u_half.h revision 7bb54c99a466883af3ac3e79426def17dcfa8d89 
1#ifndef U_HALF_H
2#define U_HALF_H
3
4#include "pipe/p_compiler.h"
5#include "u_math.h"
6
7#ifdef __cplusplus
8extern "C" {
9#endif
10
11
12extern uint32_t util_half_to_float_mantissa_table[2048];
13extern uint32_t util_half_to_float_exponent_table[64];
14extern uint32_t util_half_to_float_offset_table[64];
15extern uint16_t util_float_to_half_base_table[512];
16extern uint8_t util_float_to_half_shift_table[512];
17
18/*
19 * Note that if the half float is a signaling NaN, the x87 FPU will turn
20 * it into a quiet NaN immediately upon loading into a float.
21 *
22 * Additionally, denormals may be flushed to zero.
23 *
24 * To avoid this, use the floatui functions instead of the float ones
25 * when just doing conversion rather than computation on the resulting
26 * floats.
27 */
28
29static INLINE uint32_t
30util_half_to_floatui(half h)
31{
32	unsigned exp = h >> 10;
33	return util_half_to_float_mantissa_table[util_half_to_float_offset_table[exp] + (h & 0x3ff)]
34		+ util_half_to_float_exponent_table[exp];
35}
36
37static INLINE float
38util_half_to_float(half h)
39{
40	union fi r;
41	r.ui = util_half_to_floatui(h);
42	return r.f;
43}
44
45static INLINE half
46util_floatui_to_half(uint32_t v)
47{
48	unsigned signexp = v >> 23;
49	return util_float_to_half_base_table[signexp]
50		+ ((v & 0x007fffff) >> util_float_to_half_shift_table[signexp]);
51}
52
53static INLINE half
54util_float_to_half(float f)
55{
56	union fi i;
57	i.f = f;
58	return util_floatui_to_half(i.ui);
59}
60
61#ifdef __cplusplus
62}
63#endif
64
65#endif /* U_HALF_H */
66