1/* Function hypotf vectorized with AVX2.
2   Copyright (C) 2021-2022 Free Software Foundation, Inc.
3   This file is part of the GNU C Library.
4
5   The GNU C Library is free software; you can redistribute it and/or
6   modify it under the terms of the GNU Lesser General Public
7   License as published by the Free Software Foundation; either
8   version 2.1 of the License, or (at your option) any later version.
9
10   The GNU C Library is distributed in the hope that it will be useful,
11   but WITHOUT ANY WARRANTY; without even the implied warranty of
12   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13   Lesser General Public License for more details.
14
15   You should have received a copy of the GNU Lesser General Public
16   License along with the GNU C Library; if not, see
17   https://www.gnu.org/licenses/.  */
18
19/*
20 * ALGORITHM DESCRIPTION:
21 *
22 *      HIGH LEVEL OVERVIEW
23 *
24 *      Calculate z = (x*x+y*y)
25 *      Calculate reciplicle sqrt (z)
26 *      Calculate make two NR iterations
27 *
28 *      ALGORITHM DETAILS
29 *
30 *    Multiprecision branch for _HA_ only
31 *      Remove sigm from both arguments
32 *      Find maximum (_x) and minimum (_y) (by abs value) between arguments
33 *      Split _x int _a and _b for multiprecision
34 *      If _x >> _y we will we will not split _y for multiprecision
35 *      all _y will be put into lower part (_d) and higher part (_c = 0)
36 *      Fixing _hilo_mask for the case _x >> _y
37 *      Split _y into _c and _d for multiprecision with fixed mask
38 *
39 *      compute Hi and Lo parts of _z = _x*_x + _y*_y
40 *
41 *      _zHi = _a*_a + _c*_c
42 *      _zLo = (_x + _a)*_b + _d*_y + _d*_c
43 *      _z = _zHi + _zLo
44 *
45 *    No multiprecision branch for _LA_ and _EP_
46 *      _z = _VARG1 * _VARG1 + _VARG2 * _VARG2
47 *
48 *    Check _z exponent to be withing borders [1E3 ; 60A] else goto Callout
49 *
50 *    Compute resciplicle sqrt s0 ~ 1.0/sqrt(_z),
51 *      that multiplied by _z, is final result for _EP_ version.
52 *
53 *    First iteration (or zero iteration):
54 *       s =  z * s0
55 *       h = .5 * s0
56 *       d =  s *  h - .5
57 *
58 *    Second iteration:
59 *       h = d * h + h
60 *       s = s * d + s
61 *       d = s * s - z (in multiprecision for _HA_)
62 *
63 *    result = s - h * d
64 *
65 *    EP version of the function can be implemented as y[i]=sqrt(a[i]^2+b[i]^2)
66 *    with all intermediate operations done in target precision for i=1, .., n.
67 *    It can return result y[i]=0 in case a[i]^2 and b[i]^2 underflow in target
68 *    precision (for some i). It can return result y[i]=NAN in case
69 *    a[i]^2+b[i]^2 overflow in target precision, for some i. It can return
70 *    result y[i]=NAN in case a[i] or b[i] is infinite, for some i.
71 *
72 *
73 */
74
75/* Offsets for data table __svml_shypot_data_internal
76 */
77#define _sHiLoMask			0
78#define _sAbsMask			32
79#define _sHalf				64
80#define _LowBoundary			96
81#define _HighBoundary			128
82
83#include <sysdep.h>
84
