xref: /freebsd/contrib/arm-optimized-routines/math/aarch64/sve/expf.c (revision dd21556857e8d40f66bf5ad54754d9d52669ebf7)
1 /*
2  * Single-precision vector e^x function.
3  *
4  * Copyright (c) 2019-2024, Arm Limited.
5  * SPDX-License-Identifier: MIT OR Apache-2.0 WITH LLVM-exception
6  */
7 
8 #include "sv_math.h"
9 #include "test_sig.h"
10 #include "test_defs.h"
11 #include "sv_expf_inline.h"
12 
13 /* Roughly 87.3. For x < -Thres, the result is subnormal and not handled
14    correctly by FEXPA.  */
15 #define Thres 0x1.5d5e2ap+6f
16 
17 static const struct data
18 {
19   struct sv_expf_data d;
20   float thres;
21 } data = {
22   .d = SV_EXPF_DATA,
23   .thres = Thres,
24 };
25 
26 static svfloat32_t NOINLINE
27 special_case (svfloat32_t x, svbool_t special, const struct sv_expf_data *d)
28 {
29   return sv_call_f32 (expf, x, expf_inline (x, svptrue_b32 (), d), special);
30 }
31 
32 /* Optimised single-precision SVE exp function.
33    Worst-case error is 1.04 ulp:
34    SV_NAME_F1 (exp)(0x1.a8eda4p+1) got 0x1.ba74bcp+4
35 				  want 0x1.ba74bap+4.  */
36 svfloat32_t SV_NAME_F1 (exp) (svfloat32_t x, const svbool_t pg)
37 {
38   const struct data *d = ptr_barrier (&data);
39   svbool_t is_special_case = svacgt (pg, x, d->thres);
40   if (unlikely (svptest_any (pg, is_special_case)))
41     return special_case (x, is_special_case, &d->d);
42   return expf_inline (x, pg, &d->d);
43 }
44 
45 TEST_SIG (SV, F, 1, exp, -9.9, 9.9)
46 TEST_ULP (SV_NAME_F1 (exp), 0.55)
47 TEST_DISABLE_FENV (SV_NAME_F1 (exp))
48 TEST_SYM_INTERVAL (SV_NAME_F1 (exp), 0, Thres, 50000)
49 TEST_SYM_INTERVAL (SV_NAME_F1 (exp), Thres, inf, 50000)
50 CLOSE_SVE_ATTR
51