xref: /aosp_15_r20/external/mesa3d/src/util/rounding.h (revision 6104692788411f58d303aa86923a9ff6ecaded22)
1*61046927SAndroid Build Coastguard Worker /*
2*61046927SAndroid Build Coastguard Worker  * Copyright © 2015 Intel Corporation
3*61046927SAndroid Build Coastguard Worker  *
4*61046927SAndroid Build Coastguard Worker  * Permission is hereby granted, free of charge, to any person obtaining a
5*61046927SAndroid Build Coastguard Worker  * copy of this software and associated documentation files (the "Software"),
6*61046927SAndroid Build Coastguard Worker  * to deal in the Software without restriction, including without limitation
7*61046927SAndroid Build Coastguard Worker  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8*61046927SAndroid Build Coastguard Worker  * and/or sell copies of the Software, and to permit persons to whom the
9*61046927SAndroid Build Coastguard Worker  * Software is furnished to do so, subject to the following conditions:
10*61046927SAndroid Build Coastguard Worker  *
11*61046927SAndroid Build Coastguard Worker  * The above copyright notice and this permission notice (including the next
12*61046927SAndroid Build Coastguard Worker  * paragraph) shall be included in all copies or substantial portions of the
13*61046927SAndroid Build Coastguard Worker  * Software.
14*61046927SAndroid Build Coastguard Worker  *
15*61046927SAndroid Build Coastguard Worker  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16*61046927SAndroid Build Coastguard Worker  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17*61046927SAndroid Build Coastguard Worker  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
18*61046927SAndroid Build Coastguard Worker  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19*61046927SAndroid Build Coastguard Worker  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20*61046927SAndroid Build Coastguard Worker  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
21*61046927SAndroid Build Coastguard Worker  * IN THE SOFTWARE.
22*61046927SAndroid Build Coastguard Worker  */
23*61046927SAndroid Build Coastguard Worker 
24*61046927SAndroid Build Coastguard Worker #ifndef _ROUNDING_H
25*61046927SAndroid Build Coastguard Worker #define _ROUNDING_H
26*61046927SAndroid Build Coastguard Worker 
27*61046927SAndroid Build Coastguard Worker #include <limits.h>
28*61046927SAndroid Build Coastguard Worker #include <stdint.h>
29*61046927SAndroid Build Coastguard Worker #include <math.h>
30*61046927SAndroid Build Coastguard Worker 
31*61046927SAndroid Build Coastguard Worker #if defined(__SSE__) || (defined(_M_IX86_FP) && (_M_IX86_FP >= 1)) || (defined(_M_X64) && !defined(_M_ARM64EC))
32*61046927SAndroid Build Coastguard Worker #include <xmmintrin.h>
33*61046927SAndroid Build Coastguard Worker #include <emmintrin.h>
34*61046927SAndroid Build Coastguard Worker #endif
35*61046927SAndroid Build Coastguard Worker 
36*61046927SAndroid Build Coastguard Worker #ifdef __SSE4_1__
37*61046927SAndroid Build Coastguard Worker #include <smmintrin.h>
38*61046927SAndroid Build Coastguard Worker #endif
39*61046927SAndroid Build Coastguard Worker 
40*61046927SAndroid Build Coastguard Worker /* The C standard library has functions round()/rint()/nearbyint() that round
41*61046927SAndroid Build Coastguard Worker  * their arguments according to the rounding mode set in the floating-point
42*61046927SAndroid Build Coastguard Worker  * control register. While there are trunc()/ceil()/floor() functions that do
43*61046927SAndroid Build Coastguard Worker  * a specific operation without modifying the rounding mode, there is no
44*61046927SAndroid Build Coastguard Worker  * roundeven() in any version of C.
45*61046927SAndroid Build Coastguard Worker  *
46*61046927SAndroid Build Coastguard Worker  * Technical Specification 18661 (ISO/IEC TS 18661-1:2014) adds roundeven(),
47*61046927SAndroid Build Coastguard Worker  * but it's unfortunately not implemented by glibc.