85	.section .text.avx2, "ax", @progbits
86ENTRY(_ZGVdN8vv_hypotf_avx2)
87	pushq	%rbp
88	cfi_def_cfa_offset(16)
89	movq	%rsp, %rbp
90	cfi_def_cfa(6, 16)
91	cfi_offset(6, -16)
92	andq	$-32, %rsp
93	subq	$128, %rsp
94
95	/*
96	 *  Implementation
97	 * Multiprecision branch for _HA_ only
98	 * No multiprecision branch for _LA_
99	 * _z = _VARG1 * _VARG1 + _VARG2 * _VARG2
100	 */
101	vmulps	%ymm0, %ymm0, %ymm8
102
103	/*
104	 *  Variables
105	 *  Defines
106	 *  Constants loading
107	 */
108	vmovups	_sHalf+__svml_shypot_data_internal(%rip), %ymm7
109
110	/* Check _z exponent to be withing borders [1E3 ; 60A] else goto Callout */
111	vmovups	_LowBoundary+__svml_shypot_data_internal(%rip), %ymm2
112	vfmadd231ps %ymm1, %ymm1, %ymm8
113
114	/* _s0  ~ 1.0/sqrt(_z) */
115	vrsqrtps %ymm8, %ymm6
116	vpcmpgtd %ymm8, %ymm2, %ymm3
117
118	/* First iteration */
119	vmulps	%ymm8, %ymm6, %ymm9
120	vmulps	%ymm7, %ymm6, %ymm2
121	vfnmadd231ps %ymm9, %ymm2, %ymm7
122	vfmadd213ps %ymm9, %ymm7, %ymm9
123
124	/* Second iteration */
125	vfmadd132ps %ymm7, %ymm2, %ymm2
126	vpcmpgtd _HighBoundary+__svml_shypot_data_internal(%rip), %ymm8, %ymm4
127	vpor	%ymm4, %ymm3, %ymm5
128
129	/* Finish second iteration in native precision for _LA_ */
130	vfmsub231ps %ymm9, %ymm9, %ymm8
131	vmovmskps %ymm5, %edx
132	vfnmadd213ps %ymm9, %ymm8, %ymm2
133
134	/*  The end of implementation  */
135	testl	%edx, %edx
136
137	/* Go to special inputs processing branch */
138	jne	L(SPECIAL_VALUES_BRANCH)
139	# LOE rbx r12 r13 r14 r15 edx ymm0 ymm1 ymm2
140
141	/* Restore registers
142	 * and exit the function
143	 */
144
145L(EXIT):
146	vmovaps	%ymm2, %ymm0
147	movq	%rbp, %rsp
148	popq	%rbp
149	cfi_def_cfa(7, 8)
150	cfi_restore(6)
151	ret
152	cfi_def_cfa(6, 16)
153	cfi_offset(6, -16)
154
155	/* Branch to process
156	 * special inputs
157	 */
158
159L(SPECIAL_VALUES_BRANCH):
160	vmovups	%ymm0, 32(%rsp)
161	vmovups	%ymm1, 64(%rsp)
162	vmovups	%ymm2, 96(%rsp)
163	# LOE rbx r12 r13 r14 r15 edx ymm2
164
165	xorl	%eax, %eax
166	# LOE rbx r12 r13 r14 r15 eax edx
167
168	vzeroupper
169	movq	%r12, 16(%rsp)
170	/*  DW_CFA_expression: r12 (r12) (DW_OP_lit8; DW_OP_minus; DW_OP_const4s: -32; DW_OP_and; DW_OP_const4s: -112; DW_OP_plus)  */
171	.cfi_escape 0x10, 0x0c, 0x0e, 0x38, 0x1c, 0x0d, 0xe0, 0xff, 0xff, 0xff, 0x1a, 0x0d, 0x90, 0xff, 0xff, 0xff, 0x22
172	movl	%eax, %r12d
173	movq	%r13, 8(%rsp)
174	/*  DW_CFA_expression: r13 (r13) (DW_OP_lit8; DW_OP_minus; DW_OP_const4s: -32; DW_OP_and; DW_OP_const4s: -120; DW_OP_plus)  */
175	.cfi_escape 0x10, 0x0d, 0x0e, 0x38, 0x1c, 0x0d, 0xe0, 0xff, 0xff, 0xff, 0x1a, 0x0d, 0x88, 0xff, 0xff, 0xff, 0x22
176	movl	%edx, %r13d
177	movq	%r14, (%rsp)
178	/*  DW_CFA_expression: r14 (r14) (DW_OP_lit8; DW_OP_minus; DW_OP_const4s: -32; DW_OP_and; DW_OP_const4s: -128; DW_OP_plus)  */
179	.cfi_escape 0x10, 0x0e, 0x0e, 0x38, 0x1c, 0x0d, 0xe0, 0xff, 0xff, 0xff, 0x1a, 0x0d, 0x80, 0xff, 0xff, 0xff, 0x22
180	# LOE rbx r15 r12d r13d
181
182	/* Range mask
183	 * bits check
184	 */
185
186L(RANGEMASK_CHECK):
187	btl	%r12d, %r13d
