arch/m68k/fpsp040/ssinh.S

Source file repositories/reference/linux-study-clean/arch/m68k/fpsp040/ssinh.S

File Facts

System
Linux kernel
Corpus path
arch/m68k/fpsp040/ssinh.S
Extension
.S
Size
3410 bytes
Lines
135
Domain
Architecture Layer
Bucket
arch/m68k
Inferred role
Architecture Layer: arch/m68k
Status
atlas-only

Why This File Exists

CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.

Dependency Surface

Detected Declarations

Annotated Snippet

|
|	ssinh.sa 3.1 12/10/90
|
|       The entry point sSinh computes the hyperbolic sine of
|       an input argument; sSinhd does the same except for denormalized
|       input.
|
|       Input: Double-extended number X in location pointed to
|		by address register a0.
|
|       Output: The value sinh(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 sSINH takes approximately 280 cycles.
|
|       Algorithm:
|
|       SINH
|       1. If |X| > 16380 log2, go to 3.
|
|       2. (|X| <= 16380 log2) Sinh(X) is obtained by the formulae
|               y = |X|, sgn = sign(X), and z = expm1(Y),
|               sinh(X) = sgn*(1/2)*( z + z/(1+z) ).
|          Exit.
|
|       3. If |X| > 16480 log2, go to 5.
|
|       4. (16380 log2 < |X| <= 16480 log2)
|               sinh(X) = sign(X) * exp(|X|)/2.
|          However, invoking exp(|X|) may cause premature overflow.
|          Thus, we calculate sinh(X) as follows:
|             Y       := |X|
|             sgn     := sign(X)
|             sgnFact := sgn * 2**(16380)
|             Y'      := Y - 16381 log2
|             sinh(X) := sgnFact * exp(Y').
|          Exit.
|
|       5. (|X| > 16480 log2) sinh(X) must overflow. Return
|          sign(X)*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.

|SSINH	idnt	2,1 | Motorola 040 Floating Point Software Package

	|section	8

T1:	.long 0x40C62D38,0xD3D64634 | ... 16381 LOG2 LEAD
T2:	.long 0x3D6F90AE,0xB1E75CC7 | ... 16381 LOG2 TRAIL

	|xref	t_frcinx
	|xref	t_ovfl
	|xref	t_extdnrm
	|xref	setox
	|xref	setoxm1

	.global	ssinhd
ssinhd:
|--SINH(X) = X FOR DENORMALIZED X

Annotation

Implementation Notes