+__svml_sacos_data_internal(%rip), %xmm5
        movmskps  %xmm7, %edx
        orps      %xmm2, %xmm6
        addps     %xmm12, %xmm5
        mulps     %xmm13, %xmm5
        pxor      %xmm3, %xmm6
        movups    PiH+__svml_sacos_data_internal(%rip), %xmm7
        andps     %xmm1, %xmm7
        addps     poly_coeff+64+__svml_sacos_data_internal(%rip), %xmm5
        mulps     %xmm13, %xmm5
        andps     %xmm14, %xmm7
        mulps     %xmm6, %xmm5
        andnps    Pi2H+__svml_sacos_data_internal(%rip), %xmm15
        addps     %xmm5, %xmm6
        addps     %xmm15, %xmm7
        addps     %xmm6, %xmm7
        testl     %edx, %edx

/* Go to special inputs processing branch */
        jne       L(SPECIAL_VALUES_BRANCH)
                                # LOE rbx rbp r12 r13 r14 r15 edx xmm0 xmm7

/* Restore registers
 * and exit the function
 */

L(EXIT):
        movaps    %xmm7, %xmm0
        addq      $72, %rsp
        cfi_def_cfa_offset(8)
        ret
        cfi_def_cfa_offset(80)

/* Branch to process
 * special inputs
 */

L(SPECIAL_VALUES_BRANCH):
        movups    %xmm0, 32(%rsp)
        movups    %xmm7, 48(%rsp)
                                # LOE rbx rbp r12 r13 r14 r15 edx

        xorl      %eax, %eax
        movq      %r12, 16(%rsp)
        cfi_offset(12, -64)
        movl      %eax, %r12d
        movq      %r13, 8(%rsp)
        cfi_offset(13, -72)
        movl      %edx, %r13d
        movq      %r14, (%rsp)
        cfi_offset(14, -80)
                                # LOE rbx rbp r15 r12d r13d

/* Range mask
 * bits check
 */

L(RANGEMASK_CHECK):
        btl       %r12d, %r13d

/* Call scalar math function */
        jc        L(SCALAR_MATH_CALL)
                                # LOE rbx rbp r15 r12d r13d

/* Special inputs
 * processing loop
 */

L(SPECIAL_VALUES_LOOP):
        incl      %r12d
        cmpl      $4, %r12d

/* Check bits in range mask */
        jl        L(RANGEMASK_CHECK)
                                # LOE rbx rbp r15 r12d r13d

        movq      16(%rsp), %r12
        cfi_restore(12)
        movq      8(%rsp), %r13
        cfi_restore(13)
        movq      (%rsp), %r14
        cfi_restore(14)
        movups    48(%rsp), %xmm7

/* Go to exit */
        jmp       L(EXIT)
        cfi_offset(12, -64)
        cfi_offset(13, -72)
        cfi_offset(14, -80)
                                # LOE rbx rbp r12 r13 r14 r15 xmm7

/* Scalar math fucntion call
 * to process special input
 */

L(SCALAR_MATH_CALL):
        movl      %r12d, %r14d
        movss     32(%rsp,%r14,4), %xmm0
        call      acosf@PLT
                                # LOE rbx rbp r14 r15 r12d r13d xmm0

        movss     %xmm0, 48(%rsp,%r14,4)

/* Process special inputs in loop */
        jmp       L(SPECIAL_VALUES_LOOP)
                                # LOE rbx rbp r15 r12d r13d
END(_ZGVbN4v_acosf_sse4)

        .section .rodata, "a"
        .align 16

#ifdef __svml_sacos_data_internal_typedef
typedef unsigned int VUINT32;
typedef struct {
        __declspec(align(16)) VUINT32 SgnBit[4][1];
        __declspec(align(16)) VUINT32 OneHalf[4][1];
        __declspec(align(16)) VUINT32 SmallNorm[4][1];
        __declspec(align(16)) VUINT32 MOne[4][1];
        __declspec(align(16)) VUINT32 Two[4][1];
        __declspec(align(16)) VUINT32 sqrt_coeff[2][4][1];
        __declspec(align(16)) VUINT32 poly_coeff[5][4][1];
        __declspec(align(16)) VUINT32 Pi2H[4][1];
        __declspec(align(16)) VUINT32 PiH[4][1];
} __svml_sacos_data_internal;
#endif
__svml_sacos_data_internal:
        /*== SgnBit ==*/
        .long 0x80000000, 0x80000000, 0x80000000, 0x80000000
        /*== OneHalf ==*/
        .align 16
        .long 0x3f000000, 0x3f000000, 0x3f000000, 0x3f000000
        /*== SmallNorm ==*/
        .align 16
        .long 0x2f800000, 0x2f800000, 0x2f800000, 0x2f800000
        /*== MOne ==*/
        .align 16
        .long 0xbf800000, 0xbf800000, 0xbf800000, 0xbf800000
        /*== Two ==*/
        .align 16
        .long 0x40000000, 0x40000000, 0x40000000, 0x40000000
        /*== sqrt_coeff[2] ==*/
        .align 16
        .long 0xbdC00004, 0xbdC00004, 0xbdC00004, 0xbdC00004 /* sqrt_coeff2 */
        .long 0x3e800001, 0x3e800001, 0x3e800001, 0x3e800001 /* sqrt_coeff1 */
        /*== poly_coeff[5] ==*/
        .align 16
        .long 0x3d2EDC07, 0x3d2EDC07, 0x3d2EDC07, 0x3d2EDC07 /* poly_coeff5 */
        .long 0x3CC32A6B, 0x3CC32A6B, 0x3CC32A6B, 0x3CC32A6B /* poly_coeff4 */
        .long 0x3d3A9AB4, 0x3d3A9AB4, 0x3d3A9AB4, 0x3d3A9AB4 /* poly_coeff3 */
        .long 0x3d997C12, 0x3d997C12, 0x3d997C12, 0x3d997C12 /* poly_coeff2 */
        .long 0x3e2AAAFF, 0x3e2AAAFF, 0x3e2AAAFF, 0x3e2AAAFF /* poly_coeff1 */
        /*== Pi2H ==*/
        .align 16
        .long 0x3fc90FDB, 0x3fc90FDB, 0x3fc90FDB, 0x3fc90FDB
        /*== PiH ==*/
        .align 16
        .long 0x40490FDB, 0x40490FDB, 0x40490FDB, 0x40490FDB
        .align 16
        .type	__svml_sacos_data_internal,@object
        .size	__svml_sacos_data_internal,.-__svml_sacos_data_internal