188
189	/* Call scalar math function */
190	jc	L(SCALAR_MATH_CALL)
191	# LOE rbx r15 r12d r13d
192
193	/* Special inputs
194	 * processing loop
195	 */
196
197L(SPECIAL_VALUES_LOOP):
198	incl	%r12d
199	cmpl	$8, %r12d
200
201	/* Check bits in range mask */
202	jl	L(RANGEMASK_CHECK)
203	# LOE rbx r15 r12d r13d
204
205	movq	16(%rsp), %r12
206	cfi_restore(12)
207	movq	8(%rsp), %r13
208	cfi_restore(13)
209	movq	(%rsp), %r14
210	cfi_restore(14)
211	vmovups	96(%rsp), %ymm2
212
213	/* Go to exit */
214	jmp	L(EXIT)
215	/*  DW_CFA_expression: r12 (r12) (DW_OP_lit8; DW_OP_minus; DW_OP_const4s: -32; DW_OP_and; DW_OP_const4s: -112; DW_OP_plus)  */
216	.cfi_escape 0x10, 0x0c, 0x0e, 0x38, 0x1c, 0x0d, 0xe0, 0xff, 0xff, 0xff, 0x1a, 0x0d, 0x90, 0xff, 0xff, 0xff, 0x22
217	/*  DW_CFA_expression: r13 (r13) (DW_OP_lit8; DW_OP_minus; DW_OP_const4s: -32; DW_OP_and; DW_OP_const4s: -120; DW_OP_plus)  */
218	.cfi_escape 0x10, 0x0d, 0x0e, 0x38, 0x1c, 0x0d, 0xe0, 0xff, 0xff, 0xff, 0x1a, 0x0d, 0x88, 0xff, 0xff, 0xff, 0x22
219	/*  DW_CFA_expression: r14 (r14) (DW_OP_lit8; DW_OP_minus; DW_OP_const4s: -32; DW_OP_and; DW_OP_const4s: -128; DW_OP_plus)  */
220	.cfi_escape 0x10, 0x0e, 0x0e, 0x38, 0x1c, 0x0d, 0xe0, 0xff, 0xff, 0xff, 0x1a, 0x0d, 0x80, 0xff, 0xff, 0xff, 0x22
221	# LOE rbx r12 r13 r14 r15 ymm2
222
223	/* Scalar math fucntion call
224	 * to process special input
225	 */
226
227L(SCALAR_MATH_CALL):
228	movl	%r12d, %r14d
229	vmovss	32(%rsp, %r14, 4), %xmm0
230	vmovss	64(%rsp, %r14, 4), %xmm1
231	call	hypotf@PLT
232	# LOE rbx r14 r15 r12d r13d xmm0
233
234	vmovss	%xmm0, 96(%rsp, %r14, 4)
235
236	/* Process special inputs in loop */
237	jmp	L(SPECIAL_VALUES_LOOP)
238	# LOE rbx r15 r12d r13d
239END(_ZGVdN8vv_hypotf_avx2)
240
241	.section .rodata, "a"
242	.align	32
243
244#ifdef __svml_shypot_data_internal_typedef
245typedef unsigned int VUINT32;
246typedef struct {
247	__declspec(align(32)) VUINT32 _sHiLoMask[8][1];
248	__declspec(align(32)) VUINT32 _sAbsMask[8][1];
249	__declspec(align(32)) VUINT32 _sHalf[8][1];
250	__declspec(align(32)) VUINT32 _LowBoundary[8][1];
251	__declspec(align(32)) VUINT32 _HighBoundary[8][1];
252} __svml_shypot_data_internal;
253#endif
254__svml_shypot_data_internal:
255	/* legacy algorithm */
256	.long	0xFFF80000, 0xFFF80000, 0xFFF80000, 0xFFF80000, 0xFFF80000, 0xFFF80000, 0xFFF80000, 0xFFF80000 /* _sHiLoMask */
257	.align	32
258	.long	0x7fffffff, 0x7fffffff, 0x7fffffff, 0x7fffffff, 0x7fffffff, 0x7fffffff, 0x7fffffff, 0x7fffffff /* _sAbsMask */
259	.align	32
260	.long	0x3f000000, 0x3f000000, 0x3f000000, 0x3f000000, 0x3f000000, 0x3f000000, 0x3f000000, 0x3f000000 /* _sHalf */
261	.align	32
262	.long	0x1E300000, 0x1E300000, 0x1E300000, 0x1E300000, 0x1E300000, 0x1E300000, 0x1E300000, 0x1E300000 /* _LowBoundary */
263	.align	32
264	.long	0x60A00000, 0x60A00000, 0x60A00000, 0x60A00000, 0x60A00000, 0x60A00000, 0x60A00000, 0x60A00000 /* _HighBoundary */
265	.align	32
266	.type	__svml_shypot_data_internal, @object
267	.size	__svml_shypot_data_internal, .-__svml_shypot_data_internal
268