diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/ia64/lib/idiv64.S |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'arch/ia64/lib/idiv64.S')
-rw-r--r-- | arch/ia64/lib/idiv64.S | 80 |
1 files changed, 80 insertions, 0 deletions
diff --git a/arch/ia64/lib/idiv64.S b/arch/ia64/lib/idiv64.S new file mode 100644 index 000000000000..f69bd2b0987a --- /dev/null +++ b/arch/ia64/lib/idiv64.S | |||
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1 | /* | ||
2 | * Copyright (C) 1999-2000 Hewlett-Packard Co | ||
3 | * Copyright (C) 1999-2000 David Mosberger-Tang <davidm@hpl.hp.com> | ||
4 | * | ||
5 | * 64-bit integer division. | ||
6 | * | ||
7 | * This code is based on the application note entitled "Divide, Square Root | ||
8 | * and Remainder Algorithms for the IA-64 Architecture". This document | ||
9 | * is available as Intel document number 248725-002 or via the web at | ||
10 | * http://developer.intel.com/software/opensource/numerics/ | ||
11 | * | ||
12 | * For more details on the theory behind these algorithms, see "IA-64 | ||
13 | * and Elementary Functions" by Peter Markstein; HP Professional Books | ||
14 | * (http://www.hp.com/go/retailbooks/) | ||
15 | */ | ||
16 | |||
17 | #include <asm/asmmacro.h> | ||
18 | |||
19 | #ifdef MODULO | ||
20 | # define OP mod | ||
21 | #else | ||
22 | # define OP div | ||
23 | #endif | ||
24 | |||
25 | #ifdef UNSIGNED | ||
26 | # define SGN u | ||
27 | # define INT_TO_FP(a,b) fcvt.xuf.s1 a=b | ||
28 | # define FP_TO_INT(a,b) fcvt.fxu.trunc.s1 a=b | ||
29 | #else | ||
30 | # define SGN | ||
31 | # define INT_TO_FP(a,b) fcvt.xf a=b | ||
32 | # define FP_TO_INT(a,b) fcvt.fx.trunc.s1 a=b | ||
33 | #endif | ||
34 | |||
35 | #define PASTE1(a,b) a##b | ||
36 | #define PASTE(a,b) PASTE1(a,b) | ||
37 | #define NAME PASTE(PASTE(__,SGN),PASTE(OP,di3)) | ||
38 | |||
39 | GLOBAL_ENTRY(NAME) | ||
40 | .regstk 2,0,0,0 | ||
41 | // Transfer inputs to FP registers. | ||
42 | setf.sig f8 = in0 | ||
43 | setf.sig f9 = in1 | ||
44 | ;; | ||
45 | // Convert the inputs to FP, to avoid FP software-assist faults. | ||
46 | INT_TO_FP(f8, f8) | ||
47 | INT_TO_FP(f9, f9) | ||
48 | ;; | ||
49 | frcpa.s1 f11, p6 = f8, f9 // y0 = frcpa(b) | ||
50 | ;; | ||
51 | (p6) fmpy.s1 f7 = f8, f11 // q0 = a*y0 | ||
52 | (p6) fnma.s1 f6 = f9, f11, f1 // e0 = -b*y0 + 1 | ||
53 | ;; | ||
54 | (p6) fma.s1 f10 = f7, f6, f7 // q1 = q0*e0 + q0 | ||
55 | (p6) fmpy.s1 f7 = f6, f6 // e1 = e0*e0 | ||
56 | ;; | ||
57 | #ifdef MODULO | ||
58 | sub in1 = r0, in1 // in1 = -b | ||
59 | #endif | ||
60 | (p6) fma.s1 f10 = f10, f7, f10 // q2 = q1*e1 + q1 | ||
61 | (p6) fma.s1 f6 = f11, f6, f11 // y1 = y0*e0 + y0 | ||
62 | ;; | ||
63 | (p6) fma.s1 f6 = f6, f7, f6 // y2 = y1*e1 + y1 | ||
64 | (p6) fnma.s1 f7 = f9, f10, f8 // r = -b*q2 + a | ||
65 | ;; | ||
66 | #ifdef MODULO | ||
67 | setf.sig f8 = in0 // f8 = a | ||
68 | setf.sig f9 = in1 // f9 = -b | ||
69 | #endif | ||
70 | (p6) fma.s1 f11 = f7, f6, f10 // q3 = r*y2 + q2 | ||
71 | ;; | ||
72 | FP_TO_INT(f11, f11) // q = trunc(q3) | ||
73 | ;; | ||
74 | #ifdef MODULO | ||
75 | xma.l f11 = f11, f9, f8 // r = q*(-b) + a | ||
76 | ;; | ||
77 | #endif | ||
78 | getf.sig r8 = f11 // transfer result to result register | ||
79 | br.ret.sptk.many rp | ||
80 | END(NAME) | ||