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/idiv32.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/idiv32.S')
-rw-r--r-- | arch/ia64/lib/idiv32.S | 83 |
1 files changed, 83 insertions, 0 deletions
diff --git a/arch/ia64/lib/idiv32.S b/arch/ia64/lib/idiv32.S new file mode 100644 index 000000000000..2ac28bf0a662 --- /dev/null +++ b/arch/ia64/lib/idiv32.S | |||
@@ -0,0 +1,83 @@ | |||
1 | /* | ||
2 | * Copyright (C) 2000 Hewlett-Packard Co | ||
3 | * Copyright (C) 2000 David Mosberger-Tang <davidm@hpl.hp.com> | ||
4 | * | ||
5 | * 32-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 EXTEND zxt4 | ||
28 | # define INT_TO_FP(a,b) fcvt.xuf.s1 a=b | ||
29 | # define FP_TO_INT(a,b) fcvt.fxu.trunc.s1 a=b | ||
30 | #else | ||
31 | # define SGN | ||
32 | # define EXTEND sxt4 | ||
33 | # define INT_TO_FP(a,b) fcvt.xf a=b | ||
34 | # define FP_TO_INT(a,b) fcvt.fx.trunc.s1 a=b | ||
35 | #endif | ||
36 | |||
37 | #define PASTE1(a,b) a##b | ||
38 | #define PASTE(a,b) PASTE1(a,b) | ||
39 | #define NAME PASTE(PASTE(__,SGN),PASTE(OP,si3)) | ||
40 | |||
41 | GLOBAL_ENTRY(NAME) | ||
42 | .regstk 2,0,0,0 | ||
43 | // Transfer inputs to FP registers. | ||
44 | mov r2 = 0xffdd // r2 = -34 + 65535 (fp reg format bias) | ||
45 | EXTEND in0 = in0 // in0 = a | ||
46 | EXTEND in1 = in1 // in1 = b | ||
47 | ;; | ||
48 | setf.sig f8 = in0 | ||
49 | setf.sig f9 = in1 | ||
50 | #ifdef MODULO | ||
51 | sub in1 = r0, in1 // in1 = -b | ||
52 | #endif | ||
53 | ;; | ||
54 | // Convert the inputs to FP, to avoid FP software-assist faults. | ||
55 | INT_TO_FP(f8, f8) | ||
56 | INT_TO_FP(f9, f9) | ||
57 | ;; | ||
58 | setf.exp f7 = r2 // f7 = 2^-34 | ||
59 | frcpa.s1 f6, p6 = f8, f9 // y0 = frcpa(b) | ||
60 | ;; | ||
61 | (p6) fmpy.s1 f8 = f8, f6 // q0 = a*y0 | ||
62 | (p6) fnma.s1 f6 = f9, f6, f1 // e0 = -b*y0 + 1 | ||
63 | ;; | ||
64 | #ifdef MODULO | ||
65 | setf.sig f9 = in1 // f9 = -b | ||
66 | #endif | ||
67 | (p6) fma.s1 f8 = f6, f8, f8 // q1 = e0*q0 + q0 | ||
68 | (p6) fma.s1 f6 = f6, f6, f7 // e1 = e0*e0 + 2^-34 | ||
69 | ;; | ||
70 | #ifdef MODULO | ||
71 | setf.sig f7 = in0 | ||
72 | #endif | ||
73 | (p6) fma.s1 f6 = f6, f8, f8 // q2 = e1*q1 + q1 | ||
74 | ;; | ||
75 | FP_TO_INT(f6, f6) // q = trunc(q2) | ||
76 | ;; | ||
77 | #ifdef MODULO | ||
78 | xma.l f6 = f6, f9, f7 // r = q*(-b) + a | ||
79 | ;; | ||
80 | #endif | ||
81 | getf.sig r8 = f6 // transfer result to result register | ||
82 | br.ret.sptk.many rp | ||
83 | END(NAME) | ||