48*61046927SAndroid Build Coastguard Worker  *
49*61046927SAndroid Build Coastguard Worker  * This implementation differs in that it does not raise the inexact exception.
50*61046927SAndroid Build Coastguard Worker  *
51*61046927SAndroid Build Coastguard Worker  * We use rint() to implement these functions, with the assumption that the
52*61046927SAndroid Build Coastguard Worker  * floating-point rounding mode has not been changed from the default Round
53*61046927SAndroid Build Coastguard Worker  * to Nearest.
54*61046927SAndroid Build Coastguard Worker  */
55*61046927SAndroid Build Coastguard Worker 
56*61046927SAndroid Build Coastguard Worker /**
57*61046927SAndroid Build Coastguard Worker  * \brief Rounds \c x to the nearest integer, with ties to the even integer.
58*61046927SAndroid Build Coastguard Worker  */
59*61046927SAndroid Build Coastguard Worker static inline float
_mesa_roundevenf(float x)60*61046927SAndroid Build Coastguard Worker _mesa_roundevenf(float x)
61*61046927SAndroid Build Coastguard Worker {
62*61046927SAndroid Build Coastguard Worker #ifdef __SSE4_1__
63*61046927SAndroid Build Coastguard Worker    float ret;
64*61046927SAndroid Build Coastguard Worker    __m128 m = _mm_load_ss(&x);
65*61046927SAndroid Build Coastguard Worker    m = _mm_round_ss(m, m, _MM_FROUND_CUR_DIRECTION | _MM_FROUND_NO_EXC);
66*61046927SAndroid Build Coastguard Worker    _mm_store_ss(&ret, m);
67*61046927SAndroid Build Coastguard Worker    return ret;
68*61046927SAndroid Build Coastguard Worker #else
69*61046927SAndroid Build Coastguard Worker    return rintf(x);
70*61046927SAndroid Build Coastguard Worker #endif
71*61046927SAndroid Build Coastguard Worker }
72*61046927SAndroid Build Coastguard Worker 
73*61046927SAndroid Build Coastguard Worker /**
74*61046927SAndroid Build Coastguard Worker  * \brief Rounds \c x to the nearest integer, with ties to the even integer.
75*61046927SAndroid Build Coastguard Worker  */
76*61046927SAndroid Build Coastguard Worker static inline double
_mesa_roundeven(double x)77*61046927SAndroid Build Coastguard Worker _mesa_roundeven(double x)
78*61046927SAndroid Build Coastguard Worker {
79*61046927SAndroid Build Coastguard Worker #ifdef __SSE4_1__
80*61046927SAndroid Build Coastguard Worker    double ret;
81*61046927SAndroid Build Coastguard Worker    __m128d m = _mm_load_sd(&x);
82*61046927SAndroid Build Coastguard Worker    m = _mm_round_sd(m, m, _MM_FROUND_CUR_DIRECTION | _MM_FROUND_NO_EXC);
83*61046927SAndroid Build Coastguard Worker    _mm_store_sd(&ret, m);
84*61046927SAndroid Build Coastguard Worker    return ret;
85*61046927SAndroid Build Coastguard Worker #else
86*61046927SAndroid Build Coastguard Worker    return rint(x);
87*61046927SAndroid Build Coastguard Worker #endif
88*61046927SAndroid Build Coastguard Worker }
89*61046927SAndroid Build Coastguard Worker 
90*61046927SAndroid Build Coastguard Worker /**
91*61046927SAndroid Build Coastguard Worker  * \brief Rounds \c x to the nearest integer, with ties to the even integer,
92*61046927SAndroid Build Coastguard Worker  * and returns the value as a long int.
