1/*
2 * Copyright (c) 2014 Advanced Micro Devices, Inc.
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a copy
5 * of this software and associated documentation files (the "Software"), to deal
6 * in the Software without restriction, including without limitation the rights
7 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
8 * copies of the Software, and to permit persons to whom the Software is
9 * furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice shall be included in
12 * all copies or substantial portions of the Software.
13 *
14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
17 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
18 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
19 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
20 * THE SOFTWARE.
21 */
22
23#include <clc/clc.h>
24#include "config.h"
25#include "../clcmacro.h"
26#include "math.h"
27
28_CLC_DEF _CLC_OVERLOAD float __clc_ldexp(float x, int n) {
29
30	if (!__clc_fp32_subnormals_supported()) {
31
32		// This treats subnormals as zeros
33		int i = as_int(x);
34		int e = (i >> 23) & 0xff;
35		int m = i & 0x007fffff;
36		int s = i & 0x80000000;
37		int v = add_sat(e, n);
38		v = clamp(v, 0, 0xff);
39		int mr = e == 0 | v == 0 | v == 0xff ? 0 : m;
40		int c = e == 0xff;
41		mr = c ? m : mr;
42		int er = c ? e : v;
43		er = e ? er : e;
44		return as_float( s | (er << 23) | mr );
45	}
46
47	/* supports denormal values */
48	const int multiplier = 24;
49	float val_f;
50	uint val_ui;
51	uint sign;
52	int exponent;
53	val_ui = as_uint(x);
54	sign = val_ui & 0x80000000;
55	val_ui = val_ui & 0x7fffffff;/* remove the sign bit */
56	int val_x = val_ui;
57
58	exponent = val_ui >> 23; /* get the exponent */
59	int dexp = exponent;
60
61	/* denormal support */
62	int fbh = 127 - (as_uint((float)(as_float(val_ui | 0x3f800000) - 1.0f)) >> 23);
63	int dexponent = 25 - fbh;
64	uint dval_ui = (( (val_ui << fbh) & 0x007fffff) | (dexponent << 23));
65	int ex = dexponent + n - multiplier;
66	dexponent = ex;
67	uint val = sign | (ex << 23) | (dval_ui & 0x007fffff);
68	int ex1 = dexponent + multiplier;
69	ex1 = -ex1 +25;
70	dval_ui = (((dval_ui & 0x007fffff )| 0x800000) >> ex1);
71	dval_ui = dexponent > 0 ? val :dval_ui;
72	dval_ui = dexponent > 254 ? 0x7f800000 :dval_ui;  /*overflow*/
73	dval_ui = dexponent < -multiplier ? 0 : dval_ui;  /*underflow*/
74	dval_ui = dval_ui | sign;
75	val_f = as_float(dval_ui);
76
77	exponent += n;
78
79	val = sign | (exponent << 23) | (val_ui & 0x007fffff);
80	ex1 = exponent + multiplier;
81	ex1 = -ex1 +25;
82	val_ui = (((val_ui & 0x007fffff )| 0x800000) >> ex1);
83	val_ui = exponent > 0 ? val :val_ui;
84	val_ui = exponent > 254 ? 0x7f800000 :val_ui;  /*overflow*/
85	val_ui = exponent < -multiplier ? 0 : val_ui;  /*underflow*/
86	val_ui = val_ui | sign;
87
88	val_ui = dexp == 0? dval_ui : val_ui;
89	val_f = as_float(val_ui);
90
91	val_f = isnan(x) | isinf(x) | val_x == 0 ? x : val_f;
92	return val_f;
93}
94
95#ifdef cl_khr_fp64
96
97#pragma OPENCL EXTENSION cl_khr_fp64 : enable
98
99_CLC_DEF _CLC_OVERLOAD double __clc_ldexp(double x, int n) {
100	long l = as_ulong(x);
101	int e = (l >> 52) & 0x7ff;
102	long s = l & 0x8000000000000000;
103
104	ulong ux = as_ulong(x * 0x1.0p+53);
105	int de = ((int)(ux >> 52) & 0x7ff) - 53;
106	int c = e == 0;
107	e = c ? de: e;
108
109	ux = c ? ux : l;
110
111	int v = e + n;
112	v = clamp(v, -0x7ff, 0x7ff);
113
114	ux &= ~EXPBITS_DP64;
115
116	double mr = as_double(ux | ((ulong)(v+53) << 52));
117	mr = mr * 0x1.0p-53;
118
119	mr = v > 0  ? as_double(ux | ((ulong)v << 52)) : mr;
120
121	mr = v == 0x7ff ? as_double(s | PINFBITPATT_DP64)  : mr;
122	mr = v < -53 ? as_double(s) : mr;
123
124	mr  = ((n == 0) | isinf(x) | (x == 0) ) ? x : mr;
125	return mr;
126}
127
128#endif
129