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3fc9ccc2 | 1 | /* Function exp2f vectorized with SSE4. |
dff8da6b | 2 | Copyright (C) 2021-2024 Free Software Foundation, Inc. |
3fc9ccc2 SP |
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 | * exp2(x) = 2^n * T[j] * (1 + P(y)) | |
23 | * where | |
24 | * x = m*(1/K) + y, y in [-1/K..1/K] | |
ac11206d | 25 | * m = n*K + j, m, n,j - signed integer, j in [-K/2..K/2] |
3fc9ccc2 SP |
26 | * |
27 | * values of 2^j/K are tabulated | |
28 | * | |
29 | * P(y) is a minimax polynomial approximation of exp2(x)-1 | |
30 | * on small interval [-1/K..1/K] | |
31 | * | |
32 | * Special cases: | |
33 | * | |
34 | * exp2(NaN) = NaN | |
35 | * exp2(+INF) = +INF | |
36 | * exp2(-INF) = 0 | |
37 | * exp2(x) = 1 for subnormals | |
38 | * For IEEE float | |
39 | * if x >= 128.0 then exp2f(x) overflow | |
40 | * if x < -151.0 then exp2f(x) underflow | |
41 | * | |
42 | */ | |
43 | ||
44 | /* Offsets for data table __svml_sexp2_data_internal | |
45 | */ | |
ac11206d SP |
46 | #define _sShifter 0 |
47 | #define _sPC0 16 | |
48 | #define _sPC1 32 | |
49 | #define _sPC2 48 | |
50 | #define _sPC3 64 | |
51 | #define _sPC4 80 | |
52 | #define _sPC5 96 | |
53 | #define _sPC6 112 | |
54 | #define _iAbsMask 128 | |
55 | #define _iDomainRange 144 | |
3fc9ccc2 SP |
56 | |
57 | #include <sysdep.h> | |
58 | ||
ac11206d | 59 | .section .text.sse4, "ax", @progbits |
3fc9ccc2 | 60 | ENTRY(_ZGVbN4v_exp2f_sse4) |
ac11206d SP |
61 | subq $72, %rsp |
62 | cfi_def_cfa_offset(80) | |
63 | ||
64 | /* Check for overflow\underflow */ | |
65 | movups __svml_sexp2_data_internal(%rip), %xmm1 | |
66 | ||
67 | /* Implementation */ | |
68 | movaps %xmm1, %xmm5 | |
69 | ||
70 | /* Polynomial */ | |
71 | movups _sPC6+__svml_sexp2_data_internal(%rip), %xmm4 | |
72 | addps %xmm0, %xmm5 | |
73 | movaps %xmm5, %xmm3 | |
74 | ||
75 | /* 2^N */ | |
76 | pslld $23, %xmm5 | |
77 | ||
78 | /* Check for overflow\underflow */ | |
79 | movdqu _iAbsMask+__svml_sexp2_data_internal(%rip), %xmm2 | |
80 | subps %xmm1, %xmm3 | |
81 | ||
82 | /* R */ | |
83 | movaps %xmm0, %xmm1 | |
84 | pand %xmm0, %xmm2 | |
85 | pcmpgtd _iDomainRange+__svml_sexp2_data_internal(%rip), %xmm2 | |
86 | subps %xmm3, %xmm1 | |
87 | movmskps %xmm2, %edx | |
88 | mulps %xmm1, %xmm4 | |
89 | addps _sPC5+__svml_sexp2_data_internal(%rip), %xmm4 | |
90 | mulps %xmm1, %xmm4 | |
91 | addps _sPC4+__svml_sexp2_data_internal(%rip), %xmm4 | |
92 | mulps %xmm1, %xmm4 | |
93 | addps _sPC3+__svml_sexp2_data_internal(%rip), %xmm4 | |