93*61046927SAndroid Build Coastguard Worker  */
94*61046927SAndroid Build Coastguard Worker static inline long
_mesa_lroundevenf(float x)95*61046927SAndroid Build Coastguard Worker _mesa_lroundevenf(float x)
96*61046927SAndroid Build Coastguard Worker {
97*61046927SAndroid Build Coastguard Worker #if defined(__SSE__) || (defined(_M_IX86_FP) && (_M_IX86_FP >= 1)) || (defined(_M_X64) && !defined(_M_ARM64EC))
98*61046927SAndroid Build Coastguard Worker #if LONG_MAX == INT64_MAX
99*61046927SAndroid Build Coastguard Worker    return _mm_cvtss_si64(_mm_load_ss(&x));
100*61046927SAndroid Build Coastguard Worker #elif LONG_MAX == INT32_MAX
101*61046927SAndroid Build Coastguard Worker    return _mm_cvtss_si32(_mm_load_ss(&x));
102*61046927SAndroid Build Coastguard Worker #else
103*61046927SAndroid Build Coastguard Worker #error "Unsupported long size"
104*61046927SAndroid Build Coastguard Worker #endif
105*61046927SAndroid Build Coastguard Worker #else
106*61046927SAndroid Build Coastguard Worker    return lrintf(x);
107*61046927SAndroid Build Coastguard Worker #endif
108*61046927SAndroid Build Coastguard Worker }
109*61046927SAndroid Build Coastguard Worker 
110*61046927SAndroid Build Coastguard Worker /**
111*61046927SAndroid Build Coastguard Worker  * \brief Rounds \c x to the nearest integer, with ties to the even integer,
112*61046927SAndroid Build Coastguard Worker  * and returns the value as a long int.
113*61046927SAndroid Build Coastguard Worker  */
114*61046927SAndroid Build Coastguard Worker static inline long
_mesa_lroundeven(double x)115*61046927SAndroid Build Coastguard Worker _mesa_lroundeven(double x)
116*61046927SAndroid Build Coastguard Worker {
117*61046927SAndroid Build Coastguard Worker #if defined(__SSE2__) || (defined(_M_IX86_FP) && (_M_IX86_FP >= 2)) || (defined(_M_X64) && !defined(_M_ARM64EC))
118*61046927SAndroid Build Coastguard Worker #if LONG_MAX == INT64_MAX
119*61046927SAndroid Build Coastguard Worker    return _mm_cvtsd_si64(_mm_load_sd(&x));
120*61046927SAndroid Build Coastguard Worker #elif LONG_MAX == INT32_MAX
121*61046927SAndroid Build Coastguard Worker    return _mm_cvtsd_si32(_mm_load_sd(&x));
122*61046927SAndroid Build Coastguard Worker #else
123*61046927SAndroid Build Coastguard Worker #error "Unsupported long size"
124*61046927SAndroid Build Coastguard Worker #endif
125*61046927SAndroid Build Coastguard Worker #else
126*61046927SAndroid Build Coastguard Worker    return lrint(x);
127*61046927SAndroid Build Coastguard Worker #endif
128*61046927SAndroid Build Coastguard Worker }
129*61046927SAndroid Build Coastguard Worker 
130*61046927SAndroid Build Coastguard Worker /**
131*61046927SAndroid Build Coastguard Worker  * \brief Rounds \c x to the nearest integer, with ties to the even integer,
132*61046927SAndroid Build Coastguard Worker  * and returns the value as an int64_t.
133*61046927SAndroid Build Coastguard Worker  */
134*61046927SAndroid Build Coastguard Worker static inline int64_t
_mesa_i64roundevenf(float x)135*61046927SAndroid Build Coastguard Worker _mesa_i64roundevenf(float x)
136*61046927SAndroid Build Coastguard Worker {
137*61046927SAndroid Build Coastguard Worker #if LONG_MAX == INT64_MAX
138*61046927SAndroid Build Coastguard Worker    return _mesa_lroundevenf(x);
139*61046927SAndroid Build Coastguard Worker #elif LONG_MAX == INT32_MAX
140*61046927SAndroid Build Coastguard Worker    return llrintf(x);
141*61046927SAndroid Build Coastguard Worker #else
142*61046927SAndroid Build Coastguard Worker #error "Unsupported long size"
143*61046927SAndroid Build Coastguard Worker #endif
144*61046927SAndroid Build Coastguard Worker }
145*61046927SAndroid Build Coastguard Worker 
146*61046927SAndroid Build Coastguard Worker #endif
147