/arch/m68k/fpsp040/ssinh.S

https://bitbucket.org/evzijst/gittest
Assembly | 135 lines | 116 code | 19 blank | 0 comment | 1 complexity | 351e5f41a6f66bdff931ab5d991611df MD5 | raw file
```  1|
2|	ssinh.sa 3.1 12/10/90
3|
4|       The entry point sSinh computes the hyperbolic sine of
5|       an input argument; sSinhd does the same except for denormalized
6|       input.
7|
8|       Input: Double-extended number X in location pointed to
10|
11|       Output: The value sinh(X) returned in floating-point register Fp0.
12|
13|       Accuracy and Monotonicity: The returned result is within 3 ulps in
14|               64 significant bit, i.e. within 0.5001 ulp to 53 bits if the
15|               result is subsequently rounded to double precision. The
16|               result is provably monotonic in double precision.
17|
18|       Speed: The program sSINH takes approximately 280 cycles.
19|
20|       Algorithm:
21|
22|       SINH
23|       1. If |X| > 16380 log2, go to 3.
24|
25|       2. (|X| <= 16380 log2) Sinh(X) is obtained by the formulae
26|               y = |X|, sgn = sign(X), and z = expm1(Y),
27|               sinh(X) = sgn*(1/2)*( z + z/(1+z) ).
28|          Exit.
29|
30|       3. If |X| > 16480 log2, go to 5.
31|
32|       4. (16380 log2 < |X| <= 16480 log2)
33|               sinh(X) = sign(X) * exp(|X|)/2.
34|          However, invoking exp(|X|) may cause premature overflow.
35|          Thus, we calculate sinh(X) as follows:
36|             Y       := |X|
37|             sgn     := sign(X)
38|             sgnFact := sgn * 2**(16380)
39|             Y'      := Y - 16381 log2
40|             sinh(X) := sgnFact * exp(Y').
41|          Exit.
42|
43|       5. (|X| > 16480 log2) sinh(X) must overflow. Return
44|          sign(X)*Huge*Huge to generate overflow and an infinity with
45|          the appropriate sign. Huge is the largest finite number in
46|          extended format. Exit.
47|
48
49|		Copyright (C) Motorola, Inc. 1990
51|
52|	THIS IS UNPUBLISHED PROPRIETARY SOURCE CODE OF MOTOROLA
53|	The copyright notice above does not evidence any
54|	actual or intended publication of such source code.
55
56|SSINH	idnt	2,1 | Motorola 040 Floating Point Software Package
57
58	|section	8
59
60T1:	.long 0x40C62D38,0xD3D64634 | ... 16381 LOG2 LEAD
61T2:	.long 0x3D6F90AE,0xB1E75CC7 | ... 16381 LOG2 TRAIL
62
63	|xref	t_frcinx
64	|xref	t_ovfl
65	|xref	t_extdnrm
66	|xref	setox
67	|xref	setoxm1
68
69	.global	ssinhd
70ssinhd:
71|--SINH(X) = X FOR DENORMALIZED X
72
73	bra	t_extdnrm
74
75	.global	ssinh
76ssinh:
77	fmovex	(%a0),%fp0	| ...LOAD INPUT
78
79	movel	(%a0),%d0
80	movew	4(%a0),%d0
81	movel	%d0,%a1		| save a copy of original (compacted) operand
82	andl	#0x7FFFFFFF,%d0
83	cmpl	#0x400CB167,%d0
84	bgts	SINHBIG
85
86|--THIS IS THE USUAL CASE, |X| < 16380 LOG2
87|--Y = |X|, Z = EXPM1(Y), SINH(X) = SIGN(X)*(1/2)*( Z + Z/(1+Z) )
88
89	fabsx	%fp0		| ...Y = |X|
90
91	moveml	%a1/%d1,-(%sp)
92	fmovemx %fp0-%fp0,(%a0)
93	clrl	%d1
94	bsr	setoxm1		| ...FP0 IS Z = EXPM1(Y)
95	fmovel	#0,%fpcr
96	moveml	(%sp)+,%a1/%d1
97
98	fmovex	%fp0,%fp1
100	fmovex	%fp0,-(%sp)
101	fdivx	%fp1,%fp0		| ...Z/(1+Z)
102	movel	%a1,%d0
103	andl	#0x80000000,%d0
104	orl	#0x3F000000,%d0
106	movel	%d0,-(%sp)
107
108	fmovel	%d1,%fpcr
109	fmuls	(%sp)+,%fp0	|last fp inst - possible exceptions set
110
111	bra	t_frcinx
112
113SINHBIG:
114	cmpl	#0x400CB2B3,%d0
115	bgt	t_ovfl
116	fabsx	%fp0
118	movel	#0,-(%sp)
119	movel	#0x80000000,-(%sp)
120	movel	%a1,%d0
121	andl	#0x80000000,%d0
122	orl	#0x7FFB0000,%d0
123	movel	%d0,-(%sp)	| ...EXTENDED FMT
124	fsubd	T2(%pc),%fp0	| ...|X| - 16381 LOG2, ACCURATE
125
126	movel	%d1,-(%sp)
127	clrl	%d1
128	fmovemx %fp0-%fp0,(%a0)
129	bsr	setox
130	fmovel	(%sp)+,%fpcr
131
132	fmulx	(%sp)+,%fp0	|possible exception
133	bra	t_frcinx
134
135	|end
```