94 | mulps %xmm1, %xmm4 | |
95 | addps _sPC2+__svml_sexp2_data_internal(%rip), %xmm4 | |
96 | mulps %xmm1, %xmm4 | |
97 | addps _sPC1+__svml_sexp2_data_internal(%rip), %xmm4 | |
98 | mulps %xmm4, %xmm1 | |
99 | addps _sPC0+__svml_sexp2_data_internal(%rip), %xmm1 | |
100 | ||
101 | /* Reconstruction */ | |
102 | paddd %xmm5, %xmm1 | |
103 | testl %edx, %edx | |
104 | ||
105 | /* Go to special inputs processing branch */ | |
106 | jne L(SPECIAL_VALUES_BRANCH) | |
107 | # LOE rbx rbp r12 r13 r14 r15 edx xmm0 xmm1 | |
108 | ||
109 | /* Restore registers | |
110 | * and exit the function | |
111 | */ | |
3fc9ccc2 SP |
112 | |
113 | L(EXIT): | |
ac11206d SP |
114 | movaps %xmm1, %xmm0 |
115 | addq $72, %rsp | |
116 | cfi_def_cfa_offset(8) | |
117 | ret | |
118 | cfi_def_cfa_offset(80) | |
119 | ||
120 | /* Branch to process | |
121 | * special inputs | |
122 | */ | |
3fc9ccc2 SP |
123 | |
124 | L(SPECIAL_VALUES_BRANCH): | |
ac11206d SP |
125 | movups %xmm0, 32(%rsp) |
126 | movups %xmm1, 48(%rsp) | |
127 | # LOE rbx rbp r12 r13 r14 r15 edx | |
128 | ||
129 | xorl %eax, %eax | |
130 | movq %r12, 16(%rsp) | |
131 | cfi_offset(12, -64) | |
132 | movl %eax, %r12d | |
133 | movq %r13, 8(%rsp) | |
134 | cfi_offset(13, -72) | |
135 | movl %edx, %r13d | |
136 | movq %r14, (%rsp) | |
137 | cfi_offset(14, -80) | |
138 | # LOE rbx rbp r15 r12d r13d | |
139 | ||
140 | /* Range mask | |
141 | * bits check | |
142 | */ | |
3fc9ccc2 SP |
143 | |
144 | L(RANGEMASK_CHECK): | |
ac11206d | 145 | btl %r12d, %r13d |
3fc9ccc2 | 146 | |
ac11206d SP |
147 | /* Call scalar math function */ |
148 | jc L(SCALAR_MATH_CALL) | |
149 | # LOE rbx rbp r15 r12d r13d | |
3fc9ccc2 | 150 | |
ac11206d SP |
151 | /* Special inputs |
152 | * processing loop | |
153 | */ | |
3fc9ccc2 SP |
154 | |
155 | L(SPECIAL_VALUES_LOOP): | |
ac11206d SP |
156 | incl %r12d |
157 | cmpl $4, %r12d | |
158 | ||
159 | /* Check bits in range mask */ | |
160 | jl L(RANGEMASK_CHECK) | |
161 | # LOE rbx rbp r15 r12d r13d | |
162 | ||
163 | movq 16(%rsp), %r12 | |
164 | cfi_restore(12) | |
165 | movq 8(%rsp), %r13 | |
166 | cfi_restore(13) | |
167 | movq (%rsp), %r14 | |
168 | cfi_restore(14) | |
169 | movups 48(%rsp), %xmm1 | |
170 | ||
171 | /* Go to exit */ | |
172 | jmp L(EXIT) | |
173 | cfi_offset(12, -64) | |
174 | cfi_offset(13, -72) | |
175 | cfi_offset(14, -80) | |
176 | # LOE rbx rbp r12 r13 r14 r15 xmm1 | |
177 | ||
1d2971b5 | 178 | /* Scalar math function call |
ac11206d SP |
179 | * to process special input |
