mirror of
https://github.com/adulau/aha.git
synced 2024-12-29 12:16:20 +00:00
e00d82d07f
Acked-by: Alan Cox <alan@redhat.com> Signed-off-by: Matt Waddel <Matt.Waddel@freescale.com> Cc: Roman Zippel <zippel@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
131 lines
2.9 KiB
ArmAsm
131 lines
2.9 KiB
ArmAsm
|
|
|
| scosh.sa 3.1 12/10/90
|
|
|
|
|
| The entry point sCosh computes the hyperbolic cosine of
|
|
| an input argument; sCoshd does the same except for denormalized
|
|
| input.
|
|
|
|
|
| Input: Double-extended number X in location pointed to
|
|
| by address register a0.
|
|
|
|
|
| Output: The value cosh(X) returned in floating-point register Fp0.
|
|
|
|
|
| Accuracy and Monotonicity: The returned result is within 3 ulps in
|
|
| 64 significant bit, i.e. within 0.5001 ulp to 53 bits if the
|
|
| result is subsequently rounded to double precision. The
|
|
| result is provably monotonic in double precision.
|
|
|
|
|
| Speed: The program sCOSH takes approximately 250 cycles.
|
|
|
|
|
| Algorithm:
|
|
|
|
|
| COSH
|
|
| 1. If |X| > 16380 log2, go to 3.
|
|
|
|
|
| 2. (|X| <= 16380 log2) Cosh(X) is obtained by the formulae
|
|
| y = |X|, z = exp(Y), and
|
|
| cosh(X) = (1/2)*( z + 1/z ).
|
|
| Exit.
|
|
|
|
|
| 3. (|X| > 16380 log2). If |X| > 16480 log2, go to 5.
|
|
|
|
|
| 4. (16380 log2 < |X| <= 16480 log2)
|
|
| cosh(X) = sign(X) * exp(|X|)/2.
|
|
| However, invoking exp(|X|) may cause premature overflow.
|
|
| Thus, we calculate sinh(X) as follows:
|
|
| Y := |X|
|
|
| Fact := 2**(16380)
|
|
| Y' := Y - 16381 log2
|
|
| cosh(X) := Fact * exp(Y').
|
|
| Exit.
|
|
|
|
|
| 5. (|X| > 16480 log2) sinh(X) must overflow. Return
|
|
| Huge*Huge to generate overflow and an infinity with
|
|
| the appropriate sign. Huge is the largest finite number in
|
|
| extended format. Exit.
|
|
|
|
|
|
|
|
|
|
| Copyright (C) Motorola, Inc. 1990
|
|
| All Rights Reserved
|
|
|
|
|
| For details on the license for this file, please see the
|
|
| file, README, in this same directory.
|
|
|
|
|SCOSH idnt 2,1 | Motorola 040 Floating Point Software Package
|
|
|
|
|section 8
|
|
|
|
|xref t_ovfl
|
|
|xref t_frcinx
|
|
|xref setox
|
|
|
|
T1: .long 0x40C62D38,0xD3D64634 | ... 16381 LOG2 LEAD
|
|
T2: .long 0x3D6F90AE,0xB1E75CC7 | ... 16381 LOG2 TRAIL
|
|
|
|
TWO16380: .long 0x7FFB0000,0x80000000,0x00000000,0x00000000
|
|
|
|
.global scoshd
|
|
scoshd:
|
|
|--COSH(X) = 1 FOR DENORMALIZED X
|
|
|
|
fmoves #0x3F800000,%fp0
|
|
|
|
fmovel %d1,%FPCR
|
|
fadds #0x00800000,%fp0
|
|
bra t_frcinx
|
|
|
|
.global scosh
|
|
scosh:
|
|
fmovex (%a0),%fp0 | ...LOAD INPUT
|
|
|
|
movel (%a0),%d0
|
|
movew 4(%a0),%d0
|
|
andil #0x7FFFFFFF,%d0
|
|
cmpil #0x400CB167,%d0
|
|
bgts COSHBIG
|
|
|
|
|--THIS IS THE USUAL CASE, |X| < 16380 LOG2
|
|
|--COSH(X) = (1/2) * ( EXP(X) + 1/EXP(X) )
|
|
|
|
fabsx %fp0 | ...|X|
|
|
|
|
movel %d1,-(%sp)
|
|
clrl %d1
|
|
fmovemx %fp0-%fp0,(%a0) |pass parameter to setox
|
|
bsr setox | ...FP0 IS EXP(|X|)
|
|
fmuls #0x3F000000,%fp0 | ...(1/2)EXP(|X|)
|
|
movel (%sp)+,%d1
|
|
|
|
fmoves #0x3E800000,%fp1 | ...(1/4)
|
|
fdivx %fp0,%fp1 | ...1/(2 EXP(|X|))
|
|
|
|
fmovel %d1,%FPCR
|
|
faddx %fp1,%fp0
|
|
|
|
bra t_frcinx
|
|
|
|
COSHBIG:
|
|
cmpil #0x400CB2B3,%d0
|
|
bgts COSHHUGE
|
|
|
|
fabsx %fp0
|
|
fsubd T1(%pc),%fp0 | ...(|X|-16381LOG2_LEAD)
|
|
fsubd T2(%pc),%fp0 | ...|X| - 16381 LOG2, ACCURATE
|
|
|
|
movel %d1,-(%sp)
|
|
clrl %d1
|
|
fmovemx %fp0-%fp0,(%a0)
|
|
bsr setox
|
|
fmovel (%sp)+,%fpcr
|
|
|
|
fmulx TWO16380(%pc),%fp0
|
|
bra t_frcinx
|
|
|
|
COSHHUGE:
|
|
fmovel #0,%fpsr |clr N bit if set by source
|
|
bclrb #7,(%a0) |always return positive value
|
|
fmovemx (%a0),%fp0-%fp0
|
|
bra t_ovfl
|
|
|
|
|end
|