1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (C) 2007
4  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5  */
6 /*
7  * This file is originally a part of the GCC testsuite.
8  * Check that certain subnormal numbers (formerly known as denormalized
9  * numbers) are rounded to within 0.5 ulp.  PR other/14354.
10  */
11 
12 #include <common.h>
13 
14 #include <post.h>
15 
16 GNU_FPOST_ATTR
17 
18 #if CONFIG_POST & CONFIG_SYS_POST_FPU
19 
20 union uf
21 {
22 	unsigned int u;
23 	float f;
24 };
25 
26 static float
27 u2f (unsigned int v)
28 {
29 	union uf u;
30 	u.u = v;
31 	return u.f;
32 }
33 
34 static unsigned int
35 f2u (float v)
36 {
37 	union uf u;
38 	u.f = v;
39 	return u.u;
40 }
41 
42 static int ok = 1;
43 
44 static void
45 tstmul (unsigned int ux, unsigned int uy, unsigned int ur)
46 {
47 	float x = u2f (ux);
48 	float y = u2f (uy);
49 
50 	if (f2u (x * y) != ur)
51 	/* Set a variable rather than aborting here, to simplify tracing when
52 	   several computations are wrong.  */
53 		ok = 0;
54 }
55 
56 /* We don't want to make this const and static, or else we risk inlining
57    causing the test to fold as constants at compile-time.  */
58 struct
59 {
60   unsigned int p1, p2, res;
61 } static volatile expected[] =
62 {
63 	{0xfff, 0x3f800400, 0xfff},
64 	{0xf, 0x3fc88888, 0x17},
65 	{0xf, 0x3f844444, 0xf}
66 };
67 
68 int fpu_post_test_math7 (void)
69 {
70 	unsigned int i;
71 
72 	for (i = 0; i < ARRAY_SIZE(expected); i++)
73 	{
74 		tstmul (expected[i].p1, expected[i].p2, expected[i].res);
75 		tstmul (expected[i].p2, expected[i].p1, expected[i].res);
76 	}
77 
78 	if (!ok) {
79 		post_log ("Error in FPU math7 test\n");
80 		return -1;
81 	}
82 	return 0;
83 }
84 
85 #endif /* CONFIG_POST & CONFIG_SYS_POST_FPU */
86