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author | Trond Myklebust <Trond.Myklebust@netapp.com> | 2007-02-13 01:43:25 -0500 |
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committer | Trond Myklebust <Trond.Myklebust@netapp.com> | 2007-02-13 01:43:25 -0500 |
commit | d9bc125caf592b7d081021f32ce5b717efdf70c8 (patch) | |
tree | 263b7066ba22ddce21db610c0300f6eaac6f2064 /arch/s390/lib/qrnnd.S | |
parent | 43d78ef2ba5bec26d0315859e8324bfc0be23766 (diff) | |
parent | ec2f9d1331f658433411c58077871e1eef4ee1b4 (diff) |
Merge branch 'master' of /home/trondmy/kernel/linux-2.6/
Conflicts:
net/sunrpc/auth_gss/gss_krb5_crypto.c
net/sunrpc/auth_gss/gss_spkm3_token.c
net/sunrpc/clnt.c
Merge with mainline and fix conflicts.
Diffstat (limited to 'arch/s390/lib/qrnnd.S')
-rw-r--r-- | arch/s390/lib/qrnnd.S | 77 |
1 files changed, 77 insertions, 0 deletions
diff --git a/arch/s390/lib/qrnnd.S b/arch/s390/lib/qrnnd.S new file mode 100644 index 000000000000..eb1df632e749 --- /dev/null +++ b/arch/s390/lib/qrnnd.S | |||
@@ -0,0 +1,77 @@ | |||
1 | # S/390 __udiv_qrnnd | ||
2 | |||
3 | # r2 : &__r | ||
4 | # r3 : upper half of 64 bit word n | ||
5 | # r4 : lower half of 64 bit word n | ||
6 | # r5 : divisor d | ||
7 | # the reminder r of the division is to be stored to &__r and | ||
8 | # the quotient q is to be returned | ||
9 | |||
10 | .text | ||
11 | .globl __udiv_qrnnd | ||
12 | __udiv_qrnnd: | ||
13 | st %r2,24(%r15) # store pointer to reminder for later | ||
14 | lr %r0,%r3 # reload n | ||
15 | lr %r1,%r4 | ||
16 | ltr %r2,%r5 # reload and test divisor | ||
17 | jp 5f | ||
18 | # divisor >= 0x80000000 | ||
19 | srdl %r0,2 # n/4 | ||
20 | srl %r2,1 # d/2 | ||
21 | slr %r1,%r2 # special case if last bit of d is set | ||
22 | brc 3,0f # (n/4) div (n/2) can overflow by 1 | ||
23 | ahi %r0,-1 # trick: subtract n/2, then divide | ||
24 | 0: dr %r0,%r2 # signed division | ||
25 | ahi %r1,1 # trick part 2: add 1 to the quotient | ||
26 | # now (n >> 2) = (d >> 1) * %r1 + %r0 | ||
27 | lhi %r3,1 | ||
28 | nr %r3,%r1 # test last bit of q | ||
29 | jz 1f | ||
30 | alr %r0,%r2 # add (d>>1) to r | ||
31 | 1: srl %r1,1 # q >>= 1 | ||
32 | # now (n >> 2) = (d&-2) * %r1 + %r0 | ||
33 | lhi %r3,1 | ||
34 | nr %r3,%r5 # test last bit of d | ||
35 | jz 2f | ||
36 | slr %r0,%r1 # r -= q | ||
37 | brc 3,2f # borrow ? | ||
38 | alr %r0,%r5 # r += d | ||
39 | ahi %r1,-1 | ||
40 | 2: # now (n >> 2) = d * %r1 + %r0 | ||
41 | alr %r1,%r1 # q <<= 1 | ||
42 | alr %r0,%r0 # r <<= 1 | ||
43 | brc 12,3f # overflow on r ? | ||
44 | slr %r0,%r5 # r -= d | ||
45 | ahi %r1,1 # q += 1 | ||
46 | 3: lhi %r3,2 | ||
47 | nr %r3,%r4 # test next to last bit of n | ||
48 | jz 4f | ||
49 | ahi %r0,1 # r += 1 | ||
50 | 4: clr %r0,%r5 # r >= d ? | ||
51 | jl 6f | ||
52 | slr %r0,%r5 # r -= d | ||
53 | ahi %r1,1 # q += 1 | ||
54 | # now (n >> 1) = d * %r1 + %r0 | ||
55 | j 6f | ||
56 | 5: # divisor < 0x80000000 | ||
57 | srdl %r0,1 | ||
58 | dr %r0,%r2 # signed division | ||
59 | # now (n >> 1) = d * %r1 + %r0 | ||
60 | 6: alr %r1,%r1 # q <<= 1 | ||
61 | alr %r0,%r0 # r <<= 1 | ||
62 | brc 12,7f # overflow on r ? | ||
63 | slr %r0,%r5 # r -= d | ||
64 | ahi %r1,1 # q += 1 | ||
65 | 7: lhi %r3,1 | ||
66 | nr %r3,%r4 # isolate last bit of n | ||
67 | alr %r0,%r3 # r += (n & 1) | ||
68 | clr %r0,%r5 # r >= d ? | ||
69 | jl 8f | ||
70 | slr %r0,%r5 # r -= d | ||
71 | ahi %r1,1 # q += 1 | ||
72 | 8: # now n = d * %r1 + %r0 | ||
73 | l %r2,24(%r15) | ||
74 | st %r0,0(%r2) | ||
75 | lr %r2,%r1 | ||
76 | br %r14 | ||
77 | .end __udiv_qrnnd | ||