180 | */ | |
3fc9ccc2 SP |
181 | |
182 | L(SCALAR_MATH_CALL): | |
ac11206d SP |
183 | movl %r12d, %r14d |
184 | movss 32(%rsp, %r14, 4), %xmm0 | |
185 | call exp2f@PLT | |
186 | # LOE rbx rbp r14 r15 r12d r13d xmm0 | |
3fc9ccc2 | 187 | |
ac11206d | 188 | movss %xmm0, 48(%rsp, %r14, 4) |
3fc9ccc2 | 189 | |
ac11206d SP |
190 | /* Process special inputs in loop */ |
191 | jmp L(SPECIAL_VALUES_LOOP) | |
192 | # LOE rbx rbp r15 r12d r13d | |
3fc9ccc2 SP |
193 | END(_ZGVbN4v_exp2f_sse4) |
194 | ||
ac11206d SP |
195 | .section .rodata, "a" |
196 | .align 16 | |
3fc9ccc2 SP |
197 | |
198 | #ifdef __svml_sexp2_data_internal_typedef | |
199 | typedef unsigned int VUINT32; | |
ac11206d SP |
200 | typedef struct { |
201 | __declspec(align(16)) VUINT32 _sShifter[4][1]; | |
202 | __declspec(align(16)) VUINT32 _sPC0[4][1]; | |
203 | __declspec(align(16)) VUINT32 _sPC1[4][1]; | |
204 | __declspec(align(16)) VUINT32 _sPC2[4][1]; | |
205 | __declspec(align(16)) VUINT32 _sPC3[4][1]; | |
206 | __declspec(align(16)) VUINT32 _sPC4[4][1]; | |
207 | __declspec(align(16)) VUINT32 _sPC5[4][1]; | |
208 | __declspec(align(16)) VUINT32 _sPC6[4][1]; | |
209 | __declspec(align(16)) VUINT32 _iAbsMask[4][1]; | |
210 | __declspec(align(16)) VUINT32 _iDomainRange[4][1]; | |
3fc9ccc2 SP |
211 | } __svml_sexp2_data_internal; |
212 | #endif | |
213 | __svml_sexp2_data_internal: | |
ac11206d SP |
214 | .long 0x4b400000, 0x4b400000, 0x4b400000, 0x4b400000 /* _sShifter */ |
215 | .align 16 | |
216 | .long 0x3F800000, 0x3F800000, 0x3F800000, 0x3F800000 /* _sPC0 */ | |
217 | .align 16 | |
218 | .long 0x3f317218, 0x3f317218, 0x3f317218, 0x3f317218 /* _sPC1 */ | |
219 | .align 16 | |
220 | .long 0x3e75fdef, 0x3e75fdef, 0x3e75fdef, 0x3e75fdef /* _sPC2 */ | |
221 | .align 16 | |
222 | .long 0x3d6357cf, 0x3d6357cf, 0x3d6357cf, 0x3d6357cf /* _sPC3 */ | |
223 | .align 16 | |
224 | .long 0x3c1d962c, 0x3c1d962c, 0x3c1d962c, 0x3c1d962c /* _sPC4 */ | |
225 | .align 16 | |
226 | .long 0x3aaf7a51, 0x3aaf7a51, 0x3aaf7a51, 0x3aaf7a51 /* _sPC5 */ | |
227 | .align 16 | |
228 | .long 0x39213c8c, 0x39213c8c, 0x39213c8c, 0x39213c8c /* _sPC6 */ | |
229 | //common | |
230 | .align 16 | |
231 | .long 0x7fffffff, 0x7fffffff, 0x7fffffff, 0x7fffffff /* _iAbsMask */ | |
232 | .align 16 | |
233 | .long 0x42fc0000, 0x42fc0000, 0x42fc0000, 0x42fc0000 /* _iDomainRange=126.0 */ | |
234 | .align 16 | |
235 | .type __svml_sexp2_data_internal, @object | |
236 | .size __svml_sexp2_data_internal, .-__svml_sexp2_data_internal |