1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
|
/*========================== begin_copyright_notice ============================
Copyright (C) 2017-2021 Intel Corporation
SPDX-License-Identifier: MIT
============================= end_copyright_notice ===========================*/
#include "../include/BiF_Definitions.cl"
#include "../../Headers/spirv.h"
#include "../IMF/FP32/pown_s_la.cl"
#include "../IMF/FP32/pown_s_prev.cl"
#if defined(cl_khr_fp64)
#include "../IMF/FP64/pown_d_la.cl"
#endif // defined(cl_khr_fp64)
INLINE float SPIRV_OVERLOADABLE SPIRV_OCL_BUILTIN(pown, _f32_i32, )( float x, int y )
{
if(__FastRelaxedMath && (!__APIRS))
{
// Undefined for x = 0 and y = 0.
// For x >= 0, or x < 0 and even y, derived implementations implement this as:
// exp2(y * log2(x)).
// For x < 0 and odd y, derived implementations implement this as:
// -exp2(y * log2(fabs(x)).
//
// This expansion is technically undefined when x == 0, since
// log2(x) is undefined, however our native log2 returns -inf
// in this case. Since exp2( y * -inf ) is zero for finite y,
// we'll end up with zero, hence the "correct" results.\
float pr = SPIRV_OCL_BUILTIN(fabs, _f32, )( x );
// TBD: Which is faster?
// Note that USC has a pattern match optimization to turn
// log-mul-exp into pow. Additionally, there are some specific
// LLVM optimizations for pow. So, preferring pow for now.
#if 0
pr = SPIRV_OCL_BUILTIN(log2, _f32, )( pr );
pr = y * pr;
pr = SPIRV_OCL_BUILTIN(exp2, _f32, )( pr );
#else
pr = SPIRV_OCL_BUILTIN(native_powr, _f32_f32, )( pr, y );
#endif
// Check for a positive x by checking the sign bit as an integer,
// not a float. This correctly handles x = -0.0f. Arguably, we
// don't have to do this since -cl-fast-relaxed-math implies
// -cl-no-signed-zeros, but it's easy enough to do.
float nr = -pr;
nr = ( y & 1 ) ? nr : pr; // positive result for even y, else negative result
float result = ( as_int(x) >= 0 ) ? pr : nr;// positive result for positive x, else unchanged
return result;
}
else
{
// Previous version of pown builtin is called here, because new one introduced some critical functional regressions.
// TODO: The target is to call '__ocl_svml_pownf' here.
return __ocl_svml_px_pownf1(x, y);
}
}
GENERATE_SPIRV_OCL_VECTOR_FUNCTIONS_2ARGS_VV_LOOP( pown, float, float, int, f32, i32 )
#if defined(cl_khr_fp64)
INLINE double SPIRV_OVERLOADABLE SPIRV_OCL_BUILTIN(pown, _f64_i32, )( double x, int y )
{
return __ocl_svml_pown(x, y);
}
GENERATE_SPIRV_OCL_VECTOR_FUNCTIONS_2ARGS_VV_LOOP( pown, double, double, int, f64, i32 )
#endif // defined(cl_khr_fp64)
#if defined(cl_khr_fp16)
INLINE half SPIRV_OVERLOADABLE SPIRV_OCL_BUILTIN(pown, _f16_i32, )( half x, int y )
{
return SPIRV_OCL_BUILTIN(pown, _f32_i32, )((float)x, y);
}
GENERATE_SPIRV_OCL_VECTOR_FUNCTIONS_2ARGS_VV_LOOP( pown, half, half, int, f16, i32 )
#endif // defined(cl_khr_fp16)
|
